This PDF file contains the front matter associated with SPIE Proceedings Volume 7742, including the Title Page, Copyright information, Table of Contents, introduction (if any), and the Conference Committee listing.

The design of electron multiplying CCD cameras require a very different approach from that appropriate for slow scan CCD operation. This paper describes the main problems in using electron multiplying CCDs for high-speed, photon counting applications in astronomy and how these may be substantially overcome. With careful design it is possible to operate the E2V Technologies L3CCDs at rates well in excess of that claimed by the manufacturer, and that levels of clock induced charge dramatically lower than those experienced with commercial cameras that need to operate at unity gain. Measurements of the performance of the E2V Technologies CCD201 operating at 26 MHz will be presented together with a guide to the effective reduction of clock induced charge levels. Examples of astronomical results obtained with our cameras are presented.

EMCCDs are devices capable of sub-electron read-out noise at high pixel rate, together with a high quantum efficiency (QE). However, they are plagued by an excess noise factor (ENF) which has the same effect on photometric measurement as if the QE would be halved. In order to get rid of the ENF, the photon counting (PC) operation is mandatory, with the drawback of counting only one photon per pixel per frame. The high frame rate capability of the EMCCDs comes to the rescue, at the price of increased clock induced charges (CIC), which dominates the noise budget of the EMCCD. The CIC can be greatly reduced with an appropriate clocking, which renders the PC operation of the EMCCD very efficient for faint flux photometry or spectroscopy, adaptive optics, ultrafast imaging and Lucky Imaging. This clocking is achievable with a new EMCCD controller: CCCP, the CCD Controller for Counting Photons. This new controller, which is now commercialized by Nüvü cameras inc., was integrated into an EMCCD camera and tested at the observatoire du mont-M'egantic. The results are presented in this paper.

The detector is a critical component of any Adaptive Optics WaveFront Sensing (AO WFS) system. The required combination of fast frame rate, high quantum efficiency, low noise, large number and size of pixels, and low image lag can often only be met by specialized custom developments. ESO's very active WFS detector development program is described. Key test results are presented for newly developed detectors: a) the e2v L3Vision CCD220 (the fastest/lowest noise AO detector to date) to be deployed soon on 2nd Generation VLT instruments, and b) the MPI-HLL pnCCD with its superb high "red" response. The development of still more advanced laser/natural guide-star WFS detectors is critical for the feasibility of ESO's EELT. The paper outlines: a) the multi-phased development plan that will ensure detectors are available on-time for EELT first-light AO systems, b) results of design studies performed by industry during 2007 including a comparison of the most promising technologies, c) results from CMOS technology demonstrators that were built and tested over the past two years to assess and validate various technologies at the pixel level, their fulfillment of critical requirements (especially read noise and speed), and scalability to full-size. The next step will be towards Scaled-Down Demonstrators (SDD) to retire architecture and process risks. The SDD will be large enough to be used for E-ELT first-light AO WFS systems. For full operability, 30-50 full-scale devices will be needed.

CCDs are regularly used as imaging and spectroscopic devices on space telescopes at X-ray energies due to their high quantum efficiency and linearity across the energy range. The International X-ray Observatory's X-ray Grating Spectrometer will also look to make use of these devices across the energy band of 0.3 keV to 1 keV. At these energies, when photon counting, the charge generated in the silicon is close to the noise of the system. In order to be able to detect these low energy X-ray events, the system noise of the detector has to be minimised to have a sufficient signal-to-noise-ratio. By using an EM-CCD instead of a conventional CCD, any charge that is collected in the device can be multiplied before it is read out and as long as the EM-CCD is cool enough to adequately suppress the dark current, the signal-to-noise ratio of the device can be significantly increased, allowing soft X-ray events to be more easily detected. This paper will look into the use of EM-CCDs for the detection of low energy X-rays, in particular the effect that using these devices will have on the signal to noise ratio as well as any degradation in resolution and FWHM that may occur due to the additional shot noise on the signal caused by the charge packet amplification process.

Future wide field astronomical surveys, like Large Synoptic Survey Telescope (LSST), require photometric precision on the percent level. The accuracy of sensor calibration procedures should match these requirements. Pixel size variations found in CCDs from different manufacturers are the source of systematic errors in the flat field calibration procedure. To achieve the calibration accuracy required to meet the most demanding science goals this effect should be taken into account. The study of pixel area variations was performed for fully depleted, thick CCDs produced in a technology study for LSST. These are n-channel, 100μm thick devices. We find pixel size variations in both row and column directions. The size variation magnitude is smaller in the row direction. In addition, diffusion is found to smooth out electron density variations. It is shown that the characteristic diffusion width can be extracted from the flat field data. Results on pixel area variations and diffusion, data features, analysis technique and modeling technique are presented and discussed.

Knowledge of the point spread function (PSF) of the sensors to be used in the Large Synoptic Survey Telescope (LSST) camera is essential for optimal extraction of subtle galaxy shape distortions caused by gravitational weak lensing. We have developed a number of techniques for measuring the PSF of candidate CCD sensors to be used in the LSST camera, each with its own strengths and weaknesses. The two main optical PSF measurement techniques that we use are the direct Virtual Knife Edge (VKE) scan as developed by Karcher, et al.¹ and the indirect interference fringe method after Andersen and Sorensen² that measures the modulation transfer function (MTF) directly. The PSF is derived from the MTF by Fourier transform. Other non-optical PSF measurement techniques that we employ include ⁵⁵Fe x-ray cluster image size measurements and statistical distribution analysis, and cosmic ray muon track size measurements, but are not addressed here. The VKE technique utilizes a diffraction-limited spot produced by a Point-Projection Microscope (PPM) that is scanned across the sensor with sub-pixel resolution. This technique closely simulates the actual operating condition of the sensor in the telescope with the source spot size having an f/# close to the actual telescope design value. The interference fringe method uses a simple equal-optical-path Michelson-type interferometer with a single-mode fiber source that produces interference fringes with 100% contrast over a wide spatial frequency range sufficient to measure the MTF of the sensor directly. The merits of each measurement technique and results from the various measurement techniques on prototype LSST sensors are presented and compared.

The PMAS integral field spectrophotometer, operated at the Calar Alto Observatory 3.5m Telescope, is one of the most demanded instruments of its kind. The optical system was designed for a camera field of view to accommodate a 4K×4K detector with 15μm pixels. However, due to a failure of one of the initially foreseen 2K×4K CCDs in a mosaic configuration, only half of the available field of view could be covered to date. Owing to the high demand from the user community, an upgrade to the full complement of 4K×4K pixels was envisaged, based on the availability of the new e2v CCD231 device. We describe the specification, implementation, test, and commissioning of this new detector for PMAS.

This paper is a progress report of the design and characterization of a monolithic CMOS detector with an on-chip ΣΔ ADC. A brief description of the design and operation is given. Backside processing steps to allow for backside illumination are summarized. Current characterization results are given for pre- and post-thinned detectors. Characterization results include measurements of: gain photodiode capacitance, dark current, linearity, well depth, relative quantum efficiency, and read noise. Lastly, a detector re-design is described; and initial measurements of its photodiode capacitance and read noise are presented.

This paper is a continuation of past papers written on fundamental performance differences of scientific CMOS and CCD imagers. New characterization results presented below include: 1). a new 1536 × 1536 × 8μm 5TPPD pixel CMOS imager, 2). buried channel MOSFETs for random telegraph noise (RTN) and threshold reduction, 3) sub-electron noise pixels, 4) 'MIM pixel' for pixel sensitivity (V/e-) control, 5) '5TPPD RING pixel' for large pixel, high-speed charge transfer applications, 6) pixel-to-pixel blooming control, 7) buried channel photo gate pixels and CMOSCCDs, 8) substrate bias for deep depletion CMOS imagers, 9) CMOS dark spikes and dark current issues and 10) high energy radiation damage test data. Discussions are also given to a 1024 × 1024 × 16 um 5TPPD pixel imager currently in fabrication and new stitched CMOS imagers that are in the design phase including 4k × 4k × 10 μm and 10k × 10k × 10 um imager formats.

The Rochester Imaging Detector Laboratory, University of Rochester, Infotonics Technology Center, and Jet Process Corporation developed a hybrid silicon detector with an on-chip sigma-delta (ΣΔ) ADC. This paper describes the process and reports the results of developing a fabrication process to robustly produce high-quality bump bonds to hybridize a back-illuminated detector with its ΣΔ ADC. The design utilizes aluminum pads on both the readout circuit and the photodiode array with interconnecting indium bumps between them. The development of the bump bonding process is discussed, including specific material choices, interim process structures, and final functionality. Results include measurements of bond integrity, cross-wafer uniformity of indium bumps, and effects of process parameters on the final product. Future plans for improving the bump bonding process are summarized.

A 0.18 μm process CMOS image sensor has recently been developed by e2v technologies plc. with a 0.5 megapixel imaging area consisting of 6 × 6 μm 5T pixels. The sensor is able to provide high performance in a diverse range of applications including machine vision and medical imaging, offering good low-light performance at a video rate of up to 60 fps. The CMOS sensor has desirable characteristics which make it appealing for a number of space applications. Following on from previous tests of the radiation hardness of the image sensors to proton radiation, in which the increase in dark-current and appearance of bright and RTS pixels was quantified, the sensors have now been subjected to a dose of gamma radiation. Knowledge of the performance after irradiation is important to judge suitability for space applications and radiation sensitive medical imaging applications. This knowledge will also enable image correction to mitigate the effects and allow for future CMOS devices to be designed to improve upon the findings in this paper. One device was irradiated to destruction after 120 krad(Si) while biased, and four other devices were irradiated between 5 and 20 krad(Si) while biased. This paper explores the resulting radiation damage effects on the CMOS image sensor such as increased dark current, and a central brightening effect, and discusses the implications for use of the sensor in space applications.

Fully depleted, back-illuminated, p-channel CCDs developed at Lawrence Berkeley National Laboratory exhibit high quantum efficiency in the near-infrared (700-1050nm), low fringing effects, low lateral charge diffusion (and hence small, well-controlled point spread function), and high radiation tolerance. Building on previous efforts, we have developed techniques and hardware that have produced space-qualified 4-side abuttable, high-precision detector packages for 10.5μm pixel, 3.5k x 3.5k p-channel LBNL CCDs. These packages are built around a silicon carbide mounting pedestal, providing excellent rigidity, thermal stability, and heat transfer. Precision fixturing produces packages with detector surface flatness better than 10μm P-V. These packages with active areas of 36.8mm square may be packed on a detector pitch as small as 44mm. LBNL-developed Front End Electronics (FEE) packages can mount directly to the detector packages within the same footprint and detector pitch. This combination, along with identically interfaced NIR detector/FEE packages offers excellent opportunities for high density, high pixel count focal planes for space-based, ground-based, and airborne astronomy.

In this paper we present the methodology for making absolute quantum efficiency (QE) measurements from the vacuum ultraviolet (VUV) through the near infrared (NIR) on delta-doped silicon CCDs. Delta-doped detectors provide an excellent platform to validate measurements through the VUV due to their enhanced UV response. The requirements for measuring QE through the VUV are more strenuous than measurements in the near UV and necessitate, among other things, the use of a vacuum monochromator, and good camera vacuum to prevent chip condensation, and more stringent handling requirements. The system used for these measurements was originally designed for deep UV characterization of CCDs for the WF/PC instrument on Hubble and later for Cassini CCDs.

The demand for higher red wavelength sensitivity is being met by various technological developments of modern CCDs. We discuss techniques for achieving higher red wavelength sensitivity by using thicker silicon to make backthinned CCDs, which combines with very low read noise for enhanced sensitivity. Thicker devices requires higher resistivity material including bulk (non epitaxial) silicon. An extended wavelength range also places more demand on the antireflection coatings which benefit from corresponding optimisation.

We have performed some initial characterization of back-illuminated deep-depletion CCDs from Hamamatsu Photonics. Three of these 2048×4096, three-side buttable devices will replace the current CCDs in the Gemini Multi-Object Spectrograph to improve the performance of the instrument in the red and near-infrared wavelengths. We describe our testing campaign and report on the results.

X-ray detectors based on superconducting tunnel junctions (STJs) have demonstrated good energy resolution in the soft X-ray energy range 0.1-6 keV. In particular DROIDS (Distributed Read Out Imaging Devices), consisting of a superconducting absorber strip with superconducting tunnel junctions as read-out devices on either end, could combine this high resolving power with a large sensitive area and good soft X-ray detection efficiency. In this paper we present results on the spectroscopic performance of Al and Ta/Al DROIDs with different absorber materials (Ta, Re) and with variations in absorber configurations: our standard absorber integrated with the read-out structure is compared with absorbers deposited after definition of the read-out structure. The latter allows maximising the detection efficiency through thicker layers and different absorber materials. Also, absorbers which are electrically coupled to the readout structure are compared to insulated absorbers which couple to the readout structure by phonon exchange across a thin dielectric layer. New process routes have been designed for all new configurations. Whilst not all these structures have been fabricated successfully yet, our integrated absorber sofar exhibits the best performance, with 2.45 eV FWHM at 400 eV and 16.6 eV FWHM at 5.9 keV.

Cute-1.7+APD II is the third pico-satellite developed by students at the Tokyo Institute of Technology. One of the primary goals of the mission is to validate the use of avalanche photodiodes (APDs) as a radiation detector for the first time in a space experiment. The satellite was successfully launched by an ISRO PSLV-C9 rocket in Apr 2008 and has since been in operation for more than 20 months. Cute-1.7+APD II carries two reversetype APDs to monitor the distribution of low energy particles down to 9.2 keV trapped in a Low Earth Orbit (LEO), including South Atlantic Anomaly (SAA) as well as aurora bands. We present the design parameters and various preflight tests of the APDs prior to launch, particularly, the high counting response and active gain control system for the Cute-1.7+APD II mission. Examples of electron/proton distribution, obtained in continuous 12-hour observations, will be presented to demonstrate the initial flight performance of the APDs in orbit.

The recent development of active pixel sensors as X-Ray focal plane arrays will place them in contention with CCDs on future satellite missions. Penn State University (PSU) is working with Teledyne Imaging Sensors (TIS) to develop X-Ray Hybrid CMOS devices (HCDs), a type of active pixel sensor with fast frame rates, adaptable readout timing and geometry, low power consumption, and inherent radiation hardness. CCDs have been used with great success on the current generation of X-Ray telescopes (e.g. Chandra, XMM, Suzaku, and Swift). However, their bucket-brigade readout architecture, which transfers charge across the chip with discrete component readout electronics, results in clockrate limited readout speeds that cause pileup (saturation) of bright sources and an inherent susceptibility to radiation induced displacement damage that limits mission lifetime. In contrast, HCDs read pixels through the detector substrate with low power, on-chip readout integrated circuits. Faster frame rates, achieved with adaptable readout timing and geometry, will allow the next generation's larger effective area telescopes to observe brighter sources free of pileup. In HCDs, radiation damaged lattice sites affect a single pixel instead of an entire row. The PSU X-ray group is currently testing 4 Teledyne HCDs, with low cross-talk CTIA devices in development. We will report laboratory measurements of HCD readnoise, interpixel-capacitance and its impact on event selection, linearity, and energy resolution as a function of energy.

X-ray detectors based on arrays of DEPFET macropixels, which consist of a silicon drift detector combined with a detector/amplifier structure DEPFET as readout node, provide a convenient and flexible way to adapt the pixel size of a focal plane detector to the resolving power of any given X-ray optical system. Macropixels combine the traditional benefits of an SDD, like scalability, arbitrary geometry and excellent QE even in the low energy range, with the advantages of DEPFET structures: Charge storage capability, near Fano-limited energy resolution, low power consumption and high speed readout. Being part of the scientific payload of ESA's BepiColombo mission, the MIXS instrument will be the first instrument to make use of DEPFET macropixel based FPA detectors in space. MIXS will perform a complete planetary X-ray fluorescence analysis of Mercury's crust with high spectral and spatial resolution. MIXS will contain two focal plane detectors consisting of a 64 × 64 macropixel matrix with 300 × 300 μm2 pixel size. The main challenges for the instrument are the difficult radiation and thermal environment around Mercury, requiring high speed readout and sophisticated thermal management to reduce the impact of thermally generated leakage current within an irradiated detector. Dedicated VLSI integrated readout electronics has been developed for MIXS: a fast, radiation hard, low power, high voltage switch circuit to control the device, and a low noise, high speed amplifier/shaper IC. Detector assemblies have been built, electrical screening tests for the flight models and spectroscopical qualification tests are in progress.

The Wide Field Imager (WFI) of the International X-ray Observatory (IXO) is an X-ray imaging spectrometer based on a large monolithic DePFET (Depleted P-channel Field Effect Transistor) Active Pixel Sensor. Filling an area of 10 × 10 cm² with a format of 1024 × 1024 pixels it will cover a field of view of 18 arcmin. The pixel size of 100 × 100 μm² corresponds to a fivefold oversampling of the telescope's expected 5 arcsec point spread function. The WFI's basic DePFET structure combines the functionalities of sensor and integrated amplifier with nearly Fano-limited energy resolution and high efficiency from 100 eV to 15 keV. The development of dedicated control and amplifier ASICs allows for high frame rates up to 1 kHz and flexible readout modes. Results obtained with representative prototypes with a format of 256 × 256 pixels are presented.

For the eROSITA X-ray telescope, which is planned to be launched in 2012, detectors were developed and fabricated at the MPI Semiconductor Laboratory. The fully depleted, back-illuminated pnCCDs have an ultrathin pn-junction to improve the low-energy X-ray response function and quantum efficiency. The device thickness of 450 μm is fully sensitive to X-ray photons yielding high quantum efficiency of more than 90% at photon energies of 10 keV. An on-chip filter is deposited on top of the entrance window to suppress visible and UV light which would interfere with the X-ray observations. The pnCCD type developed for the eROSITA telescope was characterized in terms of quantum efficiency and spectral response function. The described measurements were performed in 2009 at the synchrotron radiation sources BESSY II and MLS as cooperation between the MPI Semiconductor Laboratory and the Physikalisch-Technische Bundesanstalt (PTB). Quantum efficiency measurements over a wide range of photon energies from 3 eV to 11 keV as well as spectral response measurements are presented. For X-ray energies from 3 keV to 10 keV the quantum efficiency of the CCD including on-chip filter is shown to be above 90% with an attenuation of visible light of more than five orders of magnitude. A detector response model is described and compared to the measurements.

We report on the development of a 3D position sensitive prototype suitable as focal plane detector for Laue lens telescope. The basic sensitive unit is a drift strip detector based on a CZT crystal, (~19×8 mm² area, 2.4 mm thick), irradiated transversally to the electric field direction. The anode side is segmented in 64 strips, that divide the crystal in 8 independent sensor (pixel), each composed by one collecting strip and 7 (one in common) adjacent drift strips. The drift strips are biased by a voltage divider, whereas the anode strips are held at ground. Furthermore, the cathode is divided in 4 horizontal strips for the reconstruction of the third interaction position coordinate. The 3D prototype will be made by packing 8 linear modules, each composed by one basic sensitive unit, bonded on a ceramic layer. The linear modules readout is provided by a custom front end electronics implementing a set of three RENA-3 for a total of 128 channels. The front-end electronics and the operating logics (in particular coincidence logics for polarisation measurements) are handled by a versatile and modular multi-parametric back end electronics developed using FPGA technology.

The High Time Resolution Spectrometer (HTRS) is one of six scientific payload instruments of the International X-ray Observatory (IXO). HTRS is dedicated to the physics of matter at extreme density and gravity and will observe the X-rays generated in the inner accretion flows around the most compact massive objects, i.e. black holes and neutron stars. The study of their timing signature and in addition the simultaneous spectroscopy of the gravitationally shifted and broadened iron line allows for probing general relativity in the strong field regime and understanding the inner structure of neutron stars. As the sources to be observed by HTRS are the brightest in the X-ray sky and the studies require good photon statistics the instrument design is driven by the capability to operate at extremely high count rates. The HTRS instrument is based on a monolithic array of Silicon Drift Detectors (SDDs) with 31 cells in a circular envelope and a sensitive volume of 4.5 cm² × 450 μm. The SDD principle uses fast signal charge collection on an integrated amplifier by a focusing internal electrical field. It combines a large sensitive area and a small capacitance, thus facilitating good energy resolution and high count rate capability. The HTRS is specified to provide energy spectra with a resolution of 150 eV (FWHM at 6 keV) at high time resolution of 10 μsec and with high count rate capability up to a goal of 2·10⁶ counts per second, corresponding to a 12 Crab equivalent source. As the HTRS is a non-imaging instrument and will target only point sources it is placed on axis but out of focus so that the spot is spread over the array of 31 SDD cells. The SDD array is logically organized in four independent 'quadrants', a dedicated 8-channel quadrant readout chip is in development.

The International X-ray Observatory (IXO) is a merger of the former ESA XEUS and NASA Constellation-X missions, with additional collaboration from JAXA, proposed for launch ~2020. IXO will address the leading astrophysical questions in the 'hot universe' through its breakthrough capabilities in X-ray spectroscopy. The mission covers the 0.1 to 40 keV energy range, complementing the capabilities of the next generation observatories, such as ALMA, LSST, JWST and 30 meter ground-based telescopes. An X-ray Grating Spectrometer is baselined to provide science in the energy range 0.3-1.0 keV at a spectral resolution of E/ΔE > 3,000 with an effective area greater than 1,000 cm². This will require an array of soft X-ray enhanced CCDs operating at a modest frame rate to measure the diffracted light in both position and energy. Here we describe the baseline camera for the Off-plane XGS instrument using mature CCD technology.

We report on simulation results for the eROSITA instrument background obtained with Monte-Carlo simulations using the Geant4 toolkit. Besides a brief introduction to the simulation environment created at our institute, the input particle spectrum and flux as well as the post-simulation event treatment and analysis are explained. Latest results for the background level and spectral shape induced by interactions of cosmic-ray protons with the camera housing are given. In addition, we show results from different studies concerning variation of the background level as a function of the CCD thickness and the composition of the graded shield.

Like the International X-ray Observatory (IXO) mission, the Simbol-X mission is a projected X-ray space telescope with spectral and imaging capabilities covering the energy range from 500 eV up to 80 keV. To detect photons within this wide range of energies, a silicon based "Depleted P-channel Field Effect Transistor" (DePFET)- matrix is used as the Low Energy Detector (LED) on top of an array of CdTe-Caliste modules, which act as the High Energy Detector (HED). A Science Verification Model (SVM) consisting of one LED quadrant in front of one Caliste module will be set up at our institute (IAAT) and operated under laboratory conditions that approximate the expected environment in space. As a first step we use the SVM to test and optimize the performance of the LED operation and data acquisition chain, consisting of an ADC, an event-preprocessor, a sequencer, and an interface controller. All these components have been developed at our institute with the objective to handle the high readout rate of approximately 8000 frames per second. The second step is to study the behaviour and the interactions of LED and HED operating as a combined detector system. We report on the development status of the SVM and its associated electronics and present first results of the currently achieved spectral performance.

The new X-ray telescope eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the main instrument on the Russian new Spectrum-RG satellite, scheduled for launch in 2012. The primary scientific goal of eROSITA is the detection of about 100,000 clusters of galaxies in an all sky survey. This allows a systematic study on the large scale structures in the universe and will give new information about the nature of dark energy. The focal plane detector is a 5 cm × 3 cm framestore PNCCD, an advanced successor of the XMM-Newton PNCCD, designed and fabricated at the MPI Halbleiterlabor. It has 384 × 384 pixels of 75 μm × 75 μm in the image area and will provide high position, time and spectral resolution as well as a high quantum efficiency for X-ray photons in the energy range from 0.2 keV up to 10 keV. The first flight-like CCDs have been finished in 2008. In order to extensively test these new PNCCDs we developed an electronic test-setup. It is very versatile, allowing us to test the CCDs under many different conditions and is appropriate to show at the same time excellent performance of the detector. In this contribution we present in detail the electronic test-setup, some test results and the conclusions which can be drawn for the eROSITA flight modules.

The European Space Agency's Gaia mission1 is scheduled for launch in 2012. It will operate at L2 for 5 years, rotating slowly so that its two optical telescopes will repeatedly observe more than one billion stars. The resulting data set will be iteratively reduced to solve for the relative position, parallax-distance and proper motion of every observed star, yielding a three dimensional dynamical model of our galaxy. The focal plane contains 106 large area silicon CCDs continuously operating in TDI mode at a line rate synchronised with the satellite rotation.2 One of the greatest challenges facing the mission is radiation damage in the CCDs which will cause charge loss and image distortion. This is particularly severe because the large focal plane is difficult to shield and because the launch will coincide with solar maximum. Despite steps taken to minimize the effects of radiation (e.g. regular use of charge injection), the residual distortion will need to be calibrated during the pipeline data processing. Due to the volume of data involved, this requires a trapping model which is physically realistic, yet fast enough and simple enough to implement in the pipeline. The current prototype Charge Distortion Model will be presented. This model was developed specifically for Gaia in TDI mode. However, an imaging mode version has already been applied to other missions, for example, to indicate the potential impact of radiation damage on the proposed Euclid mission.

ESA's Gaia mission aims to create a complete and highly accurate stereoscopic map of the Milky Way. The stellar parallaxes will be determined at the micro-arcsecond level, as a consequence the measurement of the stellar image location on the CCD must be highly accurate. The solar wind protons will create charge traps in the CCDs of Gaia, which will induce large charge loss and distort the stellar images causing a degradation of the location measurement accuracy. Accurate modelling of the stellar image distortion induced by radiation is required to mitigate these effects. We assess the capability of a fast physical analytical model of radiation damage effects called the charge distortion model (CDM) to reproduce experimental data. To realize this assessment we developed a rigorous procedure that compares at the sub-pixel level the model outcomes to damaged images extracted from the experimental tests. We show that CDM can reproduce accurately up to a certain level the test data acquired on a highly irradiated device operated in time delay integration mode for different signal levels and different illumination histories. We discuss the potential internal and external factors that contributed to limit the agreement between the data and the charge distortion model. To investigate these limiting factors further, we plan to apply our comparison procedure on a synthetic dataset generated through detailed Monte-Carlo simulations at the CCD electrode level.

The Gaia satellite is a high-precision astrometry, photometry and spectroscopic ESA cornerstone mission, currently scheduled for launch in 2012. Its primary science drivers are the composition, formation and evolution of the Galaxy. Gaia will achieve its unprecedented accuracy requirements with detailed calibration and correction for CCD radiation damage and CCD geometric distortion. In this paper, the third of the series, we present our 3D Silvaco ATLAS model of the Gaia e2v CCD91-72 pixel. We publish e2v's design model predictions for the capacities of one of Gaia's pixel features, the supplementary buried channel (SBC), for the first time. Kohley et al. (2009) measured the SBC capacities of a Gaia CCD to be an order of magnitude smaller than e2v's design. We have found the SBC doping widths that yield these measured SBC capacities. The widths are systematically 2 μm offset to the nominal widths. These offsets appear to be uncalibrated systematic offsets in e2v photolithography, which could either be due to systematic stitch alignment offsets or lateral ABD shield doping diffusion. The range of SBC capacities were used to derive the worst-case random stitch error between two pixel features within a stitch block to be ±0.25 μm, which cannot explain the systematic offsets. It is beyond the scope of our pixel model to provide the manufacturing reason for the range of SBC capacities, so it does not allow us to predict how representative the tested CCD is. This open question has implications for Gaia's radiation damage and geometric calibration models.

The Chandrayaan-1 X-ray Spectrometer (C1XS) was launched onboard the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission in October 2008. The instrument consisted of 24 swept-charge device silicon X-ray detectors providing a total collecting area of ~24 cm², corresponding to a 14° field of view (FWHM), with the ability to measure X-rays from 0.8 - 10 keV. During the 10 months the spacecraft was located in orbit around the Moon a number of solar flare X-ray events were detected, along with calibration data from X-ray sources housed inside the movable door of the instrument. This paper presents a study of the degradation in spectral resolution of the measured X-ray calibration lines, comparing those recorded mid way through the mission lifetime with ground based calibration data collected prior to the launch of the instrument. The radiation environment the detectors were subjected to is discussed in light of the actual radiation damage effects on the spectral resolution observed in flight.

Charge trapping in bulk silicon lattice structures is a source of charge transfer inefficiency (CTI) in CCDs. These traps can be introduced into the lattice by low-energy proton radiation in the space environment, decreasing the performance of the CCD detectors over time. Detailed knowledge of the inherent trap properties, including energy level and cross section, is important for understanding the impact of the defects on charge transfer as a function of operating parameters such as temperature and clocking speeds. This understanding is also important for mitigation of charge transfer inefficiency through annealing, software correction, or improved device fabrication techniques. In this paper, we measure the bulk trap properties created by 12.5 MeV proton irradiation on p+ channel, full-depletion CCDs developed at LBNL. Using the pocket pumping technique, we identify the majority trap populations responsible for CTI in both the parallel and serial transfer processes. We find the dominant parallel transfer trap properties are well described by the silicon lattice divacancy trap, in agreement with other studies. While the properties of the defects responsible for CTI in the serial transfer are more difficult to measure, we conclude that divacancy-oxygen defect centers would be efficient at our serial clocking rate and exhibit properties consistent with our serial pocket pumping data.

We describe a CMOS image sensor with column-parallel delta-sigma (ΔΣ) analog-to-digital converter (ADC). The design employs three transistor pixels (3T¹) where the unique configuration of the ΔΣ ADC reduces the noise contribution of the readout transistor. A 128 x 128 pixel image sensor prototype is fabricated in 0.35μm TSMC technology. The reset noise and the offset fixed pattern noise (FPN) are removed in the digital domain. The measured readout noise is 37.8μV for an exposure time of 33ms. The low readout noise allows an improved low light response in comparison to other state-of-art designs. The design is suitable for applications demanding excellent low-light response such as astronomical imaging. The sensor has a measured intra-scene dynamic range (DR) of 91 dB, and a peak signal-to-noise ratio (SNR) of 54 dB.

Teledyne Imaging Sensors (TIS) has developed a CMOS device known as the SIDECAR application-specific integrated circuit (ASIC). This single chip provides all the functionality of FPA drive electronics to operate visible and infrared imaging detectors with a fully digital interface. A Teledyne 2K ×2K silicon PIN diode array hybridized to a Hawaii-2RG multiplexer, the Hybrid Visible Silicon Imager (HyViSI) was read out with the ESO standard IR detector controller IRACE, which delivers detector limited performance. We have tested the H2RG HyViSI detector with the TIS SIDECAR ASIC in 32 channel readout mode at cryogenic temperatures. The SIDECAR has been evaluated down to 105 Kelvin operating temperature and performance results have been compared to those obtained with external electronics. Furthermore ESO has developed its own interface card to replace the JADE USB card provided by Teledyne. The ASIC controller is now being embedded in the ESO standard VLT hard and software environment. This paper provides an update on the recent development of the new ESO ASIC interface card. We find that the SIDECAR ASIC provides performance equal to external electronics.

This paper describes the features and functionality of the UCam (UKATC Universal Camera Control and Data Acquisition) detector control system with a particular emphasis on development and testing of two 4K×4K CCD camera systems built recently at UKATC and delivered to a group of telescopes in India. These two camera systems use two variants of an e2v CCD203 device; a 4k×4k standard back-thinned device and a deep depleted silicon device. Apart from the expected differences with the spectral response of these devices, other performance differences have been observed between the two systems such as conversion gain non-linearity, electrical crosstalk between outputs, fringing etc. which are thought to be related to the silicon thickness. Both these detectors show charge trapping during device power on or when saturated. The effects of this charge trapping and a solution implemented to minimise it will be presented. The configuration of the UCAM system, custom built detector mount and fanout board and the overall performance of these camera systems will also be presented.

We present a process for characterizing the correlation properties of the noise in large two-dimensional detector arrays, and describe an efficient process for its removal. In the case of the 2k × 2k HAWAII-2RG detectors (H2RG) detectors from Teledyne which are being used on the Near Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope (JWST), we find that we can reduce the read noise by thirty percent. Noise on large spatial scales is dramatically reduced. With this relatively simple process, we provide a performance improvement that is equivalent to a significant increase in telescope collecting area for high resolution spectroscopy with NIRSpec.

The "Photon Collider" uses a compact array of four off axis autoguider cameras positioned with independent filtering and focus. The photon collider is two way symmetric and robustly mounted with the off axis light crossing the science field which allows the compact single frame construction to have extremely small relative deflections between guide and science CCDs. The photon collider provides four independent guiding signals with a total of 15 square arc minutes of sky coverage. These signals allow for simultaneous altitude, azimuth, field rotation and focus guiding. Guide cameras read out without exposure overhead increasing the tracking cadence. The independent focus allows the photon collider to maintain in focus guide stars when the main science camera is taking defocused exposures as well as track for telescope focus changes. Independent filters allow auto guiding in the science camera wavelength bandpass. The four cameras are controlled with a custom web services interface from a single Linux based industrial PC, and the autoguider mechanism and telemetry is built around a uCLinux based Analog Devices BlackFin embedded microprocessor. Off axis light is corrected with a custom meniscus correcting lens. Guide CCDs are cooled with ethylene glycol with an advanced leak detection system. The photon collider was built for use on Las Cumbres Observatory's 2 meter Faulks telescopes and currently used to guide the alt-az mount.

In order for Kepler to achieve its required <20 PPM photometric precision for magnitude 12 and brighter stars, instrument-induced variations in the CCD readout bias pattern (our "2D black image"), which are either fixed or slowly varying in time, must be identified and the corresponding pixels either corrected or removed from further data processing. The two principle sources of these readout bias variations are crosstalk between the 84 science CCDs and the 4 fine guidance sensor (FGS) CCDs and a high frequency amplifier oscillation on <40% of the CCD readout channels. The crosstalk produces a synchronous pattern in the 2D black image with time-variation observed in <10% of individual pixel bias histories. We will describe a method of removing the crosstalk signal using continuously-collected data from masked and over-clocked image regions (our "collateral data"), and occasionally-collected full-frame images and reverse-clocked readout signals. We use this same set to detect regions affected by the oscillating amplifiers. The oscillations manifest as time-varying moiré pattern and rolling bands in the affected channels. Because this effect reduces the performance in only a small fraction of the array at any given time, we have developed an approach for flagging suspect data. The flags will provide the necessary means to resolve any potential ambiguity between instrument-induced variations and real photometric variations in a target time series. We will also evaluate the effectiveness of these techniques using flight data from background and selected target pixels.

We report on the first results from a new setup for electrical qualification measurements of DEPFET pixel detector matrices. In order to measure the transistor properties of all pixels, the DEPFET device is placed into a benchtest setup and electrically contacted via a probecard. Using a switch matrix, each pixel of the detector array can be addressed individually for characterization. These measurements facilitate to pre-select the best DEPFET matrices as detector device prior to the mounting of the matrix and allow to investigate topics like the homogeneity of transistor parameters on device, wafer and batch level in order to learn about the stability and reproducibility of the production process. Especially with regard to the detector development for the IXO Wide Field Imager (WFI), this yield learning will be an important tool. The first electrical qualification measurements with this setup were done on DEPFET macropixel detector flight hardware, which will form the FPAs of the Mercury Imaging X-ray Spectrometer (MIXS) on board of the 5th ESA cornerstone mission BepiColombo. The DEPFET array consists of 64×64 macropixel for which the transfer, output and clear characteristics were measured.

We have developed a hybrid Active Pixel Sensor for detecting low energy X-rays. The sensor consists of a silicon diode detector array built on a high resistivity wafer and an SOI CMOS readout circuit, connected together by means of unique 3D integration technology developed at MIT Lincoln Laboratory. In this paper we will describe measurements of sense node capacitance and device depletion depth along with corresponding simulations aimed to optimize device performance. We also describe race condition in the column decoder and identify ways to eliminate it in order to reduce fixed pattern noise.

The readout noise of a H2RG HgCdTe NIR detector from Teledyne is measured at a temperature T=110K. It is shown that a Fowler mode with n = 240 allows to reach a noise of 2.63e (single read). A description of the power spectrum in terms of 3 parameters reproduces the variation of the noise as a function the number of Fowler samples, as well as its dependence on the periodicity of the sampling. The variance of the noise decreases with frequency with an effective power of 0.62 in our measurement domain. The behaviour of the detector under different experimental conditions can then be predicted.

The most promising way to overcome the CMOS noise barrier of infrared AO sensors is the amplification of the photoelectron signal directly at the point of absorption inside the infrared pixel by means of the avalanche gain. HgCdTe eAPD arrays with cut off wavelengths of λ_c ~2.64 μm produced by SELEX-Galileo have been evaluated at ESO. The arrays were hybridized to an existing non-optimized ROIC developed for laser gated imaging which has a format of 320×256 pixels and four parallel video outputs. The avalanche gain makes it possible to reduce the read noise to < 7 e rms. The dark current requirements of IR wavefront sensing are also met.

Raytheon Vision Systems (RVS) arrays are being deployed world-wide in ground based and space based platforms. RVS has a family of high performance visible through far infrared detector arrays for astronomy and civil space applications. Unique and off-the-shelf product lines are readily available to the community. Large sensor chip assemblies using various detector materials like Si PIN, HgCdTe, InSb, and Si:As IBC, covering a detection range from visible (400nm) to mid-wave infrared (28μm, MWIR) have been demonstrated with excellent quantum efficiency, dark current, and uniformity. These focal plane arrays have been designed using state-of-the-art low noise, low power, and radiation hardened readout integrated circuits. Complete with optical filters, opto-mechanical packaging, active thermal cooling with matching thermal straps, and optional electronics, RVS provides complete solutions for a multitude of sensor types and mission objectives. This paper describes the recent developments of focal plane assemblies for upcoming missions and telescope platforms.

Many future space telescope missions are designed as wide-field surveys. The increased area of the survey is often achieved by increasing the plate scale of the detectors. This can result in under-sampled instruments. Under these conditions response variations within an individual pixel degrade photometric and shape information of observed astronomical sources. These effects can be corrected for by mapping the sub-pixel response of all pixels on a detector. Measuring sub-pixel sensitivity by projecting a single, micron-size spot is effective in understanding intrapixel response variations, but the time required to create a detector-wide map is prohibitive. The existing Spot-O-Matic single spot projector concept, has been extended to the design of a multi-spot projector, the Spots-O-Matic, enabling the mapping of an entire detector. This new projector is under development to achieve the small spot size required for pixel characterization over the field of view of an entire detector.

Flux dependent non-linearity (reciprocity failure) in HgCdTe NIR detectors with 1.7 μm cut-off was investigated. A dedicated test station was designed and built to measure reciprocity failure over the full dynamic range of near infrared detectors. For flux levels between 1 and 100,000 photons/sec a limiting sensitivity to reciprocity failure of 0.3 %/decade was achieved. First measurements on several engineering grade 1.7 μm cut-off HgCdTe detectors show a wide range of reciprocity failure, from less than 0.5 %/decade to about 10%/decade. For at least two of the tested detectors, significant spatial variation in the effect was observed. No indication for wavelength dependency was found. The origin of reciprocity failure is currently not well understood. In this paper we present details of our experimental set-up and show the results of measurements for several detectors.

The Low Background Infrared (LBIR) facility has developed and tested the components of a new detector for calibration of infrared greater than 1 pW, with 0.1 % uncertainty. Calibration of such low powers could be valuable for the quantitative study of weak astronomical sources in the infrared. The pW-ACR is an absolute cryogenic radiometer (ACR) employing a high resolution transition edge sensor (TES) thermometer, ultra-weak thermal link and miniaturized receiver to achieve a noise level of around 1 fW at a temperature of 2 K. The novel thermometer employs the superconducting transition of a tin (Sn) core and has demonstrated a temperature noise floor less than 3 nK/Hz^1/2. Using an applied magnetic field from an integrated solenoid to suppress the Sn transition temperature, the operating temperature of the thermometer can be tuned to any temperature below 3.6 K. The conical receiver is coated on the inside with infrared-absorbing paint and has a demonstrated absorptivity of 99.94 % at 10.6 μm. The thermal link is made from a thin-walled polyimide tube and has exhibited very low thermal conductance near 2x10^-7 W/K. In tests with a heater mounted on the receiver, the receiver/thermal-link assembly demonstrated a thermal time constant of about 15 s. Based on these experimental results, it is estimated that an ACR containing these components can achieve noise levels below 1 fW, and the design of a radiometer merging the new thermometer, receiver and thermal link will be discussed.

PANIC, the PAnoramic Near-Infrared Camera for Calar Alto, is one of the next generation instruments for this observatory. In order to cover a field of view of approximately 30 arcmin, PANIC uses a mosaic of four 2k x 2k HAWAII-2RG arrays from Teledyne. This document presents the preliminary results of the basic characterization of the mosaic. The performance of the system as a whole, as well as the in-house readout electronics and software capabilities will also be briefly discussed.

ESO has begun an ambitious mid-IR detector program with the funded development of a new Raytheon detector (AQUARIUS) and the further development of instruments to use 5 μm cut-off material Teledyne HAWAII-2RG detectors. Both these detector types are capable of extremely high readout speeds, through multiple readout ports, resulting in data rates in excess of 250 Mbytes/s. This has required further development of our new detector controller system (NGC) to allow it to operate at these very high pixel data rates. This has also entailed the development of new high speed pre-amplifiers which can operate at 60K to allow us to drive the long cable runs typical of an astronomical instrument. We report on the development and performance of our new higher speed NGC systems with particular regard to the operation of a Hawaii-2RG detector configured to use its high speed readout stages. We will present data on the performance of such at device, configured to operate in both slow and fast readout modes, with particular regard to noise versus pixel speed and also the optimization of the voltages.

The James Webb Space Telescope Fine Guidance Sensor makes use of three 2048×2048 five micron cutoff HAWAII- 2RG HgCdTe detectors from Teledyne Imaging Systems. The FGS consists of two Guider channels and one Tunable Filter Imager (TFI) channel. We report here on our efforts to optimize the performance of the FGS detector sub-system consisting of the detector arrays, the Teledyne SIDECAR ASIC, and the FGS specific SIDECAR Control Electronics. The FGS-Guider has a number of unique readout modes which are required to support observatory operations, requiring different optimizations for these readout modes compared to those required for science observations with the TFI.

In recent years, Teledyne Imaging Sensors has begun development of Long Wave Infrared (LWIR) HgCdTe Detector Arrays for low background astronomical applications, which have a high percentage of low dark current pixels but a substantial high dark current tail. Characterization of high dark current pixels in these devices has produced I-V curves with unusual behaviors. The typical theories of diffusion current, tunneling current, and even surface current have been unable to accurately model the observed I-V curves. By modeling dislocations in and near the p-n junction as trapping sites and those near the surface as leakage channels, the behavior of these unusual I-V curves is successfully modeled, pointing to the need to reduce the number of these dislocations in order to produce LWIR HgCdTe photodiodes exhibiting very low dark current with sufficient well depth.

The traditional design of optical systems is severely complicated by the curved shape of the image surface which has to be recorded on a planar retina. This constraint decreases the image quality; optical elements are then added to avoid aberrations and lead to increase the dimensions of the system. However, miniaturization could be achieved, without decreasing resolution and sensibility, by recording the image surface on a curved retina. The optical advantages of curved sensors have been demonstrated; the simplification leads to scale down the entire system. Moreover, the hemispherical shape increases the field of view (FOV). In this paper the advantages of curved focal plane will be detailed through two applications: spectrometry and large FOV telescopes. In astronomy, large FOV and miniaturization with good resolution can only be achieved by curving the focal plane; the difficulty is to curve in a hemispherical shape large detectors. The advantages are highlighted by the European Extremely Large Telescope (E-ELT) project. Despite this high interest in curved detectors, only few articles are dedicated to this hemispherical shape technology. Some solutions exist, which mainly consist in structuring the die in sub-devices. We propose a solution to curve an IR sensor with a fill factor equal to 100%. To do so, we developed a dedicated bonding process which allows curving silicon using its mechanical properties. A curved uncooled infrared detector has been performed without mechanical and electrical damage.

In this paper we present the cryogenic design of the EMCCD (Electron Multiplication Charged Couple Device) cameras for the Brazilian Tunable Filter Imager instrument for the 4 meters SOAR telescope in Chile. The camera uses a E2V 1600 × 1600 pixels full-frame device, which is controlled by the new CCCP (CCD Controller for Counting Photons), an EMCCD controller developed by the University of Montreal. We present the design of the camera, its thermal analysis and cryogenic performance.

The Torrent detector control system is being developed at NOAO as a follow-on to the MONSOON systems that have been used successfully for instruments at several institutions. The poster will cover the evolution of MONSOON into Torrent and will cover: Motivations, What's gained/What's lost, Major Technological Differences, Goals, plans and first users.

With the advance of the PFPA technology, the design methodology of digital systems is changing. In recent years we develop a method to implement the CCD timing generator based on FPGA and VHDL. This paper presents the principles and implementation skills of the method. Taking a developed camera as an example, we introduce the structure, input and output clocks/signals of a timing generator implemented in the camera. The generator is composed of a top module and a bottom module. The bottom one is made up of 4 sub-modules which correspond to 4 different operation modes. The modules are implemented by 5 VHDL programs. Frame charts of the architecture of these programs are shown in the paper. We also describe implementation steps of the timing generator in Quartus II, and the interconnections between the generator and a Nios soft core processor which is the controller of this generator. Some test results are presented in the end.

The 1.6-meter New Solar Telescope (NST) is currently the world's largest aperture solar telescope. The NST is newly built at Big Bear Solar Observatory (BBSO). Among other instruments, the NST is equipped with several focal plane instruments operating in the near infrared (NIR). In order to satisfy the diverse observational requirements of these scientific instruments, a 1024 × 1024 HgCdTe TCM8600 CMOS camera manufactured by Rockwell Scientific Company has been repackaged and upgraded at Infrared Laboratories Inc. A new ND-5 dewar was designed to house the TCM8600 array with a low background filter wheel, inverted operation and at least 12 hours of hold time between fills. The repackaged camera will be used for high-resolution NIR photometry at the NST Nasmyth focus on the telescope and high-precision NIR spectro-polarimetry in the NST Coud´e Lab below. In March 2010, this repackaged camera was characterized in the Coud´e Lab at BBSO. This paper presents the design of new dewar, the detailed process of repackaging and characterizing the camera, and a series of test results.

The Detector Characterization Laboratory at NASA/GSFC has investigated the reciprocity failure characteristics of 1.7μm cut-off HgCdTe devices provided by Teledyne Imaging Sensors to the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) project. The reciprocity failure follows a power law behavior over the range of fluxes tested (0.1-10⁴ photons/second). The slope of the power law varies among detectors, ranging from ~0.3-1%/dex at 1.0μm, which is much smaller than the ~6%/dex effect observed with the HST NICMOS 2.5μm cut-off detectors. In addition, the reciprocity failure exhibits no wavelength dependence, although only a restricted range of wavelengths (0.85-1.0μm) has been explored to date. Despite its relatively small magnitude, reciprocity failure is nevertheless an important effect in the calibration of WFC3 data, as well as in other applications in which there is a large difference in flux between the photometric standards and the scientific sources of interest.

We report on the testing of a set of InAs/GaSb multicolor strained-layer superlattice photodetectors and Dotin- Well detectors grown with InAs dots in InGaAs/GaAs wells fabricated by the Center for High Technology Materials at the University of New Mexico. These devices are 2-color devices sensitive to near-IR and mid-IR wavelengths. The wavelength sensitivities of these devices are a function of the applied forward and reverse bias. We present measurements of the dark current and relative spectral response of these photodetectors measured at both cryogenic and room temperatures.

We present the integration of a low dark current extended wavelength (2.3μm cutoff) InGaAs array into the Cornell-Massachusetts Slit Spectrograph (CorMASS) spectrograph. The InGaAs array was fabricated onto a SB- 206 512×512 readout integrated circuit (ROIC) by Goodrich/Sensors Unlimited and subsequently went through a series of laboratory characterization tests at the University of Virginia demonstrating dark current performance of better than 10 e^-/s. The InGaAs array is adapted for use with the CorMASS to verify its performance in a proven astronomical instrument, and for eventual deployment to a telescope to test stability and performance.

We report the effects of radiation damage due to ionizing protons on InGaAs photodiodes. The photodiodes were irradiated at energies of 30, 52, and 98 MeV and fluences up to 10¹⁰ protons/cm² in experiments at the Indiana University Cyclotron Facility. The photodiodes were tested for changes in their dark current, their relative responsivity as a function of wavelength from 1000 - 1600 nm, and their absolute responsivity in narrow bandpasses spread throughout the same wavelength region. The measurements were all made with detectors traceable to NIST standards. At these exposures and energies, the most significant effects are seen in the dark current levels.

In a recent optical design study of CODEX - a visible spectrograph planned for the European Extremely Large Telescope (E-ELT) - it was determined that a significant simplification of the optical design - accompanied by an improvement of the image quality - could be achieved through the application of large format (90mm square) concave spherically curved detectors with a low radius of curvature (500 to 250mm). Current assemblies of image sensors and optics rely on the optics to project a corrected image onto a flat detector. While scientific large-size CCDs (49mm square) have been produced unintentionally with a spherical radius of convex curvature of around 5m, in the past most efforts have concentrated onto flattening the light-sensitive detector silicon area as best as possible for both scientific state-of-the-art systems, as well as commercial low-cost consumer products. In some cases curved focal planes are mosaicked out of individual flat detectors, but a standard method to derive individual spherically curved large size detectors has not been demonstrated. This paper summarizes important developments in the area of curved detectors in the past and their different technical approaches mostly linked to specific thinning processes. ESO's specifications for an ongoing feasibility study are presented. First results of the latter are described with a link to theoretical and practical examinations of currently available technology to implement curved CCD and CMOS detectors for scientific applications.

We obtained 960,200 22-by-22-pixel windowed images of a pinhole spot using the Teledyne H2RG CMOS detector with un-cooled SIDECAR readout. We performed an analysis to determine the precision we might expect in the position error signals to a telescope's guider system. We find that, under non-optimized operating conditions, the error in the computed centroid is strongly dependent on the total counts in the point image only below a certain threshold, approximately 50,000 photo-electrons. The LSST guider camera specification currently requires a 0.04 arcsecond error at 10 Hertz. Given the performance measured here, this specification can be delivered with a single star at 14^th to 18^th magnitude, depending on the passband.

Hyper Suprime-Cam (HSC) is a second-generation wide field imaging camera for Subaru telescope with 10 times wider field of view (FOV) compared with Suprime-Cam (SC) currently being used. HSC makes the survey speed considerably faster than SC, while maintaining the high image quality of SC. The 1.5 degrees in diameter FOV is covered with 116 of 2K × 4K fully depleted back-illuminated CCDs with 15 μm pixels developed by HAMAMATSU Photonics K. K. and National Astronomical Observatory of Japan (NAOJ). The CCDs for HSC are designed to have higher quantum efficiency than those for SC in a wider range in the visible wavelengths, especially in the blue region. We at NAOJ have started acceptance inspection of the CCDs being delivered from HAMAMATSU. We used the X-ray source of ⁵⁵Fe and the LED to measure charge transfer efficiency, readout noise, linearity, and full-well capacity of 33 CCDs. In addition, we measured the quantum efficiency of 7 CCDs. We confirmed all the CCDs have good performances and quality. In this paper, we report the results from the acceptance inspection and characterization of these CCDs.

In the optical position observations to the near earth objects, the differential measurement methods are commonly used to improve positional accuracy, in which the object positions are calibrated by the star positions. However, due to the characteristics of motion of the observed object and the restrictions on current CCD imaging technology, single measurement accuracy of these methods for the object is not high. This is because there is relative motion between the calibration stars and the observed object in the field of view of the telescope. This paper analyzes characteristics of relative movement of the space objects on the Geosynchronous Earth Orbit and the stars in the field of view of an equatorial telescope, and CCD imaging effects for these objects and stars, then present a new CCD imaging technique for moving objects and stationary objects. One half of the CCD photosensitive area is used to acquire images of the moving objects in the field of view in drift scan mode, the other half to take simultaneously images of the stationary objects in the field of view in stare mode. Discussions about possibilities for developing this camera and its applications are presented. A prototype camera controller has been developed in our laboratory. The paper also describes the structure of the camera controller, the implementation method and skills, and some experimental results.

MIT Lincoln Laboratories and MIT Kavli Institute for Astrophysics and Space Research have developed an active pixel sensor for use as a photon counting device for imaging spectroscopy in the soft X-ray band. A silicon-on-insulator (SOI) readout circuit was integrated with a high-resistivity silicon diode detector array using a per-pixel 3D integration technique developed at Lincoln Laboratory. We have tested these devices at 5.9 keV and 1.5 keV. Here we examine the interpixel cross-talk measured with 5.9 keV X-rays.

We have developed a design for packaging Charged Coupled Devices (CCDs) for use as optical imaging devices for space applications, although the design is also useful for any large ground-based mosaic. We have constructed and assembled prototype packages using this design. Testing of these prototypes has demonstrated that these packaged CCDs are flight worthy. The design, construction, and testing of these prototypes are described in this article.

This article reports the results of radiation resistance tests of fully depleted p-channel Charge Coupled Devices (CCDs) developed at the Lawrence Berkeley National Laboratory for imaging applications in space. Several such devices were irradiated by 12 MeV protons at the tandem accelerator at the Wright Nuclear Structure Laboratory at Yale University by doses up to 8 x 10¹⁰ protons/cm². The equivalent dose at an orbit near L2 for a six year mission in space was estimated to be an equivalent 7.3 x 10⁸ 12.5 MeV protons/cm². The performance of the CCDs was measured both before and after irradiation. The charge transfer efficiency CTE was degraded from 0.999999 before irradiation to 0.999996 after the expected six year dose. The dark current, which was 3 electrons/pixel/hour before irradiation, is degraded to an equilibrium rate of 15 electrons/pixel/hour in orbit. We conclude that the performance of these devices is quite acceptable for high precision imaging in a space mission.

As terrestrial and spaceborne astronomical telescopes advance in multi-functional design sophistication, incorporating greater spectral resolutions, the utilization of curved focal plane ccd and cmos imaging detectors, contoured to match the telescope's Petzval field of curvature, provides a fundamental and novel optical simplicity facilitating new imaging frontiers in astronomical research. For space based telescopes, curved focal plane detector devices require significantly fewer optics than their flat counterparts, which require field flattening optics, in achieving maximum imaging resolutions for adjoining spectrometers or imaging cameras. consequently, with fewer optics comes greater room to place other optics within the same space to accomplish other tasks, providing much greater diversification of observing functions and techniques reserved simultaneously for the telescope. Included within this is the operational capability of producing multi-wavelength spectrometers gathering data concurrently at a multitude of selected wavelengths, with greater sensitivity, reliability, size reduction, and operational longevity of the restructured optical system. Specialized applications involving optical interferometry are also achievable with further enhancements when the curved detectors are applied specifically to refine or maximize detection of fringes, and when employing occulting mask algorithms for existing light paths. for planetary surface mapping space probes, curved focal plane detection provides real-time 3D multi-perspective image acquisition for streaming 3D data sets, replacing onboard or remote computationally intensive 3D reconstructions used for examining terrestrial surface features performed with corresponding flat detectors. For earth based telescopes, where mass of the telescope's optics are not so constrained, more degrees of freedom are also part of the benefits introduced by curved focal plane detector device optimization. Associated with the very large Petzval radii of curvature for very large and extreme telescopes within this class are wide field spatial distortions which are instantaneously corrected when arrays of curved CCD's or CMOS devices are joined homogeneously and precisely together along the converging field of curvature, without field flattening optics, insuring complete full field detection superior to flat facet detectors which compromise the telescope's imaging field curvature detection abilities.

SIDECAR is an Application Specific Integrated Circuit (ASIC), which can be used for control and data acquisition from near-IR HAWAII detectors offered by Teledyne Imaging Sensors (TIS), USA. The standard interfaces provided by Teledyne are COM API and socket servers running under MS Windows platform. These interfaces communicate to the ASIC (and the detector) through an intermediate card called JWST ASIC Drive Electronics (JADE2). As part of an ongoing programme of several years, for developing astronomical focal plane array (CCDs, CMOS and Hybrid) controllers and data acquisition systems (CDAQs), IUCAA is currently developing the next generation controllers employing Virtex-5 family FPGA devices. We present here the capabilities which are built into these new CDAQs for handling HAWAII detectors. In our system, the computer which hosts the application programme, user interface and device drivers runs on a Linux platform. It communicates through a hot-pluggable USB interface (with an optional optical fibre extender) to the FPGA-based card which replaces the JADE2. The FPGA board in turn, controls the SIDECAR ASIC and through it a HAWAII-2RG detector, both of which are located in a cryogenic test Dewar set up which is liquid nitrogen cooled. The system can acquire data over 1, 4, or 32 readout channels, with or without binning, at different speeds, can define sub-regions for readout, offers various readout schemes like Fowler sampling, up-theramp etc. In this paper, we present the performance results obtained from a prototype system.