We are presenting a new readout circuit developed for the PbWO4 scintillation detectors for the Electron Ion Collider (EIC) EEEMCAL. The design is centered around a 4 x 4 matrix of fast silicon photomultiplier (SiPM) sensors which are directly coupled to a preamplification stage, and which cover an area of 20 mm x 20 mm. The architecture allows for a small footprint where the signal extraction, summation and amplification are performed in addition to the SiPM bias supply and a gain and offset adjustment circuit with settings saved in local memory. The SiPM overvoltage is temperature compensated to provide additional gain stability to the unit. Adjustments to gain and offset are done remotely through a communication port. The design was optimized for spectral resolution, fast response and large dynamic range with a small footprint and low energy consumption/heat dissipation that does not require active cooling for stable operation. These features are very important for future implementation at EIC where thousands of modules will be assembled in a compact manner for the Electron Endcap Electromagnetic Calorimeter. In addition, this readout development presents many features and performance capabilities that make it an excellent choice for scintillation detectors in other research and industrial applications. The signal output can be adjusted for negative amplitude with 0V baseline like that of a PMT to mate to existing pulse acquisition infrastructure. A detector prototype was constructed with a 3x3 array of 20 mm x 20 mm x 200 mm PbWO4 crystals coupled to individual sensor arrays and readouts. The detector was tested at the Thomas Jefferson National Accelerator Facility with 5GeV positrons. We will present the results of these detector characterization measurements.
Crytur recently introduced MonaLIGHT, a novel ultrabright light source built on an integrated OSARAM 5W laser diode pumping a single crystal phosphor element in a transmission configuration. The module can produce a luminous flux of 1200 lm and luminous intensity of 8000 cd, unattainable with existing LED technology. This new fit-for-purpose light source (Modular Narrow Angle Light) is characterized by a very low étendue <0.2mm2.sr and brings high system efficiency in a very compact and energy efficient package. The phosphor is an optical element of the system which can produce excellent beam characteristics with a viewing angle as low as 4 degrees without the use of secondary optics. The internal quantum efficiency (QE) of the phosphor is 0.96 and external QE is greater than 0.55. The non-coherent emission spectrum is broad and continuous from 500 to 700 nm with no speckle pattern with applications in head up displays, micro projectors, navigation and instrument lighting, dazzlers, endoscopy, microscopy, and optical communications.
A defunct technology of lead tungstate (PbWO4, PWO) crystal growth was re-established and improved at Crytur. It has been discovered that key to crystal quality is pretreatment of raw material and double crystallization, although time consuming, but very effective in optimizing the final product. Several important technological advances have been made to be able to industrialize and scale up the crystal production for the needs of the large-scale physics experiments. These crystals have been evaluated at the Jefferson Accelerator facility in Newport News, VA, and found to meet the stringent requirements of the future detectors for EIC, unlike PWO crystals grown by different methods by other suppliers. Comparison of the crystal performance conducted by JLAB will be shown.
A new line of G4S detectors has been developed at Crytur, which combines the high-Z scintillators GAGG:Ce and LuAG:Ce with Silicon photomultipliers (SiPM). The detectors’ performance was established by identifying natural radionuclides in samples of rock and building materials. Due to the high detection efficiency of the chosen scintillator materials, and the small footprint of SiPMs, these detectors are very compact and can be made rugged for applications of gamma-ray detection and spectroscopy in the range of 30 keV to several MeV. Crytur’s material development and coupling design make these detectors a superior and affordable alternative to the conventional NaI:Tl based detectors. Due to the compact size these detectors are portable and suited for both lab and field use
Illicit nuclear materials represent a threat for the safety of the American citizens, and the detection and interdiction of a
nuclear weapon is a national problem that has not been yet solved. Alleviating this threat represents an enormous
challenge to current detection methods that have to be substantially improved to identify and discriminate threatening
from benign incidents. Rugged, low-power and less-expensive radiation detectors and imagers are needed for large-scale
wireless deployment.
Detecting the gamma rays emitted by nuclear and fissionable materials, particularly special nuclear materials (SNM), is
the most convenient way to identify and locate them. While there are detectors that have the necessary sensitivity, none
are suitable to meet the present need, primarily because of the high occurrence of false alarms.
The exploitation of neutron signatures represents a promising solution to detecting illicit nuclear materials. This work
presents the development of several detector configurations such as a mobile active interrogation system based on a
compact RF-Plasma neutron generator developed at LBNL and a fast neutron telescope that uses plastic scintillating-fibers
developed at the University of New Hampshire. A human-portable improved Solid-State Neutron Detector
(SSND) intended to replace pressurized 3He-tubes will be also presented. The SSND uses an ultra-compact CMOS-SSPM
(Solid-State Photomultiplier) detector, developed at Radiation Monitoring devices Inc., coupled to a neutron
sensitive scintillator. The detector is very fast and can provide time and spectroscopy information over a wide energy
range including fast neutrons.
We report on developments of an intraoperative probe, capable of functioning in real time with high spatial resolution
and high sensitivity. This probe combines two novel technologies and is based on an electron multiplying charge
coupled device (EMCCD) bonded to a high spatial resolution microcolumnar CsI(Tl) scintillator via a flexible fiberoptic
cable. Our data demonstrates that the probe can be used with such beta-emitting radiolabels as 18F, 131I, and 32P. The
basic design of the probe and its evaluation using standard clinical phantoms is presented. In addition, the operational
data obtained on swine models is included to demonstrate the probe's efficacy in practical procedures.
We are developing a probe for image-guided surgery of cancer to be used in conjunction with traditional beta emitting radiopharmaceuticals such as I131 and F18-FDG. This device is based on a combination of two novel technologies, a microcolumnar film scintillator, CsI(Tl) and low-noise high sensitivity Electron-Multiplying CCD (EMCCD). The former allows high spatial resolution nuclear imaging and the latter facilitates detection of signal with significantly higher SNR than conventional CCDs by the virtue of internal signal gain built into its readout register. CsI(Tl) is bonded to the EMCCD via a flexible coherent fiberopic cable for easy handling. Due to its high sensitivity the probe is capable of functioning in real time providing high spatial resolution nuclear images for precise detection, delineation and excision of tumors. The evaluation of the probe using standard clinical phantoms as well as the operational data obtained on swine models and in clinical surgery will be presented.
We examined the spatial resolution of a columnar CsI(Tl), single-photon imaging system using an approach that
estimates the interaction position to better than the spread of the light distribution. A columnar scintillator was directly
coupled to a 512×512 electron multiplying CCD (EMCCD) camera (16 μm pixels) binned at 2×2 to sample at 32 μm
pixels. Optical photons from gamma-ray/scintillator interactions are sampled over multiple pixels. Resultant images
show clusters of signal at the original interaction site, clusters from Cs and I K x-rays up to several hundred microns
away, and clusters from collimator K x-rays. Also evident are depth-of-interaction effects which result in a broadening
of the light distribution. These effects result in a degradation of spatial and energy resolution. Cluster pixel data was
processed to better estimate the interaction position within the initial interaction cluster. Anger (centroid) estimation of
individual gamma-ray events yielded spatial resolutions better than 100 μm; a result previously achievable only with
pixellated semiconductor detector arrays. After proper calibration, depth-of-interaction (DOI) effects are corrected by
performing maximum-likelihood 3D position and energy estimation of individual gamma-ray interactions.
Columnar CsI(Tl) screens are now routinely used in indirect digital x ray imaging detectors. The CsI(Tl) scintillator provides high density, high atomic number, and high scintillation efficiency. These properties, coupled with the fact that CsI(Tl) can be grown in columnar form, provide excellent spatial resolution, high x-ray absorption, and low noise resulting in detectors with high overall detective quantum efficiency (DQE(f)). While such screens are now commercially available, developments leading to further improvements in scintillator performance are ongoing at RMD. Here we report on the recent progress in developing very thin (10 μm) to very thick (~3 mm) columnar screens and discuss their application potential in digital radiology and nuclear medicine.
We report on recent advances in the development of powdered Lu2O3:Eu scintillator screens. The Lu2O3:Eu scintillator has excellent intrinsic material properties including high density (9.5 g/cm3), high average atomic number (63), and a peak emission of 610 nm. We have characterized the performance of screens fabricated from this material in comparison with commercial Gd2O2S:Tb screens. This paper presents resolution in terms of MTF(f), noise properties in terms of NPS(f), and overall NEQ(f), obtained by coupling the screens to a CCD detector. We have included sample radiographic images that demonstrate the ability to produce high quality images. These screens are currently under development, and further improvements in performance are expected with optimization of the scintillator and fabrication methods.
We report on a new x-ray converter screen based on the powdered Lu2O3:Eu scintillator. Lu2O3:Eu offers high density (9.4 g/cm3), high average atomic number (63), and a peak emission of 610 nm. The high density of the material and a high packing fraction of the coating provide higher x-ray absorption efficiency, even with thin screens. As a result Lu2O3:Eu screens are expected to provide superior spatial resolution and x-ray stopping power compared to commercial powdered screens. This newly developed screen has excellent imaging performance and offers several practical advantages such as ease of fabrication, low cost, and durability. This paper will discuss preliminary results of the imaging performance of this novel screen.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.