In order to optimize the surface flatness and roughness of borosilicate glass, this study employs the chemical mechanical polishing technology(CMP) for the surface flattening of borosilicate glass. The polishing characteristics of the sample has been studied by adjusting the process parameters of CMP, including the polishing time, the rotate speed of polishing disk, the rate of polishing liquid flow, and the polishing pressure. And finally, the surface flattening treatment of the sample was realized in the study. The results show that when the process parameters varied, the surface peak-valley value and surface roughness value of the glass shared the similar trend. As the polishing time increased, they decreased rapidly and then gradually stabilized. During the increase of the rotate speed of polishing disk, the rate of polishing liquid flow, and the polishing pressure, they showed a trend of firstly decreasing and then increasing.
Because of the obvious deformation difference for the alkali resistant glass tubes with different internal stress, in this paper, a new method for evaluating the internal stress and annealing quality of alkali resistant glass tubes based on digital image correlation algorithm is proposed. According to the deformation change rate of alkali resistant glass tube that obtained by digital image correlation algorithm, it can directly determine whether the internal stress meets the production standard. The alkali resistant glass tubes which have undergone abnormal(annealing time less than 5 hours and annealing temperature lower than 630 ℃) and normal annealing operation were selected as samples of experimental group and control group. The samples of these two groups were heated to 200 ℃ and then cooled to room temperature. The displacement fields between deformed images and the initial image are calculated by digital image correlation algorithm and the mean values change rate of the displacement fields are regard as the evaluated basis for the internal stress and annealing quality. Since the new method has many advantages such as simple, efficient and non-contact and only two continuous pictures are required in the detection process, it has been applied in the actual industrial production testing. In addition, this method provides a new approach for the internal stress detection of other solid materials.
In this paper, the properties of transition metal oxide borate glass were studied. It was found that introducing a small amount of CaO and BaO into borate glass could improve the crystal resistance and chemical stability of the glass. The introduction of V2O5, ZnO, Al2O3, SiO2 and other components is beneficial to widen the glass forming range and improve the anti-crystal performance of glass. The introduction of MgO and ZrO2 can improve the acid resistance of glass. The mixed and co-mixing of Fe2O3, MnO2, V2O5 and other transition metal oxides can increase the total doping amount by more than 30%. At the same time, the introduction of multiple components can effectively prevent glass crystallization and improve the anti-crystallization ability. The developed transition metal oxide borate glass has a resistivity up to 5×1010•cm, good chemical stability and anti-crystallization ability, and is suitable for the production of large crucible melting, realizing the preparation of 100×100×1mm glass samples.
Microchannel plate (MCP) is an important compact two-dimension multiplier for parallel multiplication of charged particles. With the advantages of high temporal resolution, high spatial resolution, high electron gain and compact structure, microchannel plate has become an important potential readout device for cryogenic quantum computing, such as the quantum computation based on floating electrons of liquid helium surface. For the sake of ultra-fast reading, it requires the signal readout time is less than 10-5 s at a temperature lower than 30K in the cryogenic quantum computing. However, the bulk resistance of MCP multiplier became giant at cryogenic temperature for the property of huge negative temperature coefficient of resistance, almost 105 Gohm at 20K~30K, resulting in a readout time of 10-2 -1s at cryogenic temperature, which was one of the major bottlenecks for the application of MCPs in the cryogenic quantum computing. In this paper, the bulk resistance of MCPs in two different bismuth contents (1at%, 2.4at%) under the same hydrogen reduction temperatures (730K) were present as the surrounding temperature controlled from 300K to 20K. The cryogenic bulk resistance of MCP was only decreased into 24% with the increase bismuth content from 1at% to 2.4at%, while thereof the normal bulk resistance was decline into 5%. The normal bulk resistance reduced only in the manner of improving the conductivity of conductive layer, could also increase the temperature-resistance sensitivity of MCP, leading an even greater temperature coefficient of resistance, which deteriorated the stability of readout in the cryogenic quantum computing.
Microchannel plate (MCP) is an important compact signal multiplier. The dynamic range of MCP is the key index influencing the detection quality of high flux, high energy and wide output linearity signals, but limited on the bulk resistance of MCP multiplier. Therefore, the problem of the bulk resistance-dependent of dynamic range transition in these devices needs to further continues to be investigated. In this paper, lead silicate glass microchannel plates in three different bismuth contents (0at%, 1at%, 2at%) were present. The bulk resistance decreased exponentially (from 6000MΩ into 15MΩ) with the increase of the content of bismuth in the lead silicate glass from 0at% to 2at%, meanwhile, the dynamic range was increased from 3.3×102 to 2.3×103 . As the bulk resistance of MCP multipliers dropped from 150MΩ into 15 MΩ (dropped about 90%), while the dynamic range of that just extended by seven times, meanwhile, the dark current of that boosted almost ten times (from 1pA to 10pA). It implicated that the dynamic range of MCP multiplier was influenced not only by the charge replenishment abilities involved in the bulk resistance, but also by the joule heating effect-depended dark current variation concerned with the bulk resistance.
Wolter microchannel plate (W-MCP) is a two dimensional array of capillary channel EUV/X-ray imaging precision optics. Detection efficiency and imaging quality are vital to the micro-focusing optics for X-ray. As a key factor of the detection efficiency and imaging quality, the micropore geometry of the W-MCP was investigated in the paper. The transformations of simulative imagings for different geometries were investigated both with Tracepro by the ray trace method of Monte Carlo algorithm and the real images of the specific manufactured plates were measured by the spectrometer. Symmetry axes, circular-arc structures and stacked density of layers on the focal imaging characteristics and detection efficiency of the W-MCPs were explored. The simulation results indicated that the detection efficiency of the ideal Lobster eye microchannel plate (L-MCP) was about 80% than that of the ideal W-MCP. Besides, the detection efficiency and the quality of focal imaging changing both obeyed Parabola distribution with the increasing of the numbers of symmetry axes from three to six in the W-MCP. The visible spectrum demonstrated that the detection efficiency was changed with the structural geometry of the MCP optics transforming. The standard W-MCP had an outstanding detection performance. The relative detection efficiency of the standard L-MCP was only 75% than that of the standard W-MCP. Moreover, the integrity of the outermost ring had the greatest impact on the relative detection efficiency of W-MCP, but the closest-packed-losing geometry rarely affected the detection performance.
The resistive plate chamber (RPC) is a gaseous parallel-plate detector, the glass resistive plate is the key element of RPC. In order to meet the requirement of high flux particle detection, it is urgent to develop low resistivity electroconductive glass. For this purpose, we designed the glass of SiO2-B2O3-P2O5-Al2O3-MxOysystem, the MxOy was chosen as Fe2O3, V2O5 and MnO2. In this paper, the formation abilities and conductive properties of glass were studied by adjusting the contents of the glass forming body and MxOy. The results showed that P2O5-Al2O3and P2O5-B2O3 built a quasi-[SiO4] tetrahedron structure as the glass forming body, the SiO2strengthened the network, which greatly improved the stability of the glass. Meanwhile, the addition of B2O3 and P2O5 could enhance the doping ability of MxOy in the whole glass system, which was benefit to reduce the resistivity of glass. Three transition metal oxides were added to the same base glass, and their resistivity was in order: ρFe<ρV<ρMn. The relationships between the oxidation-reduction atmosphere of glass melting and the resistivity of glass were investigated. The conductivity types was confirmed to be electronic conductive by testing the Seebeck coefficient and Hall effect of glass. The resistivity of the developed SiO2- B2O3-P2O5-Al2O3-Fe2O3 electronic conductive glass system was reached to1010Ω·cmlevel.
Microchannel plate (MCP) is an important signal multiplier. The original reduced lead silicate glass MCP was coated with amorphous alumina by atomic layer deposition (ALD), using trimethylaluminium Al(CH3)3(TMA) and water as precursors, to enhance the electron gain characteristics. The electrical properties of ALD-MCP at different deposition temperatures, cycles and annealing processing were investigated. The results indicated that the electron gain showed a Bigaussion trended electron gain-deposition temperature behavior at the ALD deposition temperature controlled from 120°C to 300°C with 60 deposition pulse cycles of TMA/H2O, while, the bulk resistances of which were basically unchanged. Moreover, the optimum deposition cycles were increased at the maximum electron gains with the rising deposition temperature. Besides, the modified effect of ALD-MCP was significantly affected by the processing parameters, the electrical properties of which even deteriorated with the unsuitable one. The electron gain and dark current was mainly related to the concentration of hydroxyl on the surface of microchannel layer. With an excessive annealing temperature at 400°C, despite the electron gain of ALD-MCP was almost 2×104 , the dark current of which would increase dramatically, even more than four times larger than that of the original hydrogen reduced MCP.
As a two dimensional arrays of micro-channel X-ray imaging precision optics, detection efficiency and imaging quality are crucial to micro-channel optics (MPO). As a key factor of the detection efficiency and imaging quality, cell packed geometries in the Wolter type micro-channel optics were investigated in the paper. The characteristics of simulative images for different cell packed geometries were compared with the software Tracepro by ray trace method of Monte Carlo algorithm. The influences for the amount of symmetry axes, chamber types and stacked density of layers on the focal imaging characteristics and detection efficiency of Wolter type micro-channel optics were explored. The results indicated that the detection efficiency and the quality of focal imaging changing both obeyed Parabola distribution with the increasing of the numbers of symmetry axis from three to six. In the cambered stacking models, focusing images showed a petaline shape dispersion background with the same symmetry axis in non-full-cambered stacking types. In the close-packed loss model, it had a minimal and maximal impact on the detection efficiency in the outmost layer and subouter layer, respectively. Besides, characteristics of simulative images for Lobster eye micro-channel optics (L-MPO) and Wolter type micro-channel optics (W-MPO) were compared by ray trace method in this paper. Results indicated that under a constant illumination with the same cell size, the simulated detection efficiency of ideal W-MPO was over 41.0%, which was 1.3 times than that of ideal L-MPO.
With the development of electronic displays becoming flat and portable, field emission displays (FED) get the widespread attention because they have the advantages of flat-panel displays and CRT displays together. At present, as one of the core components in FED, the screen is still the short board in the application of FED. With thin film phosphor as the phosphor layer, the screen will be very beneficial to the application of FED because of many advantages of extremely high resolution, strong adhesion, good smoothness, low release of gas, good conductivity and so on. That highlights the important application value and research significance of thin film phosphor in FED. In this review, we summarize the recent advances in the thin film phosphors for FED with emphasis on the film materials, preparation technology, and the main problems in the film. And the further study of thin film phosphors in FED is also presented.
Micro-channel plate (MCP) is a two dimensional arrays of microscopic channel charge particle multiplier. Silicate composition and hydrogen reduction are keys to determine surface morphology of micro-channel wall in MCP. In this paper, lead silicate glass micro-channel plates in two different cesium contents (0at%, 0.5at%) and two different hydrogen reduction temperatures (400°C,450°C) were present. The nano-scale morphology, elements content and chemical states of microporous wall surface treated under different alkaline compositions and reduction conditions was investigated by Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS), respectively. Meanwhile, the electrical characterizations of MCP, including the bulk resistance, electron gain and the density of dark current, were measured in a Vacuum Photoelectron Imaging Test Facility (VPIT).The results indicated that the granular phase occurred on the surface of microporous wall and diffuses in bulk glass is an aggregate of Pb atom derived from the reduction of Pb2+. In micro-channel plate, the electron gain and bulk resistance were mainly correlated to particle size and distribution, the density of dark current (DDC) went up with the increasing root-mean-square roughness (RMS) on the microporous wall surface. Adding cesiums improved the size of Pb atomic aggregation, lowered the relative concentration of [Pb] reduced from Pb2+ and decreased the total roughness of micro-channel wall surface, leading a higher bulk resistance, a lower electron gain and a less dark current. Increasing hydrogen reduction temperature also improved the size of Pb atomic aggregation, but enhanced the relative concentration of [Pb] and enlarged the total roughness of micro-channel wall surface, leading a higher bulk resistance, a lower electron gain and a larger dark current. The reasons for the difference of electrical characteristics were discussed.
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