Showing papers on "Microchannel published in 1986"
16 Jun 1986
TL;DR: In this article, the performance of an improved Microchannel Spatial Light Modulator is discussed, where a very thin crystal (approx. 50μm thickness) is adopted and the device structure is refined.
Abstract: The performance of an improved Microchannel Spatial Light Modulator is discussed. In order to improve the spatial resolution, a very thin crystal (approx. 50μm thickness) is adopted and the device structure is refined. This new device has a spatial resolution of approx. 10 1p/mm at 50 % modulation. Also, the contrast ratio is improved. It is achieved by coating the surface for the charge storage of the crystal with a dielectric mirror and coating the opposite surface with an anti-reflection coating. Moreover both surfaces of the output glass window are coated with an anti-reflection coating. The improved contrast ratio is more than 3000:1.
22 citations
TL;DR: A microchannel spatial light modulator having the functions of writing positive and negative charges has been developed and it has the special functions of zooming, deflecting, and rotating images.
Abstract: A microchannel spatial light modulator having the functions of writing positive and negative charges has been developed Moreover it has the special functions of zooming, deflecting, and rotating images The device can achieve image differentiation and Laplacian operation as well as image addition, subtraction, and logic operations The device facilitates pattern recognition
22 citations
TL;DR: In this article, the output energy distribution of microchannel plates with different output electrode structures has been studied experimentally and it is shown that the penetration depth of the output electrode into the microchannel plate ω is a very important factor affecting both output energy spread and the gain.
Abstract: The output energy distribution of microchannel plates with different output electrode structures has been studied experimentally. It is shown that the penetration depth of the output electrode into the microchannel plates ω is a very important factor affecting both the output energy spread and the gain. When ω becomes twice the length of a channel diameter, the unfavorable tail component in the energy distribution can be suppressed. Improvement in the output energy spread, however, results in a considerable gain reduction. These characteristics are clarified by the internal current behavior in MCPs inferred from two operating dynode currents at the input and output ends.
18 citations
13 Oct 1986
TL;DR: In this paper, the capability and initial use of the Multi-Anode Microchannel Array (MAMA) detector in the time-tag mode is reported, which consists of a visible-light detector tube with a semitransparent photocathode proximity-focused to a high-gain curved-channel microchannel plate MCP.
Abstract: The capability and initial use of the Multi-Anode Microchannel Array (MAMA) detector in the time-tag mode is reported. The detector hardware currently in use consists of a visible-light detector tube with a semitransparent photocathode proximity-focused to a high-gain curved-channel microchannel plate MCP. The photoevents are detected by a (256 x 1024)-pixel coincidence-anode array with pixel dimensions of 25 x 25 microns connected to charge-sensitive amplifiers and event-detection circuitry. In the time-lag mode, the detector delivers the pixel address and the time of arrival for each detected photon to an accuracy of 10 microns. The maximum count rate is limited by the speed of data-acquisition hardware. The MAMA detector in the time-lag mode is currently being evaluated in programs of astrometry and speckle imaging.
18 citations
14 Jul 1986
TL;DR: Barstow et al. as discussed by the authors used a CsI-coated micro-channel plate (MCP) for XUV sky survey experiments on ROSAT, where the MCPs and their resistive anode readout are curved to the same radius as the WFC telescope focal surface.
Abstract: Imaging microchannel plate detectors for XUV sky survey experimentsM.A. Barstow, G.W. Fraser and S.R. MilwardX -ray astronomy group, Department of PhysicsUniversity of Leicester, Leicester LE1 7RH EnglandAbstractWe describe the development of microchannel plate detectors for the Wide Field Camera(WFC) XUV (50 -300A) sky survey experiment on ROSAT. A novel feature of the detector designis that the microchannel plates (MCPs) and their resistive anode readout are curved to thesame radius as the WFC telescope focal surface. We show that curving the channel plates isnot detrimental to gain uniformity. We describe the design of a curved resistive anodereadout element and contrast our measurements of spatial resolution, global and localuniformity and temperature coefficient of resistance with the poor performance recentlyascribed to resistive anodes in the literature. We present the first measurements of thequantum detection efficiency of a CsI- coated MCP in the wavelength range 67 -256A.IntroductionCosmic Extreme Ultraviolet (EUV) astronomy is a young science. At present only a fewsources are known but there is evidence that many more may exist. The next major stepsforward in this field will be the all sky - surveys performed by the UK Wide Field Camera
16 citations
15 Jun 1986-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the detection efficiency of microchannel plates (MCP) for electrons with energies between 1 and 15 keV and input angles between 0° and 60° was investigated.
Abstract: Measurements of the detection efficiency (ϵ) of microchannel plates (MCP) for electrons with energies between 1 and 15 keV and input angles between 0° and 60° are reported. In addition, saturation effects at intensities up to 4.5 electrons/channel per second and the efficiency increase by a collecting field at the MCP surface are considered.
11 citations
15 Nov 1986-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this paper, the detection efficiency and position resolution of a microchannel plate chevron for electron beams of 12 to 300 keV energy at 0° to 45° angles of incidence have been investigated.
Abstract: The detection efficiency and position resolution of a microchannel plate chevron for electron beams of 12 to 300 keV energy at 0° to 45° angles of incidence have been investigated. The chevron is shown to ensure good stability, high detection efficiency and high position resolution in the energy range under study.
11 citations
13 Oct 1986
TL;DR: The 25mm microchannel-plate, position-sensitive UV astronomy photomultiplier tube presented in this paper is intended for the EOM-1 Spacelab Mission's FAUST payload and conducts wide-field imaging surveys in the VUV over the 1400-1800-A range.
Abstract: The 25-mm microchannel-plate, position-sensitive UV astronomy photomultiplier tube presented is intended for the EOM-1 Spacelab Mission's FAUST payload and conducts wide-field imaging surveys in the VUV over the 1400-1800-A range. The sealed detector encompasses a CsI photocathode deposited on the inner surface of a MgF2 window, a stack of microchannel plates, and a wedge-and-strip two-dimensional position-sensing anode. Since the wedge-and-strip principle requires only three anode signals, flight electronics can be reduced to three charge amplifiers and three analog-to-digital converters.
10 citations
01 Feb 1986-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, position sensitive detection was used to record spectra of Ti XIII and XII emitted by a low velocity titanium beam after one and two electron capture in a gas cell.
Abstract: Position sensitive detection was used to record spectra of Ti XIII and XII emitted by a low velocity titanium beam after one and two electron capture in a gas cell. A three meter quasi-grazing-incidence spectrometer was equipped with two 25 mm microchannel plates coupled with a sensitive anode encoder. The detector was successively positioned to record EUV radiations in the wavelength range from 30 to 60 nm. Observed lines are unambiguously assigned to transition in Ne-like and Na-like titanium.
10 citations
TL;DR: This note describes a microchannel electron multiplier which has been modified from its intended application as a direct-viewing night-vision system to render it suitable as an image intensifier for X-ray microscopic studies.
Abstract: This note describes a microchannel electron multiplier which has been modified from its intended application as a direct-viewing night-vision system to render it suitable as an image intensifier for X-ray microscopic studies. A micro-channel is a narrow tube of semiconducting lead glass, covered by a secondary electron emission layer. It operates by application of a potential of about 1000 V across the channel, producing a longitudinal electric field inside the tube. When an electron strikes the channel input, it generates two or three secondary electrons by colliding with the channelplate walls. These electrons enter the electric field and after acceleration repeatedly strike the wall, producing further secondary electrons. The total gain of this multiplication process is usually of the order of 104 to 105. These tubes can be fused together to form a microchannel plate (MCP). The working principles of MCPs have been described in detail by Eschard and Manley (1971).
8 citations
TL;DR: In this article, the gain and pulse height distribution width of a microchannel plate (MCP) chevron pair were measured as a function of the voltages applied to each plate and across the interplate gap.
Abstract: We present measurements of the gain and pulse height distribution width of a microchannel plate (MCP) chevron pair as a function of the voltages applied to each plate and across the interplate gap. These data are used to test an existing theory which describes how the gain of the chevron pair is related to the gains of the individual plates under conditions of single-electron input. In addition, we show how the requirement for high mean gain and narrow pulse-height distribution may be achieved.
Patent•
01 Oct 1986
TL;DR: In this paper, a microchannel plate with a plurality of microchannel portions, a portion in an amplifying direction from another portion having a lower surface zone resistance than the other, materials and circuitry being provided to permit controlled higher-temperature operation.
Abstract: A microchannel plate with a plurality of microchannel portions, a portion in an amplifying direction from another portion having a lower surface zone resistance than the other, materials and circuitry being provided to permit controlled higher-temperature operation.
Patent•
03 Jun 1986
TL;DR: In this paper, a plate type photosensitive glass base body is made of a material crystallized by ultraviolet rays and the microchannel plates which work as the secondary electron multiplicator are constituted, and the manufacturing process can be simplified and the product of either a large area or a different shape can be obtained easily.
Abstract: PURPOSE: To simplify a manufacturing process, by radiating ultraviolet rays to a photosensitive glass base body which is crystallized after being irradiated by the ultraviolet rays through a mask, and forming plural microchannels through a prosess of eliminating the irradiated portion by etching. CONSTITUTION: A plate type photosensitive glass base body 11 made of a material crystallized by ultraviolet rays is diagonally irradiated by the ultraviolet rays 16 through a mask 15, and plural microchannels are formed along its thickness direction by eliminating the irradiated portion by etching. Then, the secondary electron emission faces 23 are formed on the inside face of the microchannels 12 by processes of plating of metal film and oxidation and also, acceleration electrodes 13 are formed on both faces of the base body 11 by a lift off method. And the microchannel plates which work as the secondary electron multiplicator are constituted. Thus, a manufacturing process can be simplified and the product of either a large area or a different shape can be obtained easily. COPYRIGHT: (C)1987,JPO&Japio
09 Jun 1986
TL;DR: In this paper, a two dimensional optical logic operation with three micro-channel spatial light modulators (MSLMs) is demonstrated, and the proposed system is shown to work well with three MSLMs.
Abstract: operation withMicrochannel Spatial Light ModulatorTsutomu Hara, Naohisa Mukohzaka, Yoshiji SuzukiHamamatsu Photonics K.K.1126 -1 Ichino -cho, Hamamatsu, JapanAbstractA two dimensional optical logic operation with three microchannel spatial lightmodulators (MSLMs) is demonstrated. In this proposed system,
14 Jul 1986
TL;DR: The use of CsI photocathodes produces very high quantum efficiencies to wavelengths between about 100 and 1A (0.1 to 10 keV) with moderate energy resolution as mentioned in this paper.
Abstract: Detector systems based on the high-gain microchannel plate (MCP) electron multiplier have been used extensively for imaging at soft X-ray wavelengths both on the ground and in space. The latest pulse-counting electronic readout systems provide zero readout-noise, spatial resolutions (FWM) of 25 microns or better and can determine the arrival times of detected photons to an accuracy of the order of 100 ns. These systems can br developed to produce detectors with active areas of 100 mm in diameter or greater. The use of CsI photocathodes produces very high detective quantum efficiencies to wavelengths between about 100 and 1A (0.1 to 10 keV) with moderate energy resolution. The operating characteristics of the different types of soft X-ray MCP detector systems are described, and the prospects for future developments are discussed.
TL;DR: In this article, preliminary x-ray imaging characteristics of a vacuum-demountable, X-ray sensitive, microchannel spatial light modulator are presented along with a discussion of the principles of operation and the noise performance of the device in the high gain limit.
Abstract: Preliminary x-ray imaging characteristics of a vacuum-demountable, x-ray sensitive, microchannel spatial light modulator are presented. The measurements include spatial resolution, x-ray exposure sensitivity, framing speed, and built-in image postprocessing capabilities. These results are presented together with a discussion of the principles of operation and the noise performance of the device in the high gain limit.
Patent•
17 May 1986
TL;DR: In this article, an exhauster was used to facilitate degassing within each channel of the titled device by exhausting gas molecules or the like stuck on a microchannel plate by actuating a vacuum pump and each part before using when the plate is exposed to gas.
Abstract: PURPOSE:To facilitate degassing within each channel of the titled device by exhausting gas molecules or the like stuck on a microchannel plate by actuating an exhauster and each part before using when the plate is exposed to gas. CONSTITUTION:When detecting parts 4A-4D are adjusted outside a vacuum chamber, a vacuum pump 9 is actuated after these parts are arranged at the specified position of the vacuum. Then, when the degree of vacuum of the vacuum chamber attains to a specified value, the voltage lower than the ordi nary service voltage is impressed to the microchannel plates of the detecting parts 4A-4D. Then, a low pressure mercury lamp 8 is lighted and the microchannel plate of each detecting part is irradiated by light. As a result, the gas absorbed to the inside of the microchannel plate is disorbed fully.
TL;DR: In this paper, an yttrium aluminum garnet laser emitting single pulses in the regime of mode self-locking was used to study the response time of prototype photomultipliers fitted with two microchannel plates.
Abstract: An yttrium aluminum garnet laser emitting single pulses in the regime of mode self-locking was used to study the response time of prototype photomultipliers fitted with two microchannel plates. The best photomultipliers with a gain of at least 106 generated anode pulses with a rise time not exceeding 0.4 nsec and duration not exceeding 0.6 nsec at midamplitude.
01 May 1986
TL;DR: In this paper, a new approach to sub-nanosecond spectroscopy using a stripline microchannel plate as an optical gate for a stack of seven linear arrays is discussed.
Abstract: A new approach to subnanosecond spectroscopy using a stripline microchannel plate as an optical gate for a stack of seven linear arrays is discussed. This new technique allows seven subnanosecond time slices of the spectrum to be read out on a single cable with a frame time of 1 ms. Each of the seven time slices is capable of 500 channels of spectral data, with each channel having a dynamic range of 1000/1.
TL;DR: In this paper, the dynamic range and the spatial and temporal resolution of radiation detectors were optimized by the use of microchannel electron multipliers for amplification purposes for x-ray, gamma, electron, and daughter product detection for iodine 125, americium 241, thulium 170, cerium 139, and mercury 203.
Abstract: The authors establish criteria and procedures for optimizing the dynamic range and the spatial and temporal resolution of radiation detectors by the implementation of microchannel electron multipliers for amplification purposes To this end they give performance and material evaluations for multiplier configurations and for x-ray, gamma, electron, and daughter product detection for iodine 125, americium 241, thulium 170, cerium 139, and mercury 203