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Sample records for photon-counting microchannel plate

  1. High Speed Large Format Photon Counting Microchannel Plate Imaging Sensors

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; Ertley, C.; Vallerga, J.

    The development of a new class of microchannel plate technology, using atomic layer deposition (ALD) techniques applied to a borosilicate microcapillary array is enabling the implementation of larger, more stable detectors for Astronomy and remote sensing. Sealed tubes with MCPs with SuperGenII, bialkali, GaAs and GaN photocathodes have been developed to cover a wide range of optical/UV sensing applications. Formats of 18mm and 25mm circular, and 50mm (Planacon) and 20cm square have been constructed for uses from night time remote reconnaissance and biological single-molecule fluorescence lifetime imaging microscopy, to large area focal plane imagers for Astronomy, neutron detection and ring imaging Cherenkov detection. The large focal plane areas were previously unattainable, but the new developments in construction of ALD microchannel plates allow implementation of formats of 20cm or more. Continuing developments in ALD microchannel plates offer improved overall sealed tube lifetime and gain stability, and furthermore show reduced levels of radiation induced background. High time resolution astronomical and remote sensing applications can be addressed with microchannel plate based imaging, photon time tagging detector sealed tube schemes. Photon counting imaging readouts for these devices vary from cross strip (XS), cross delay line (XDL), to stripline anodes, and pad arrays depending on the intended application. The XS and XDL readouts have been implemented in formats from 22mm, and 50mm to 20cm. Both use MCP charge signals detected on two orthogonal layers of conductive fingers to encode event X-Y positions. XDL readout uses signal propagation delay to encode positions while XS readout uses charge cloud centroiding. Spatial resolution readout of XS detectors can be better than 20 microns FWHM, with good image linearity while using low gain (<10^6), allowing high local counting rates and longer overall tube lifetime. XS tubes with electronics can encode event

  2. Silicon microchannel plates: initial results for photon counting detectors

    NASA Astrophysics Data System (ADS)

    Siegmund, Oswald H.; Tremsin, Anton S.; Vallerga, John V.; Beetz, Charles P.; Boerstler, Robert W.; Winn, D. R.

    2000-12-01

    The emergence of Silicon based microchannel plates (MCP's) has been awaited for a number of years, with many proposed advantages over standard glass MCPs for space-based detectors. Si should have a very low inherent background (< 0.01 events sec-1 cm-2), as well as being a low Z element with low stopping power for x, gamma and cosmic rays. The surface is oxidized and can be baked to very high temperatures (> 800 degrees Celsius), and will not react with photocathodes deposited on the surface. This could potentially allow opaque photocathodes, with their higher resolution and efficiency, to be used in the near UV/optical bands. Since the microchannel positions are determined photolithographically, the pattern will be uniform and coherent, resulting in more uniform flat fields and less differential non-linearity in the spatial response. Microchannel spacing could decrease to the micron regime, while size formats could increase. The potential advantages of Si MCPs encompass increased gain, stability, longevity, event rate, and QE. However, glass MCPs have a strong and successful heritage in space-based detector systems and the advantages of Si MCP's must be demonstrated in the laboratory before being considered for flight applications. We have tested some newly developed silicon (Si) MCP's provided by Nanosciences Corp. Although these are still in the developmental stage we have achieved a number of significant results. The gain, pulse height, response and gain uniformity, and quantum detection efficiency are very similar to glass MCP's. However the Si MCP background is approximately 0.02 events sec-1 cm-2 without shielding, a significant improvement over even low noise MCP's. The small samples we have tested are 25 mm format with 8 micrometer pore spacing, but they are taken from a 75 mm substrate, which offers the possibility of large MCP's in the near future. More testing and process development are underway to probe other operational parameters and optimize the

  3. Calibration of photon counting imaging microchannel plate detectors for EUV astronomy

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Vallerga, J.; Jelinsky, P.

    1986-01-01

    The calibration of photon counting imaging detectors for satellite based EUV astronomy is a complex process designed to ensure the validity of the data received 'in orbit'. The methods developed to accomplish calibration of microchannel plate detectors for the Extreme Ultraviolet Explorer are described and illustrated. The characterization of these detectors can be subdivided into three categories: stabilization, performance tests, and environmental tests.

  4. Photon-counting detector arrays based on microchannel array plates. [for image enhancement

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1975-01-01

    The recent development of the channel electron multiplier (CEM) and its miniaturization into the microchannel array plate (MCP) offers the possibility of fully combining the advantages of the photographic and photoelectric detection systems. The MCP has an image-intensifying capability and the potential of being developed to yield signal outputs superior to those of conventional photomultipliers. In particular, the MCP has a photon-counting capability with a negligible dark-count rate. Furthermore, the MCP can operate stably and efficiently at extreme-ultraviolet and soft X-ray wavelengths in a windowless configuration or can be integrated with a photo-cathode in a sealed tube for use at ultraviolet and visible wavelengths. The operation of one- and two-dimensional photon-counting detector arrays based on the MCP at extreme-ultraviolet wavelengths is described, and the design of sealed arrays for use at ultraviolet and visible wavelengths is briefly discussed.

  5. Development and test of photon-counting microchannel plate detector arrays for use on space telescopes

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1976-01-01

    The full sensitivity, dynamic range, and photometric stability of microchannel array plates(MCP) are incorporated into a photon-counting detection system for space operations. Components of the system include feedback-free MCP's for high gain and saturated output pulse-height distribution with a stable response; multi-anode readout arrays mounted in proximity focus with the output face of the MCP; and multi-layer ceramic headers to provide electrical interface between the anode array in a sealed detector tube and the associated electronics.

  6. Development of a single-photon-counting camera with use of a triple-stacked micro-channel plate.

    PubMed

    Yasuda, Naruomi; Suzuki, Hitoshi; Katafuchi, Tetsuro

    2016-01-01

    At the quantum-mechanical level, all substances (not merely electromagnetic waves such as light and X-rays) exhibit wave–particle duality. Whereas students of radiation science can easily understand the wave nature of electromagnetic waves, the particle (photon) nature may elude them. Therefore, to assist students in understanding the wave–particle duality of electromagnetic waves, we have developed a photon-counting camera that captures single photons in two-dimensional images. As an image intensifier, this camera has a triple-stacked micro-channel plate (MCP) with an amplification factor of 10(6). The ultra-low light of a single photon entering the camera is first converted to an electron through the photoelectric effect on the photocathode. The electron is intensified by the triple-stacked MCP and then converted to a visible light distribution, which is measured by a high-sensitivity complementary metal oxide semiconductor image sensor. Because it detects individual photons, the photon-counting camera is expected to provide students with a complete understanding of the particle nature of electromagnetic waves. Moreover, it measures ultra-weak light that cannot be detected by ordinary low-sensitivity cameras. Therefore, it is suitable for experimental research on scintillator luminescence, biophoton detection, and similar topics. PMID:26486629

  7. Evaluation of a photon-counting x-ray imaging detector based on microchannel plates for mammography applications

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Xu, Tong; Molloi, Sabee

    2004-05-01

    Experimental prototype of a photon counting scanning slit X-ray imaging system is being evaluated for potential application in digital mammography. This system is based on a recently developed and tested "edge-on" illuminated Microchannel Plate (MCP) detector. The MCP detectors are well known for providing a combination of capabilities such as direct conversion, physical charge amplification, pulse counting, high spatial and temporal resolution, and very low noise. However, their application for medical imaging was hampered by their low detection efficiency. This limitation was addressed using an "edge-on" illumination mode for MCP. The current experimental prototype was developed to investigate the imaging performance of this detector concept for digital mammography. The current prototype provides a 60 mm field of view, 200 kHz count rate with 20% non-paralysable dead time and >7 lp/mm limiting resolution. A 0.3 mm focal spot W target X-ray tube was used for image acquisition. The detector noise is 0.3 count/pixel for 50x50 micron pixels. The count rate of the current prototype is limited by the delay line readout electronics, which causes long scanning times (minutes) and high tube loading. This problem will be addressed using multichannel ASIC electronics for clinical implementation. However, the current readout architecture is adequate for evaluation of the performance parameters of the new detector concept. It is very simple and provides a maximum intrinsic resolution of 28 micron FWHM. The prototype was evaluated using resolution, contrast detail and breast Phantoms. The MTF and DQE of the system are being evaluated at different tube voltages. The design parameters of a scanning multiple slit mammography system are being evaluated. It is concluded that a photon counting, quantum limited and virtually scatter free digital mammography system can be developed based on the proposed detector.

  8. A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

    NASA Technical Reports Server (NTRS)

    Kimble, Randy A.; Pain, Bedabrata; Norton, Timothy J.; Haas, J. Patrick; Oegerle, William R. (Technical Monitor)

    2002-01-01

    Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest of by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

  9. A High-Speed, Event-Driven, Active Pixel Sensor Readout for Photon-Counting Microchannel Plate Detectors

    NASA Technical Reports Server (NTRS)

    Kimble, Randy A.; Pain, B.; Norton, T. J.; Haas, P.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Silicon array readouts for microchannel plate intensifiers offer several attractive features. In this class of detector, the electron cloud output of the MCP intensifier is converted to visible light by a phosphor; that light is then fiber-optically coupled to the silicon array. In photon-counting mode, the resulting light splashes on the silicon array are recognized and centroided to fractional pixel accuracy by off-chip electronics. This process can result in very high (MCP-limited) spatial resolution for the readout while operating at a modest MCP gain (desirable for dynamic range and long term stability). The principal limitation of intensified CCD systems of this type is their severely limited local dynamic range, as accurate photon counting is achieved only if there are not overlapping event splashes within the frame time of the device. This problem can be ameliorated somewhat by processing events only in pre-selected windows of interest or by using an addressable charge injection device (CID) for the readout array. We are currently pursuing the development of an intriguing alternative readout concept based on using an event-driven CMOS Active Pixel Sensor. APS technology permits the incorporation of discriminator circuitry within each pixel. When coupled with suitable CMOS logic outside the array area, the discriminator circuitry can be used to trigger the readout of small sub-array windows only when and where an event splash has been detected, completely eliminating the local dynamic range problem, while achieving a high global count rate capability and maintaining high spatial resolution. We elaborate on this concept and present our progress toward implementing an event-driven APS readout.

  10. High Speed Optical Imaging Photon Counting Microchannel Plate Detectors for Astronomical and Space Sensing Applications

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; Vallerga, J.; Welsh, B.; McPhate, J.; Rogers, D.

    In recent years we have implemented a variety of high-resolution, photon-counting MCP detectors in space instrumentation for satellite FUSE, GALEX, IMAGE, SOHO, SSULI, HST-COS, rocket, and shuttle payloads as well as sensors for ground based Astronomy, reconnaissance and biology. These detectors can meet many of the challenging imaging and timing demands of applications including astronomy of transient and time-variable sources, Earth atmospheric imaging and spectroscopy for real time space weather monitoring, biological single-molecule fluorescence lifetime microscopy, airborne and space situational awareness, and optical night-time/reconnaissance. Our recent work on high performance photon counting imaging readouts enables significant advancements over previous detector systems used for these applications. We have developed novel Cross-Strip and Cross-Delay-Line anode structures that can, in combination with small pore MCP's in sealed tube detectors, can achieve high spatial resolution (better than 10 um FWHM) with self triggered ~1 ns timing accuracy at up to 10 MHz event rates. Sealed tubes with formats, of 18mm, and 25mm with efficient S25 photocathodes have been built and are being used in several applications. The detectors and their properties will be discussed in this paper. Our installation and astronomical commissioning of one of these detectors at the South African Astronomical Observatory, South African Large Telescope (SALT) 10m telescope will be described. Our photometer is positioned in an auxiliary instrument port of the SALT. This is a stand-alone instrument that includes our detector system with two filter wheels (neutral density and U, B, V), an iris, and all the control modules necessary to operate the system. This instrument gives us access to the southern sky with significant sensitivity and unprecedented time resolution (microsec). High time resolution astronomy is still in its infancy, such that high cadence observations of the variable

  11. Cross strip anode readouts for large format, photon counting microchannel plate detectors: developing flight qualified prototypes of the detector and electronics

    NASA Astrophysics Data System (ADS)

    Vallerga, John; Raffanti, Rick; Cooney, Michael; Cumming, Harley; Varner, Gary; Seljak, Andrej

    2014-07-01

    Photon counting microchannel plate (MCP) imagers have been the detector of choice for most UV astronomical missions over the last two decades (e.g. EUVE, FUSE, COS on Hubble etc.). Over this duration, improvements in the MCP laboratory readout technology have resulted in better spatial resolution (x10), temporal resolution (x1000) and output event rate (x100), all the while operating at lower gain (x 10) resulting in lower high voltage requirements and longer MCP lifetimes. One such technology is the parallel cross strip (PXS) readout. Laboratory versions of PXS electronics have demonstrated < 20 μm FWHM spatial resolution, count rates on the order of 2 MHz, and temporal resolution of ~ 1ns. In 2012 our group at U.C. Berkeley, along with our partners at the U. Hawaii, received a Strategic Astrophysics Technology grant to raise the TRL of the PXS detector and electronics from 4 to 6 by replacing most of the high powered electronics with application specific integrated circuits (ASICs) which will lower the power, mass and volume requirements of the PXS detector. We were also tasked to design and fabricate a "standard" 50mm square active area MCP detector incorporating these electronics that can be environmentally qualified for flight (temperature, vacuum, vibration). The first ASICs designed for this program have been fabricated and are undergoing testing. We present the latest progress on these ASIC designs and performance and show imaging results from the new 50 x 50 mm XS detector.

  12. Fractal multifiber microchannel plates

    NASA Technical Reports Server (NTRS)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  13. Optical Ranicon detectors for photon counting imaging.

    NASA Astrophysics Data System (ADS)

    Clampin, Mark; Crocker, Jim; Paresce, Francesco; Rafal, Marc

    1988-08-01

    The design and development of two detectors, known as Ranicon and advanced Ranicon, for optical photon counting imaging on ground-based telescopes are discussed. The proximity focusing, microchannel-plate stack, resistive anode, and signal processing characteristics are described. The theory behind the overall resolution of the Ranicon system is reviewed. Resolution measurements for the instruments are reported and discussed.

  14. Microchannel plate streak camera

    DOEpatents

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  15. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1989-03-21

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras is disclosed. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1,000 KeV x-rays. 3 figs.

  16. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1984-09-28

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (uv to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 keV x-rays.

  17. Ultrafast microchannel plate photomultipliers.

    PubMed

    Kume, H; Koyama, K; Nakatsugawa, K; Suzuki, S; Fatlowitz, D

    1988-03-15

    Performance characteristics of several new types of photomultiplier tubes (PMT) with microchannel plates (MCP) are presented in this paper. They are the MCP-PMT with 6-microm diam channels, MCP-PMT with an S-l photocathode, and MCP-PMT with multi (discrete) anode and gatable MCP-PMT. Important requirements of an optical detector for picosecond lasers, fluorescence measurements, and material analysis are low light detectability, ultrafast time response, and versatile operation including modulation. The basic configuration, characteristics, and practical results of these detectors are described. PMID:20531532

  18. Micro-channel plate detector

    DOEpatents

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  19. Highly curved microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Cully, S.; Warren, J.; Gaines, G. A.; Priedhorsky, W.; Bloch, J.

    1990-01-01

    Several spherically curved microchannel plate (MCP) stack configurations were studied as part of an ongoing astrophysical detector development program, and as part of the development of the ALEXIS satellite payload. MCP pairs with surface radii of curvature as small as 7 cm, and diameters up to 46 mm have been evaluated. The experiments show that the gain (greater than 1.5 x 10 exp 7) and background characteristics (about 0.5 events/sq cm per sec) of highly curved MCP stacks are in general equivalent to the performance achieved with flat MCP stacks of similar configuration. However, gain variations across the curved MCP's due to variations in the channel length to diameter ratio are observed. The overall pulse height distribution of a highly curved surface MCP stack (greater than 50 percent FWHM) is thus broader than its flat counterpart (less than 30 percent). Preconditioning of curved MCP stacks gives comparable results to flat MCP stacks, but it also decreases the overall gain variations. Flat fields of curved MCP stacks have the same general characteristics as flat MCP stacks.

  20. Single-molecule localization software applied to photon counting imaging.

    PubMed

    Hirvonen, Liisa M; Kilfeather, Tiffany; Suhling, Klaus

    2015-06-01

    Centroiding in photon counting imaging has traditionally been accomplished by a single-step, noniterative algorithm, often implemented in hardware. Single-molecule localization techniques in superresolution fluorescence microscopy are conceptually similar, but use more sophisticated iterative software-based fitting algorithms to localize the fluorophore. Here, we discuss common features and differences between single-molecule localization and photon counting imaging and investigate the suitability of single-molecule localization software for photon event localization. We find that single-molecule localization software packages designed for superresolution microscopy-QuickPALM, rapidSTORM, and ThunderSTORM-can work well when applied to photon counting imaging with a microchannel-plate-based intensified camera system: photon event recognition can be excellent, fixed pattern noise can be low, and the microchannel plate pores can easily be resolved. PMID:26192667

  1. Time-correlated single photon counting: an advancing technique in a plate reader for assay development and high throughput screening

    NASA Astrophysics Data System (ADS)

    Näther, Dirk U.; Fenske, Roger; Hurteaux, Reynald; Majno, Sandra; Smith, S. Desmond

    2006-10-01

    A new plate reader (Nanotaurus) has been developed by Edinburgh Instruments that has the principle design features of a confocal microscope and utilises the technique of Time Correlated Single Photon Counting for data acquisition. The advantages of Fluorescence Lifetime Measurements in the nanosecond time scale and analysis methods to recover lifetime parameters are discussed based on experimental data. First working assays using changes of lifetime parameters are presented that clearly demonstrate the advantages of the new instrument for biochemical assays and show strong promise for cell-based assays, by utilising the independence of lifetime parameters from sample volume and concentration.

  2. X-ray imaging with ``edge-on'' microchannel plate detector: first experimental results

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Molloi, Sabee

    2003-09-01

    A novel scanning slit X-ray imaging system based on an "edge-on" microchannel plate detector was developed and tested. Images were acquired at 50 kV(p) X-ray tube voltage with a limiting spatial resolution of 7 lp/mm. The pixel noise was measured to be 0.3 count/pixel/s for a 50×70 μm 2 pixel size. This photon counting detector can be considered to be virtually noise free.

  3. Background events in microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Vallerga, J.; Wargelin, B.

    1988-01-01

    Measurements have been made to assess the characteristics and origins of background events in microchannel plates (MCPs). An overall background rate of about 0.4 events/sq cm persec has been achieved consistently for MCPs that have been baked and scrubbed. The temperature and gain of the MCPs are found to have no significant effect on the background rate. Detection of 1.46-MeV gamma rays from the MCP glass confirms the presence of K-40, with a concentration of 0.0007 percent, in MCP glass. It is shown that beta decay from K-40 is sufficient to cause the background rate and spectrum observed. Anticoincidence measurements indicate the the background rate caused by cosmic ray interactions is small (less than 0.016 events/sq cm per sec).

  4. Micro-channel plates and vacuum detectors

    NASA Astrophysics Data System (ADS)

    Gys, T.

    2015-07-01

    A micro-channel plate is an array of miniature electron multipliers that are each acting as a continuous dynode chain. The compact channel structure results in high spatial and time resolutions and robustness to magnetic fields. Micro-channel plates have been originally developed for night vision applications and integrated as an amplification element in image intensifiers. These devices show single-photon sensitivity with very low noise and have been used as such for scintillating fiber tracker readout in high-energy physics experiments. Given their very short transit time spread, micro-channel plate photomultiplier tubes are also being used in time-of-flight and particle identification detectors. The present paper will cover the history of the micro-channel plate development, basic features, and some of their applications. Emphasis will be put on various new manufacturing processes that have been developed over the last few years, and that result in a significant improvement in terms of efficiency, noise, and lifetime performance.

  5. Electronic readout systems for microchannel plates

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1985-01-01

    The modes of operation of position-sensitive electronic readout systems which use high-gain microchannel plate (MCP) electron multipliers are described, and their performance characteristics, along with those of the MCP, are compared. Among the structures presented are the wedge-and-strip, Codacon, and multilayer coincidence-anode MAMA (Multimode Microchannel Array) arrays. Spatial resolution of 25 x 25 sq microns (coincidence anode arrays) is achieved with an array format of 256 x 1024 pixels. On the basis of the performance data it is concluded that the readout systems using only conducting electrodes offer the best performance characteristics.

  6. Imaging characteristics of the Extreme Ultraviolet Explorer microchannel plate detectors

    NASA Technical Reports Server (NTRS)

    Vallerga, J. V.; Kaplan, G. C.; Siegmund, O. H. W.; Lampton, M.; Malina, R. F.

    1989-01-01

    The Extreme Ultraviolet Explorer (EUVE) satellite will conduct an all-sky survey over the wavelength range from 70 A to 760 A using four grazing-incidence telescopes and seven microchannel-plate (MCP) detectors. The imaging photon-counting MCP detectors have active areas of 19.6 cm2. Photon arrival position is determined using a wedge-and-strip anode and associated pulse-encoding electronics. The imaging characteristics of the EUVE flight detectors are presented including image distortion, flat-field response, and spatial differential nonlinearity. Also included is a detailed discussion of image distortions due to the detector mechanical assembly, the wedge-and-strip anode, and the electronics. Model predictions of these distortions are compared to preflight calibration images which show distortions less than 1.3 percent rms of the detector diameter of 50 mm before correction. The plans for correcting these residual detector image distortions to less than 0.1 percent rms are also presented.

  7. Performance of low resistance microchannel plate stacks

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Stock, J.

    1991-01-01

    Results are presented from an evaluation of three sets of low resistance microchannel plate (MCP) stacks; the tests encompassed gain, pulse-height distribution, background rate, event rate capacity as a function of illuminated area, and performance changes due to high temperature bakeout and high flux UV scrub. The MCPs are found to heat up, requiring from minutes to hours to reach stabilization. The event rate is strongly dependent on the size of the area being illuminated, with larger areas experiencing a gain drop onset at lower rates than smaller areas.

  8. Microporous microchannel plates and method of manufacturing same

    DOEpatents

    Beetz, Jr., Charles P.; Boerstler, Robert W.; Steinbeck, John; Winn, David R.

    2000-01-01

    A microchannel plate and method of manufacturing same is provided. The microchannel plate includes a plate consisting of an anodized material and a plurality of channels which are formed during the anodization of the material and extend between the two sides of the plate. Electrodes are also disposed on each side of the plate for generating an electrical field within the channels. Preferably, the material is alumina and the channels are activated such that the channel walls are conductive and highly secondary emissive.

  9. Unique microchannel plate process doubles MCPI resolution

    SciTech Connect

    Thomas, S.; Power, G.

    1994-08-22

    Applying a dielectric layer to the output of a microchannel plate (MCP) has allowed the screen voltage of a sealed microchannel-plate intensifier tube (MCPI) to be raised to over 10 kV, producing a field strength of 36 kV/mm without any detectable field emission or breakdown of the MCP/screen gap. Tube resolution exceeded 16 lp/mm at 50% modulation. Breakdown is higher in a dielectric than in a vacuum. In a concept being patented by Gary Power, a few-{mu}m-thick layer of a dielectric was sputtered onto the output surface of an 18-mm MCP, which was incorporated into a tube under a contract for four tube starts. This process is applicable to any device incorporating a proximity-focused MCP and screen, including streak tubes and gated MCP x-ray imagers. Other improvements discussed include a patented use of a collimator for eliminating the electrons that are elastically scattered from the screen. This method also provides for further improvements in screen gap limited resolution to any desired degree by eliminating electrons with high transverse energy. This occurs at the expense of output brightness, which can be recovered through an appropriate increase in screen voltage.

  10. Progress towards a 256 channel multi-anode microchannel plate photomultiplier system with picosecond timing

    PubMed Central

    Lapington, J.S.; Ashton, T.J.R.; Ross, D.; Conneely, T.

    2012-01-01

    Despite the rapid advances in solid state technologies such as the silicon photomultiplier (SiPM), microchannel plate (MCP) photomultipliers still offer a proven and practical technological solution for high channel count pixellated photon-counting systems with very high time resolution. We describe progress towards a 256 channel optical photon-counting system using CERN-developed NINO and HTDC ASICs, and designed primarily for time resolved spectroscopy in life science applications. Having previously built and demonstrated a 18 mm diameter prototype tube with an 8×8 channel readout configuration and <43 ps rms single photon timing resolution, we are currently developing a 40 mm device with a 32×32 channel readout. Initially this will be populated with a 256 channel electronics system comprising four sets of modular 64 channel preamplifier/discriminator, and time-to-digital converter units, arranged in a compact three dimensional configuration. We describe the detector and electronics design and operation, and present performance measurements from the 256 channel development system. We discuss enhancements to the system including higher channel count and the use of application specific on-board signal processing capabilities. PMID:25843997

  11. One hundred anode microchannel plate ion detector

    SciTech Connect

    He Yi; Poehlman, John F.; Alexander, Andrew W.; Boraas, Kirk; Reilly, James P.

    2011-08-15

    A one-hundred-anode microchannel plate detector is constructed on a 10 cm x 15 cm printed circuit board and attached to a homebuilt matrix assisted laser desorption ionization (MALDI) time-of-flight mass spectrometer. Ringing and cross talk between anodes have been successfully eliminated and preliminary mass spectra of peptide ions recorded. With one hundred anodes on the printed circuit board, spatial information about the ion beam can also be readily determined with this detector. During operation, the detector anode assembly loses sensitivity after ions strike it for a considerable period of time due to charging of the non-conductive regions between anodes. However, this effect can be minimized by deflecting matrix ions away from the detector.

  12. X-ray focusing using microchannel plates

    NASA Technical Reports Server (NTRS)

    Kaaret, P.; Geissbuehler, P.; Chen, A.; Glavinas, E.

    1992-01-01

    We present measurements of the X-ray focusing properties of square-pore microchannel plates (MCP's). Square-pore MCP's contain large numbers of closely packed optical surfaces, as required for grazing incidence X-ray optics. The surface of individual MCP channels has been measured and found to have high microroughness transverse to the channel axis and low microroughness parallel to the axis. The high frequency transverse roughness, on length scales greater than 400 nm, has a rms value of 5.9 nm and a Gaussian autocorrelation function with correlation length of 1.41 micron. We find that the geometric misalignments of the surfaces of different channels limit the angular resolution obtainable with current samples of MCP's to 7.1 arcmin.

  13. Microchannel plate modal gain variations with temperature

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Timothy, J. G.

    1993-01-01

    Measurements of the modal gain of two high-gain curved-channel microchannel plates (MCPs) at various operating temperatures are presented. Both MCPs were fabricated from the Long Life glass with 12-micron diam channels on 15-micron centers. The modal gain was found to decrease with increasing temperature at a rate of -0.1 percent C. This reduction of gain with temperature is attributed primarily to an axial temperature gradient along each MCP channel creating a nonuniform electric field within the channel that lowers the effective output gain. A lowering of the secondary electron yield resulting from increased phonon scattering of secondary electrons released within the walls of the MCP channels was assessed, but was found to have a negligible contribution to the drop in gain with temperature.

  14. Low noise and conductively cooled microchannel plates

    NASA Technical Reports Server (NTRS)

    Feller, W. B.

    1990-01-01

    Microchannel plate (MCP) dynamic range has recently been enhanced for both very low and very high input flux conditions. Improvements in MCP manufacturing technology reported earlier have led to MCPs with substantially reduced radioisotope levels, giving dramatically lower internal background-counting rates. An update is given on the Galileo low noise MCP. Also, new results in increasing the MCP linear counting range for high input flux densities are presented. By bonding the active face of a very low resistance MCP (less than 1 megaohm) to a substrate providing a conductive path for heat transport, the bias current limit (hence, MCP output count rate limit) can be increased up to two orders of magnitude. Normal pulse-counting MCP operation was observed at bias currents of several mA when a curved-channel MCP (80:1) was bonded to a ceramic multianode substrate; the MCP temperature rise above ambient was less than 40 C.

  15. Studies of high-gain microchannel plate photomultipliers

    SciTech Connect

    Oba, K.; Rehak, P.

    1980-01-01

    The characteristics and performance of several kinds of high-gain micro-channel plate photomultipliers have been investigated. Special attention was directed toward (1) lifetime studies, (2) performance in the magnetic field, and (3) timing properties. Lifetime studies include separate investigations of the photocathode quantum efficiency degradation caused by ion feedback, and the deterioration of the micro-channel plate gain. The dependence of the micro-channel plate photomultiplier gain on the intensity and the direction of the magnetic field (up to 7 kGauss) is reported.

  16. Photon-counting image sensors for the ultraviolet

    NASA Technical Reports Server (NTRS)

    Jenkins, E. B.

    1985-01-01

    An investigation on specific performance details of photon counting, ultraviolet image sensors having 2-dimensional formats is reviewed. In one study, controlled experiments were performed which compare the quantum efficiencies, in pulse counting mode, of CsI photocathodes deposited on: (1) the front surface of a microchannel plate (MCP), (2) a solid surface in front of an MCP, and (3) an intensified CCD image sensor (ICCD) where a CCD is directly bombarded by accelerated photoelectrons. Tests indicated that the detection efficiency of the CsI-coated MCP at 1026 A is lower by a factor of 2.5 than that of the MCP with a separate, opaque CsI photocathode, and the detection efficiency ratio increases substantially at longer wavelengths (ratio is 5 at 1216 A and 20 at 1608 A).

  17. Large area 200 psec gated microchannel plate detector

    SciTech Connect

    Eckart, M.J.; Hanks, R.L.; Kilkenny, J.D.; Pasha, R.; Wiedwald, J.D.; Hares, J.D.

    1986-03-01

    Results are presented with a 15 mm wide gated microchannel plate uv and x-ray detector. The active area is part of a 6 ohm transmission line driven by an electronically generated gate pulse. The microchannel plate is coated with CsI allowing tests with a frequency quadrupled, high repetition rate 1.05 ..mu..m laser. Results showing optical gate widths as short as 100 psec are presented.

  18. Large-area 200-ps gated microchannel plate detector

    SciTech Connect

    Eckart, M.J.; Hanks, R.L.; Kilkenny, J.D.; Pasha, R.; Wiedwald, J.D.; Hares, J.D.

    1986-08-01

    Results are presented with a 15-mm-wide gated microchannel plate UV and x-ray detector. The active area is part of a 6-..cap omega.. transmission line driven by an electronically generated gate pulse. The microchannel plate is coated with CsI allowing tests with a frequency-quadrupoled, high-repetition-rate 1.05-..mu..m laser. Results showing optical gate widths as short as 100 ps are presented.

  19. Study of the electric field inside microchannel plate multipliers

    SciTech Connect

    Gatti, E.; Oba, K.; Rehak, P.

    1982-01-01

    Electric field inside high gain microchannel plate multipliers was studied. The calculations were based directly on the solution of the Maxwell equations applied to the microchannel plate (MCP) rather than on the conventional lumped RC model. The results are important to explain the performance of MCP's, (1) under a pulsed bias tension and, (2) at high rate conditions. The results were tested experimentally and a new method of MCP operation free from the positive ion feedback was demonstrated.

  20. A Simple Model for Microchannel Plate Output

    NASA Astrophysics Data System (ADS)

    Harding, E. C.; Weaver, J. L.

    2005-10-01

    Microchannel plates (MCPs) are an essential component in an imaging diagnostic known as an x-ray framing camera, which is currently used by NIF, Omega, Nike, and Z to image radiation imploded targets. An MCP is used to convert incident x-ray photons into electrons with gains of 10^2 to 10^4. These electrons are accelerated into a phosphor and the subsequent visible light is captured with a CCD. A variety of parameters, such as photocathode material type (Au, Ni, CsI), photocathode coating depth, and MCP bias angle, affect the gain and gain variations in the MCP electron output. This poster presents initial results of a simple 3D MCP computer model along with an experimental comparison. Several ideas for increasing MCP imaging performance by reducing gain variations and increasing MCP quantum efficiency are presented. Work supported by the Naval Research Laboratory, National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grant DE-FG52-03NA00064, and through DE FG53 2005 NA26014, and Livermore National Laboratory.

  1. Performance of Small Pore Microchannel Plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Gummin, M. A.; Ravinett, T.; Jelinsky, S. R.; Edgar, M.

    1995-01-01

    Small pore size microchannel plates (MCP's) are needed to satisfy the requirements for future high resolution small and large format detectors for astronomy. MCP's with pore sizes in the range 5 micron to 8 micron are now being manufactured, but they are of limited availability and are of small size. We have obtained sets of Galileo 8 micron and 6.5 micron MCP's, and Philips 6 micron and 7 micron pore MCP's, and compared them to our larger pore MCP Z stacks. We have tested back to back MCP stacks of four of these MCP's and achieved gains greater than 2 x 1O(exp 7) with pulse height distributions of less than 40% FWHM, and background rates of less than 0.3 events sec(exp -1) cm(exp -2). Local counting rates up to approx. 100 events/pore/sec have been attained with little drop of the MCP gain. The bare MCP quantum efficiencies are somewhat lower than those expected, however. Flat field images are characterized by an absence of MCP fixed pattern noise.

  2. Microchannel plate special nuclear materials sensor

    NASA Astrophysics Data System (ADS)

    Feller, W. B.; White, P. L.; White, P. B.; Siegmund, O. H. W.; Martin, A. P.; Vallerga, J. V.

    2011-10-01

    Nova Scientific Inc., is developing for the Domestic Nuclear Detection Office (DNDO SBIR #HSHQDC-08-C-00190), a solid-state, high-efficiency neutron detection alternative to 3He gas tubes, using neutron-sensitive microchannel plates (MCPs) containing 10B and/or Gd. This work directly supports DNDO development of technologies designed to detect and interdict nuclear weapons or illicit nuclear materials. Neutron-sensitized MCPs have been shown theoretically and more recently experimentally, to be capable of thermal neutron detection efficiencies equivalent to 3He gas tubes. Although typical solid-state neutron detectors typically have an intrinsic gamma sensitivity orders of magnitude higher than that of 3He gas detectors, we dramatically reduce gamma sensitivity by combining a novel electronic coincidence rejection scheme, employing a separate but enveloping gamma scintillator. This has already resulted in a measured gamma rejection ratio equal to a small 3He tube, without in principle sacrificing neutron detection efficiency. Ongoing improvements to the MCP performance as well as the coincidence counting geometry will be described. Repeated testing and validation with a 252Cf source has been underway throughout the Phase II SBIR program, with ongoing comparisons to a small commercial 3He gas tube. Finally, further component improvements and efforts toward integration maturity are underway, with the goal of establishing functional prototypes for SNM field testing.

  3. All-digital full waveform recording photon counting flash lidar

    NASA Astrophysics Data System (ADS)

    Grund, Christian J.; Harwit, Alex

    2010-08-01

    Current generation analog and photon counting flash lidar approaches suffer from limitation in waveform depth, dynamic range, sensitivity, false alarm rates, optical acceptance angle (f/#), optical and electronic cross talk, and pixel density. To address these issues Ball Aerospace is developing a new approach to flash lidar that employs direct coupling of a photocathode and microchannel plate front end to a high-speed, pipelined, all-digital Read Out Integrated Circuit (ROIC) to achieve photon-counting temporal waveform capture in each pixel on each laser return pulse. A unique characteristic is the absence of performance-limiting analog or mixed signal components. When implemented in 65nm CMOS technology, the Ball Intensified Imaging Photon Counting (I2PC) flash lidar FPA technology can record up to 300 photon arrivals in each pixel with 100 ps resolution on each photon return, with up to 6000 range bins in each pixel. The architecture supports near 100% fill factor and fast optical system designs (f/#<1), and array sizes to 3000×3000 pixels. Compared to existing technologies, >60 dB ultimate dynamic range improvement, and >104 reductions in false alarm rates are anticipated, while achieving single photon range precision better than 1cm. I2PC significantly extends long-range and low-power hard target imaging capabilities useful for autonomous hazard avoidance (ALHAT), navigation, imaging vibrometry, and inspection applications, and enables scannerless 3D imaging for distributed target applications such as range-resolved atmospheric remote sensing, vegetation canopies, and camouflage penetration from terrestrial, airborne, GEO, and LEO platforms. We discuss the I2PC architecture, development status, anticipated performance advantages, and limitations.

  4. Hybrid analog/digital, large format, photon counting detectors for astronomy

    NASA Astrophysics Data System (ADS)

    Crocker, J.; Rafal, M.; Denman, B.; Paresce, F.; Hiltner, A.

    1986-01-01

    The development of a new microchannel plate photon-counting detector with an analog readout method based on a resistive anode is reported. This detector exhibits extremely high, stable electron gains of 10 to the 8th. At this gain, the spatial resolution is no longer primarily limited by the noise of the resistive anode, so that digital methods of readout, such as discrete conductors, lose their advantage. These detectors can be readily scaled to 40 mm and 70 mm formats to match plate scales of 2-m (and larger) telescopes. New, high speed digital electronics fully exploit the high spatial and time resolution made possible by gains of this level. Analysis of the theoretical performance of this detector shows that the major limitation to the spatial resolution is the proximity focus of the photocathode and the first microchannel plate. The detector has been mated to an echelle spectrograph developed.

  5. Photon counting digital holography

    NASA Astrophysics Data System (ADS)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario; Pavičić, Mladen

    2016-05-01

    Digital holography uses electronic sensors for hologram recording and numerical method for hologram reconstruction enabling thus the development of advanced holography applications. However, in some cases, the useful information is concealed in a very wide dynamic range of illumination intensities and successful recording requires an appropriate dynamic range of the sensor. An effective solution to this problem is the use of a photon-counting detector. Such detectors possess counting rates of the order of tens to hundreds of millions counts per second, but conditions of recording holograms have to be investigated in greater detail. Here, we summarize our main findings on this problem. First, conditions for optimum recording of digital holograms for detecting a signal significantly below detector's noise are analyzed in terms of the most important holographic measures. Second, for time-averaged digital holograms, optimum recordings were investigated for exposures shorter than the vibration cycle. In both cases, these conditions are studied by simulations and experiments.

  6. Electronic measurement of microchannel plate pulse height distributionsa)

    NASA Astrophysics Data System (ADS)

    Gamboa, E. J.; Huntington, C. M.; Harding, E. C.; Drake, R. P.

    2010-10-01

    Microchannel plates are a central component of the x-ray framing cameras used as analog imagers in many plasma experiment diagnostic systems. The microchannel plate serves as an amplifying element, increasing the electronic signal from incident radiation by factors of 103-105, with a broad pulse-height distribution. Seeking to optimize the photon-to-electron conversion efficiency and noise distribution of x-ray cameras, we will characterize the pulse-height distribution of the electron output from a single microchannel plate. Replacing the framing camera's phosphor-coated fiber optic screen with a charge-collection plate and coupling to a low-noise multichannel analyzer, we quantified the distribution in the total charge generated per photon event. The electronically measured pulse height distribution is used to estimate the signal-to-noise ratio of radiographic images from framing cameras.

  7. Performance comparison of high speed microchannel plate photomultiplier tubes

    NASA Technical Reports Server (NTRS)

    Varghese, Thomas; Selden, Michael; Oldham, Thomas

    1993-01-01

    The transit time spread characteristics of high speed microchannel photomultipliers has improved since the upgrade of the NASA CDSLR network to MCP-PMT's in the mid-1980's. The improvement comes from the incorporation of 6 micron (pore size) microchannels and offers significant improvement to the satellite ranging precision. To examine the impact on ranging precision, two microchannel plate photomultiplier tubes (MCP-PMT) were evaluated for output pulse characteristics and temporal jitter. These were a Hamamatsu R 2566 U-7 MCP-PMT (6 micron) and an ITT 4129f MCP-PMT (12 micron).

  8. Photon-counting H33D detector for biological fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Michalet, X.; Siegmund, O. H. W.; Vallerga, J. V.; Jelinsky, P.; Millaud, J. E.; Weiss, S.

    2006-11-01

    We have developed a photon-counting High-temporal and High-spatial resolution, High-throughput 3-Dimensional detector (H33D) for biological imaging of fluorescent samples. The design is based on a 25 mm diameter S20 photocathode followed by a 3-microchannel plate stack, and a cross-delay line anode. We describe the bench performance of the H33D detector, as well as preliminary imaging results obtained with fluorescent beads, quantum dots and live cells and discuss applications of future generation detectors for single-molecule imaging and high-throughput study of biomolecular interactions.

  9. Photon-Counting H33D Detector for Biological Fluorescence Imaging.

    PubMed

    Michalet, X; Siegmund, O H W; Vallerga, J V; Jelinsky, P; Millaud, J E; Weiss, S

    2006-11-01

    We have developed a photon-counting High-temporal and High-spatial resolution, High-throughput 3-Dimensional detector (H33D) for biological imaging of fluorescent samples. The design is based on a 25 mm diameter S20 photocathode followed by a 3-microchannel plate stack, and a cross delay line anode. We describe the bench performance of the H33D detector, as well as preliminary imaging results obtained with fluorescent beads, quantum dots and live cells and discuss applications of future generation detectors for single-molecule imaging and high-throughput study of biomolecular interactions. PMID:20151021

  10. Development efforts to improve curved-channel microchannel plates

    NASA Technical Reports Server (NTRS)

    Corbett, M. B.; Feller, W. B.; Laprade, B. N.; Cochran, R.; Bybee, R.; Danks, A.; Joseph, C.

    1993-01-01

    Curved-channel microchannel plate (C-plate) improvements resulting from an ongoing NASA STIS microchannel plate (MCP) development program are described. Performance limitations of previous C-plates led to a development program in support of the STIS MAMA UV photon counter, a second generation instrument on the Hubble Space Telescope. C-plate gain, quantum detection efficiency, dark noise, and imaging distortion, which are influenced by channel curvature non-uniformities, have all been improved through use of a new centrifuge fabrication technique. This technique will be described, along with efforts to improve older, more conventional shearing methods. Process optimization methods used to attain targeted C-plate performance goals will be briefly characterized. Newly developed diagnostic measurement techniques to study image distortion, gain uniformity, input bias angle, channel curvature, and ion feedback, will be described. Performance characteristics and initial test results of the improved C-plates will be reported. Future work and applications will also be discussed.

  11. High background photon counting lidar

    NASA Technical Reports Server (NTRS)

    Lentz, W. J.

    1992-01-01

    Photon counting with lidar returns is usually limited to low light levels, while wide dynamic range is achieved by counting for long times. The broad emission spectrum of inexpensive high-power semiconductor lasers makes receiver filters pass too much background light for traditional photon counting in daylight. Very high speed photon counting is possible, however, at more than 500 MHz which allows the construction of eyesafe lidar operating in the presence of bright clouds. Detector improvements are possible to count to 20 GHz producing a single shot dynamic range of ten decades.

  12. Fundamental and practical limitations of FUV/EUV photon-counting image detectors

    NASA Technical Reports Server (NTRS)

    Lampton, M.

    1991-01-01

    In EUV and FUV space-astronomy applications, the best contemporary detector designs are based on the use of microchannel plates due to their ability to deliver photon-counting performance with high efficiency. The major unresolved issue is the choice of position-readout system for the individual photoevents. Electrical event-readout systems are divided into two classes: the discrete wire anodes that perform coordinate digitization by wire-group selection, and the continuous centroid-position encoders for which coordinates are digitized in the associated electronics. The centroid-position encoder techniques are discussed in terms of how they overcome the four chief limitations of the discrete-wire readouts - their limited format size, their flat focal surface, their fundamental hex-channel vs squared-pixel moire pattern, and their image undersampling. With these limitations overcome, microchannel based image systems can deliver the performance demanded by the forthcoming generation of applications in space astronomy.

  13. High Spatial Resolution Investigations of Microchannel Plate Imaging Properties for UV Detectors

    NASA Technical Reports Server (NTRS)

    Siegmund, Oswald

    1996-01-01

    Microchannel plate (MCP) photon counting detectors are currently being used with great success on many of the recent NASA/ESA ultraviolet (UV) astrophysics missions that make observations in the 1OO A - 1600 A range. These include HUT, the Wide Field Camera on ROSAT, EUVE, ALEXIS, ORFEUS, and SOHO. These devices have also been chosen to fly on future UV astrophysics missions such as FUSE, FUVITA, IMAGE, and both the HST STIS and Advanced Camera instruments. During the period of this award we have fabricated a dual-chamber vacuum test facility to carry out laboratory testing of detector resolution, image stability and linearity, and flat field performance to enable us to characterize the performance of MCPs and their associated read-out architectures. We have also fabricated and tested a laboratory 'test-bed' delay line detector, which can accommodate MCP's with a wide range of formats and run at high data rates, to continue our studies of MCP image fixed pattern noise, and particularly for new small pore MCP's which have recently come onto the market. These tests were mainly focussed on the assessment of cross delay-line (XDL) and double delay line (DDL) anode read-out schemes, with particular attention being focussed on flat-field and spatial resolution performance.

  14. Improved lifetime of microchannel-plate PMTs

    NASA Astrophysics Data System (ADS)

    Lehmann, A.; Britting, A.; Eyrich, W.; Uhlig, F.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Höhler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Dodokhov, V. Kh.; Düren, M.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Cowie, E.; Keri, T.; Montgomery, R.; Rosner, G.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Sfienti, C.; Thiel, M.; Bühler, P.; Gruber, L.; Marton, J.; Suzuki, K.

    2014-12-01

    The charged particle identification at the PANDA experiment will be mainly performed with DIRC detectors. Because of their advantageous properties the preferred photon sensors are MCP-PMTs. However, until recently these devices showed serious aging problems which resulted in a diminishing quantum efficiency (QE) of the photo cathode. By applying innovative countermeasures against the aging causes, the manufacturers recently succeeded in drastically improving the lifetime of MCP-PMTs. Especially the application of an ALD coating technique to seal the material of the micro-channels proves very powerful and results in a lifetime of ≈ 6 C /cm2 integrated anode charge without a substantial QE degradation for the latest PHOTONIS XP85112. This paper will present a comparative measurement of the lifetime of several older and recent MCP-PMTs demonstrating this progress.

  15. Short recovery time, multianode, microchannel plate photomultiplier for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Bassan, M.; Sardella, A.; Perdon, E.

    1989-12-01

    Laser scattering-based plasma diagnostics are presently undertaken by means of a multianode microchannel plate (MCP) photomultiplier (PM) whose recovery time is two orders of magnitude shorter than that typical of conventional MCP devices. This PM is suitable for detection of fast light-pulse bursts whose repetition rate is sufficiently low for heat dissipation between successive bursts. Attention is given to the device's thermal behavior, measuring the temperature increase of the Z-plate due to a single, high-voltage square pulse as a function of pulse energy. The Z-plate recovers from the maximum linear pulse in about 50 microsec.

  16. Tracking rare-isotope beams with microchannel plates

    NASA Astrophysics Data System (ADS)

    Rogers, A. M.; Sanetullaev, A.; Lynch, W. G.; Tsang, M. B.; Lee, J.; Bazin, D.; Coupland, D.; Henzl, V.; Henzlova, D.; Kilburn, M.; Wallace, M. S.; Youngs, M.; Delaunay, F.; Famiano, M.; Shapira, D.; Jones, K. L.; Schmitt, K. T.; Sun, Z. Y.

    2015-09-01

    A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival times of ions at the reaction target. The current design is an adaptation of an assembly used for low-energy beams (~ 1.4 MeV / nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1 mm for beam intensities up to 5 ×105 pps.

  17. Using Neural Networks to Recover Microchannel Plate Tracking Data

    NASA Astrophysics Data System (ADS)

    Howard, Meredith E.; Schradin, Leslie J.; Cizewski, Jolie A.

    2014-09-01

    Tracking nuclei in reaction experiments is a common method for improving energy resolution or reducing uncertainties in reaction kinematics. The microchannel plate (MCP) detector is an ideal tool for non-destructive ion beam tracking. Here, we outline a method using widely available software for training neural networks to solve the problem of extracting 2D positions from only three of the four corner signals of an MCP detector.

  18. A new approach to large area microchannel plate manufacture

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Methods of manufacture of twisted single elements as the base for producing microchannel plates (MCP) are discussed. Initial evaluations validated the off-axis channel concept and no technological roadblocks were identified which would prevent fabrication of high gain, high spatial resolution, large format MCP's using this technique. The first MP's have operated at stable gains of 3 million with pulse height resolution superior to results obtained by standard chevron MCP's.

  19. Laser ranging and mapping with a photon-counting detector.

    PubMed

    Priedhorsky, W C; Smith, R C; Ho, C

    1996-01-20

    We propose a new technique for remote sensing: photon-counting laser mapping. MicroChannel plate detectors with a crossed delay-line (MCP/CDL) readout combine high position accuracy and subnanosecond photon timing, at event rates of 10(6) detected photons per second and more. A mapping system would combine an MCP/CDL detector with a fast-pulse, high-repetition-rate laser illuminator. The system would map solid targets with exceptional in-range and cross-range resolution. The resulting images would be intrinsically three dimensional, without resorting to multiple viewing angles, so that objects of identical albedo could be discriminated. For a detector time resolution and pulse width of the order of 10(-10) s, the in-range resolution would be a few centimeters, permitting the discrimination of surfaces by their textures. Images could be taken at night, at illumination levels up to full moonlight, from ground, airborne, or space platforms. We discuss signal to noise as a function of laser flux and background level and present simulated images. PMID:21069029

  20. Characterization of a photon-counting ICCD prototype

    NASA Astrophysics Data System (ADS)

    Bergamini, Paolo; Bonelli, Giuseppe; Poletto, Luca; Tanzi, Enrico G.; Uslenghi, Michela; Tondello, Giuseppe

    1998-11-01

    The result obtained in the course of the characterization of a photon-counting ICCD prototype. The detector consists of a 40 mm diameter, Z stack, high gain microchannel plate intensifier, endowed with a RbTe photocathode. The intensifier electron cascade is transduced, via a phosphor screen and a 1:3.6 fiber optics reducer, into a 3 by 3 pixel, quasi-gaussian charge distribution on a 512 by 512 pixel format CCD matrix with square pixels of 15 micrometers . The CCD is read out, in the frame-transfer mode, through a single output amplifier at a frequency of 20 MHz. The data flow is acquired serially and fed to a virtual shift- register system, as to generate a 3 by 3 pixel even sash that sweeps dynamically the CCD matrix at the 50 ns clock pace. Each and every events has is searched for the presence of events whose integral charge distribution lie within set threshold levels, and satisfy given morphological rules, i.e. a single-peaked charge profile. The centroid coordinates of identified events are then determined with sub-pixel accuracy and subsequently stored in an external, high resolution memory. Detective quantum efficiency, spatial resolution and dynamic range obtained for the prototype system in the 150-600 nm spectral domain, are given and discussed, together with the up-graded performance expected for a second-generation prototype, presently being assembled.

  1. Three-dimensional model of x-ray induced microchannel plate output

    NASA Astrophysics Data System (ADS)

    Harding, E. C.; Drake, R. P.

    2006-10-01

    Microchannel plates are an important component in a type of imaging diagnostic known as an x-ray framing camera, used in x-ray radiography of high-energy-density physics experiments. A microchannel plate is responsible for detecting x rays and then converting them into amplified bursts of electrons, which are then imaged onto a phosphor-coated fiber optic screen. We present the preliminary development of a three-dimensional model of a single microchannel plate channel in attempt to simulate the pulse height distribution of the microchannel plate electron output. Using a novel technique, initial simulations are compared with experimental data from an ungated x-ray framing camera.

  2. Three-dimensional model of x-ray induced microchannel plate output

    SciTech Connect

    Harding, E. C.; Drake, R. P.

    2006-10-15

    Microchannel plates are an important component in a type of imaging diagnostic known as an x-ray framing camera, used in x-ray radiography of high-energy-density physics experiments. A microchannel plate is responsible for detecting x rays and then converting them into amplified bursts of electrons, which are then imaged onto a phosphor-coated fiber optic screen. We present the preliminary development of a three-dimensional model of a single microchannel plate channel in attempt to simulate the pulse height distribution of the microchannel plate electron output. Using a novel technique, initial simulations are compared with experimental data from an ungated x-ray framing camera.

  3. Low-Noise, Long-Life, High-Gain Microchannel-Plate Glass

    NASA Technical Reports Server (NTRS)

    Feller, W. Bruce; Cook, Lee M.

    1990-01-01

    Dark noise reduced substantially without degrading other properties. Glass suitable for use as active material for microchannel plates (MCP's) free of constituents including significant amounts of radioactive isotopes.

  4. Imaging by terahertz photon counting

    NASA Astrophysics Data System (ADS)

    Ikushima, Kenji; Komiyama, Susumu

    2010-08-01

    Photon counting method is indispensable in visible/near-infrared optical measurements for detecting extremely weak radiation. The method, however, has been inaccessible in terahertz region, where the photon energies are more than 100 times smaller and catching individual photons is difficult. Here we review photon counting measurements of terahertz waves, by incorporating a semiconductor quantum-dot terahertz-photon detector into a scanning terahertz microscope. By using a quantum Hall effect detector as well, measurements cover the intensity dynamic range more than six orders of magnitude. Applying the measurement system to the study of semiconductor quantum Hall effect devices, we image extremely weak cyclotron radiation emitted by nonequilibrium electrons. Owing to the unprecedented sensitivity, a variety of new features of electron kinetics are unveiled. Besides semiconductor electric devices studied here, the experimental method will find application in diverse areas of molecular dynamics, microthermography, and cell activities.

  5. Photon Counting - One More Time

    NASA Astrophysics Data System (ADS)

    Stanton, Richard H.

    2012-05-01

    Photon counting has been around for more than 60 years, and has been available to amateurs for most of that time. In most cases single photons are detected using photomultiplier tubes, "old technology" that became available after the Second World War. But over the last couple of decades the perfection of CCD devices has given amateurs the ability to perform accurate photometry with modest telescopes. Is there any reason to still count photons? This paper discusses some of the strengths of current photon counting technology, particularly relating to the search for fast optical transients. Technology advances in counters and photomultiplier modules are briefly mentioned. Illustrative data are presented including FFT analysis of bright star photometry and a technique for finding optical pulses in a large file of noisy data. This latter technique is shown to enable the discovery of a possible optical flare on the polar variable AM Her.

  6. Microchannel-plate-based x-ray optics

    NASA Astrophysics Data System (ADS)

    Beijersbergen, Marco W.; Bavdaz, Markos; Peacock, Anthony J.; Tomaselli, Enrico; Fraser, G.; Brunton, A.; Flyckt, E.; Krumrey, Michael K.; Souvorov, Alexei

    1999-10-01

    X-ray optics based on micro-channel plates (MCPs) offer some distinctive advantages over conventional technologies used to produce imagin optics for astrophysics applications. Such micro-pore optics (MPOs) are far lighter and allow a larger stacking density than optics based on metallic foils or plates. Until recent, x-ray optics based on MCPs were not feasible or useful because of the limited quality of the MCPs. We have produced thick square pore MPOs of improved quality and have developed methods to stack the channels in a radial pattern, as required for imagin optics based on Wolter type I or II designs. The individual plates were tested in synchrotron radiation facilities and conventional beam lines to determine their geometric and surface scattering properties.

  7. Thermal dependence of electrical characteristics of micromachined silica microchannel plates

    NASA Astrophysics Data System (ADS)

    Tremsin, Anton S.; Vallerga, John V.; Siegmund, Oswald H. W.; Beetz, Charles P.; Boerstler, Robert W.

    2004-04-01

    Micromachined silica microchannel plates (MCPs) under development have a number of advantages over standard glass MCPs and open completely new possibilities in detector technologies. In this article we present the results of our studies on the thermal properties of silica microchannel plates (sMCPs). Similar to standard glass microchanel plates the resistance of silica MCPs was measured to change exponentially with temperature with a negative thermal coefficient of -0.036 per °C, somewhat larger than that of standard glass MCPs. The resistance also decreases linearly with the applied voltage, with the voltage coefficient of -3.1×10-4 V-1. With the knowledge of these two coefficients, our thermal model allows the calculation of the maximum voltage, which can be applied to a given MCP without inducing a thermal runaway. A typical 25 mm diam, 240 μm thick sMCP with 6 μm pores has to have the resistance larger than ˜30 MΩ to operate safely at voltages up to 800 V. With this model we can also calculate the time required for a given silica MCP to reach the point of thermal equilibrium after a voltage increase. We hope that the ongoing efforts on a proper modification of the sMCP semiconducting layer will lead to the production of new MCPs with a small negative or even a positive thermal coefficient, reducing the possibility of thermal runaways of low-resistance MCPs required for high count rate applications.

  8. The capacitive division image readout: a novel imaging device for microchannel plate detectors

    NASA Astrophysics Data System (ADS)

    Lapington, J. S.; Conneely, T. M.; Leach, S. A.; Moore, L.

    2013-09-01

    The Capacitive Division Image Readout (C-DIR) is a simple and novel image readout for photon counting detectors offering major performance advantages. C-DIR is a charge centroiding device comprising three elements; (i) a resistive anode providing event charge localization, event current return path and electrical isolation from detector high voltage, (ii) a dielectric substrate which capacitively couples the event transient signal to the third element, (iii) the readout device; an array of capacitively coupled electrodes which divides the signal among the readout charge measurement nodes. The resistive anode and dielectric substrate constitute the rear interface of the detector and capacitively couple the signal to the external C-DIR readout device. The C-DIR device is a passive, multilayer printed circuit board type device comprising a matrix of isolated electrodes whose geometries define the capacitive network. C-DIR is manufactured using conventional PCB geometries and is straightforward and economical to construct. C-DIR's robustness and simplicity belie its performance advantages. Its capacitive nature avoids partition noise, the Poisson noise associated with collection of discrete charges. The dominant noise limiting position resolution is electronic noise. However C-DIR also presents a low input capacitance to the readout electronics, minimising this noise component thus maximising spatial resolution. Optimisation of the C-DIR pattern-edge geometry can provide ~90% linear dynamic range. We present data showing image resolution and linearity of the C-DIR device in a microchannel plate detector and describe various electronic charge measurement scheme designed to exploit the full performance potential of the C-DIR device.

  9. Angular sensitivity of gated microchannel plate framing cameras

    SciTech Connect

    Landen, O. L.; Lobban, A.; Tutt, T.; Bell, P. M.; Costa, R.; Hargrove, D. R.; Ze, F.

    2001-01-01

    Gated, microchannel-plate-based (MCP) framing cameras have been deployed worldwide for 0.2--9 keV x-ray imaging and spectroscopy of transient plasma phenomena. For a variety of spectroscopic and imaging applications, the angular sensitivity of MCPs must be known for correctly interpreting the data. We present systematic measurements of angular sensitivity at discrete relevant photon energies and arbitrary MCP gain. The results can been accurately predicted by using a simple two-dimensional approximation to the three-dimensional MCP geometry and by averaging over all possible photon ray paths.

  10. Angular Sensitivity of Gated Micro-Channel Plate Framing Cameras

    SciTech Connect

    Landen, O L; Lobban, A; Tutt, T; Bell, P M; Costa, R; Ze, F

    2000-07-24

    Gated, microchannel-plate-based (MCP) framing cameras have been deployed worldwide for 0.2 - 9 keV x-ray imaging and spectroscopy of transient plasma phenomena. For a variety of spectroscopic and imaging applications, the angular sensitivity of MCPs must be known for correctly interpreting the data. We present systematic measurements of angular sensitivity at discrete relevant photon energies and arbitrary MCP gain. The results can been accurately predicted by using a simple 2D approximation to the 3D MCP geometry and by averaging over all possible photon ray paths.

  11. Persistence of phosphor glow in microchannel plate image intensifiers

    NASA Technical Reports Server (NTRS)

    Torr, M. R.

    1985-01-01

    Image intensifier tubes using microchannel plate amplification stages and phosphor output stages are being increasingly used in various detection applications. In this paper, measurements of the decay times of what are attributed to be the P20 phosphors in various image intensifiers are reported. It is found that the long tail on the decay curve of the phosphor following illumination can be a limitation for certain observations. In addition, the background level of phosphor glow (which is seen by the subsequent detection system as a light signal) continues to build with continuing illumination.

  12. Performance characteristics of a new helical-channel microchannel plate

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Timothy, J. Gethyn; Graves, Peter W.; Loretz, Thomas J.; Roy, Raymond L.

    1988-01-01

    An advanced version of the 'helical-channel' microchannel plate (MCP) is presented. This MCP is composed of four channels per fiber with each channel having a diameter of 50 microns. The dynamic range, pulse-height distribution, and gain characteristics of this MCP are discussed. It is found that increasing the twist density of the channels makes it possible to increase the detection efficiency and further improve the suppression of ion-feedback providing a tighter saturated pulse-height distribution and improved high-voltage characteristics.

  13. Dead-time effects in microchannel-plate imaging detectors

    NASA Technical Reports Server (NTRS)

    Zombeck, Martin V.; Fraser, George W.

    1991-01-01

    The observed counting rates of microchannel plate (MCP) based detectors for high resolution observations of celestial EUV and X-ray sources vary over many orders of magnitude; the counting capability of an individual channel, however, is not high, and is associated with dead-times ranging from 0.1 msec to 1 sec. The dead-time increases with the area illuminated; attention is presently given to laboratory determinations of the count rate characteristics of a MCP detector as a function of illuminated area, and a model is developed for these results' use in the interpretation of space observations.

  14. Characterization of borosilicate microchannel plates functionalized by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Ertley, C.; Siegmund, O. H. W.; Schwarz, J.; Mane, A. U.; Minot, M. J.; O'Mahony, A.; Craven, C. A.; Popecki, M.

    2015-08-01

    Borosilicate microcapillary arrays have been functionalized by Atomic Layer Deposition (ALD) of resistive and secondary emissive layers to produce robust microchannel plates (MCPs) with improved performance characteristics over traditional MCPs. These techniques produce MCP's with enhanced stability and lifetime, low background rates, and low levels of adsorbed gas. Using ALD to functionalize the substrate decouples the two and provides the opportunity to explore many new materials. The borosilicate substrates have many advantages over traditional lead glass MCPs, including the ability to be fabricated in large areas (currently at 400 cm2).

  15. Investigations of bonded and curved microchannel plate stacks

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.

    1988-01-01

    The technique of fusing, or bonding, individual microchannel plate (MCP) stacks together offers the possibility of improving the uniformity of MCP stack operating characteristics and provides a convenient monolithic format. Here, the effectiveness of bonded MCP stacks and stacks of MCPs with curved surfaces is investigated to determine if MCP requirements for future astrophysical detectors can be achieved. The results show that both configurations give superior MCP performance characteristics. However, some problems remain with regard to the fabrication of bonded MCP stacks resulting in poor flat field characteristics and increased background.

  16. Curved-channel microchannel array plates. [photoelectric detectors

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1981-01-01

    The microchannel array plate (MCP) is a photoelectric detector with an imaging capability comparable to that of a photographic plate. Recently MCPs in which the channels are curved to inhibit ion feedback have become available. These devices represent a major advance in MCP technology, since a single curved-channel MCP can be operated stably at high gain in the pulse-counting mode without any of the problems of stability of response or short lifetime reported for 'chevron' MCP detectors. Attention is given to the mode of operation of channel electron multipliers (CEM) and MCP, curved-channel MCP, test procedures, and performance characteristics. The accumulated test data show that the fundamental operating characteristics of the curved-channel MCP are directly related to those for the CEM.

  17. Using induced signals to sense position from a microchannel plate detector

    NASA Astrophysics Data System (ADS)

    deSouza, R. T.; Gosser, Z. Q.; Hudan, S.

    2012-05-01

    We demonstrate a novel concept for a position sensitive microchannel plate detector. This detector provides sub-millimeter spatial resolution by examining the signal induced on a wire harp by the electron cloud from a microchannel plate detector. Wires in the harp are efficiently read out by coupling them to a delay line.

  18. Application of atomic layer deposited microchannel plates to imaging photodetectors with high time resolution

    NASA Astrophysics Data System (ADS)

    Siegmund, O. H. W.; McPhate, J. B.; Tremsin, A. S.; Vallerga, J. V.; Ertley, C. D.; Richner, N. J.; Gerard, T. M.; Frisch, H. J.; Elam, J. W.; Mane, A. U.; Wagner, R. G.; Minot, M. J.; O`Mahony, A.; Craven, C. A.

    2015-07-01

    Novel microchannel plates have been constructed using borosilicate glass micro-capillary array substrates with 20 μm and 10 μm pores and coated with resistive, and secondary electron emissive, layers by atomic layer deposition. Microchannel plates in 33 mm, 50 mm and 20 cm square formats have been made and tested. Although their amplification, imaging, and timing properties are comparable to standard glass microchannel plates, the background rates and lifetime characteristics are considerably improved. Sealed tube detectors based on the Planacon tube, and a 25 mm cross delay line readout tube with a GaN(Mg) opaque photocathode deposited on borosilicate microchannel plates have been fabricated. Considerable progress has also been made with 20 cm microchannel plates for a 20 cm format sealed tube sensor with strip-line readout that is being developed for Cherenkov light detection.

  19. Noise factor of microchannel plate with ion barrier film

    NASA Astrophysics Data System (ADS)

    Liu, Shu-lin; Shi, Feng; Li, Zhou-kui; Zhu, Yu-feng; Zhang, Ni; Gu, Yan; Sun, Jian-ning; Cong, Xiao-qing; Zhao, Hui-min; Pan, Jing-sheng; Qian, Yun-sheng; Zheng, Shao-cheng; Chang, Ben-kang

    2012-10-01

    According to definition of noise factor of microchannel plate and the test principle, the authors set up a test installation, and measured the numerical values of MCPs which were made of different materials and channel pore including no / with ion barrier film in input of MCP. In order to seek the technical approach to reduce noise factor of MCP at the same time, we tested and analyzed the relation between noise factor and MCP voltage, combined relation between signal-to-noise ratio of GEN Ⅲ image intensifier and MCP voltage, open out relation between signal-to-noise ratio of GEN Ⅲ image intensifier and noise factor of MCP with ion barrier film.

  20. Gated Microchannel Plate Photomultiplier For Longitudinal BeamDiagnostics

    SciTech Connect

    Byrd, John M.; De Santis, Stefano; Thurman-Keup, Randy

    2006-05-03

    A gated microchannel plate photomultiplier can be used as aneffective tool for measuring the longitudinal distribution of particlesaround most electron and high-energy proton rings. The broad availablewavelength range,low noise, and high sensitivity allow using such adevice for measuring the emitted synchrotron radiation and to extract thebeam intensity. The fast gate rise time can be used to reject strongsignals coming from filled RF buckets and avoid saturation of thephotocathode so that it is possible to monitor, with a high degree ofresolution, gaps in the machine fill and growth of parasitic bunches. Therugged characteristics of the device and its simplicity of use make itideal for all those applications where more complex and expensiveinstrumentation is not absolutely necessary. We present the experimentalresults obtained at the Advanced Light Source and on the Tevatron usingan Hamamatsu R5916U-50 series model.

  1. Collimator application for microchannel plate image intensifier resolution improvement

    DOEpatents

    Thomas, S.W.

    1996-02-27

    A collimator is included in a microchannel plate image intensifier (MCPI). Collimators can be useful in improving resolution of MCPIs by eliminating the scattered electron problem and by limiting the transverse energy of electrons reaching the screen. Due to its optical absorption, a collimator will also increase the extinction ratio of an intensifier by approximately an order of magnitude. Additionally, the smooth surface of the collimator will permit a higher focusing field to be employed in the MCP-to-collimator region than is currently permitted in the MCP-to-screen region by the relatively rough and fragile aluminum layer covering the screen. Coating the MCP and collimator surfaces with aluminum oxide appears to permit additional significant increases in the field strength, resulting in better resolution. 2 figs.

  2. Collimator application for microchannel plate image intensifier resolution improvement

    DOEpatents

    Thomas, Stanley W.

    1996-02-27

    A collimator is included in a microchannel plate image intensifier (MCPI). Collimators can be useful in improving resolution of MCPIs by eliminating the scattered electron problem and by limiting the transverse energy of electrons reaching the screen. Due to its optical absorption, a collimator will also increase the extinction ratio of an intensifier by approximately an order of magnitude. Additionally, the smooth surface of the collimator will permit a higher focusing field to be employed in the MCP-to-collimator region than is currently permitted in the MCP-to-screen region by the relatively rough and fragile aluminum layer covering the screen. Coating the MCP and collimator surfaces with aluminum oxide appears to permit additional significant increases in the field strength, resulting in better resolution.

  3. High-resolution microchannel plate image tube results

    NASA Astrophysics Data System (ADS)

    Johnson, C. Bruce; Patton, Stanley B.; Bender, E.

    1992-07-01

    The present 18-mm active diameter proximity-focused microchannel plate (MCP) image tube design has been modified to produce significantly higher limiting spatial resolution. A glass input window of the `bulls-eye' design with the blackened glass border, reduced cathode-to-MCP spacing, reduced channel center-to-center distance, reduced MCP-to-phosphor screen spacing, a brushed P20 phosphor screen, and a fiber optic output window were used to achieve a limiting resolution in excess of 50 lp/mm. Test results, showing limiting resolution versus applied potentials, are correlated with a simple physical model of performance. The low-light-level white-light sine-wave modulation transfer function, T(f), has been measured to be T(f) equals exp[-(f/21.5)1.46], where f is the spatial frequency in cycles per millimeter.

  4. Note: Non-gain microchannel plate gated framing camera

    SciTech Connect

    Cai Houzhi; Peng Xiang; Liu Jinyuan; Niu Lihong; Peng Wenda; Niu Hanben; Long Jinghua

    2011-05-15

    An x-ray framing camera using a non-gain microchannel plate (MCP) is reported in this article. The advantage of the non-gain MCP is the less transit time spread. The non-gain MCP gated framing camera has four microstrip line cathodes with 6 mm in width. The time domain reflectometry curves of the four microstrip lines are measured, which show that the characteristic impedance of each microstrip line is about 17 {Omega}. While the photocathode is driven by the gating electrical pulse with width of 125 ps and amplitude of -1.48 kV with -400 V bias, the measured exposure time of this camera is about 72 ps.

  5. A high resolution delay line readout for microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. S. W.; Lampton, M. L.; Raffanti, R.

    1989-01-01

    Investigations are reported of delay line configurations used to encode photon event locations in microchannel plate (MCP) detectors. Several delay line schemes of planar and multilayer structure are discussed. The importance of the delay line substrate material is examined, and it is shown that the raw signals from delay lines are narrow (about 3-4 ns FWHM). The factors determining the delay line resolution are evaluated, and it is demonstrated that these are in agreement with measurements. Resolutions of about 18-micron FWHM have been achieved. Measurements of the linearity of the delay line readout show that event centroid locations deviate from perfect linearity by less than 50 microns, even with the very simple anode fabrication methods employed. The image stability has also been evaluated and it is shown that image shifts are less than one resolution element over a period of two months.

  6. Photon counting compressive depth mapping.

    PubMed

    Howland, Gregory A; Lum, Daniel J; Ware, Matthew R; Howell, John C

    2013-10-01

    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 × 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 × 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second. PMID:24104293

  7. Performance evaluation of a photon-counting intensified CCD

    NASA Astrophysics Data System (ADS)

    Bergamini, Paolo; Bonelli, Giuseppe; D'Angelo, Sergio; Latorre, Stefano; Poletto, Luca; Sechi, Giacomo; Tanzi, Enrico G.; Tondello, Giuseppe; Uslenghi, Michela

    1997-10-01

    The performance of a prototype photon counting imaging detector, being developed for the international UV space mission spectrum-UV, is presented. The detector is based on a 4-cm diameter, Z stack, high gain microchannel plate (MCP) intensifier endowed with a RbTe photocathode. The electron cascade generated by the MCP intensifier is transduced, via a phosphor screen and a 1:3.6 fiber optics reducer, into a 5 by 5 pixel(superscript 2), quasi-Gaussian charge distribution on a 15 micrometer, 512 by 512 pixel(superscript 2) format CCD matrix read out in the frame-transfer mode at 20 MHz, corresponding to 60 frame sec(superscript -1) in the full frame mode and to 220 frame sec(superscript -1) in the window (128 by 512 pixel(superscript 2)) mode. The data flow is acquired serially as to generate a 5 by 5 pixel(superscript 2) event sash that sweeps dynamically the CCD matrix at the 50 ns place of the readout clock. Each and every event sash is searched for the presence of events whose charge distribution lie within set thresholds and satisfy given morphological rules, i.e. a peaked charge profile. The centroid coordinates of identified events are subsequently determined with sub-pixel accuracy and stored in an external, high resolution memory. The data acquisition and processing system, based on field programmable gate array technology, is well able to resolve the front MCP pore geometry (10 micrometer diameter pores at 12 micrometer pitch).

  8. Nano-engineered ultra-high-gain microchannel plates

    NASA Astrophysics Data System (ADS)

    Beaulieu, D. R.; Gorelikov, D.; de Rouffignac, P.; Saadatmand, K.; Stenton, K.; Sullivan, N.; Tremsin, A. S.

    2009-08-01

    Highly localized and very fast electron amplification of microchannel plates (MCPs) enables a large number of high-resolution and high-sensitivity detection technologies, which provide spatial and/or temporal information for each detected photon/electron/ion/neutron. Although there has been significant progress in photocathode and readout technologies the MCPs themselves have not evolved much from the technology developed several decades ago. Substantial increases in the gain of existing MCP technology have been accomplished by utilizing state-of-the-art processes developed for nano-engineered structures. The gain of treated MCPs with aspect ratio of 40:1 is reproducibly measured to reach unprecedented values of 2×10 5. This gain enhancement is shown to be stable during MCP operation. In addition, the initial experiments indicate improved stability of gain as a function of extracted charge and MCP storage conditions. We also present results from a fully independent thin-film process for manufacturing non-lead glass MCPs using engineered thin films for both the resistive and emissive layers. These substrate-independent MCPs show high gain, less gain degradation with extracted charge, and greater pore-to-pore and plate-to-plate uniformity than has been possible with conventional lead glass structures.

  9. High event rate ROICs (HEROICs) for astronomical UV photon counting detectors

    NASA Astrophysics Data System (ADS)

    Harwit, Alex; France, Kevin; Argabright, Vic; Franka, Steve; Freymiller, Ed; Ebbets, Dennis

    2014-07-01

    The next generation of astronomical photocathode / microchannel plate based UV photon counting detectors will overcome existing count rate limitations by replacing the anode arrays and external cabled electronics with anode arrays integrated into imaging Read Out Integrated Circuits (ROICs). We have fabricated a High Event Rate ROIC (HEROIC) consisting of a 32 by 32 array of 55 μm square pixels on a 60 μm pitch. The pixel sensitivity (threshold) has been designed to be globally programmable between 1 × 103 and 1 × 106 electrons. To achieve the sensitivity of 1 × 103 electrons, parasitic capacitances had to be minimized and this was achieved by fabricating the ROIC in a 65 nm CMOS process. The ROIC has been designed to support pixel counts up to 4096 events per integration period at rates up to 1 MHz per pixel. Integration time periods can be controlled via an external signal with a time resolution of less than 1 microsecond enabling temporally resolved imaging and spectroscopy of astronomical sources. An electrical injection port is provided to verify functionality and performance of each ROIC prior to vacuum integration with a photocathode and microchannel plate amplifier. Test results on the first ROICs using the electrical injection port demonstrate sensitivities between 3 × 103 and 4 × 105 electrons are achieved. A number of fixes are identified for a re-spin of this ROIC.

  10. Optimization of microchannel plate multipliers for tracking minimum-ionizing particles

    SciTech Connect

    Oba, K.; Rehak, P.; Potter, D.

    1981-01-01

    The progress in development of special Microchannel Plates for particle tracking is reported. The requirements of (1) high spatial resolution; (2) high density of information; and (3) rate capability were found to be satisfied in a thick Microchannel Plate with a CsI coating operating in a focusing magnetic field. The measurements of the Microchannel Plate detection efficiency, gain and noise are presented for several detectors. The pictures of the passage and interaction of the high energy charged particles inside the detector are shown.

  11. High Throughput, High Yield Fabrication of High Quantum Efficiency Back-Illuminated Photon Counting, Far UV, UV, and Visible Detector Arrays

    NASA Technical Reports Server (NTRS)

    Nikzad, Shouleh; Hoenk, M. E.; Carver, A. G.; Jones, T. J.; Greer, F.; Hamden, E.; Goodsall, T.

    2013-01-01

    In this paper we discuss the high throughput end-to-end post fabrication processing of high performance delta-doped and superlattice-doped silicon imagers for UV, visible, and NIR applications. As an example, we present our results on far ultraviolet and ultraviolet quantum efficiency (QE) in a photon counting, detector array. We have improved the QE by nearly an order of magnitude over microchannel plates (MCPs) that are the state-of-the-art UV detectors for many NASA space missions as well as defense applications. These achievements are made possible by precision interface band engineering of Molecular Beam Epitaxy (MBE) and Atomic Layer Deposition (ALD).

  12. Photon counts from stellar occultation sources

    NASA Technical Reports Server (NTRS)

    Buglia, James J.

    1987-01-01

    The feasibility of using stars as radiation sources for Earth atmospheric occultation experiments is investigated. Exoatmospheric photon counts of the order of 10 to the 6th power photons/sq cm/sec are realized for the 15 visually brightest stars. Most photon counts appear to be marginally detectable unless photomultiplier or cascade detection devices can be used.

  13. Cross strip anode readouts for microchannel plate detectors: developing flight qualified prototypes

    NASA Astrophysics Data System (ADS)

    Vallerga, John; Cooney, M.; Raffanti, R.; Varner, G.; Siegmund, O.; McPhate, J. B.; Tremsin, A.

    2014-01-01

    Photon counting microchannel plate (MCP) imagers have been the detector of choice for most UV astronomical missions over the last two decades (eg. EUVE, FUSE, COS on Hubble etc.). Over this duration, improvements in the MCP laboratory readout technology have resulted in better spatial resolution (x10), temporal resolution (x 1000) and output event rate (x100), all the while operating at lower gain (x 10) resulting in lower high voltage requirements and longer MCP lifetimes. One such technology is the parallel cross strip (PXS) readout. The PXS anode is a set of orthogonal conducting strips (80 x 80), typically spaced at a 635 micron pitch onto which charge clouds from MCP amplified events land. Each strip has its own charge sensitive amplifier that is sampled continuously by a dedicated analog to digital (ADC) converter at 50MHz. All of the 160 ADC digital output lines are fed into a field programmable gate array (FGPA) which can detect charge events landing on the strips, measure the peak amplitudes of those charge events and calculate their spatial centroid along with their time of arrival (X,Y,T). Laboratory versions of these electronics have demonstrated < 20 microns FWHM spatial resolution, count rates on the order of 2 MHz, and temporal resolution of ~ 1ns. In 2012 the our group at U.C. Berkeley, along with our partners at the U. Hawaii, received a Strategic Astrophysics Technology grant to raise the TRL of the PXS detector from 4 to 6 by replacing most of the 19" rack mounted, high powered electronics with application specific integrated circuits (ASICs) which will lower the power, mass and volume requirements of the PXS detector. We were also tasked to design and fabricate a "standard" 50mm square active area MCP detector incorporating these electronics that can be environmentally qualified for flight (temperature, vacuum, vibration). This detector design could then be modified for individual flight opportunities with a higher level of confidence than

  14. Monte Carlo simulations of microchannel plate detectors I: steady-state voltage bias results

    SciTech Connect

    Ming Wu, Craig Kruschwitz, Dane Morgan, Jiaming Morgan

    2008-07-01

    X-ray detectors based on straight-channel microchannel plates (MCPs) are a powerful diagnostic tool for two-dimensional, time-resolved imaging and timeresolved x-ray spectroscopy in the fields of laser-driven inertial confinement fusion and fast z-pinch experiments. Understanding the behavior of microchannel plates as used in such detectors is critical to understanding the data obtained. The subject of this paper is a Monte Carlo computer code we have developed to simulate the electron cascade in a microchannel plate under a static applied voltage. Also included in the simulation is elastic reflection of low-energy electrons from the channel wall, which is important at lower voltages. When model results were compared to measured microchannel plate sensitivities, good agreement was found. Spatial resolution simulations of MCP-based detectors were also presented and found to agree with experimental measurements.

  15. Measurement and analysis of signal to noise ratio for image intensifier tube, 18mm microchannel plate

    NASA Astrophysics Data System (ADS)

    Bai, Xiaofeng; Shi, Feng; Feng, Hanliang; Liu, Rong; Yin, Lei; He, Yingping

    2011-08-01

    Output signal to noise ratio is an important technical index for evaluating detectability of microchannel plate image intensifier tube, and the characteristic for detecting of microchannel plate image intensifier tube restricts the detectability of the night vision system. It has been proved in theory and in practice that the value of output signal to noise ratio of image intensifier tube equipped for night vision system decides the farthest distance and imaging definition of system which used under low light level in square root way. In this article, method and device for measuring the output signal to noise ratio of 18mm microchannel plate image intensifier tube has been introduced in detail. Output signal to noise ratio values of several 18mm microchannel plate image intensifier tube selected have been measured. Contacting to work condition of image intensifier tube, relationship between voltage of cathode, microchannel plate, screen and output signal to noise ratio of 18mm microchannel plate image intensifier tube bas been studied, which is available for other image intensifier tube.

  16. Readout for a large area neutron sensitive microchannel plate detector

    NASA Astrophysics Data System (ADS)

    Wang, Yiming; Yang, Yigang; Wang, Xuewu; Li, Yuanjing

    2015-06-01

    A neutron sensitive microchannel plate (MCP) detector was developed for neutron imaging on the beamline of a compact pulsed hadron source (CPHS). The detector was set up with a Wedge-and-Strip Anode (WSA) and a delay line anode readout to compare the spatial resolution and throughput with these two anodes. Tests show that the WSA readout is suitable for small area imaging with a spatial resolution of 200 μm with low energy X-rays in a 50 mm diameter MCP-WSA assembly. However, the spatial resolution deteriorated to ~2 mm in a 106 mm diameter MCP-WSA assembly because the noise caused by the parasitic capacitance is 10 times larger in the larger assembly than in the 50 mm diameter assembly. A 120 mm by 120 mm delay line anode was then used for the 106 mm MCP readout. The spatial resolution was evaluated for various voltages applied to the MCP V-stack, various readout voltages and various distances between the MCP V-stack rear face and the delay line. The delay line readout had resolutions of 65.6 μm in the x direction and 63.7 μm in the y direction and the throughput was greater than 600 kcps. The MCP was then used to acquire a neutron image of an USAF1951 Gd-mask.

  17. Understanding the dynamic performance of microchannel plates in pulsed mode

    SciTech Connect

    Ray Thomas; Ming Wu; Nathan Joseph; Craig Kruschwitz; Gregroy A. Rochau

    2007-06-22

    The dynamic performance of a microchannel plate (MCP) is highly dependent on the high-voltage waveforms that are applied to it. Impedance mismatches in MCP detectors can significantly vary the waveforms on the MCP compared to the input pulses. High-voltage pulse waveforms launched onto surface coatings on the MCPs have historically been difficult and expensive to measure. Over the past few years, we have developed and tested techniques utilizing probes to measure the voltage propagation on the surface of MCPs. Square and Gaussian pulses with widths ranging from 200 ps to 2 ns have been applied. We have investigated the effects of coating thickness, microstrip width, and openended versus terminated strips. These data provide a wealth of knowledge that is enabling a better understanding of images recorded with these devices. This presentation discusses a method for measuring voltage profiles on the surface of the MCP and presents Monte Carlo simulations of the optical gate profiles based on the measured waveforms. Excellent agreement in the optical gate profiles have been achieved between the simulations and the experimental measurements using a short-pulse ultraviolet laser.

  18. Analysis and modeling on noise factor of microchannel plate

    NASA Astrophysics Data System (ADS)

    Li, Yanhong; Chen, Xiaomei; Ni, Guoqiang

    2013-12-01

    The Microchannel plate (MCP) is the main noise source of low-level light (LLL) image intensifier. Material and the whole manufacturing process of MCP have great impact on the noises of MCP. In this paper, based on the physical mechanisms of MCP, noises of MCP are classified scientifically. By using the data obtained from the actual production and the process test, the regression equation of the noise figure of MCP is derived, and the theoretical model of MCP noise figure is established, including the background noise figure model caused by the dark current of the MCP primarily about the time of the alkali corrosion technic, the ion feedback induced noise figure model caused by the patterns of the MCP channel wall primarily about the time and temperature of the hydrogen reduction technic, and the electronic scattering noise figure model caused by the open area ratio of the MCP primarily about the time of the alkali corrosion technic. Guided by the theoretical model of noise figure, the methods of suppressing noises of MCP are obtained and the technics are optimized. Taking advantage of the new techniques, the noise figure of the third generation MCP has been reduced to below 1.8.

  19. Application research on microchannel plate in new fields

    NASA Astrophysics Data System (ADS)

    Li, Yanhong; Chen, Xiaomei; Ni, Guoqiang

    2015-08-01

    Microchannel plate (MCP) is a photoelectron multiplier as the core component of low-level light (LLL) image intensifier. MCP has two-dimensional space, time, and energy resolution, fast response time, low background noise, wide dynamic range and high gain characteristics, as well as electrons, ions, UV and soft X-ray photon detection capability directly. In recent years, with the publication of foreign advanced technology and Chinese research staff in-depth understanding of MCP's unique characteristics, the applications of MCP have extended into many new fields accordingly in China. In addition to the image intensifier, the MCP can be used in deep space exploration and scientific experiments, detecting kinds of trace rays and particles, such as pulsars navigation, nuclear simulation diagnostics, UV, EUV, neutron, neutrino detection and imaging. North Night Vision Technology Co. Ltd (NVT) as the only unit possessing MCP production capacity in China is constantly working on improving, innovation and application research on MCP technology. In this paper, based on the researches on MCP in some new fields the NVT Company has undertaken and ongoing, the technological breakthroughs and application research progresses achieved are described.

  20. Development of a novel position-sensitive microchannel plate detector

    NASA Astrophysics Data System (ADS)

    Wiggins, Blake; Siwal, Davinder; Desouza, Romualdo

    2015-10-01

    Position sensitive microchannel plate (MCP) detectors which measure the position of an incident electron, ion, or photon, are useful in imaging applications. Recently, a novel detector, which utilizes an induced approach to provide position sensitivity, has been developed. In the prototype detector, using only the zero-crossing point of the inherently bipolar signals, a position resolution of 466 μm (FWHM) has been achieved. Implementing a differential readout may improve on this resolution. To realize this differential approach, a better understanding of the dependence of the induced signal shape on the position of the electron cloud is required. To characterize the dependence of the induced signal shape on position a resistive anode (RA) has been incorporated into the detector. The RA will allow determination of the centroid of the electron cloud. Factors impacting the position resolution obtained with the RA will be discussed and the achieved position resolution of 157 μm (FWHM) will be presented. Supported by the US DOE NNSA under Award No. DE-NA0002012.

  1. Development of microchannel plates in advanced wind-tunnel instrumentation

    NASA Technical Reports Server (NTRS)

    Feller, W. Bruce

    1990-01-01

    Microchannel plate (MCP) electron multiplier dynamic range has been increased 3 to 4 orders of magnitude at ambient temperatures, through enhanced input count rate capability and reduced background or 'dark' noise. The previous upper limit of roughly 10(exp 7) - 10(exp 8) cm(exp -2)s(exp -1) at ambient has been extended to levels approach 10(exp 10) cm(exp -2)s(exp -1) under continuous dc operation. The lower limit, previously set by an irreducible background component (approximately 0.6 cm(exp -2)s(exp -1)), has been lowered to the cosmic ray limit of .01 cm(exp -2)s(exp -1). The high end improvement was achieved by conductively cooling a very low resistance MCP by bonding it to a heat sink, while maintaining pulse-counting operation with multianode readouts. The low-end improvement was achieved by removing all radioisotopes from the MCP matrix glass. The detectors will benefit optical and mass spectrometry, flow visualization, plasma diagnostics, magnetometry, and other high signal flux applications. Very low MCP background noise will benefit X-ray and UV astronomy, medical imaging, trace isotope mass spectrometry, and other applications where the signal flux is often extremely low.

  2. Lithography process of micropore array pattern in Si microchannel plates

    NASA Astrophysics Data System (ADS)

    Fan, Linlin; Han, Jun; Liu, Huan; Wang, Yawei

    2015-02-01

    Microchannel plates - MCPs - are the key component of the image intensifier. Compared with the traditional MCPs, the Si MCPs which are fabricated by micro-nanofabrication technologies have a high gain, low noise and high resolution etc. In this paper, the lithography process is studied in the process of fabricating periodic micropore array with 10 um pores and 5 um pitch on Si. The effects of exposure time, reversal bake temperature and development time on the lithography quality are focused. By doing a series of experiments the better result is got: the photoresist film is obtained at a low speed 500/15(rpm/s) and a high speed 4500/50(rpm/s); the soft bake time is 10min at 100°; the exposure time is 10s; the reversal bake time is 80s at 115°; the development time is 55s. By microscope observation and measurement, the pattern is complete and the size of the pattern is accure, it meets the requirement of lithography process for fabricating Si-MCP.

  3. Breakthrough in the lifetime of microchannel plate photomultipliers

    NASA Astrophysics Data System (ADS)

    Uhlig, F.; Britting, A.; Eyrich, W.; Lehmann, A.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Kumawat, H.; Lehmann, D.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Dodokhov, V. Kh.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Cowie, E.; Keri, T.; Montgomery, R.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.; Bühler, P.; Gruber, L.; Marton, J.; Suzuki, K.

    2015-07-01

    Cherenkov detectors using the DIRC (Detection of Internally Reflected Cherenkov Light) principle are foreseen for particle identification in the P bar ANDA experiment at FAIR. Promising sensors for the detection of the Cherenkov light are the so-called micro-channel plate (MCP) photomultipliers (PMT). They have an excellent time resolution, can be operated at high gain for single photon detection and have a high resistivity against magnetic fields. The disadvantage of these devices was their limited lifetime, due to damage by feedback ions on the photocathode. The lifetime of various types of MCP-PMTs from different manufactures has been tested under conditions similar to that in the P bar ANDA experiment. The sensors are assembled in one setup, to ensure the same illumination conditions. The measurement procedure requires permanent monitoring of the illumination and interruptions after about 2-3 weeks to measure dark count rate, gain and spectral quantum efficiency of all sensors. Furthermore surface scans of the whole photocathode are done every 2-4 months to determine faster aging areas. The latest results show very good lifetime performance for MCP-PMTs, where the MCPs have been treated with the atomic layer deposition (ALD) technique.

  4. The gain, temporal resolution and magnetic-field immunity of microchannel plates

    NASA Astrophysics Data System (ADS)

    Fraser, G. W.

    1990-06-01

    The variation of microchannel plate (MCP) pulse gain, pulse transit time and transit time spread with channel diameter and length-to-diameter ratio is described, using a variable-spacing dynode model of the electron avalanche which accounts for the effects of wall charge saturation. The analysis includes a description of the response of a single microchannel to the prompt arrival of N electrons, thus providing a microscopic basis for the empirical laws currently used to describe the gain of two- or three-stage MCP multipliers. Preliminary results of microchannel plate gain fatigue "lifetests" conducted in software are described. Finally, an expression is derived for the gain of a microchannel plate, as a function of bias voltage, in the presence of a strong axial magnetic field. Here, as throughout the paper, the results of calculation are compared with experiment.

  5. SIS Detectors for Terahertz Photon Counting System

    NASA Astrophysics Data System (ADS)

    Ezawa, Hajime; Matsuo, Hiroshi; Ukibe, Masahiro; Fujii, Go; Shiki, Shigetomo

    2016-07-01

    An Intensity interferometer with photon counting detector is a candidate to realize a THz interferometer for astronomical observations. We have demonstrated that synthesis imaging is possible even with intensity interferometers. An SIS junction (or STJ) with low leakage current of 1 pA is a suitable device for photon counting detectors. Readout circuit utilizing FETs with low gate leakage, low gate capacitance, and fast response is discussed.

  6. Microchannel plates as detectors and amplifiers of x-ray images

    SciTech Connect

    Wiedwald, J.D.

    1992-08-01

    Two decades of development driven largely by military night vision applications has led to the availability of a wide selection of microchannel plates for use by the scientific community. Microchannel plates (MCPs) are electron multipliers which retain a high degree of spatial resolution making it possible to amplify electron images by factors of 1,000 or more. Plates having 40 mm diameter and intrinsic spatial resolution of 8 [mu]m are readily available. By coating the front surface of a microchannel plate with an x-ray sensitive photocathode material, x-ray images can be detected and amplified. While the detective quantum efficiency is relatively low, the low noise of the MCP (including the ability to construct images by single photon detection) and its high dynamic range make it suitable for some x-ray microscopy applications. The principles of MCP operation and typical performance are discussed. Examples of related applications and commercial capabilities are also presented.

  7. Microchannel plates as detectors and amplifiers of x-ray images

    SciTech Connect

    Wiedwald, J.D.

    1992-08-01

    Two decades of development driven largely by military night vision applications has led to the availability of a wide selection of microchannel plates for use by the scientific community. Microchannel plates (MCPs) are electron multipliers which retain a high degree of spatial resolution making it possible to amplify electron images by factors of 1,000 or more. Plates having 40 mm diameter and intrinsic spatial resolution of 8 {mu}m are readily available. By coating the front surface of a microchannel plate with an x-ray sensitive photocathode material, x-ray images can be detected and amplified. While the detective quantum efficiency is relatively low, the low noise of the MCP (including the ability to construct images by single photon detection) and its high dynamic range make it suitable for some x-ray microscopy applications. The principles of MCP operation and typical performance are discussed. Examples of related applications and commercial capabilities are also presented.

  8. A high-throughput, multi-channel photon-counting detector with picosecond timing

    NASA Astrophysics Data System (ADS)

    Lapington, J. S.; Fraser, G. W.; Miller, G. M.; Ashton, T. J. R.; Jarron, P.; Despeisse, M.; Powolny, F.; Howorth, J.; Milnes, J.

    2009-06-01

    High-throughput photon counting with high time resolution is a niche application area where vacuum tubes can still outperform solid-state devices. Applications in the life sciences utilizing time-resolved spectroscopies, particularly in the growing field of proteomics, will benefit greatly from performance enhancements in event timing and detector throughput. The HiContent project is a collaboration between the University of Leicester Space Research Centre, the Microelectronics Group at CERN, Photek Ltd., and end-users at the Gray Cancer Institute and the University of Manchester. The goal is to develop a detector system specifically designed for optical proteomics, capable of high content (multi-parametric) analysis at high throughput. The HiContent detector system is being developed to exploit this niche market. It combines multi-channel, high time resolution photon counting in a single miniaturized detector system with integrated electronics. The combination of enabling technologies; small pore microchannel plate devices with very high time resolution, and high-speed multi-channel ASIC electronics developed for the LHC at CERN, provides the necessary building blocks for a high-throughput detector system with up to 1024 parallel counting channels and 20 ps time resolution. We describe the detector and electronic design, discuss the current status of the HiContent project and present the results from a 64-channel prototype system. In the absence of an operational detector, we present measurements of the electronics performance using a pulse generator to simulate detector events. Event timing results from the NINO high-speed front-end ASIC captured using a fast digital oscilloscope are compared with data taken with the proposed electronic configuration which uses the multi-channel HPTDC timing ASIC.

  9. Characterisation of low power readout electronics for a UV microchannel plate detector with cross-strip readout

    NASA Astrophysics Data System (ADS)

    Pfeifer, M.; Barnstedt, J.; Diebold, S.; Hermanutz, S.; Kalkuhl, C.; Kappelmann, N.; Schanz, T.; Schütze, B.; Werner, K.

    2014-07-01

    Astronomical observations in the ultraviolet (UV) wavelength range between 91 and 300nm are fundamental for the progress in astrophysics. Scientific success of future UV observatories raises the need for technology development in the areas of detectors, optical components, and their coatings. We develop solar blind and photon counting microchannel plate (MCP) UV detectors as a contribution to the progress in UV observation technology. New combinations of materials for the photocathode (see paper No. 9144-111, this volume, for details) as well as a cross-strip (XS) anode, having 64 strips on each layer, are used. Pre-amplification of the charge deposited onto the anode is performed by the Beetle chip designed at the Max-Planck-Institute for Nuclear Physics in Heidelberg for LHCb at CERN. It features 128 pre-amplifiers on one die and provides the analogue output in a four-fold serial stream. This stream is digitised by only four ADCs and is processed in an FPGA. This concept results in a reduced power consumption well below 10W as well as a reduced volume, weight and complexity of the readout electronics compared to existing cross-strip readouts. We developed an electronics prototype assembly and a setup in a vacuum chamber that is similar to the configuration in the final detector. The setup in the chamber is used for the burn-in of the MCPs as well as for tests of the readout electronics prototype assembly incorporating realistic signals. In this paper, information on the XS anodes as well as on the hybrid PCB carrying the Beetle pre-amplifier chip is shown. Details on the readout electronics design as well as details of the setup in the vacuum chamber are presented. An outlook to the next steps in the development process is given.

  10. Preliminary results with saturable microchannel array plates. [featuring positive ion feedback elimination

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1974-01-01

    Microchannel array plates with a performance comparable to that of a conventional channel electron multiplier have been obtained for the first time. These array plates employ an angled electrostatic field to inhibit the feedback of positive ions within the microchannels. Saturated output pulse height distributions with modal gain values in excess of 10 million have been obtained and stable operation demonstrated over a range of ambient pressures from 0.0000001 to 0.00008 torr. However, a time-dependent reduction in the gain has been observed with these experimental plates because of the accumulation of charge on the insulating strips which are inserted in the wall of the microchannel to establish the angled electrostatic field.

  11. Study on the strain in a silicon microchannel plate by micro-Raman analysis

    NASA Astrophysics Data System (ADS)

    Xu, Shaohui; Fang, Jiabing; Wu, Dajun; Zhang, Chi; Zhu, Yiping; Xiong, Dayuan; Wang, Lianwei; Yang, Pingxiong; Chu, Paul K.

    2016-05-01

    Micro-Raman analysis was used to identify the oxidation of a silicon microchannel plate (SiMCP) and it indicated that the bend phenomenon of the SiMCP was related to the release of stress and the volume expending of the silicon wall during the oxidation process.

  12. Flare star monitoring with a new photon-counting imaging detector

    SciTech Connect

    Casperson, D.

    1997-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). A search for faint time-varying optical signals from the nighttime sky has been conducted in parallel with the programmatic development of a new type of imaging detector. This detector combines high spatial and high temporal resolution with single-photon-counting sensitivity over a 40-mm diameter large-area format. It is called a microchannel plate with crossed delay line readout, or MCP/CDL, and is placed in the focal plane of a telescope to collect time-resolved images from objects such as flaring stars and other astrophysical transient sources. A short-lived prototype MCP/CDL was used to provide the initial stellar images for this project, but the author could not generate any extended database with which to characterize flare star populations. Consequently, a supplementary experimental search for optical transients was begun, utilizing the NASA 3-meter-aperture Liquid Mirror Telescope (LMT) facility in Cloudcroft, NM.

  13. Physical characterization of photon-counting tomosynthesis

    NASA Astrophysics Data System (ADS)

    Berggren, Karl; Lundqvist, Mats; Cederström, Björn; Danielsson, Mats E.; Fredenberg, Erik

    2015-03-01

    Tomosynthesis is emerging as a next generation technology in mammography. Combined with photon-counting detectors with the ability for energy discrimination, a novel modality is enabled — spectral tomosynthesis. Further advantages of photon-counting detectors in the context of tomosynthesis include elimination of electronic noise, efficient scatter rejection (in some geometries) and no lag. Fourier-based linear-systems analysis is a well-established method for optimizing image quality in two-dimensional x-ray systems. The method has been successfully adapted to threedimensional imaging, including tomosynthesis, but several areas need further investigation. This study focuses on two such areas: 1) Adaption of the methodology to photon-counting detectors, and 2) violation of the shift-invariance and stationarity assumptions in non-cylindrical geometries. We have developed a Fourier-based framework to study the image quality in a photon-counting tomosynthesis system, assuming locally linear, stationary, and shift-invariant system response. The framework includes a cascaded-systems model to propagate the modulation-transfer function (MTF) and noise-power spectrum (NPS) through the system. The model was validated by measurements of the MTF and NPS. High degrees of non-shift invariance and non-stationarity were observed, in particular for the depth resolution as the angle of incidence relative the reconstruction plane varied throughout the imaging volume. The largest effects on image quality in a given point in space were caused by interpolation from the inherent coordinate system of the x-rays to the coordinate system that was used for reconstruction. This study is part of our efforts to fully characterize the spectral tomosynthesis system, we intend to extend the model further to include the detective-quantum efficiency, observer modelling, and spectral effects.

  14. Capacity approaching codes for photon counting receivers

    NASA Astrophysics Data System (ADS)

    Mondin, Marina; Daneshgaran, Fred; Bari, Inam; Delgado, Maria Teresa

    2012-10-01

    [1] a low-complexity photon-counting receiver has been presented, which may be employed for weak-energy optical communications and which is typically modeled through its equivalent Binary Symmetric Channel (BSC) model. In this paper we consider the scheme described in [1], we model it as a time varying Binary Input-Multiple Output (BIMO) channel and analyze its performance in presence of soft-metric based capacity approaching iteratively decoded error correcting codes, and in particular using soft-metric based Low Density Parity Check (LDPC) codes. To take full advantage of such detector, soft information is generated in the form of Log-Likelihood Ratios (LLRs), achieving reduction in Bit Error Rate (BER) and Frame Error Rate (FER) with respect to classical BSC and Additive White Gaussian Noise (AWGN) channel models. Furthermore, we explore the limits of the achievable performance gains when using photon counting detectors as compared to the case when such detectors are not available. To this end, we find the classical capacity of the considered BIMO channel, clearly showing the potential gains that photon counting detectors can provide in the context of a realistic cost-effective scheme from an implementation point of view. Furthermore, we show that from a channel modeling point of view, we can observe that the BIMO channel can be approximated with an AWGN channel for high values of mean photon count Nc, while the AWGN model offers an unreliable result with a low mean photon number Nc, (i.e. with low raw BER). This effect is more evident with lower coding rates.

  15. Micro-channel plate photon detector studies for the TORCH detector

    NASA Astrophysics Data System (ADS)

    Castillo García, L.; Brook, N.; Cowie, E. N.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Piedigrossi, D.; Van Dijk, M.

    2015-07-01

    The Time Of internally Reflected Cherenkov light (TORCH) detector is under development. Charged particle tracks passing through a 1 cm plate of quartz will generate the Cherenkov photons, and their arrival will be timed by an array of micro-channel plate photon detectors. As part of the TORCH R&D studies, commercial and custom-made micro-channel plate detectors are being characterized. The final photon detectors for this application are being produced in a three-phase program in collaboration with industry. Custom-made single-channel devices with extended lifetime have been manufactured and their performance is being systematically investigated in the laboratory. Optical studies for the preparation of beam and laboratory tests of a TORCH prototype are also underway.

  16. Optimizing the position resolution of a Z-stack microchannel plate resistive anode detector for low intensity signals

    SciTech Connect

    Wiggins, B. B.; Richardson, E.; Siwal, D.; Hudan, S.; Souza, R. T. de

    2015-08-15

    A method for achieving good position resolution of low-intensity electron signals using a microchannel plate resistive anode detector is demonstrated. Electron events at a rate of 7 counts s{sup −1} are detected using a Z-stack microchannel plate. The dependence of position resolution on both the distance and the potential difference between the microchannel plate and resistive anode is investigated. Using standard commercial electronics, a measured position resolution of 170 μm (FWHM) is obtained, which corresponds to an intrinsic resolution of 157 μm (FWHM)

  17. High resolution decoding techniques and single-chip decoders for multi-anode microchannel arrays

    NASA Technical Reports Server (NTRS)

    Kasle, David B.

    1989-01-01

    While the pixel size in a standard multianode microchannel array (MAMA) photon-counting detector is determined by the spacing of the anode array, the factor most fundamentally limiting pixel resolution is the spacing of the channels in the microchannel plate. Detector resolution can be improved by means of digitization followed by a centroiding procedure. The decoding hardware and the techniques for enhanced pixel resolution are presently discussed with a view to the factors of speed and complexity. A single-chip CMOS gate-array implementation of the decoder is devised and compared with existing multichip decoders' performance.

  18. Calibration of a microchannel plate based extreme ultraviolet grazing incident spectrometer at the Advanced Light Source.

    PubMed

    Bakeman, M S; van Tilborg, J; Sokollik, T; Baum, D; Ybarrolaza, N; Duarte, R; Toth, C; Leemans, W P

    2010-10-01

    We present the design and calibration of a microchannel plate based extreme ultraviolet spectrometer. Calibration was performed at the Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL). This spectrometer will be used to record the single shot spectrum of radiation emitted by the tapered hybrid undulator (THUNDER) undulator installed at the LOASIS GeV-class laser-plasma-accelerator. The spectrometer uses an aberration-corrected concave grating with 1200 lines/mm covering 11-62 nm and a microchannel plate detector with a CsI coated photocathode for increased quantum efficiency in the extreme ultraviolet. A touch screen interface controls the grating angle, aperture size, and placement of the detector in vacuum, allowing for high-resolution measurements over the entire spectral range. PMID:21034012

  19. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

    SciTech Connect

    Andresen, G. B.; Bowe, P. D.; Hangst, J. S.; Bertsche, W.; Butler, E.; Charlton, M.; Humphries, A. J.; Joergensen, L. V.; Kerrigan, S. J.; Madsen, N.; Werf, D. P. van der; Bray, C. C.; Chapman, S.; Fajans, J.; Povilus, A. P.; Cesar, C. L.; Lambo, R.; Fujiwara, M. C.; Gill, D. R.; Collaboration: ALPHA Collaboration; and others

    2009-12-15

    A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons.

  20. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector.

    PubMed

    Andresen, G B; Bertsche, W; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jørgensen, L V; Kerrigan, S J; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Povilus, A P; Pusa, P; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; van der Werf, D P; Yamazaki, Y

    2009-12-01

    A microchannel plate (MCP)/phosphor screen assembly has been used to destructively measure the radial profile of cold, confined antiprotons, electrons, and positrons in the ALPHA experiment, with the goal of using these trapped particles for antihydrogen creation and confinement. The response of the MCP to low energy (10-200 eV, <1 eV spread) antiproton extractions is compared to that of electrons and positrons. PMID:20073120

  1. Characteristics of square pore and low noise microchannel plate stacks. [for x-ray astronomy

    NASA Technical Reports Server (NTRS)

    Siegmund, Oswald H. W.; Marsh, Daniel; Stock, Joseph; Gaines, Geoffrey

    1992-01-01

    An evaluation is conducted of several square-pore microchannel plates (MCPs) with either 25- or 85-micron diameter pores and 80:1 or 50:1 channel length/diameter ratio. Flat field measurements show that the 25-micron-pored MCPs, unlike those with 85-micron pores, exhibit periodic modulation; this may be due to the MCP stacking configurations. Attention is given to the relative quantum detection efficiency advantages of the two MCPs.

  2. Note: A timing micro-channel plate detector with backside fast preamplifier

    SciTech Connect

    Wang, Wei; Yu, Deyang Lu, Rongchun; Liu, Junliang; Cai, Xiaohong

    2014-03-15

    A timing micro-channel plate detector with a backside double-channel fast preamplifier was developed to avoid distortion during signal propagation from the anode to the preamplifier. The mechanical and electronic structure is described. The detector including its backside preamplifier is tested by a {sup 241}Am α-source and a rise time of ∼2 ns with an output background noise of 4 mV{sub rms} was achieved.

  3. Advances in photon counting for bioluminescence

    NASA Astrophysics Data System (ADS)

    Ingle, Martin B.; Powell, Ralph

    1998-11-01

    Photon counting systems were originally developed for astronomy, initially by the astronomical community. However, a major application area is in the study of luminescent probes in living plants, fishes and cell cultures. For these applications, it has been necessary to develop camera system capability at very low light levels -- a few photons occasionally -- and also at reasonably high light levels to enable the systems to be focused and to collect quality images of the object under study. The paper presents new data on MTF at extremely low photon flux and conventional ICCD illumination, counting efficiency and dark noise as a function of temperature.

  4. Fabrication and characterization of monolithically integrated microchannel plates based on amorphous silicon

    PubMed Central

    Franco, Andrea; Geissbühler, Jonas; Wyrsch, Nicolas; Ballif, Christophe

    2014-01-01

    Microchannel plates are vacuum-based electron multipliers for particle—in particular, photon— detection, with applications ranging from image intensifiers to single-photon detectors. Their key strengths are large signal amplification, large active area, micrometric spatial resolution and picosecond temporal resolution. Here, we present the first microchannel plate made of hydrogenated amorphous silicon (a-Si:H) instead of lead glass. The breakthrough lies in the possibility of realizing amorphous silicon-based microchannel plates (AMCPs) on any kind of substrate. This achievement is based on mastering the deposition of an ultra-thick (80–120 μm) stress-controlled a-Si:H layer from the gas phase at temperatures of about 200°C and micromachining the channels by dry etching. We fabricated AMCPs that are vertically integrated on metallic anodes of test structures, proving the feasibility of monolithic integration of, for instance, AMCPs on application-specific integrated circuits for signal processing. We show an electron multiplication factor exceeding 30 for an aspect ratio, namely channel length over aperture, of 12.5:1. This result was achieved for input photoelectron currents up to 100 pA, in the continuous illumination regime, which provides a first evidence of the a-Si:H effectiveness in replenishing the electrons dispensed in the multiplication process. PMID:24698955

  5. Developments in microchannel plate detectors for imaging X-ray astronomy

    NASA Astrophysics Data System (ADS)

    Fraser, G. W.; Whiteley, M. J.; Pearson, J. F.

    The authors present new results in four areas of microchannel plate (MCP) X-ray detector operation. The performance in pulse counting mode of MCPs with 8 micron channel diameters is reported. The effects on MCP quantum detection efficiency and energy discrimination of multiple CsI coatings are described. A new mode of operation of two-stage multipliers is evaluated. Replacing the conventional electron-accelerating inter-plate potential difference by a retarding field is shown to result in definite advantages with regard to X-ray energy discrimination and detector lifetime. The source of the MCP internal background is discussed.

  6. Performance studies of high gain photomultiplier having Z-configuration of microchannel plates

    NASA Astrophysics Data System (ADS)

    Lo, C. C.; Leskovar, B.

    1980-11-01

    The characteristics of a high gain type ITT F4129 photomultiplier having three microchannel plates in cascade for electron multiplications were investigated. These plates are in the Z-configuration. Measurements are given of the gain dark current, cathode quantum efficiency, anode pulse linearity, electron transit time, single and multiphoton time spreads, fatigue, and pulse height resolution. The gain as a function of transverse magnetic field was measured and discussed. Photomultiplier characteristics as a function of the input pulse repetition frequency were also investigated and discussed.

  7. Radiation hardness tests and characterization of the CLARO-CMOS, a low power and fast single-photon counting ASIC in 0.35 micron CMOS technology

    NASA Astrophysics Data System (ADS)

    Fiorini, M.; Andreotti, M.; Baldini, W.; Calabrese, R.; Carniti, P.; Cassina, L.; Cotta Ramusino, A.; Giachero, A.; Gotti, C.; Luppi, E.; Maino, M.; Malaguti, R.; Pessina, G.; Tomassetti, L.

    2014-12-01

    The CLARO-CMOS is a prototype ASIC that allows fast photon counting with 5 ns peaking time, a recovery time to baseline smaller than 25 ns, and a power consumption of less than 1 mW per channel. This chip is capable of single-photon counting with multi-anode photomultipliers and finds applications also in the read-out of silicon photomultipliers and microchannel plates. The prototype is realized in AMS 0.35 micron CMOS technology. In the LHCb RICH environment, assuming 10 years of operation at the nominal luminosity expected after the upgrade in Long Shutdown 2 (LS2), the ASIC must withstand a total fluence of about 6×1012 1 MeV neq /cm2 and a total ionizing dose of 400 krad. A systematic evaluation of the radiation effects on the CLARO-CMOS performance is therefore crucial to ensure long term stability of the electronics front-end. The results of multi-step irradiation tests with neutrons and X-rays up to the fluence of 1014 cm-2 and a dose of 4 Mrad, respectively, are presented, including measurement of single event effects during irradiation and chip performance evaluation before and after each irradiation step.

  8. Research on resistance properties of conductive layer materials of microchannel plate film dynode

    NASA Astrophysics Data System (ADS)

    Peng, Ling-ling; Duanmu, Qingduo; Yang, Ji-kai; Wang, Guo-zheng

    2015-03-01

    Silicon Microchannel Plate - MCP - is a new image multiplier devices based semiconductor process technology. Compared with the traditional glass MCP, Silicon MCP has an advantage in technology that the dynode materials and the substrate materials are separate. At the same time, the dynode preparation process and the microchannel arrays are also separate. Two different dynode conductive layer films are prepared: polysilicon conductive films prepared by low pressure chemical vapor deposition (LPCVD) and AZO thin films coated by atomic layer deposition (ALD). The conductive films coated by ALD are superior to dynode conductive films prepared by LPCVD. By comparing the resistivity of conductive polysilicon thin film and AZO thin film of different Al concentrations doped, AZO thin film of different Al concentrations doped is a more suitable conductive layer dynode material to satisfy the MCP conductive layer resistivity requirements.

  9. Three-dimensional photon counting double-random-phase encryption.

    PubMed

    Cho, Myungjin; Javidi, Bahram

    2013-09-01

    In this Letter, we present a three-dimensional (3D) photon counting double-random-phase encryption (DRPE) technique using passive integral imaging. A 3D photon counting DRPE can encrypt a 3D scene and provides more security and authentications due to photon counting Poisson nonlinear transformation on the encrypted image. In addition, 3D imaging allows verification of the 3D object at different depths. Preliminary results and performance evaluation have been presented. PMID:23988912

  10. Photon Counting Using Edge-Detection Algorithm

    NASA Technical Reports Server (NTRS)

    Gin, Jonathan W.; Nguyen, Danh H.; Farr, William H.

    2010-01-01

    New applications such as high-datarate, photon-starved, free-space optical communications require photon counting at flux rates into gigaphoton-per-second regimes coupled with subnanosecond timing accuracy. Current single-photon detectors that are capable of handling such operating conditions are designed in an array format and produce output pulses that span multiple sample times. In order to discern one pulse from another and not to overcount the number of incoming photons, a detection algorithm must be applied to the sampled detector output pulses. As flux rates increase, the ability to implement such a detection algorithm becomes difficult within a digital processor that may reside within a field-programmable gate array (FPGA). Systems have been developed and implemented to both characterize gigahertz bandwidth single-photon detectors, as well as process photon count signals at rates into gigaphotons per second in order to implement communications links at SCPPM (serial concatenated pulse position modulation) encoded data rates exceeding 100 megabits per second with efficiencies greater than two bits per detected photon. A hardware edge-detection algorithm and corresponding signal combining and deserialization hardware were developed to meet these requirements at sample rates up to 10 GHz. The photon discriminator deserializer hardware board accepts four inputs, which allows for the ability to take inputs from a quadphoton counting detector, to support requirements for optical tracking with a reduced number of hardware components. The four inputs are hardware leading-edge detected independently. After leading-edge detection, the resultant samples are ORed together prior to deserialization. The deserialization is performed to reduce the rate at which data is passed to a digital signal processor, perhaps residing within an FPGA. The hardware implements four separate analog inputs that are connected through RF connectors. Each analog input is fed to a high-speed 1

  11. Second generation airborne 3D imaging lidars based on photon counting

    NASA Astrophysics Data System (ADS)

    Degnan, John J.; Wells, David; Machan, Roman; Leventhal, Edward

    2007-09-01

    The first successful photon-counting airborne laser altimeter was demonstrated in 2001 under NASA's Instrument Incubator Program (IIP). This "micro-altimeter" flew at altitudes up to 22,000 ft (6.7 km) and, using single photon returns in daylight, successfully recorded high resolution images of the underlying topography including soil, low-lying vegetation, tree canopies, water surfaces, man-made structures, ocean waves, and moving vehicles. The lidar, which operated at a wavelength of 532 nm near the peak of the solar irradiance curve, was also able to see the underlying terrain through trees and thick atmospheric haze and performed shallow water bathymetry to depths of a few meters over the Atlantic Ocean and Assawoman Bay off the Virginia coast. Sigma Space Corporation has recently developed second generation systems suitable for use in a small aircraft or mini UAV. A frequency-doubled Nd:YAG microchip laser generates few microjoule, subnanosecond pulses at fire rates up to 22 kHz. A Diffractive Optical Element (DOE) breaks the transmit beam into a 10x10 array of quasi-uniform spots which are imaged by the receive optics onto individual anodes of a high efficiency 10x10 GaAsP segmented anode microchannel plate photomultiplier. Each anode is input to one channel of a 100 channel, multistop timer demonstrated to have a 100 picosecond timing (1.5 cm range) resolution and an event recovery time less than 2 nsec. The pattern and frequency of a dual wedge optical scanner, synchronized to the laser fire rate, are tailored to provide contiguous coverage of a ground scene in a single overflight.

  12. Detecting small debris using a ground-based photon counting detector

    SciTech Connect

    Ho, C.; Priedhorsky, W.C.; Baron, M.H.

    1993-05-01

    We describe a sensitive technique for detecting small space debris that exploits a fast photon-counting imager. Microchannel plate detectors using crossed delay-line readout can achieve a resolution of 2048 {times} 2048 spatial pixels and a maximum count rate of about 10{sup 6} photons per second. A baseline debris-tracking system might couple this detector to a 16-cm aperture telescope. The detector yields x, y, and time information for each detected photon. When visualized in (x, y, t) space, photons from a fast-moving orbital object appear on a straight line. They can be distinguished from diffuse background photons, randomly scattered in the space, and star photons, which fall on a line with sidereal velocity. By searching for this unique signature, we can detect and track small debris objects. At dawn and dusk, a spherical object of 1.3 cm diameter at 400 km will reflect sunlight for an apparent magnitude of V {approx} 16. The baseline system would detect about 16 photons from this object as it crosses a 1 degree field of view in about 1 second. The Ene in (x, y, t) space will be significant in a diffuse background of {approximately} 10{sup 6} photons. We discuss the data processing scheme and line detection algorithm. The advantages of this technique are that one can (1) detect cm-size debris objects with a small telescope, and (2) detect debris moving with any direction and velocity. In this paper, we describe the progress in the development of detector and data acquisition system, the preparation for a field test for such a system, and the development and optimization of the data analysis algorithm. Detection sensitivity would currently be constrained by the capability of the data acquisition and the data processing systems, but further improvements could alleviate these bottlenecks.

  13. Detecting small debris using a ground-based photon counting detector

    SciTech Connect

    Ho, C.; Priedhorsky, W.C.; Baron, M.H.

    1993-01-01

    We describe a sensitive technique for detecting small space debris that exploits a fast photon-counting imager. Microchannel plate detectors using crossed delay-line readout can achieve a resolution of 2048 [times] 2048 spatial pixels and a maximum count rate of about 10[sup 6] photons per second. A baseline debris-tracking system might couple this detector to a 16-cm aperture telescope. The detector yields x, y, and time information for each detected photon. When visualized in (x, y, t) space, photons from a fast-moving orbital object appear on a straight line. They can be distinguished from diffuse background photons, randomly scattered in the space, and star photons, which fall on a line with sidereal velocity. By searching for this unique signature, we can detect and track small debris objects. At dawn and dusk, a spherical object of 1.3 cm diameter at 400 km will reflect sunlight for an apparent magnitude of V [approx] 16. The baseline system would detect about 16 photons from this object as it crosses a 1 degree field of view in about 1 second. The Ene in (x, y, t) space will be significant in a diffuse background of [approximately] 10[sup 6] photons. We discuss the data processing scheme and line detection algorithm. The advantages of this technique are that one can (1) detect cm-size debris objects with a small telescope, and (2) detect debris moving with any direction and velocity. In this paper, we describe the progress in the development of detector and data acquisition system, the preparation for a field test for such a system, and the development and optimization of the data analysis algorithm. Detection sensitivity would currently be constrained by the capability of the data acquisition and the data processing systems, but further improvements could alleviate these bottlenecks.

  14. A fast readout and processing electronics for photon counting intensified charge-coupled device

    NASA Astrophysics Data System (ADS)

    Bergamini, P.; Bonelli, G.; Tanzi, E. G.; Uslenghi, M.; Poletto, L.; Tondello, G.

    2000-04-01

    The design features and the performances of a prototype photon counting imaging detector, being developed for the international ultraviolet (UV) space mission Spectrum UV, are presented. The photon counter is an intensified charge coupled device (ICCD) in which photon events, generating an electron cascade through a high gain microchannel plate (MCP) stack, are transduced, via a phosphor screen and a fiber optics reducer, into a 3×3 pixel2, quasi-Gaussian charge distributions on a 15×15 μm2,512×512 pixel2 format CCD matrix. The CCD is read out in the frame-transfer mode at a pixel rate of 19.75 MHz, and its output data flow is acquired serially as to generate a 3×3 pixel2 event sash that sweeps dynamically the CCD matrix at the 50.6 ns rate of the readout clock. Each and every event sash is searched for the presence of events whose charge content lie within proper limits and satisfy a given set of morphological rules, i.e., a single peak charge profile. The centroid coordinates of identified events are determined with subpixel accuracy (up to a 210 bin/pixel) and subsequently stored as photon list coordinate pairs. The data acquisition and processing system is based on field programmable gate array technology and is capable of satisfying the requirements of real-time operation. The modular construction of the data acquisition and processing electronics provides a great deal of flexibility for supporting advancements in CCD readout techniques (multiple output and higher clocking speed) and of MCPs (larger formats, smaller pore, and higher dynamic range). The results of the performance verification of the data acquisition and processing system integrated with a laboratory ICCD prototype are presented and discussed.

  15. Method and apparatus for enhancing microchannel plate data

    DOEpatents

    Thoe, R.S.

    1983-10-24

    A method and apparatus for determining centroid channel locations are disclosed for use in a system activated by one or more multichannel plates and including a linear diode array providing channels of information 1, 2, ...,n, ..., N containing signal amplitudes A/sub n/. A source of analog A/sub n/ signals, and a source of digital clock signals n, are provided. Non-zero A/sub n/ values are detected in a discriminator. A digital signal representing p, the value of n immediately preceding that whereat A/sub n/ takes its first non-zero value, is generated in a scaler. The analog A/sub n/ signals are converted to digital in an analog to digital converter. The digital A/sub n/ signals are added to produce a digital ..sigma..A/sub n/ signal in a full adder. Digital 1, 2, ..., m signals representing the number of non-zero A/sub n/ are produced by a discriminator pulse counter. Digital signals representing 1 A/sub p+1/, 2 A/sub p+2/, ..., m A/sub p+m/ are produced by pairwise multiplication in multiplier. These signal are added in multiplier summer to produce a digital ..sigma..nA/sub n/ - p..sigma..A/sub n/ signal. This signal is divided by the digital ..sigma..A/sub n/ signal in divider to provide a digital (..sigma..nA/sub n//..sigma..A/sub n/) -p signal. Finally, this last signal is added to the digital p signal in an offset summer to provide ..sigma..nA/sub n//..sigma..A/sub n/, the centroid channel locations.

  16. Method and apparatus for enhancing microchannel plate data

    DOEpatents

    Thoe, Robert S.

    1987-01-01

    A method and apparatus for determining centroid channel locations is disclosed for use in a system activated by one or more multichannel plates (16,18) and including a linear diode array (24) providing channels of information 1, 2, . . . , n, . . . , N containing signal amplitudes A.sub.n. A source of analog A.sub.n signals (40), and a source of digital clock signals n (48), are provided. Non-zero A.sub.n values are detected in a discriminator (42). A digital signal representing p, the value of n immediately preceding that whereat A.sub.n takes its first non-zero value, is generated in a scaler (50). The analog A.sub.n signals are converted to digital in an analog to digital converter (44). The digital A.sub.n signals are added to produce a digital .SIGMA.A.sub.n signal in a full adder (46). Digital 1, 2, . . . , m signals representing the number of non-zero A.sub.n are produced by a discriminator pulse counter (52). Digital signals representing 1 A.sub.p+ 1, 2 A.sub.p+2, . . . , m A.sub.p+m are produced by pairwise multiplication in multiplier (54). These signals are added in multiplier summer (56) to produce a digital .SIGMA.nA.sub.n -p.SIGMA.A.sub.n signal. This signal is divided by the digital .SIGMA.A.sub.n signal in divider (58) to provide a digital (.SIGMA.nA.sub.n /.SIGMA.A.sub.n) -p signal. Finally, this last signal is added to the digital p signal in an offset summer (60) to provide .SIGMA.nA.sub.n /.SIGMA.A.sub.n, the centroid channel locations.

  17. Development of a low-cost fast-timing microchannel plate photodetector

    NASA Astrophysics Data System (ADS)

    Xie, Junqi; Byrum, Karen; Demarteau, Marcel; May, Edward; Wagner, Robert; Walters, Dean; Wang, Jingbo; Xia, Lei; Zhao, Huyue

    2016-07-01

    We report on the design, fabrication and characterization of a prototype 6 × 6cm2 microchannel plate photodetector with precise fast-timing measurement capability. The whole assembly is made of low cost glass materials with a bialkali photocathode top window. All components are hermetically sealed in vacuum. The prototype photodetector exhibits time resolution of 65 ps and 16 ps at single-photoelectron and multi-photoelectron levels, respectively. The spatial resolution reaches 0.54 mm for multi-photoelectron measurements. The bialkali photocathode exhibits a maximum quantum efficiency exceeding 20% with a uniformity of ± 40 %.

  18. Microchannel plate pinhole camera for 20 to 100 keV x-ray imaging

    SciTech Connect

    Wang, C.L.; Leipelt, G.R.; Nilson, D.G.

    1984-10-03

    We present the design and construction of a sensitive pinhole camera for imaging suprathermal x-rays. Our device is a pinhole camera consisting of four filtered pinholes and microchannel plate electron multiplier for x-ray detection and signal amplification. We report successful imaging of 20, 45, 70, and 100 keV x-ray emissions from the fusion targets at our Novette laser facility. Such imaging reveals features of the transport of hot electrons and provides views deep inside the target.

  19. Note: Determining the detection efficiency of excited neutral atoms by a microchannel plate detector

    SciTech Connect

    Berry, Ben; Zohrabi, M.; Hayes, D.; Ablikim, U.; Jochim, Bethany; Severt, T.; Carnes, K. D.; Ben-Itzhak, I.

    2015-04-15

    We present a method for determining the detection efficiency of neutral atoms relative to keV ions. Excited D* atoms are produced by D{sub 2} fragmentation in a strong laser field. The fragments are detected by a micro-channel plate detector either directly as neutrals or as keV ions following field ionization and acceleration by a static electric field. Moreover, we propose a new mechanism by which neutrals are detected. We show that the ratio of the yield of neutrals and ions can be related to the relative detection efficiency of these species.

  20. Determining time resolution of microchannel plate detectors for electron time-of-flight spectrometers.

    PubMed

    Zhang, Qi; Zhao, Kun; Chang, Zenghu

    2010-07-01

    The temporal resolution of a 40 mm diameter chevron microchannel plate (MCP) detector followed by a constant fraction discriminator and a time-to-digital converter was determined by using the third order harmonic of 25 fs Ti:sapphire laser pulses. The resolution was found to deteriorate from 200 to 300 ps as the total voltage applied on the two MCPs increased from 1600 to 2000 V. This was likely due to a partial saturation of the MCP and/or the constant fraction discriminator working with signals beyond its optimum range of pulse width and shape. PMID:20687710

  1. Extreme ultraviolet quantum efficiency of opaque alkali halide photocathodes on microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Everman, E.; Vallerga, J. V.; Lampton, M.

    1988-01-01

    Comprehensive measurements are presented for the quantum detection efficiency (QDE) of the microchannel plate materials CsI, KBr, KCl, and MgF2, over the 44-1800 A wavelength range. QDEs in excess of 40 percent are achieved by several materials in specific wavelength regions of the EUV. Structure is noted in the wavelength dependence of the QDE that is directly related to the valence-band/conduction-band gap energy and the onset of atomic-like resonant transitions. A simple photocathode model allows interpretation of these features, together with the QDE efficiency variation, as a function of illumination angle.

  2. Optimizing the input and output transmission lines that gate the microchannel plate in a high-speed framing camera

    NASA Astrophysics Data System (ADS)

    Lugten, John B.; Brown, Charles G.; Piston, Kenneth W.; Beeman, Bart V.; Allen, Fred V.; Boyle, Dustin T.; Brown, Christopher G.; Cruz, Jason G.; Kittle, Douglas R.; Lumbard, Alexander A.; Torres, Peter; Hargrove, Dana R.; Benedetti, Laura R.; Bell, Perry M.

    2015-08-01

    We present new designs for the launch and receiver boards used in a high speed x-ray framing camera at the National Ignition Facility. The new launch board uses a Klopfenstein taper to match the 50 ohm input impedance to the ~10 ohm microchannel plate. The new receiver board incorporates design changes resulting in an output monitor pulse shape that more accurately represents the pulse shape at the input and across the microchannel plate; this is valuable for assessing and monitoring the electrical performance of the assembled framing camera head. The launch and receiver boards maximize power coupling to the microchannel plate, minimize cross talk between channels, and minimize reflections. We discuss some of the design tradeoffs we explored, and present modeling results and measured performance. We also present our methods for dealing with the non-ideal behavior of coupling capacitors and terminating resistors. We compare the performance of these new designs to that of some earlier designs.

  3. Urea separation in flat-plate microchannel hemodialyzer; experiment and modeling.

    PubMed

    Tuhy, Alana R; Anderson, Eric K; Jovanovic, Goran N

    2012-06-01

    Two flat-plate microchannel hemodialyzers were constructed consisting of two identical laminae separated by a 20[μm] thick ultrafiltration membrane (Gambro AN69). Each lamina contains a parallel array of microchannels 100[μm] deep, 200[μm] wide, and 5.6[cm] or 9.9[cm] in length respectively. Urea was removed from the aqueous stream containing 1.0[g] urea per liter de-ionized water in the blood side, by countercurrent contact with pure de-ionized water in the dialysate side of the flat-plate hemodialyzer. In all cases volumetric flow rate of water in the dialysate side was equal or less than the volumetric flow rate in the blood side, which is in large contrast to commercial applications of hollow-fiber hemodialyzers where dialysate flow is severalfold larger than blood flow rate. A three-dimensional finite volume mass transport model, built entirely from the first principles with no adjustable parameters, was written in FORTRAN. The results of the mathematical model excellently predict experimental results. The fractional removals of urea predicted by the model are within 2.7%-11% of experimentally obtained values for different blood and dialysate velocities/flow rates in microchannels, and for different transmembrane pressures. The overall mass transfer coefficient was calculated using the urea outlet concentrations obtained at various average velocities (1.0-5.0[cm/s]) in the blood and dialysate, and two nominal transmembrane pressures (∆P(tm) = 0 and 10,000.[Pa]). Overall mass transfer coefficients obtained experimentally ranged from 0.068 to 0.14 [cm/min]. The numerical model predicted an average overall mass transfer coefficient of 0.08 [cm/min]. This value is 60% higher than those found in commercial dialyzers (~0.05[cm/min]). PMID:22374475

  4. Multidimensional time-correlated single photon counting

    NASA Astrophysics Data System (ADS)

    Becker, Wolfgang; Bergmann, Axel

    2006-10-01

    Time-correlated single photon counting (TCSPC) is based on the detection of single photons of a periodic light signal, measurement of the detection time of the photons, and the build-up of the photon distribution versus the time in the signal period. TCSPC achieves a near ideal counting efficiency and transit-time-spread-limited time resolution for a given detector. The drawback of traditional TCSPC is the low count rate, long acquisition time, and the fact that the technique is one-dimensional, i.e. limited to the recording of the pulse shape of light signals. We present an advanced TCSPC technique featuring multi-dimensional photon acquisition and a count rate close to the capability of currently available detectors. The technique is able to acquire photon distributions versus wavelength, spatial coordinates, and the time on the ps scale, and to record fast changes in the fluorescence lifetime and fluorescence intensity of a sample. Biomedical applications of advanced TCSPC techniques are time-domain optical tomography, recording of transient phenomena in biological systems, spectrally resolved fluorescence lifetime imaging, FRET experiments in living cells, and the investigation of dye-protein complexes by fluorescence correlation spectroscopy. We demonstrate the potential of the technique for selected applications.

  5. Enabling photon counting detectors with dynamic attenuators

    NASA Astrophysics Data System (ADS)

    Hsieh, Scott S.; Pelc, Norbert J.

    2014-03-01

    Photon-counting x-ray detectors (PCXDs) are being investigated as a replacement for conventional x-ray detectors because they promise several advantages, including better dose efficiency, higher resolution and spectral imaging. However, many of these advantages disappear when the x-ray flux incident on the detector is too high. We recently proposed a dynamic, piecewise-linear attenuator (or beam shaping filter) that can control the flux incident on the detector. This can restrict the operating range of the PCXD to keep the incident count rate below a given limit. We simulated a system with the piecewise-linear attenuator and a PCXD using raw data generated from forward projected DICOM files. We investigated the classic paralyzable and nonparalyzable PCXD as well as a weighted average of the two, with the weights chosen to mimic an existing PCXD (Taguchi et al, Med Phys 2011). The dynamic attenuator has small synergistic benefits with the nonparalyzable detector and large synergistic benefits with the paralyzable detector. Real PCXDs operate somewhere between these models, and the weighted average model still shows large benefits from the dynamic attenuator. We conclude that dynamic attenuators can reduce the count rate performance necessary for adopting PCXDs.

  6. The LAMBDA photon-counting pixel detector

    NASA Astrophysics Data System (ADS)

    Pennicard, D.; Lange, S.; Smoljanin, S.; Hirsemann, H.; Graafsma, H.; Epple, M.; Zuvic, M.; Lampert, M.-O.; Fritzsch, T.; Rothermund, M.

    2013-03-01

    The Medipix3 photon-counting detector chip has a number of novel features that are attractive for synchrotron experiments, such as a high frame rate with zero dead time and high spatial resolution. DESY are developing a large-area Medipix3-based detector array (LAMBDA). A single LAMBDA module consists of 2 by 6 Medipix3 chips on a ceramic carrier board, bonded to either a single large silicon sensor or two smaller high-Z sensors. The readout system fits behind the carrier board to allow module tiling, and uses a large on-board RAM and multiple 10 Gigabit Ethernet links to permit high-speed readout. Currently, the first large silicon modules have been constructed and read out at low speed, and the firmware for highspeed readout is being developed. In addition to these silicon sensors, we are developing a germanium hybrid pixel detector in collaboration with Canberra for higher-energy beamlines. Canberra have produced a set of 256-by-256-pixel planar germanium sensors with 55μm pitch, and these are currently being bonded to Medipix3 readout chips by Fraunhofer IZM (Berlin).

  7. Calculating and optimizing inter-electrode capacitances of charge division microchannel plate detectors

    NASA Astrophysics Data System (ADS)

    Xing, Yan; Chen, Bo; Zhang, Hong-Ji; Wang, Hai-Feng; He, Ling-Ping; Jin, Fang-Yuan

    2016-04-01

    Based on the principle of charge division microchannel plate detectors, the inter-electrode capacitances of charge division anodes which are related to electronic noise of the charge sensitive amplifier and crosstalk effect of the anode are presented. Under all the requirements of charge division microchannel plate detectors such as the imaging linearity and spatial resolution, decreasing the inter-electrode capacitances is one way to improve the imaging performance. In this paper, we illustrate the simulation process of calculating the inter-electrode capacitances. Moreover, a Wedge and Strip (WSZ) anode is fabricated with the picosecond laser micromachining process. Comparing the simulated capacitances and measured capacitances, the three-dimensional finite element method is proved to be valid. Furthermore, by adjusting the design parameters of the anode, the effects of the substrate permittivity, insulation width and the size of pitch on the inter-electrode capacitances have been analysed. The structure of the charge division anode has been optimized based on the simulation data.

  8. Three-dimensional particle-in-cell simulation on gain saturation effect of microchannel plate

    NASA Astrophysics Data System (ADS)

    Wang, Qiangqiang; Yuan, Zheng; Cao, Zhurong; Deng, Bo; Chen, Tao; Deng, Keli

    2016-07-01

    We present here the results of the simulation work, using the three-dimensional particle-in-cell method, on the performance of the lead glass microchannel plate under saturated state. We calculated the electron cascade process with different DC bias voltages under both self-consistent condition and non-self-consistent condition. The comparative results have demonstrated that the strong self-consistent field can suppress the cascade process and make the microchannel plate saturated. The simulation results were also compared to the experimental data and good agreement was obtained. The simulation results also show that the electron multiplication process in the channel is accompanied by the buildup process of positive charges in the channel wall. Though the interactions among the secondary electron cloud in the channel, the positive charges in the channel wall, and the external acceleration field can make the electron-surface collision more frequent, the collision energy will be inevitably reduced, thus the electron gain will also be reduced.

  9. Three-dimensional particle-in-cell simulation on gain saturation effect of microchannel plate.

    PubMed

    Wang, Qiangqiang; Yuan, Zheng; Cao, Zhurong; Deng, Bo; Chen, Tao; Deng, Keli

    2016-07-01

    We present here the results of the simulation work, using the three-dimensional particle-in-cell method, on the performance of the lead glass microchannel plate under saturated state. We calculated the electron cascade process with different DC bias voltages under both self-consistent condition and non-self-consistent condition. The comparative results have demonstrated that the strong self-consistent field can suppress the cascade process and make the microchannel plate saturated. The simulation results were also compared to the experimental data and good agreement was obtained. The simulation results also show that the electron multiplication process in the channel is accompanied by the buildup process of positive charges in the channel wall. Though the interactions among the secondary electron cloud in the channel, the positive charges in the channel wall, and the external acceleration field can make the electron-surface collision more frequent, the collision energy will be inevitably reduced, thus the electron gain will also be reduced. PMID:27475552

  10. Microchannel Plates for the UVCS and SUMER Instruments on the SOHO Satellite

    NASA Technical Reports Server (NTRS)

    Siegmund, O. H. W.; Gummin, M. A.; Sasseen, T.; Jelinsky, P.; Gaines, G. A.; Hull, J.; Stock, J. M.; Edgar, M.; Welsh, B.; Jelinsky, S.; Vallerga, J.

    1995-01-01

    The microchannel plates for the detectors in the SUMER (Solar Ultraviolet Measurements of Emitted Radiation) and UVCS (Ultraviolet Coronograph Spectrometer) instruments aboard the Solar Orbiting Heliospheric Observatory (SOHO) mission to be launched in late 1995 are described. A low resistance Z stack of microchannel plates (MCP's) is employed in a detector format of 27 mm x 10 mm using a multilayer cross delay line anode (XDL) with 1024 x 360 digitized pixels. The MCP stacks provide gains of greater than 2 x 10(exp 7) with good pulse height distributions (as low as 25% FWHM) under uniform flood illumination. Background rates of approx. 0.6 event cm(exp -2) sec(exp -1) are obtained for this configuration. Local counting rates up to about 800 events/pixel/sec have been achieved with little drop of the MCP gain. MCP preconditioning results are discussed, showing that some MCP stacks fail to have gain decreases when subjected to a high flux UV scrub. Also, although the bare MCP quantum efficiencies are close to those expected (10%), we found that the long wavelength response of KBr photocathodes could be substantially enhanced by the MCP scrubbing process. Flat field images are characterized by a low level of MCP fixed pattern noise and are stable. Preliminary calibration results for the instruments are shown.

  11. An embedded microchannel in a MEMS plate resonator for ultrasensitive mass sensing in liquid.

    PubMed

    Agache, V; Blanco-Gomez, G; Baleras, F; Caillat, P

    2011-08-01

    A mass sensor innovative concept is presented here, based on a hollow plate Micro Electro Mechanical System (MEMS) resonator. This approach consists in running a solution through an embedded microchannel, while the plate resonator is actuated according to a Lamé-mode by electrostatic coupling in dry environment. The experimental results have shown a clear relationship between the measured shift of the resonance frequency and the sample solution density. Additionally, depending on the channel design and the solution properties, the quality factor (Q-factor) was noticed maintaining its level and even substantial improvement in particular cases. Resonators demonstrate resonance frequencies close to 78 MHz and Q-factor of a few thousands for liquid phase detection operating at ambient temperature and atmospheric pressure. Frequency fluctuations study revealed a 13 Hz instability level, equivalent to 1.5 fg in mass. Using a fully electronic readout configuration, a mass responsivity of ca. 850 fg kHz(-1) was monitored. PMID:21660349

  12. High resolution, two-dimensional imaging, microchannel plate detector for use on a sounding rocket experiment

    NASA Technical Reports Server (NTRS)

    Bush, Brett C.; Cotton, Daniel M.; Siegmund, Oswald H.; Chakrabarti, Supriya; Harris, Walter; Clarke, John

    1991-01-01

    We discuss a high resolution microchannel plate (MCP) imaging detector to be used in measurements of Doppler-shifted hydrogen Lyman-alpha line emission from Jupiter and the interplanetary medium. The detector is housed in a vacuum-tight stainless steel cylinder (to provide shielding from magnetic fields) with a MgF2 window. Operating at nominal voltage, the four plate configuration provides a gain of 1.2 x 10 exp 7 electrons per incident photon. The wedge-and-strip anode has two-dimensional imaging capabilities, with a resolution of 40 microns FWHM over a one centimeter diameter area. The detector has a high quantum efficiency while retaining a low background rate. A KBr photocathode is used to enhance the quantum efficiency of the bare MCPs to a value of 35 percent at Lyman-alpha.

  13. Microchannel plate as a novel bipolar electrode for high-performance enrichment of anions.

    PubMed

    Cao, Zhen; Yobas, Levent

    2013-07-01

    Microchannel plate (MCP), a high-porosity glass membrane used as an electron multiplier in analytical/scientific instruments for the detection of energetic photons and charged particles is demonstrated here as a highly effective bipolar electrode (BPE) for electrokinetic focusing of anions. Assembled between a pair of microfluidic channels filled with an electrolyte buffer and subjected to a sufficient bias potential, MCP supports faradaic reactions, owing to its semiconducting characteristics. Thousands of microcapillary tubes fused together define MCP and act in unison such that each microcapillary serves as a tiny BPE surrounding an infinitesimal element of bulk electrolyte with a large surface-area-to-volume ratio and hence performs highly effective as compared to a planar electrode inlaid into a microchannel. This performance has been validated here where concentration enrichment of a fluorescent tracer has been demonstrated at a remarkable rate of up to 175-fold/s exceeding those reported for planar BPEs. We attribute such high performance to the rapid onset of ion-depletion zone and subsequent steep field gradient, signifying the high-porosity structure of MCP as an effective BPE. PMID:24024243

  14. Cascaded systems analysis of photon counting detectors

    SciTech Connect

    Xu, J.; Zbijewski, W.; Gang, G.; Stayman, J. W.; Taguchi, K.; Carrino, J. A.; Lundqvist, M.; Fredenberg, E.; Siewerdsen, J. H.

    2014-10-15

    Purpose: Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low-dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). Methods: A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon-strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1–7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy-integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored. Results: The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f{sub 50} (spatial

  15. Cascaded systems analysis of photon counting detectors

    PubMed Central

    Xu, J.; Zbijewski, W.; Gang, G.; Stayman, J. W.; Taguchi, K.; Lundqvist, M.; Fredenberg, E.; Carrino, J. A.; Siewerdsen, J. H.

    2014-01-01

    Purpose: Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low-dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). Methods: A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon-strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1–7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy-integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored. Results: The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f50 (spatial-frequency at

  16. A microcontroller-based failsafe for single photon counting modules

    NASA Astrophysics Data System (ADS)

    Gordon, Matthew P.; Selvin, Paul R.

    2003-02-01

    Avalanche photodiode-based single photon counting modules (SPCMs) can be damaged by exposure to excessive light levels. A flexible and inexpensive failsafe is presented which has been shown to protect SPCMs from light levels far exceeding the damage threshold.

  17. Multiple-Event, Single-Photon Counting Imaging Sensor

    NASA Technical Reports Server (NTRS)

    Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

    2011-01-01

    The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

  18. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    NASA Astrophysics Data System (ADS)

    Milnes, J. S.; Horsfield, C. J.; Conneely, T. M.; Howorth, J.

    2014-11-01

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  19. Simulating the growth of an charge cloud for a microchannel plate detector

    NASA Astrophysics Data System (ADS)

    Siwal, Davinder; Wiggins, Blake; Desouza, Romualdo

    2015-10-01

    Position sensitive microchannel plate (MCP) detectors have a variety of applications in the fields of astronomy, medical imaging, neutron imaging, and ion beam tracking. Recently, a novel approach has been implemented to detect the position of an incident particle. The charge cloud produced by the MCP induces a signal on a wire harp placed between the MCP and an anode. On qualitative grounds it is clear that in this detector the induced signal shape depends on the size of the electron cloud. A detailed study has therefore been performed to investigate the size of the charge cloud within the MCP and its growth as it propagates from the MCP to the anode. A simple model has been developed to calculate the impact of charge repulsion on the growth of the electron cloud. Both the details of the model and its predictions will be presented. Supported by the US DOE NNSA under Award No. DE-NA0002012.

  20. Using pulse shape analysis to improve the position resolution of a resistive anode microchannel plate detector

    NASA Astrophysics Data System (ADS)

    Siwal, Davinder; Wiggins, B. B.; deSouza, R. T.

    2015-12-01

    Digital signal processing techniques were employed to investigate the joint use of charge division and risetime analyses for the resistive anode (RA) coupled to a microchannel plate detector (MCP). In contrast to the typical approach of using the relative charge at each corner of the RA, this joint approach results in a significantly improved position resolution. A conventional charge division analysis utilizing analog signal processing provides a measured position resolution of 170 μm (FWHM). By using the correlation between risetime and position we were able to obtain a measured resolution of 92 μm (FWHM), corresponding to an intrinsic resolution of 64 μm (FWHM) for a single Z-stack MCP detector.

  1. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    SciTech Connect

    Milnes, J. S. Conneely, T. M.; Howorth, J.; Horsfield, C. J.

    2014-11-15

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  2. The effect of gain variation in micro-channel plates on gamma-ray energy resolution

    PubMed Central

    Han, Ling; Barrett, Harrison H.; Barber, H. Bradford; Furenlid, Lars R.

    2015-01-01

    A Monte Carlo simulation of micro-channel plate (MCP) with particular interest in its effect on energy resolution performance is presented. Important physical processes occurring in MCP channels are described and modeled, including secondary electron (SE) yield, SE emission, and primary electron reflection. The effects causing channel saturation are also introduced. A two dimensional Monte Carlo simulation is implemented under the assumption of unsaturated channel. Simulation results about basic MCP performances and especially gain and energy resolution performances are presented and analyzed. It’s found that energy resolution as an intrinsic property of MCP cannot be improved simply by adjusting system parameters; however it can be improved by increasing input signal or number of photoelectrons (PEs) in the context of image intensifier. An initial experiment with BazookaSPECT detector and CsI(Tl) scintillator is performed to validate and correlate with the simulation results and good agreement is achieved. PMID:26339114

  3. Two-dimensional ultraviolet imagery with a microchannel-plate/resistive-anode detector

    NASA Technical Reports Server (NTRS)

    Opal, C. B.; Feldman, P. D.; Weaver, H. A.; Mcclintock, J. A.

    1979-01-01

    An imaging ultraviolet detector has been designed for use with a precision pointed telescope flown on a sounding rocket. Resolution of better than 80 microns over a field of 5 mm has been achieved. The ultraviolet image is converted to electrons at the front surface of a CsI coated chevron microchannel-plate electron multiplier. For each photoelectron, the multiplier produces a burst of about 3,000,000 electrons, which impinges on a tellurium-coated resistive anode with four evaporated hyperbolic readout electrodes. The sizes of the four resulting output pulses are digitized to 10 bit accuracy and telemetered to the ground, where they are divided in pairs to give the x and y coordinates of the photoelectron event. The coordinates are used to generate a picture in real time, and are recorded for computer processing later. The detector was successfully flown in December 1978. Good images of Jupiter and Capella in hydrogen Lyman alpha emission were obtained.

  4. Multiple-photon disambiguation on stripline-anode Micro-Channel Plates

    NASA Astrophysics Data System (ADS)

    Jocher, Glenn R.; Wetstein, Matthew J.; Adams, Bernhard; Nishimura, Kurtis; Usman, Shawn M.

    2016-06-01

    Large-Area Picosecond Photo-Detectors (LAPPDs) show great potential for expanding the performance envelope of Micro-Channel Plates (MCPs) to areas of up to 20×20 cm and larger. Such scaling introduces new challenges, including how to meet the electronics readout burden of ever larger area MCPs. One solution is to replace the traditional grid anode used for readout with a microwave stripline anode, thus allowing the channel count to scale with MCP width rather than area. However, stripline anodes introduce new issues not commonly dealt with in grid-anodes, especially as their length increases. One of these issues is the near simultaneous arrival of multiple photons on the detector, creating possible confusion about how to reconstruct their arrival times and positions. We propose a maximum a posteriori solution to the problem and verify its performance in simulated scintillator and water-Cherenkov detectors.

  5. Super capacitance properties of SnO2 coated nickel/silicon microchannel plates

    NASA Astrophysics Data System (ADS)

    Hui, Keshuang; Zhu, Yiping; Xu, Shaohui; Wang, Lianwei; Chu, Paul K.

    2013-12-01

    Supercapacitor is achieved by combining tin oxide with three dimensional silicon microchannel plates (Si-MCPs) deposited with nickel film. Electro deposition is applied to deposit the tin oxide on the Ni/Si-MCPs structure followed by sintering at 450°C. The structure and morphology of the samples are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties are investigated in 1 M Na2SO4 solution by cyclic voltammetry, galvanostatic charging-discharging, and electrochemical impedance spectroscopy. The highest specific capacitance of 0.814 F/cm2 (171.37 F/g) is achieved from the sample deposited for 2 h followed by sintering for 2 h.

  6. Operation of a microchannel plate counting system in a mass spectrometer

    NASA Technical Reports Server (NTRS)

    Murphy, D. M.; Mauersberger, K.

    1985-01-01

    A multiplier detector system has been developed as part of a mass spectrometer in an ion counting mode. During its operation ions striking a microchannel plate release pulses of electrons which are accelerated to a phosphor layer. The resulting flash of light is carried by a fiber-optic bundle to a photodiode array. The detector simultaneously counts ions throughout a mass spectrum covering more than 30 amu. It extends the mass spectrometer's operation toward low count rates for trace gas analysis. Each mass peak can be independently measured at count rates between 0.1 and 1000 counts/s. Higher rates on a few peaks do not blind the entire detector. The detector's capabilities have been demonstrated by measuring Kr and Xe isotopes in air at natural abundances. The mass spectrometer, detector, and readout electronics are sufficiently compact to permit use in a balloon-borne experiment.

  7. A fast microchannel plate-scintillator detector for velocity map imaging and imaging mass spectrometry

    SciTech Connect

    Winter, B.; King, S. J.; Vallance, C.; Brouard, M.

    2014-02-15

    The time resolution achievable using standard position-sensitive ion detectors, consisting of a chevron pair of microchannel plates coupled to a phosphor screen, is primarily limited by the emission lifetime of the phosphor, around 70 ns for the most commonly used P47 phosphor. We demonstrate that poly-para-phenylene laser dyes may be employed extremely effectively as scintillators, exhibiting higher brightness and much shorter decay lifetimes than P47. We provide an extensive characterisation of the properties of such scintillators, with a particular emphasis on applications in velocity-map imaging and microscope-mode imaging mass spectrometry. The most promising of the new scintillators exhibits an electron-to-photon conversion efficiency double that of P47, with an emission lifetime an order of magnitude shorter. The new scintillator screens are vacuum stable and show no signs of signal degradation even over longer periods of operation.

  8. An Application of Micro-channel Plate Photomultiplier Tube to Positron Emission Tomography.

    PubMed

    Kim, H; Chen, C-T; Frisch, H; Tang, F; Kao, C-M

    2012-01-01

    We are developing a Time-of-Flight Positron Emission Tomography detector using flat panel micro-channel plate photomultiplier tubes (MCP PMT). The high-speed waveform sampling data acquisition is adopted to exploit the fast time response of MCP PMT efficiently by using transmission-line readout scheme. To demonstrate the feasibility of the proposed detector, prototype detector modules were built using Photonis XP85022 MCP PMT, transmission-line board (TL), and high-speed waveform sampling electronics equipped with DRS4 chips. The MCP/TL module was coupled to single LYSO crystal, and experimental tests have been conducted in a coincidence setup to measure the responses to 511 keV annihilation photon. The details of the prototype module, experimental setup, and the preliminary results are presented and discussed. PMID:23227135

  9. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics.

    PubMed

    Milnes, J S; Horsfield, C J; Conneely, T M; Howorth, J

    2014-11-01

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year. PMID:25430347

  10. Nanosecond Gating of Microstripline Microchannel Plate Framing Cameras: Characterization and Simulation

    SciTech Connect

    Holder, J; Hargrove, D; Sibernagel, C; Perry, T; Bradley, D; Bell, P

    2004-04-09

    The soft x-ray microstripline microchannel plate (MCP) framing camera has become one of the workhorses of ICF diagnostics. Much progress has been made in making these diagnostics work well with gate times of 100 ps and below. Often weak input signal or source timing uncertainties dictate a requirement for longer gate times, preferably in the same instrument that also has fast gating capability. The large power-law dependence of MCP gain on applied voltage is useful in shortening the gating time of the microstripline camera. However, this sensitivity leads to tight constraints on the shape of the long duration electrical pulses that are needed to drive the MCP to produce experimentally desirable optical gating profiles. Simple modeling and measurements are used to better understand the character of the voltage pulses needed to achieve optical gate widths between 500 ps and {approx}2 ns.

  11. Ultraviolet quantum detection efficiency of potassium bromide as an opaque photocathode applied to microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, Oswald H. W.; Everman, E.; Vallerga, J. V.; Sokolowski, J.; Lampton, M.

    1987-01-01

    The quantum detection efficiency (QDE) of potassium bromide as a photocathode applied directly to the surface of a microchannel plate over the 250-1600 A wavelength range has been measured. The contributions of the photocathode material in the channels and on the interchannel web to the QDE have been determined. Two broad peaks in the QDE centered at about 450 and about 1050 A are apparent, the former with about 50 percent peak QDE and the latter with about 40 percent peak QDE. The photoelectric threshold is observed at about 1600 A, and there is a narrow QDE minimum at about 750 A which correlates with 2X the band gap energy for KBr. The angular variation of the QDE from 0 to 40 deg to the channnel axis has also been examined. The stability of Kbr with time is shown to be good with no significant degradation of QDE at wavelengths below 1216 A over a 15-day period in air.

  12. An Application of Micro-channel Plate Photomultiplier Tube to Positron Emission Tomography

    PubMed Central

    Kim, H.; Chen, C.-T.; Frisch, H.; Tang, F.; Kao, C.-M.

    2012-01-01

    We are developing a Time-of-Flight Positron Emission Tomography detector using flat panel micro-channel plate photomultiplier tubes (MCP PMT). The high-speed waveform sampling data acquisition is adopted to exploit the fast time response of MCP PMT efficiently by using transmission-line readout scheme. To demonstrate the feasibility of the proposed detector, prototype detector modules were built using Photonis XP85022 MCP PMT, transmission-line board (TL), and high-speed waveform sampling electronics equipped with DRS4 chips. The MCP/TL module was coupled to single LYSO crystal, and experimental tests have been conducted in a coincidence setup to measure the responses to 511 keV annihilation photon. The details of the prototype module, experimental setup, and the preliminary results are presented and discussed. PMID:23227135

  13. Physical Vapor Deposition Chamber for Coating Microchannel Plates in X-Ray Radiography

    NASA Astrophysics Data System (ADS)

    Perry, S. L.; Drake, R. P.; Swain, A. D.; Cornwall, N. C.; Forsyth, M. A.; Harding, E. C.; Huntington, C. M.

    2010-11-01

    Experiments to characterize microchannel plates (MCPs) at the University of Michigan aim to maximize the quantum efficiency of our detector by coating the layers of a photocathode directly on a bare MCP. These experiments can be improved with more control over the processing of coating MCPs, parts often used in diagnosing high-energy-density laser experiments. Process control will allow us to alter factors that influence photocathode quantum efficiency, such as film thickness, coating angle, and substrate baking. This should ultimately reduce costs of characterizing MCPs and improve our x-ray radiography data. A thin film deposition chamber was designed and built, achieving high vacuum pressures of 1E-7 torr and temperatures of 1800 C to vaporize coating materials. A rotating substrate platform and a quartz crystal microbalance help achieve precise, even coatings. A design overview of this system is presented, with a discussion of most recent coating results.

  14. Observation of Ultra-Slow Antiprotons using Micro-channel Plate

    SciTech Connect

    Imao, H.; Toyoda, H.; Shimoyama, T.; Kanai, Y.; Mohri, A.; Yamazaki, Y.; Torii, H. A.; Nagata, Y.; Enomoto, Y.; Higaki, H.

    2008-08-08

    Our group ASACUSA-MUSASHI has succeeded in accumulating several million antiprotons and extracting them as monochromatic ultra-slow antiproton beams (10 eV-1 keV) at CERN AD. We have observed ultra-slow antiprotons using micro-channel plates (MCP). The integrated pulse area of the output signals generated when the MCP was irradiated by ultra-slow antiprotons was 6 times higher than that by electrons. As a long-term effect, we also observed an increase in the background rate presumably due to the radioactivation of the MCP surface. Irradiating the antiproton beams on the MCP induces antiproton-nuclear annihilations only on the first layer of the surface. Low-energy and short-range secondary particles like charged nuclear fragments caused by the 'surface nuclear reactions' would be the origin of our observed phenomena.

  15. Response of microchannel plates to single particles and to electromagnetic showers

    NASA Astrophysics Data System (ADS)

    Brianza, L.; Cavallari, F.; Del Re, D.; Gelli, S.; Ghezzi, A.; Gotti, C.; Govoni, P.; Jorda Lopez, C.; Martelli, A.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Pernié, L.; Pigazzini, S.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Tabarelli de Fatis, T.; Trevisani, N.

    2015-10-01

    We report on the response of microchannel plates (MCPs) to single relativistic particles and to electromagnetic showers. Particle detection by means of secondary emission of electrons at the MCP surface has long been proposed and is used extensively in ion time-of-flight mass spectrometers. What has not been investigated in depth is their use to detect the ionizing component of showers. The time resolution of MCPs exceeds anything that has been previously used in calorimeters and, if exploited effectively, could aid in the event reconstruction at high luminosity colliders. Several prototypes of photodetectors with the amplification stage based on MCPs were exposed to cosmic rays and to 491 MeV electrons at the INFN-LNF Beam-Test Facility. The time resolution and the efficiency of the MCPs are measured as a function of the particle multiplicity, and the results used to model the response to high-energy showers.

  16. Further investigation of CsI-coated microchannel plate quantum efficiencies

    NASA Technical Reports Server (NTRS)

    Carruthers, George R.

    1988-01-01

    Previously, pulse-counting detection efficiencies measured for CsI-coated microchannel plate (MCP) detectors (two-stage chevron configuration with a single collecting anode) have been reported to be 15-20 percent near Lyman-alpha (1216 A), compared to typical 65 percent quantum yields of opaque CsI photocathodes. To investigate the possibility that an improvement in quantum yield could result from use of MCPs with a bias angle of about 25 deg instead of 8 deg as used previously, the previous measurements were reported with new MCPs having the larger bias angle. No significant improvement in detection efficiency was achieved; the new detector tests still yielded maximum efficiencies of the order of 20 percent near 1216 A.

  17. Direct tests of a pixelated microchannel plate as the active element of a shower maximum detector

    DOE PAGESBeta

    Apresyan, A.; Los, S.; Pena, C.; Presutti, F.; Ronzhin, A.; Spiropulu, M.; Xie, S.

    2016-05-07

    One possibility to make a fast and radiation resistant shower maximum detector is to use a secondary emitter as an active element. We report our studies of microchannel plate photomultipliers (MCPs) as the active element of a shower-maximum detector. We present test beam results obtained using Photonis XP85011 to detect secondary particles of an electromagnetic shower. We focus on the use of the multiple pixels on the Photonis MCP in order to find a transverse two-dimensional shower distribution. A spatial resolution of 0.8 mm was obtained with an 8 GeV electron beam. As a result, a method for measuring themore » arrival time resolution for electromagnetic showers is presented, and we show that time resolution better than 40 ps can be achieved.« less

  18. Direct tests of a pixelated microchannel plate as the active element of a shower maximum detector

    NASA Astrophysics Data System (ADS)

    Apresyan, A.; Los, S.; Pena, C.; Presutti, F.; Ronzhin, A.; Spiropulu, M.; Xie, S.

    2016-08-01

    One possibility to make a fast and radiation resistant shower maximum detector is to use a secondary emitter as an active element. We report our studies of microchannel plate photomultipliers (MCPs) as the active element of a shower-maximum detector. We present test beam results obtained using Photonis XP85011 to detect secondary particles of an electromagnetic shower. We focus on the use of the multiple pixels on the Photonis MCP in order to find a transverse two-dimensional shower distribution. A spatial resolution of 0.8 mm was obtained with an 8 GeV electron beam. A method for measuring the arrival time resolution for electromagnetic showers is presented, and we show that time resolution better than 40 ps can be achieved.

  19. Performance characteristics of a curved-channel microchannel plate with a curved input face and a plane output face

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Morgan, Jeffrey S.; Timothy, J. Gethyn

    1989-01-01

    The presently performance-evaluated format, in which a high-gain curved-channel microchannel plate (M2MCP) has a spherical concave input face and a plane output face, allows the input face of the MCP (1) to match such curved focal surfaces as that of a Rowland-circle spectrometer mounting, while (2) having a high-resolution plane readout array in proximity focus with the output face. This MCP has been evaluated in a discrete-anode multicathode microchannel array detector system. The saturated modal gain was found to be inversely proportional to the length/diameter ratio of the channels and directly proportional to the applied MCP voltage.

  20. Influence and analysis on ion barrier film to the noise factor of micro-channel plate

    NASA Astrophysics Data System (ADS)

    Zhu, Yu-feng; Zhang, Fan; Zhang, Ni; Nie, Jing; Li, Dan; Zhang, Tai-min; Wang, Shu-fei; Liu, Xiao-jian; Liu, Zhao-lu

    2015-03-01

    The noise factor, which is the main factor affecting the noise performance of image intensifier and can accurately reflect the noise characteristics of the micro-channel plate(MCP), is the ratio of the input signal to noise ratio (SNR) and the output SNR. According to definition of noise factor of micro channel plate, noise mechanism and test principle, noise factor of filmed MCP test system is established in order to study the technical way to reduce noise factor of MCP. Because the input surface of the MCP is covered with ion barrier film to block the feedback ions, which have a great impact on the noise factor of the MCP. Hence, noise factor of filmed MCP and un-filmed MCP is measured respectively, and noise factors with different materials and different filmed thickness are measured too. Relationships between noise factor and filmed thickness, noise factor and output SNR of image intensifier have been obtained. That is valuable to reduce the noise of filmed MCP.

  1. Advanced Photon Counting Imaging Detectors with 100ps Timing for Astronomical and Space Sensing Applications

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; Vallerga, J.; Welsh, B.; Rabin, M.; Bloch, J.

    In recent years EAG has implemented a variety of high-resolution, large format, photon-counting MCP detectors in space instrumentation for satellite FUSE, GALEX, IMAGE, SOHO, HST-COS, rocket, and shuttle payloads. Our scheme of choice has been delay line readouts encoding photon event position centroids, by determination of the difference in arrival time of the event charge at the two ends of a distributed resistive-capacitive (RC) delay line. Our most commonly used delay line configuration is the cross delay line (XDL). In its simplest form the delay-line encoding electronics consists of a fast amplifier for each end of the delay line, followed by time-to-digital converters (TDC's). We have achieved resolutions of < 25 μm in tests over 65 mm x 65 mm (3k x3k resolution elements) with excellent linearity. Using high speed TDC's, we have been able to encode event positions for random photon rates of ~1 MHz, while time tagging events using the MCP output signal to better than 100 ps. The unique ability to record photon X,Y,T high fidelity information has advantages over "frame driven" recording devices for some important applications. For example we have built open face and sealed tube cross delay line detectors used for biological fluorescence lifetime imaging, observation of flare stars, orbital satellites and space debris with the GALEX satellite, and time resolved imaging of the Crab Pulsar with a telescope as small as 1m. Although microchannel plate delay line detectors meet many of the imaging and timing demands of various applications, they have limitations. The relatively high gain (107) reduces lifetime and local counting rate, and the fixed delay (10's of ns) makes multiple simultaneous event recording problematic. To overcome these limitations we have begun development of cross strip readout anodes for microchannel plate detectors. The cross strip (XS) anode is a coarse (~0.5 mm) multi-layer metal and ceramic pattern of crossed fingers on an alumina

  2. Synthesis of Rh/Macro-Porous Alumina Over Micro-Channel Plate and Its Catalytic Activity Tests for Diesel Reforming.

    PubMed

    Seong, Yeon Baek; Kim, Yong Sul; Park, No-Kuk; Lee, Tae Jin

    2015-11-01

    Macro-porous Al2O3 as the catalytic support material was synthesized using colloidal polystyrene spheres over a micro-channel plate. The colloidal polystyrene spheres were used as a template for the production of an ordered macro porous material using an alumina nitrate solution as the precursor for Al2O3. The close-packed colloidal crystal array template method was applied to the formulation of ordered macro-porous Al2O3 used as a catalytic support material over a micro-channel plate. The solvent in the mixture solution, which also contained the colloidal polystyrene solution, aluminum nitrate solution and the precursor of the catalytic active materials (Rh), was evaporated in a vacuum oven at 50 degrees C. The ordered polystyrene spheres and aluminum salt of the solid state were deposited over a micro channel plate, and macro-porous Al2O3 was formed after calcination at 600 degrees C to remove the polystyrene spheres. The catalytic activity of the Rh/macro-porous alumina supported over the micro-channel plate was tested for diesel reforming. PMID:26726602

  3. Response of Microchannel Plate (MCP) Detectors to MeV Electrons: Beamline tests in support of Juno, JUICE, and Europa Mission UVS instrument investigations

    NASA Astrophysics Data System (ADS)

    Retherford, Kurt D.; Davis, Michael W.; Greathouse, Thomas K.; Gladstone, G. Randall; Steffl, Andrew J.; Grodent, Denis; Siegmund, Oswald H.W.

    2014-11-01

    The response of Microchannel Plate (MCP) detectors to far-UV photons is excellent. MCPs provide a photon-counting capability that is especially useful for high-quality stellar and solar occultation measurements. However, use of MCPs within the Jovian magnetosphere for UV measurements is hampered by their ~30% detection efficiency to energetic electrons and ~1% efficiency to γ-rays. High-Z shielding stops energetic electrons, but creates numerous secondary particles; γ-rays are the most important of these for MCPs. These detected particles are a noise background to the measured far-UV photon signal, and at particularly intense times their combination can approach detector global count rates of ~500 kHz when operating at nominal HV levels. To address the challenges presented by the intense radiation environment experienced during Europa encounters we performed electron beam radiation testing of the Juno-UVS flight spare cross-delay line (XDL) MCP in June 2012 at MIT’s High Voltage Research Laboratory (HVRL), and again in Nov. 2013 adding an atomic-layer deposition (ALD) coated test-MCP, to measure the detection efficiency and pulse height distribution characteristics for energetic electrons and γ-rays. A key result from this UVS-dedicated SwRI IR&D project is a detailed characterization of our XDL’s response to both particles (electrons and γ-rays) and photons as a function of HV level. These results provide confidence that good science data quality is achievable when operating at Europa closest approach and/or in orbit. Comparisons with in-flight data obtained with New Horizons Pluto-Alice MeV electron response measurements at Jupiter (Steffl et al., JGR, 2012), LRO-LAMP electron and proton event data, and Juno-UVS Earth proton-belt flyby data, and recent bench tests with radioactive sources at Sensor Sciences increase this confidence. We present a description of the test setup, quantitative results, and several lessons learned to help inform future beamline

  4. Advantages of Photon Counting Detectors for Terahertz Astronomy

    NASA Astrophysics Data System (ADS)

    Matsuo, Hiroshi; Ezawa, Hajime

    2016-08-01

    For astronomical observation at terahertz frequencies, a variety of cryogenic detector technologies are being developed to achieve background-limited observation from space, where a noise equivalent power (NEP) of less than 10^{-18} W/Hz^{0.5} is often required. When each photon signal is resolved in time, the requirements on NEP are reduced and 1 ns time resolution corresponds to an NEP of approximately 10^{-17} W/Hz^{0.5} at THz frequencies. Furthermore, fast photon counting detectors have a high dynamic range to observe bright terahertz sources such as stars and active galactic nuclei. Applications of photon counting detector are discussed for cosmic microwave background and photon counting terahertz interferometry.

  5. Photon counting detector array algorithms for deep space optical communications

    NASA Astrophysics Data System (ADS)

    Srinivasan, Meera; Andrews, Kenneth S.; Farr, William H.; Wong, Andre

    2016-03-01

    For deep-space optical communications systems utilizing an uplink optical beacon, a single-photon-counting detector array on the flight terminal can be used to simultaneously perform uplink tracking and communications as well as accurate downlink pointing at photon-starved (pW=m2) power levels. In this paper, we discuss concepts and algorithms for uplink signal acquisition, tracking, and parameter estimation using a photon-counting camera. Statistical models of detector output data and signal processing algorithms are presented, incorporating realistic effects such as Earth background and detector/readout blocking. Analysis and simulation results are validated against measured laboratory data using state-of-the-art commercial photon-counting detector arrays, demonstrating sub-microradian tracking errors under channel conditions representative of deep space optical links.

  6. Development of the micro-channel plate photomultiplier for the Belle II time-of-propagation counter

    NASA Astrophysics Data System (ADS)

    Hirose, Shigeki; Iijima, Toru; Inami, Kenji; Furumura, Daiki; Hayakawa, Tomokatsu; Kato, Yuji; Matsuoka, Kodai; Mizuno, Ryo; Sato, Yutaro; Suzuki, Kazuhito; Yonekura, Takuya

    2015-07-01

    The time-of-propagation counter for the Belle II experiment is a new particle identification device using ring imaging Cherenkov technique. In order to detect each Cherenkov photon with a timing precision of 30-40 ps in a 1.5 T magnetic field, a micro-channel plate photomultiplier tube is a suitable device for the TOP counter. By introducing an atomic layer deposition technique on the micro-channel plate surface, the tube lifetime was improved by a factor of 3-10 relative to more conventional devices. A total of 530 tubes have been produced. To ensure appropriate tube performance, the quantum efficiency, gain and transit time spread have been measured for all units. The results from each measurement are discussed. Results from a beamtest with a 2 GeV/c positron beam are also reported and demonstrate the good tube performance.

  7. Negative Avalanche Feedback Detectors for Photon-Counting Optical Communications

    NASA Technical Reports Server (NTRS)

    Farr, William H.

    2009-01-01

    Negative Avalanche Feedback photon counting detectors with near-infrared spectral sensitivity offer an alternative to conventional Geiger mode avalanche photodiode or phototube detectors for free space communications links at 1 and 1.55 microns. These devices demonstrate linear mode photon counting without requiring any external reset circuitry and may even be operated at room temperature. We have now characterized the detection efficiency, dark count rate, after-pulsing, and single photon jitter for three variants of this new detector class, as well as operated these uniquely simple to use devices in actual photon starved free space optical communications links.

  8. Photon counting modules using RCA silicon avalanche photodiodes

    NASA Technical Reports Server (NTRS)

    Lightstone, Alexander W.; Macgregor, Andrew D.; Macsween, Darlene E.; Mcintyre, Robert J.; Trottier, Claude; Webb, Paul P.

    1989-01-01

    Avalanche photodiodes (APD) are excellent small area, solid state detectors for photon counting. Performance possibilities include: photon detection efficiency in excess of 50 percent; wavelength response from 400 to 1000 nm; count rate to 10 (exp 7) counts per sec; afterpulsing at negligible levels; timing resolution better than 1 ns. Unfortunately, these performance levels are not simultaneously available in a single detector amplifier configuration. By considering theoretical performance predictions and previous and new measurements of APD performance, the anticipated performance of a range of proposed APD-based photon counting modules is derived.

  9. Quantum efficiencies of imaging detectors with alkali halide photocathodes. I - Microchannel plates with separate and integral CsI photocathodes

    NASA Technical Reports Server (NTRS)

    Carruthers, George R.

    1987-01-01

    Measurements and comparisons have been made of the quantum efficiencies of microchannel plate (MCP) detectors in the far-UV (below 2000-A) wavelength range using CsI photocathodes (a) deposited on the front surfaces of microchannel plates and (b) deposited on solid substrates as opaque photocathodes with the resulting photoelectrons input to microchannel plates. The efficiences were measured in both pulse-counting and photodiode modes of operation. Typical efficiencies are about 15 percent at 1216 A for a CsI-coated MCP compared with 65 percent for an opaque CsI photocathode MCP detector. Special processing has yielded an efficiency as high as 20 percent for a CsI-coated MCP. This may possibly be further improved by optimization of the tilt angle of the MCP channels relative to the front face of the MCP and incident radiation. However, at present there still remains a factor of at least 3 quantum efficiency advantage in the separate opaque CsI photocathode configuration.

  10. Applicability of micro-channel plate followed by phosphor screen to charged particles

    NASA Astrophysics Data System (ADS)

    Himura, H.; Nakata, S.; Sanpei, A.

    2016-06-01

    This paper experimentally investigates the applicability of a micro-channel plate (MCP) followed by a phosphor screen to charged particles along with a calibration method for estimating the acceptable limit of input particle flux and appropriate operation parameters of a particular MCP. For the first time, plasmas consisting of only lithium ions are injected into the MCP. Despite large ion numbers (Ni) on the order of ≃107, no deterioration in the effective gain (αG) of the MCP owing to an excess amount of the extracted charge occurs in a certain range of the amplifier voltage (ΔUM) applied to the MCP. The measured αG nearly agrees with the expected value. However, once ΔUM exceeds a limit value, αG eventually begins to saturate. This is also verified in experiments using pure electron plasmas. An appropriate range of ΔUM is presented to avoid saturation and, finally, derive Ni directly from the secondary electron current outputted from the MCP only after the indispensable calibration.

  11. Development of output signal-to-noise ratio tester for microchannel plate and fluorescent screen component

    NASA Astrophysics Data System (ADS)

    Wu, Xinglin; Qiu, Yafeng; Zhou, Jin; Qian, Yunsheng

    The core components of Image intensifier is microchannel plate (MCP) and fluorescent screen component. The present paper deeply studies output signal-to-noise ratio (SNR) characteristics of MCP and fluorescent screen component. A tester system using to the evaluation of characteristics of the output SNR of MCP and fluorescent screen component, consists of a vacuum system, a surface electron source, mechanical mechanism components ,a high-voltage power supply system, a signal processing system, communication interfaces, a data acquisition and control system, computer system, and testing software. a hot cathode used as an electron source, generates a surface electron flow to provide the input signal. A photomultiplier tube is used to detection faceplate output brightness of the light spot. Then, the output SNR of MCP and fluorescent screen component is processed with a combination of methods of the hardware filter and digital filtering software. The output SNR of MCP and fluorescent screen component is measured under different conditions, and the results are analyzed. This test system Provide a technical to promote the image intensifier research, and experience to testing other parameters or in other areas of research.

  12. Cross strip microchannel plate imaging photon counters with high time resolution

    SciTech Connect

    Stonehill, Laura C; Shirey, Robert; Rabin, Michael W; Thompson, David C; Siegmund, Oswald H W; Vallerga, John V; Tremsin, Anton S

    2010-01-01

    We have implemented cross strip readout microchannel plate detectors in 18 mm active area format including open face (UV/particle) and sealed tube (optical) configurations. These have been tested with a field programmable gate array based parallel channel electronics for event encoding which can process high input event rates (> 5 MHz) with high spatial resolution. Using small pore MCPs (6 {micro}m) operated in a pair, we achieve gains of >5 x 10{sup 5} which is sufficient to provide spatial resolution of <35 {micro}m FHWM, with self triggered event timing accuracy of {approx}2 ns for sealed tube optical sensors. A peak quantum efficiency of {approx}19% at 500 nm has been achieved with SuperGenII photocathodes that have response over the 400 nm to 900 nm range. Local area counting rates of up to >200 events/mcp pore sec{sup -1} have been attained, along with image linearity and stability to better than 50 {micro}m.

  13. Development of the microchannel plate detector for FUV spectroscopy in the BepiColombo mission

    NASA Astrophysics Data System (ADS)

    Murakami, Go; Yoshioka, Kazuo; Sakai, Kouichi; Honma, Tatsuro; Yoshikawa, Ichiro; Maria, Jean-Luc; Quemerais, E.

    PHEBUS (Probing of Hermean Exosphere By Ultraviolet Spectroscopy) is a double ultraviolet spectrometer for the MPO spacecraft of the BepiColombo mission, which is dedicated to the study of the Mercury. The purpose of this instrument is to reveal the composition and the distribution of the Mercury's exosphere by detecting emission lines in the wavelength range from 55 to 315 nm. The instrument is basically composed of two ultraviolet spectrometers and one scanning mirror with a single axis of rotation. Each detector has a specific range of wavelengths: the Extreme Ultraviolet (EUV) channel from 55 to 155 nm, and the Far Ultraviolet (FUV) channel from 145 to 315 nm. The FUV detector consists of a MgF2 input window, a Cs2 Te photocathode, microchannel plates (MCPs), and a resistive anode encoder (RAE). We have manufactured and tested the optical prototype of the FUV detector. In a position-sensitive system with an RAE, the spatial resolution depends on the bias voltage applied to each part of the detector. We optimized the bias voltage and achieved a high spatial resolution of 45 m, corresponding to 480480 pixels. In addition, the long-term aging of the detector against incidence of photon flux was tested. Based on the result of our laboratory measurement, both gain and quantum efficiency of the MCPs will decrease by about 40% during the BepiColombo mission. In our presentation we report the specific performance of the optical prototype of the FUV detector.

  14. Optimization of high count rate event counting detector with Microchannel Plates and quad Timepix readout

    NASA Astrophysics Data System (ADS)

    Tremsin, A. S.; Vallerga, J. V.; McPhate, J. B.; Siegmund, O. H. W.

    2015-07-01

    Many high resolution event counting devices process one event at a time and cannot register simultaneous events. In this article a frame-based readout event counting detector consisting of a pair of Microchannel Plates and a quad Timepix readout is described. More than 104 simultaneous events can be detected with a spatial resolution of ~55 μm, while >103 simultaneous events can be detected with <10 μm spatial resolution when event centroiding is implemented. The fast readout electronics is capable of processing >1200 frames/sec, while the global count rate of the detector can exceed 5×108 particles/s when no timing information on every particle is required. For the first generation Timepix readout, the timing resolution is limited by the Timepix clock to 10-20 ns. Optimization of the MCP gain, rear field voltage and Timepix threshold levels are crucial for the device performance and that is the main subject of this article. These devices can be very attractive for applications where the photon/electron/ion/neutron counting with high spatial and temporal resolution is required, such as energy resolved neutron imaging, Time of Flight experiments in lidar applications, experiments on photoelectron spectroscopy and many others.

  15. Research of ion feedback-induced noise of micro-channel plate

    NASA Astrophysics Data System (ADS)

    Li, Dan; Zhu, Yufeng; Zhang, Ni; Nie, Jing; Zhang, Fan; Zhang, Taimin; Li, Shilong; Liu, Xiaojian; Liu, Zhaolu

    2014-09-01

    Rb+, Cs+ and other alkali metal ions in the Micro-channel Plate (MCP) channel, under the action of an electric field, leave out of the channel wall of MCP, and accelerate to input surface of channel along the opposite direction of the electric field to form ion feedback-induced noise. The feedback ions will cause great harms, it will bombard the cathode surface, resulting in decreased cathode sensitivity, reducing tube life, so you must take measures to reduce ion feedback-induced noise. This paper analyzes how to reduce ion feedback-induced noise from five aspects of the MCP materials, etching, annealing in hydrogen, high-temperature baking and electron scrubbing. Through the utilization of mixed alkali effect of suppressing mutual diffusion and decreasing internal network cavity to improve structure of MCP glass wall, the diffusion coefficient of each ion is reduced; the content of Al2O3 is reduced to reduce the Na+, K+ diffusion losses; etching process is optimized, except for the acid corrosion, the alkali corrosion, special acid etching and vacuum baking process are used; annealing in hydrogen technology is also optimized, the time of annealing in hydrogen was chosen on 270 ~ 350 minutes; and the vacuum baking and electron scrubbing are handled before manufacturing. By the above methods the ion feedback-induced noise is reduced.

  16. Microchannel Plate Imaging Photon Counters for Ultraviolet through NIR Detection with High Time Resolution

    PubMed Central

    Siegmund, Oswald H.W.; Vallerga, John V.; Tremsin, Anton S.; McPhate, Jason; Michalet, X.; Colyer, R. A.; Weiss, S.

    2013-01-01

    Cross strip and cross delay line readout microchannel plate detectors in 18 mm, 25 mm and 40 mm active area formats including open face (UV/particle) and sealed tube (optical) configurations have been constructed. These have been tested with a field programmable gate array based electronics for single event encoding. Using small pore MCPs (6 μm) operated in a pair, we achieve gains of >1 × 106 which is sufficient to provide spatial resolution of ~17 μm FHWM with the 18 mm and 40 mm cross strip readouts. New cross strip electronics can process high output event rates (> 4 MHz) with high spatial resolution, and self triggered event timing accuracy of ~1.5 ns for sealed tube XS optical sensors. A peak quantum efficiency of between 13% and 19% at 500 nm has been achieved with SuperGenII photocathodes with response from 400 nm to 900 nm for both cross strip and cross delay line sealed tubes. Local area counting rates of up to 40 kHz (100μm spot) have been attained with XS sealed tubes, along with image linearity and stability to better than 50 μm. 25mm cross delay line tubes achieve ~50 μm resolution and > 2 MHz output event rates. PMID:23833700

  17. Exploring the spatial resolution of position-sensitive microchannel plate detectors

    NASA Astrophysics Data System (ADS)

    Wiggins, Blake; Siwal, Davinder; Desouza, Romualdo

    2016-03-01

    High amplification and excellent timing make microchannel plate (MCP) detectors excellent devices for detection of photons, electrons, and ions. In addition to providing sub-nanosecond time resolution MCP detectors can also provide spatial resolution, thus making them useful in imaging applications. Use of a resistive anode (RA) is a routinely used approach to make an MCP position-sensitive. The spatial resolution of the RA associated with detection of a single incident electron was determined. Factors impacting the spatial resolution obtained with the RA will be discussed and the achieved spatial resolution of 64 μm (FWHM) will be presented. Recently, a novel approach has been developed to provide position-sensitivity for an MCP detector. In this approach, namely the induced signal approach, the position of the incident particle is determined by sensing the electron cloud emanating from a MCP stack. By utilizing the zero-crossing point of the inherently bipolar signals, a spatial resolution of 466 μm (FWHM) has been achieved. Work to improve the spatial resolution of the induced signal approach further will be presented. Supported by the US DOE NNSA under Award No. DE-NA0002012.

  18. Monte Carlo Simulations of Microchannel Plate Detectors II: Pulsed Voltage Results

    SciTech Connect

    Kruschwitz, Craig A.; Wu, Ming; Rochau, Greg A.

    2011-02-11

    This paper is part of a continuing study of straight-channel microchannel plate (MCP)–based x-ray detectors. Such detectors are a useful diagnostic tool for two-dimensional, time-resolved imaging and time-resolved x-ray spectroscopy. To interpret the data from such detectors, it is critical to develop a better understanding of the behavior of MCPs biased with subnanosecond voltage pulses. The subject of this paper is a Monte Carlo computer code that simulates the electron cascade in a MCP channel under an arbitrary pulsed voltage, particularly those pulses with widths comparable to the transit time of the electron cascade in the MCP under DC voltage bias. We use this code to study the gain as a function of time (also called the gate profile or optical gate) for various voltage pulse shapes, including pulses measured along the MCP. In addition, experimental data of MCP behavior in pulsed mode are obtained with a short-pulse UV laser. Comparisons between the simulations and experimental data show excellent agreement for both the gate profile and the peak relative sensitivity along the MCP strips. We report that the dependence of relative gain on peak voltage increases in sensitivity in pulsed mode when the width of the high-voltage waveform is smaller than the transit time of cascading electrons in the MCP.

  19. Development of atomic layer deposition-activated microchannel plates for single particle detection at cryogenic temperatures

    SciTech Connect

    Gorelikov, Dmitry Sullivan, Neal; Rouffignac, Philippe de; Li, Huazhi; Narayanamoorthy, Jayasri; Tremsin, Anton S.

    2014-03-15

    Atomic layer deposition (ALD) technology is used to nanoengineer functional films inside the pores of microchannel plate (MCP) electron multipliers, enabling a novel MCP manufacturing technology that substantially improves performance and opens novel applications. The authors have developed custom tools and recipes for the growth of conformal films, with optimized conductance and secondary electron emission inside very long channels (∼6–20 μm diameter and >600 μm length, with tens of millions of channels per single MCP) by ALD. The unique ability to tune the characteristics of these ALD films enables their optimization to applications where time-resolved single particle imaging can be performed in extreme conditions, such as high counting rates at cryogenic temperatures. Adhesion of the conductive and emissive nanofilms to the 20 μm pore MCP glass substrates and their mechanical stability over a very wide range of temperatures (10–700 K) were confirmed experimentally. Resistance of ALD MCPs was reproducible during multiple cool-down cycles with no film degradation observed. Optimizing resistance of novel MCPs for operation at cryogenic temperature should enable high count rate event detection at temperatures below 20 K.

  20. Nano-oxide thin films deposited via atomic layer deposition on microchannel plates

    NASA Astrophysics Data System (ADS)

    Yan, Baojun; Liu, Shulin; Heng, Yuekun

    2015-04-01

    Microchannel plate (MCP) as a key part is a kind of electron multiplied device applied in many scientific fields. Oxide thin films such as zinc oxide doped with aluminum oxide (ZnO:Al2O3) as conductive layer and pure aluminum oxide (Al2O3) as secondary electron emission (SEE) layer were prepared in the pores of MCP via atomic layer deposition (ALD) which is a method that can precisely control thin film thickness on a substrate with a high aspect ratio structure. In this paper, nano-oxide thin films ZnO:Al2O3 and Al2O3 were prepared onto varied kinds of substrates by ALD technique, and the morphology, element distribution, structure, and surface chemical states of samples were systematically investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoemission spectroscopy (XPS), respectively. Finally, electrical properties of an MCP device as a function of nano-oxide thin film thickness were firstly studied, and the electrical measurement results showed that the average gain of MCP was greater than 2,000 at DC 800 V with nano-oxide thin film thickness approximately 122 nm. During electrical measurement, current jitter was observed, and possible reasons were preliminarily proposed to explain the observed experimental phenomenon.

  1. Synchrotron beam test with a photon-counting pixel detector.

    PubMed

    Brönnimann, C; Florin, S; Lindner, M; Schmitt, B; Schulze-Briese, C

    2000-09-01

    Synchrotron beam measurements were performed with a single-photon-counting pixel detector to investigate the influence of threshold settings on charge sharing. Improvement of image homogeneity by adjusting the threshold of each pixel individually was demonstrated. With a flat-field correction, the homogeneity could be improved. A measurement of the point spread function is reported. PMID:16609212

  2. Time-resolved non-contact fluorescence diffuse optical tomography measurements with ultra-fast time-correlated single photon counting avalanche photodiodes

    NASA Astrophysics Data System (ADS)

    Bérubé-Lauzière, Yves; Robichaud, Vincent; Lapointe, Éric

    2007-07-01

    The design and fabrication of time-correlated single photon counting (TCSPC) avalanche photodiodes (APDs) and associated quenching circuits have made significant progresses in recent years. APDs with temporal resolutions comparable to microchannel plate photomultiplier tubes (MCP-PMTs) are now available. MCP-PMTs were until these progresses the best TCSPC detectors with timing resolutions down to 30ps. APDs can now achieve these resolutions at a fraction of the cost. Work is under way to make the manufacturing of TCSPC APDs compatible with standard electronics fabrication practices. This should allow to further reduce their cost and render them easier to integrate in complex multi-channel TCSPC electronics, as needed in diffuse optical tomography (DOT) systems. Even if their sensitive area is much smaller than that of the ubiquitous PMT used in TCSPC, we show that with appropriate selection of optical components, TCSPC APDs can be used in time-domain DOT. To support this, we present experimental data and calculations clearly demonstrating that comparable measurements can be obtained with APDs and PMTs. We are, to our knowledge, the first group using APDs in TD DOT, in particular in non-contact TD fluorescence DOT.

  3. Centroiding algorithms for high speed crossed strip readout of microchannel plate detectors.

    PubMed

    Vallerga, John; Tremsin, Anton; Raffanti, Rick; Siegmund, Oswald

    2011-05-01

    Imaging microchannel plate (MCP) detectors with cross strip (XS) readout anodes require centroiding algorithms to determine the location of the amplified charge cloud from the incident radiation, be it photon or particle. We have developed a massively parallel XS readout electronic system that employs an amplifier and ADC for each strip and uses this digital data to calculate the centroid of each event in real time using a field programmable gate array (FPGA). Doing the calculations in real time in the front end electronics using an FPGA enables a much higher input event rate, nearly two orders of magnitude faster, by avoiding the bandwidth limitations of the raw data transfer to a computer. We report on our detailed efforts to optimize the algorithms used on both an 18 mm and 40 mm diameter XS MCP detector with strip pitch of 640 microns and read out with multiple 32 channel "Preshape32" ASIC amplifiers (developed at Rutherford Appleton Laboratory). Each strip electrode is continuously digitized to 12 bits at 50 MHz with all 64 digital channels (128 for the 40 mm detector) transferred to a Xilinx Virtex 5 FPGA. We describe how events are detected in the continuous data stream and then multiplexed into firmware modules that spatially and temporally filter and weight the input after applying offset and gain corrections. We will contrast a windowed "center of gravity" algorithm to a convolution with a special centroiding kernel in terms of resolution and distortion and show results with < 20 microns FWHM resolution at input rates > 1 MHz. PMID:21918588

  4. Three-Dimensional Photon Counting Imaging with Axially Distributed Sensing.

    PubMed

    Cho, Myungjin; Javidi, Bahram

    2016-01-01

    In this paper, we review three-dimensional (3D) photon counting imaging with axially distributed sensing. Under severely photon-starved conditions, we have proposed various imaging and algorithmic approaches to reconstruct a scene in 3D, which are not possible by using conventional imaging system due to lack of sufficient number of photons. In this paper, we present an overview of optical sensing and imaging system along with dedicated algorithms for reconstructing 3D scenes by photon counting axially distributed sensing, which may be implemented by moving a single image sensor along its optical axis. To visualize the 3D image, statistical estimation methods and computational reconstruction of axially distributed sensing is applied. PMID:27483262

  5. The non-linearity of the ESA Photon Counting Detector

    NASA Astrophysics Data System (ADS)

    Llebaria, A.; Nieto, J.-L.; di Serego Alighieri, S.

    1986-11-01

    The time-resolved imaging mode (TRIM) suggested by di Serego Alighieri and Perryman (1986), in which photons are recorded separately on each television camera frame, was used to analyze the data obtained in 1984 on the nucleus of M31 with the ESA Photon Counting Detector (PCD) on the Canada-France-Hawaii telescope. Through the examination of the TRIM data, it was possible to detect nonlinearity in the response of the ESA PCD, which is interpreted as being due to phosphorescence in the intensifier. A quantitative measurement of this effect is shown. It is argued that if the interpretation is correct, the same kind of nonlinearity should be found in all photon counting detectors with phosphor screen. The amount of the nonlinearity is presumably higher in detectors with lower thresholds.

  6. Towards a Graphene-Based Low Intensity Photon Counting Photodetector.

    PubMed

    Williams, Jamie O D; Alexander-Webber, Jack A; Lapington, Jon S; Roy, Mervyn; Hutchinson, Ian B; Sagade, Abhay A; Martin, Marie-Blandine; Braeuninger-Weimer, Philipp; Cabrero-Vilatela, Andrea; Wang, Ruizhi; De Luca, Andrea; Udrea, Florin; Hofmann, Stephan

    2016-01-01

    Graphene is a highly promising material in the development of new photodetector technologies, in particular due its tunable optoelectronic properties, high mobilities and fast relaxation times coupled to its atomic thinness and other unique electrical, thermal and mechanical properties. Optoelectronic applications and graphene-based photodetector technology are still in their infancy, but with a range of device integration and manufacturing approaches emerging this field is progressing quickly. In this review we explore the potential of graphene in the context of existing single photon counting technologies by comparing their performance to simulations of graphene-based single photon counting and low photon intensity photodetection technologies operating in the visible, terahertz and X-ray energy regimes. We highlight the theoretical predictions and current graphene manufacturing processes for these detectors. We show initial experimental implementations and discuss the key challenges and next steps in the development of these technologies. PMID:27563903

  7. Deep UV photon-counting detectors and applications

    NASA Astrophysics Data System (ADS)

    Shaw, Gary A.; Siegel, Andrew M.; Model, Joshua; Geboff, Adam; Soloviev, Stanislav; Vert, Alexey; Sandvik, Peter

    2009-05-01

    Photon counting detectors are used in many diverse applications and are well-suited to situations in which a weak signal is present in a relatively benign background. Examples of successful system applications of photon-counting detectors include ladar, bio-aerosol detection, communication, and low-light imaging. A variety of practical photon-counting detectors have been developed employing materials and technologies that cover the waveband from deep ultraviolet (UV) to the near-infrared. However, until recently, photoemissive detectors (photomultiplier tubes (PMTs) and their variants) were the only viable technology for photon-counting in the deep UV region of the spectrum. While PMTs exhibit extremely low dark count rates and large active area, they have other characteristics which make them unsuitable for certain applications. The characteristics and performance limitations of PMTs that prevent their use in some applications include bandwidth limitations, high bias voltages, sensitivity to magnetic fields, low quantum efficiency, large volume and high cost. Recently, DARPA has initiated a program called Deep UV Avalanche Photodiode (DUVAP) to develop semiconductor alternatives to PMTs for use in the deep UV. The higher quantum efficiency of Geiger-mode avalanche photodiode (GM-APD) detectors and the ability to fabricate arrays of individually-addressable detectors will open up new applications in the deep UV. In this paper, we discuss the system design trades that must be considered in order to successfully replace low-dark count, large-area PMTs with high-dark count, small-area GM-APD detectors. We also discuss applications that will be enabled by the successful development of deep UV GM-APD arrays, and we present preliminary performance data for recently fabricated silicon carbide GM-APD arrays.

  8. Avalanche photodiode photon counting receivers for space-borne lidars

    NASA Technical Reports Server (NTRS)

    Sun, Xiaoli; Davidson, Frederic M.

    1991-01-01

    Avalanche photodiodes (APD) are studied for uses as photon counting detectors in spaceborne lidars. Non-breakdown APD photon counters, in which the APD's are biased below the breakdown point, are shown to outperform: (1) conventional APD photon counters biased above the breakdown point; (2) conventional APD photon counters biased above the breakdown point; and (3) APD's in analog mode when the received optical signal is extremely weak. Non-breakdown APD photon counters were shown experimentally to achieve an effective photon counting quantum efficiency of 5.0 percent at lambda = 820 nm with a dead time of 15 ns and a dark count rate of 7000/s which agreed with the theoretically predicted values. The interarrival times of the counts followed an exponential distribution and the counting statistics appeared to follow a Poisson distribution with no after pulsing. It is predicted that the effective photon counting quantum efficiency can be improved to 18.7 percent at lambda = 820 nm and 1.46 percent at lambda = 1060 nm with a dead time of a few nanoseconds by using more advanced commercially available electronic components.

  9. Correction for nonlinear photon counting effects in lidar systems

    NASA Technical Reports Server (NTRS)

    Donovan, D. P.; Whiteway, J. A.; Carswell, A. I.

    1992-01-01

    Photomultiplier tubes (PMT's) employed in the photon counting (PC) mode of operation are widely used as detectors in lidar systems. In our laboratory, we have developed a versatile Nd:YAG lidar which is used for measurement of both the middle atmosphere and the troposphere. With this system, we encounter a very wide range of signal levels ranging from the extremely weak signals from the top of the mesosphere to the very strong returns from low level clouds. Although the system is capable of operating the PMT's in either the analog detection or photon counting mode, we find that often when we use photon counting we have portions of our lidar return which contain very useful information but are not within the linear operating regime of the PC system. We report the results of our efforts to explore the extent to which such high intensity PC signals can be quantitatively analyzed. In particular, a useful model relating the mean 'true' count rate and the observed count rate is presented and it's application to our system demonstrated. This model takes into account the variation in height of the PMT output pulses and the effect of the pulse height discrimination threshold.

  10. Electron-beam processing effect on photoemitting-structures parameters and the noise factor of microchannel plates

    NASA Astrophysics Data System (ADS)

    Avdeev, Sergey P.; Kravchenko, Aleksandr A.; Gusev, Evgeny Yu.; Petrov, Sergey N.

    2007-05-01

    This paper presents invesigation findings of electron-beam influence on parameters and characteristics of trialcali and bialkali photocathocles of vacuum photoelectric devices and electron-beam amplification channels modification of microchannel plate image intensifier (MCP) of the electrooptical transducer. The electron-beam processing (EBP) increases total sensitivity by 10 - 12% and reduces spoilage in photocathode production to a fourth. The noise factor of MCP subjected EBP before recovery procedure MCP, reduces in 1.5 - 2.0 times, the sensibility of electrooptical transducer increases.

  11. Charge coupled devices vs. microchannel plates in the extreme and far ultraviolet - A comparison based on the latest laboratory measurements

    NASA Technical Reports Server (NTRS)

    Vallerga, J.; Lampton, M.

    1988-01-01

    While microchannel plates (MCPs) have been established as imaging photon counters in the EUV and FUV for some years, CCDs are associated with low light level sensing at visible and near-IR wavelengths. Attention is presently given to recent proposals for CCDs' use as EUV and FUV detectors with quantum efficiencies sometimes exceeding those of MCPs; quantum resolution, format size, dynamic range, and long-term stability are also used as bases of comparison, for the cases of both space-based astronomical and spectroscopic applications.

  12. The high-resolution microchannel plate detector for FUV spectroscopy in the BepiColombo mission

    NASA Astrophysics Data System (ADS)

    Murakami, Go; Ezawa, Fukuhiro; Yoshioka, Kazuo; Yoshikawa, Ichiro; Chassefiere, Eric; Maria, Jean-Luc

    Mariner-10 UV measurements and telescopic spectroscopy from the Earth identified six elements (Ca, Na, K, H, He, and O) in the Mercury's exosphere. Other species are expected, e.g. H2 , OH, and some noble gasses (Ar, Ne, and Xe). All species representative of the surface composition, directly produced by impact vaporization driven by micrometeoroids, physical sputtering, photo-stimulated desorption, and thermal desorption from the regolith, should also be present. To determine the composition of the Mercury's exosphere, the PHEBUS (Probing of Hermean Exosphere By Ultraviolet Spectroscopy) instrument on Mercury Planetary Orbiter (MPO) will measure the emission lines of the exosphere. PHEBUS is a dual FUV-EUV spectrometer working in the wavelength range from 55 to 315 nm. We are now developing the compact detector system sensitive to FUV airglow emissions of the Mercury. The FUV detector is required to have high spatial resolution (80 µm) so that the wavelength resolution of the PHEBUS instrument should be 2 nm at the FUV range. The FUV detector consists of a Cs2 Te photocathode, microchannel plates (MCPs), and a resistive anode encoder (RAE). In a position-sensitive system with an RAE, the spatial resolution is determined by the signal-to-noise ratios at the anode terminals. Therefore, a high and stable electron gain of MCPs allows the position determination of each photoelectron event with high spatial resolution. We studied a method for achieving a high and stable electron gain. We fabricated a test model of the FUV detector incorporating a clamped pair of MCPs (V-stack) followed by a gap and a clamped triplet of MCPs (Z-stack) in cascade. We have investigated the effect of the negative potential applied across the inter-stack (V-Z) gap on the PHD and the spatial resolution by means of calculation and experiments. The calculation with a simple ballistic model showed that the negative inter-stack potential reduced the size of the electron cloud by 70%. The result

  13. Dark-Field Scanning Transmission Ion Microscopy via Detection of Forward-Scattered Helium Ions with a Microchannel Plate.

    PubMed

    Woehl, Taylor J; White, Ryan M; Keller, Robert R

    2016-06-01

    A microchannel plate was used as an ion sensitive detector in a commercial helium ion microscope (HIM) for dark-field transmission imaging of nanomaterials, i.e. scanning transmission ion microscopy (STIM). In contrast to previous transmission HIM approaches that used secondary electron conversion holders, our new approach detects forward-scattered helium ions on a dedicated annular shaped ion sensitive detector. Minimum collection angles between 125 mrad and 325 mrad were obtained by varying the distance of the sample from the microchannel plate detector during imaging. Monte Carlo simulations were used to predict detector angular ranges at which dark-field images with atomic number contrast could be obtained. We demonstrate atomic number contrast imaging via scanning transmission ion imaging of silica-coated gold nanoparticles and magnetite nanoparticles. Although the resolution of STIM is known to be degraded by beam broadening in the substrate, we imaged magnetite nanoparticles with high contrast on a relatively thick silicon nitride substrate. We expect this new approach to annular dark-field STIM will open avenues for more quantitative ion imaging techniques and advance fundamental understanding of underlying ion scattering mechanisms leading to image formation. PMID:27153003

  14. Noise filtering techniques for photon-counting ladar data

    NASA Astrophysics Data System (ADS)

    Magruder, Lori A.; Wharton, Michael E., III; Stout, Kevin D.; Neuenschwander, Amy L.

    2012-06-01

    Many of the recent small, low power ladar systems provide detection sensitivities on the photon(s) level for altimetry applications. These "photon-counting" instruments, many times, are the operational solution to high altitude or space based platforms where low signal strength and size limitations must be accommodated. Despite the many existing algorithms for lidar data product generation, there remains a void in techniques available for handling the increased noise level in the photon-counting measurements as the larger analog systems do not exhibit such low SNR. Solar background noise poses a significant challenge to accurately extract surface features from the data. Thus, filtering is required prior to implementation of other post-processing efforts. This paper presents several methodologies for noise filtering photoncounting data. Techniques include modified Canny Edge Detection, PDF-based signal extraction, and localized statistical analysis. The Canny Edge detection identifies features in a rasterized data product using a Gaussian filter and gradient calculation to extract signal photons. PDF-based analysis matches local probability density functions with the aggregate, thereby extracting probable signal points. The localized statistical method assigns thresholding values based on a weighted local mean of angular variances. These approaches have demonstrated the ability to remove noise and subsequently provide accurate surface (ground/canopy) determination. The results presented here are based on analysis of multiple data sets acquired with the high altitude NASA MABEL system and photon-counting data supplied by Sigma Space Inc. configured to simulate the NASA upcoming ICESat-2 mission instrument expected data product.

  15. Ultrafast three-photon counting in a photomultiplier tube.

    PubMed

    Nevet, Amir; Hayat, Alex; Orenstein, Meir

    2011-03-01

    We demonstrate experimentally ultrafast three-photon counting by three-photon absorption in a GaAsP photomultiplier tube at the wavelength range of 1800-1900 nm, and analyze its sensitivity and time response. Pulse energy of ∼500 fJ is shown to be detectable for ultrafast 170 fs pulses. The presented three-photon counter may serve as a unique tool for ultrafast quantum state characterization as well as for ultrasensitive third-order temporal measurements. PMID:21368962

  16. High quantum efficiency S-20 photocathodes in photon counting detectors

    NASA Astrophysics Data System (ADS)

    Orlov, D. A.; DeFazio, J.; Duarte Pinto, S.; Glazenborg, R.; Kernen, E.

    2016-04-01

    Based on conventional S-20 processes, a new series of high quantum efficiency (QE) photocathodes has been developed that can be specifically tuned for use in the ultraviolet, blue or green regions of the spectrum. The QE values exceed 30% at maximum response, and the dark count rate is found to be as low as 30 Hz/cm2 at room temperature. This combination of properties along with a fast temporal response makes these photocathodes ideal for application in photon counting detectors, which is demonstrated with an MCP photomultiplier tube for single and multi-photoelectron detection.

  17. Optical and UV Sensing Sealed Tube Microchannel Plate Imaging Detectors with High Time Resolution

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; Vallerga, J.; Tremsin, A.; Hull, J.; Elam, J.; Mane, A.

    2014-09-01

    Microchannel plate (MCP) based imaging, photon time tagging detector sealed tube schemes have a unique set of operational features that enable high time resolution astronomical and remote sensing applications to be addressed. New detectors using the cross strip (XS), cross delay line (XDL), or stripline anode readouts, a wide range of photocathode types, and advanced MCP technologies have been implemented to improve many performance characteristics. A variety of sealed tubes have been developed including 18mm XS readout devices with GaAs and SuperGenII photocathodes, 25mm XDL readout devices with SuperGenII and GaN photocathodes, and 20 x 20 cm sealed tubes with bialkali photocathodes and strip line readout. One key technology that has just become viable is the ability to make MCPs using atomic layer deposition (ALD) techniques. This employs nanofabrication of the active layers of an MCP on a microcapillary array. This technique opens new performance opportunities, including, very large MCP areas (>20cm), very low intrinsic background, lower radiation induced background, much longer overall lifetime and gain stability, and markedly lower outgassing which can improve the sealed tube lifetime and ease of fabrication. The XS readout has been implemented in formats of 22mm, 50mm and 100mm, and uses MCP charge signals detected on two orthogonal layers of conductive fingers to encode event X-Y positions. We have achieved spatial resolution XS detectors better than 25 microns FWHM, with good image linearity while at low gain (<10^6), substantially increasing local counting rate capabilities and the overall tube lifetime. XS tubes with updated electronics can encode event rates of >5 MHz with ~12% dead time and event timing accuracy of ~100ps. XDL sealed tubes in 25mm format demonstrate ~40 micron spatial resolution at up to ~2 MHz event rates, and have been developed with SupergenII visible regime photocathodes. The XDL tubes also achieve ~100 ps time resolution. Most

  18. Ultrafast photon counting applied to resonant scanning STED microscopy.

    PubMed

    Wu, Xundong; Toro, Ligia; Stefani, Enrico; Wu, Yong

    2015-01-01

    To take full advantage of fast resonant scanning in super-resolution stimulated emission depletion (STED) microscopy, we have developed an ultrafast photon counting system based on a multigiga sample per second analogue-to-digital conversion chip that delivers an unprecedented 450 MHz pixel clock (2.2 ns pixel dwell time in each scan). The system achieves a large field of view (∼50 × 50 μm) with fast scanning that reduces photobleaching, and advances the time-gated continuous wave STED technology to the usage of resonant scanning with hardware-based time-gating. The assembled system provides superb signal-to-noise ratio and highly linear quantification of light that result in superior image quality. Also, the system design allows great flexibility in processing photon signals to further improve the dynamic range. In conclusion, we have constructed a frontier photon counting image acquisition system with ultrafast readout rate, excellent counting linearity, and with the capacity of realizing resonant-scanning continuous wave STED microscopy with online time-gated detection. PMID:25227160

  19. Novel photon-counting detectors for free-space communication

    NASA Astrophysics Data System (ADS)

    Krainak, M. A.; Yang, G.; Sun, X.; Lu, W.; Merritt, S.; Beck, J.

    2016-03-01

    We present performance data for novel photon-counting detectors for free space optical communication. NASA GSFC is testing the performance of three types of novel photon-counting detectors 1) a 2x8 mercury cadmium telluride (HgCdTe) avalanche array made by DRS Inc., and a 2) a commercial 2880-element silicon avalanche photodiode (APD) array. We present and compare dark count, photon-detection efficiency, wavelength response and communication performance data for these detectors. We discuss system wavelength trades and architectures for optimizing overall communication link sensitivity, data rate and cost performance. The HgCdTe APD array routinely demonstrated photon detection efficiencies of greater than 50% across 5 arrays, with one array reaching a maximum PDE of 70%. We performed high-resolution pixel-surface spot scans and measured the junction diameters of its diodes. We found that decreasing the junction diameter from 31 μm to 25 μm doubled the e- APD gain from 470 for an array produced in the year 2010 to a gain of 1100 on an array delivered to NASA GSFC recently. The mean single-photon SNR was over 12 and the excess noise factors measurements were 1.2-1.3. The commercial silicon APD array exhibited a fast output with rise times of 300 ps and pulse widths of 600 ps. On-chip individually filtered signals from the entire array were multiplexed onto a single fast output.

  20. Novel Photon-Counting Detectors for Free-Space Communication

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Yang, Guan; Sun, Xiaoli; Lu, Wei; Merritt, Scott; Beck, Jeff

    2016-01-01

    We present performance data for novel photon counting detectors for free space optical communication. NASA GSFC is testing the performance of three novel photon counting detectors 1) a 2x8 mercury cadmium telluride avalanche array made by DRS Inc. 2) a commercial 2880 silicon avalanche photodiode array and 3) a prototype resonant cavity silicon avalanche photodiode array. We will present and compare dark count, photon detection efficiency, wavelength response and communication performance data for these detectors. We discuss system wavelength trades and architectures for optimizing overall communication link sensitivity, data rate and cost performance. The HgCdTe APD array has photon detection efficiencies of greater than 50 were routinely demonstrated across 5 arrays, with one array reaching a maximum PDE of 70. High resolution pixel-surface spot scans were performed and the junction diameters of the diodes were measured. The junction diameter was decreased from 31 m to 25 m resulting in a 2x increase in e-APD gain from 470 on the 2010 array to 1100 on the array delivered to NASA GSFC. Mean single photon SNRs of over 12 were demonstrated at excess noise factors of 1.2-1.3.The commercial silicon APD array has a fast output with rise times of 300ps and pulse widths of 600ps. Received and filtered signals from the entire array are multiplexed onto this single fast output. The prototype resonant cavity silicon APD array is being developed for use at 1 micron wavelength.

  1. Ultrafast Photon Counting Applied to Resonant Scanning STED Microscopy

    PubMed Central

    Wu, Xundong; Toro, Ligia; Stefani, Enrico; Wu, Yong

    2014-01-01

    Summary To take full advantage of fast resonant scanning in super-resolution STimulated Emission Depletion (STED) microscopy, we have developed an ultrafast photon counting system based on a multi-giga-sample per second analog-to-digital conversion (ADC) chip that delivers an unprecedented 450 MHz pixel clock (2.2 ns pixel dwell time in each scan). The system achieves a large field of view (~50 × 50 μm) with fast scanning that reduces photobleaching, and advances the time-gated continuous wave (CW) STED technology to the usage of resonant scanning with hardware based time-gating. The assembled system provides superb signal-to-noise ratio and highly linear quantification of light that result in superior image quality. Also, the system design allows great flexibility in processing photon signals to further improve the dynamic range. In conclusion, we have constructed a frontier photon counting image acquisition system with ultrafast readout rate, excellent counting linearity, and with the capacity of realizing resonant-scanning CW-STED microscopy with on-line time-gated detection. PMID:25227160

  2. Energy dispersive photon counting detectors for breast imaging

    NASA Astrophysics Data System (ADS)

    Barber, William C.; Wessel, Jan C.; Malakhov, Nail; Wawrzyniak, Gregor; Hartsough, Neal E.; Gandhi, Thulasidharan; Nygard, Einar; Iwanczyk, Jan S.

    2013-09-01

    We report on our efforts toward the development of silicon (Si) strip detectors for energy-resolved clinical breast imaging. Typically, x-ray integrating detectors based on scintillating cesium iodide CsI(Tl) or amorphous selenium (a- Se) are used in most commercial systems. Recently, mammography instrumentation has been introduced based on photon counting silicon Si strip detectors. Mammography requires high flux from the x-ray generator, therefore, in order to achieve energy resolved single photon counting, a high output count rate (OCR) for the detector must be achieved at the required spatial resolution and across the required dynamic range for the application. The required performance in terms of the OCR, spatial resolution, and dynamic range must be obtained with sufficient field of view (FOV) for the application thus requiring the tiling of pixel arrays and scanning techniques. Room temperature semiconductors, operating as direct conversion x-ray sensors, can provide the required speed when connected to application specific integrated circuits (ASICs) operating at fast peaking times with multiple fixed thresholds per pixel, provided that the sensors are designed for rapid signal formation across the x-ray energy ranges of the application at the required energy and spatial resolutions. We present our methods and results from the optimization of prototype detectors based on Si strip structures. We describe the detector optimization and the development of ASIC readout electronics that provide the required spatial resolution, low noise, high count rate capabilities and minimal power consumption.

  3. Improved photon counting efficiency calibration using superconducting single photon detectors

    NASA Astrophysics Data System (ADS)

    Gan, Haiyong; Xu, Nan; Li, Jianwei; Sun, Ruoduan; Feng, Guojin; Wang, Yanfei; Ma, Chong; Lin, Yandong; Zhang, Labao; Kang, Lin; Chen, Jian; Wu, Peiheng

    2015-10-01

    The quantum efficiency of photon counters can be measured with standard uncertainty below 1% level using correlated photon pairs generated through spontaneous parametric down-conversion process. Normally a laser in UV, blue or green wavelength range with sufficient photon energy is applied to produce energy and momentum conserved photon pairs in two channels with desired wavelengths for calibration. One channel is used as the heralding trigger, and the other is used for the calibration of the detector under test. A superconducting nanowire single photon detector with advantages such as high photon counting speed (<20 MHz), low dark count rate (<50 counts per second), and wideband responsivity (UV to near infrared) is used as the trigger detector, enabling correlated photons calibration capabilities into shortwave visible range. For a 355nm single longitudinal mode pump laser, when a superconducting nanowire single photon detector is used as the trigger detector at 1064nm and 1560nm in the near infrared range, the photon counting efficiency calibration capabilities can be realized at 532nm and 460nm. The quantum efficiency measurement on photon counters such as photomultiplier tubes and avalanche photodiodes can be then further extended in a wide wavelength range (e.g. 400-1000nm) using a flat spectral photon flux source to meet the calibration demands in cutting edge low light applications such as time resolved fluorescence and nonlinear optical spectroscopy, super resolution microscopy, deep space observation, and so on.

  4. Subnanosecond time-correlated photon counting with tunable lasers.

    PubMed

    Spears, K G; Cramer, L E; Hoffland, L D

    1978-02-01

    We present several laser based methods to improve the technique of time-correlated photon counting. Our Ar(+) laser pumped tunable dye laser can be operated in three timing configurations: acousto-optically mode locked, cavity dumped, and cavity dumped-mode locked. Performance characteristics of the laser system in various operational modes are described along with measurement techniques for both gas and liquid phase. The subnanosecond pulses generated by mode locking are extremely stable and they maintain identical pulse shapes over a 6-h period, as shown via photon counting measurements at a 15-psec channel resolution. Our RCA C31034 photomultiplier with a red sensitive GaAs photocathode provides wavelength-independent response to detected fluorescence in both the visible and ultraviolet. The present limit of our apparatus is controlled by the accuracy of deconvoluting fluorescence decay from the finite response width caused by photomultiplier transit time dispersion (0.8 nsec FWHM). Our system stability is sufficient to accurately determine exponential decays as short as 50 psec. Furthermore, we can successfully analyze dual exponential decays such as those arising from solution reorientation times of 390 psec competing with a fluorescence lifetime of 725 psec. Examples of the laser performance are selected from a variety of measurements in the gas phase and from the fluorescent dye rose bengal in the liquid phase. PMID:18699071

  5. Development of a New Fast Shower Maximum Detector Based on Microchannel Plates Photomultipliers (MCP-PMT) as an Active Element

    SciTech Connect

    Ronzhin, A.; Los, S.; Ramberg, E.; Spiropulu, M.; Apresyan, A.; Xie, S.; Kim, H.; Zatserklyaniy, A.

    2014-09-21

    One possibility to make a fast and radiation resistant shower maximum (SM) detector is to use a secondary emitter as an active element. We present below test beam results, obtained with different types of photodetectors based on microchannel plates (MCPs) as the secondary emitter. We performed the measurements at the Fermilab Test Beam Facility with 120GeV proton beam and 12GeV and 32GeV secondary beams. The goal of the measurement with 120GeV protons was to determine time resolution for minimum ionizing particles (MIPs). The SM time resolution we obtained for this new type of detector is at the level of 20-30ps. We estimate that a significant contribution to the detector response originates from secondary emission of the MCP. This work can be considered as the first step in building a new type of calorimeter based on this principle.

  6. Thomson spectrometer-microchannel plate assembly calibration for MeV-range positive and negative ions, and neutral atoms

    SciTech Connect

    Prasad, R.; Abicht, F.; Braenzel, J.; Priebe, G.; Schnuerer, M.; Borghesi, M.; Ter-Avetisyan, S.; Nickles, P. V.

    2013-05-15

    We report on the absolute calibration of a microchannel plate (MCP) detector, used in conjunction with a Thomson parabola spectrometer. The calibration delivers the relation between a registered count numbers in the CCD camera (on which the MCP phosphor screen is imaged) and the number of ions incident on MCP. The particle response of the MCP is evaluated for positive, negative, and neutral particles at energies below 1 MeV. As the response of MCP depends on the energy and the species of the ions, the calibration is fundamental for the correct interpretation of the experimental results. The calibration method and arrangement exploits the unique emission symmetry of a specific source of fast ions and atoms driven by a high power laser.

  7. Dynamic Characterizations of an 8-frame Half-Strip High-speed X-ray Microchannel Plate Imager

    SciTech Connect

    Ken Moy, Ming Wu, Craig Kruschwitz, Aric Tibbits, Matt Griffin, Greg Rochau

    2008-09-05

    High-speed microchannel plate (MCP)–based imagers are critical detectors for x-ray diagnostics employed on Z-experiments at Sandia National Laboratories (SNL) to measure time-resolved x-ray spectra and to image dynamic hohlraums. A multiframe design using eight half strips in one imager permits recordings of radiation events in discrete temporal snapshots to yield a time-evolved movie. We present data using various facilities to characterize the performance of this design. These characterization studies include DC and pulsed-voltage biased measurements in both saturated and linear operational regimes using an intense, short-pulsed UV laser. Electrical probe measurements taken to characterize the shape of the HV pulse propagating across the strips help to corroborate the spatial gain dependence.

  8. Characterization Studies and Performance of Half-strip High-speed X-ray Microchannel Plate Imager

    SciTech Connect

    Kenneth Moy; Ming Wu

    2008-03-01

    High-speed microchannel plate (MCP)–based imagers are critical detectors for x-ray diagnostics employed on Z-experiments at Sandia National Laboratories (SNL) to measure time-resolved x-ray spectra and to image dynamic hohlraums. A design using eight half-strip x-ray photocathodes in one imager permits recordings of radiation events in discrete temporal snapshots to yield a time-evolved movie. We present data using various facilities to characterize the performance of this design. These characterization studies include DC and pulsed-voltage biased measurements in both saturated and linear operational regimes using an intense, short-pulsed UV laser and Manson source. Surface voltage profile measurements using a picoprobe help to determine the gain variation across the strips. Test data from a recent SNL ZR-experiment demonstrates the flexibility and high-quality images obtained by this MCP imager.

  9. Development of a new fast shower maximum detector based on microchannel plates photomultipliers (MCP-PMT) as an active element

    NASA Astrophysics Data System (ADS)

    Ronzhin, A.; Los, S.; Ramberg, E.; Spiropulu, M.; Apresyan, A.; Xie, S.; Kim, H.; Zatserklyaniy, A.

    2014-09-01

    One possibility to make a fast and radiation resistant shower maximum (SM) detector is to use a secondary emitter as an active element. We present below test beam results, obtained with different types of photodetectors based on microchannel plates (MCPs) as the secondary emitter. We performed the measurements at the Fermilab Test Beam Facility with 120 GeV proton beam and 12 GeV and 32 GeV secondary beams. The goal of the measurement with 120 GeV protons was to determine time resolution for minimum ionizing particles (MIPs). The SM time resolution we obtained for this new type of detector is at the level of 20-30 ps. We estimate that a significant contribution to the detector response originates from secondary emission of the MCP. This work can be considered as the first step in building a new type of calorimeter based on this principle.

  10. Design and fabrication of prototype 6×6 cm2 microchannel plate photodetector with bialkali photocathode for fast timing applications

    NASA Astrophysics Data System (ADS)

    Xie, Junqi; Byrum, Karen; Demarteau, Marcel; Gregar, Joseph; May, Edward; Virgo, Mathew; Wagner, Robert; Walters, Dean; Wang, Jingbo; Xia, Lei; Zhao, Huyue

    2015-06-01

    Planar microchannel plate-based photodetectors with a bialkali photocathode are able to achieve photon detection with very good time and position resolution. A 6×6 cm2 photodetector production facility was designed and built at Argonne National Laboratory. Small form-factor MCP-based photodetectors completely constructed out of glass were designed and prototypes were successfully fabricated. Knudsen effusion cells were incorporated in the photocathode growth chamber to achieve uniform and high quantum efficiency photocathodes. The thin film uniformity was simulated and measured for an antimony film deposition, showing uniformity of better than 10%. Several prototype devices with bialkali photocathodes have been fabricated with the described system and their characteristics were evaluated in the large signal (multi-PE) limit. A typical prototype device exhibits time-of-flight resolution of ~27 psec and differential time resolution of ~9 psec, corresponding to spatial resolution of ~0.65 mm.

  11. A low noise front end electronics for micro-channel plate detector with wedge and strip anode

    NASA Astrophysics Data System (ADS)

    Hu, K.; Li, F.; Liang, F.; Chen, L.; Jin, G.

    2016-03-01

    A low noise Front End Electronics (FEE) for two-dimensional position sensitive Micro-Channel Plate (MCP) detector has been developed. The MCP detector is based on Wedge and Strip Anode (WSA) with induction readout mode. The WSA has three electrodes, the wedge electrode, the strip electrode, and the zigzag electrode. Then, three readout channels are designed in the Printed Circuit Board (PCB). The FEE is calibrated by a pulse generator from Agilent. We also give an analysis of the charge loss from the CSA. The noise levels of the three channels are less than 1 fC RMS at the shaping time of 200 ns. The experimental result shows that the position resolution of the MCP detector coupled with the designed PCB can reach up to 110 μm.

  12. Position and time resolution measurements with a microchannel plate image intensifier: A comparison of monolithic and pixelated CeBr3 scintillators

    NASA Astrophysics Data System (ADS)

    Ackermann, Ulrich; Eschbaumer, Stephan; Bergmaier, Andreas; Egger, Werner; Sperr, Peter; Greubel, Christoph; Löwe, Benjamin; Schotanus, Paul; Dollinger, Günther

    2016-07-01

    To perform Four Dimensional Age Momentum Correlation measurements in the near future, where one obtains the positron lifetime in coincidence with the three dimensional momentum of the electron annihilating with the positron, we have investigated the time and position resolution of two CeBr3 scintillators (monolithic and an array of pixels) using a Photek IPD340/Q/BI/RS microchannel plate image intensifier. The microchannel plate image intensifier has an active diameter of 40 mm and a stack of two microchannel plates in chevron configuration. The monolithic CeBr3 scintillator was cylindrically shaped with a diameter of 40 mm and a height of 5 mm. The pixelated scintillator array covered the whole active area of the microchannel plate image intensifier and the shape of each pixel was 2.5·2.5·8 mm3 with a pixel pitch of 3.3 mm. For the monolithic setup the measured mean single time resolution was 330 ps (FWHM) at a gamma energy of 511 keV. No significant dependence on the position was detected. The position resolution at the center of the monolithic scintillator was about 2.5 mm (FWHM) at a gamma energy of 662 keV. The single time resolution of the pixelated crystal setup reached 320 ps (FWHM) in the region of the center of the active area of the microchannel plate image intensifier. The position resolution was limited by the cross-section of the pixels. The gamma energy for the pixel setup measurements was 511 keV.

  13. Soft tissue imaging with photon counting spectroscopic CT

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.

    2015-03-01

    The purpose of this work was experimental investigation of photon counting spectroscopic CT (PCS-CT) imaging of anatomical soft tissue with clinically relevant size. The imaging experiments were performed using a spectroscopic CT system based on CdZnTe photon counting detector with two rows of pixels, 256 pixels in each row, 1  ×  1 mm2 pixel size, and 25.6 cm detector length. The detector could split the x-ray energy spectrum to 5 regions (energy bins), and acquire 5 multi-energy (spectroscopic) CT images in a single CT scan. A sample of round shaped anatomical soft tissue of 14 cm diameter including lean and fat was used for imaging. To avoid the negative effect of anatomical noise on quantitative analysis, a spectroscopic CT phantom with tissue equivalent solid materials was used. The images were acquired at 60, 90, and 120 kVp tube voltages, and spectroscopic image series were acquired with 3 and 5 energy bins. Spectroscopic CT numbers were introduced and used to evaluate an energy selective image series. The anatomical soft tissue with 14 cm diameter was visualized with good quality and without substantial artifacts by the photon counting spectroscopic CT system. The effects of the energy bin crosstalk on spectroscopic CT numbers were quantified and analyzed. The single and double slice PCS-CT images were acquired and compared. Several new findings were observed, including the effect of soft tissue non-uniformity on image artifacts, unique status of highest energy bin, and material dependent visualization in spectroscopic image series. Fat-lean decomposition was performed using dual energy subtraction and threshold segmentation methods, and compared. Using K-edge filtered x-rays improved fat-lean decomposition as compared to conventional x-rays. Several new and important aspects of the PCS-CT were investigated. These include imaging soft tissue with clinically relevant size, single- and double-slice PCS-CT imaging, using spectroscopic CT

  14. Soft tissue imaging with photon counting spectroscopic CT.

    PubMed

    Shikhaliev, Polad M

    2015-03-21

    The purpose of this work was experimental investigation of photon counting spectroscopic CT (PCS-CT) imaging of anatomical soft tissue with clinically relevant size. The imaging experiments were performed using a spectroscopic CT system based on CdZnTe photon counting detector with two rows of pixels, 256 pixels in each row, 1  ×  1 mm(2) pixel size, and 25.6 cm detector length. The detector could split the x-ray energy spectrum to 5 regions (energy bins), and acquire 5 multi-energy (spectroscopic) CT images in a single CT scan. A sample of round shaped anatomical soft tissue of 14 cm diameter including lean and fat was used for imaging. To avoid the negative effect of anatomical noise on quantitative analysis, a spectroscopic CT phantom with tissue equivalent solid materials was used. The images were acquired at 60, 90, and 120 kVp tube voltages, and spectroscopic image series were acquired with 3 and 5 energy bins. Spectroscopic CT numbers were introduced and used to evaluate an energy selective image series. The anatomical soft tissue with 14 cm diameter was visualized with good quality and without substantial artifacts by the photon counting spectroscopic CT system. The effects of the energy bin crosstalk on spectroscopic CT numbers were quantified and analyzed. The single and double slice PCS-CT images were acquired and compared. Several new findings were observed, including the effect of soft tissue non-uniformity on image artifacts, unique status of highest energy bin, and material dependent visualization in spectroscopic image series. Fat-lean decomposition was performed using dual energy subtraction and threshold segmentation methods, and compared. Using K-edge filtered x-rays improved fat-lean decomposition as compared to conventional x-rays. Several new and important aspects of the PCS-CT were investigated. These include imaging soft tissue with clinically relevant size, single- and double-slice PCS-CT imaging, using spectroscopic CT

  15. Single Photon Counting Detectors for Low Light Level Imaging Applications

    NASA Astrophysics Data System (ADS)

    Kolb, Kimberly

    2015-10-01

    This dissertation presents the current state-of-the-art of semiconductor-based photon counting detector technologies. HgCdTe linear-mode avalanche photodiodes (LM-APDs), silicon Geiger-mode avalanche photodiodes (GM-APDs), and electron-multiplying CCDs (EMCCDs) are compared via their present and future performance in various astronomy applications. LM-APDs are studied in theory, based on work done at the University of Hawaii. EMCCDs are studied in theory and experimentally, with a device at NASA's Jet Propulsion Lab. The emphasis of the research is on GM-APD imaging arrays, developed at MIT Lincoln Laboratory and tested at the RIT Center for Detectors. The GM-APD research includes a theoretical analysis of SNR and various performance metrics, including dark count rate, afterpulsing, photon detection efficiency, and intrapixel sensitivity. The effects of radiation damage on the GM-APD were also characterized by introducing a cumulative dose of 50 krad(Si) via 60 MeV protons. Extensive development of Monte Carlo simulations and practical observation simulations was completed, including simulated astronomical imaging and adaptive optics wavefront sensing. Based on theoretical models and experimental testing, both the current state-of-the-art performance and projected future performance of each detector are compared for various applications. LM-APD performance is currently not competitive with other photon counting technologies, and are left out of the application-based comparisons. In the current state-of-the-art, EMCCDs in photon counting mode out-perform GM-APDs for long exposure scenarios, though GM-APDs are better for short exposure scenarios (fast readout) due to clock-induced-charge (CIC) in EMCCDs. In the long term, small improvements in GM-APD dark current will make them superior in both long and short exposure scenarios for extremely low flux. The efficiency of GM-APDs will likely always be less than EMCCDs, however, which is particularly disadvantageous for

  16. Photon-counting array detectors for space and ground-based studies at ultraviolet and vacuum ultraviolet /VUV/ wavelengths

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Bybee, R. L.

    1981-01-01

    The Multi-Anode Microchannel Arrays (MAMAs) are a family of photoelectric photon-counting array detectors, with formats as large as (256 x 1024)-pixels that can be operated in a windowless configuration at vacuum ultraviolet (VUV) and soft X-ray wavelengths or in a sealed configuration at ultraviolet and visible wavelengths. This paper describes the construction and modes of operation of (1 x 1024)-pixel and (24 x 1024)-pixel MAMA detector systems that are being built and qualified for use in sounding-rocket spectrometers for solar and stellar observations at wavelengths below 1300 A. The performance characteristics of the MAMA detectors at ultraviolet and VUV wavelengths are also described.

  17. Single-quantum dot imaging with a photon counting camera

    PubMed Central

    Michalet, X.; Colyer, R. A.; Antelman, J.; Siegmund, O.H.W.; Tremsin, A.; Vallerga, J.V.; Weiss, S.

    2010-01-01

    The expanding spectrum of applications of single-molecule fluorescence imaging ranges from fundamental in vitro studies of biomolecular activity to tracking of receptors in live cells. The success of these assays has relied on progresses in organic and non-organic fluorescent probe developments as well as improvements in the sensitivity of light detectors. We describe a new type of detector developed with the specific goal of ultra-sensitive single-molecule imaging. It is a wide-field, photon-counting detector providing high temporal and high spatial resolution information for each incoming photon. It can be used as a standard low-light level camera, but also allows access to a lot more information, such as fluorescence lifetime and spatio-temporal correlations. We illustrate the single-molecule imaging performance of our current prototype using quantum dots and discuss on-going and future developments of this detector. PMID:19689323

  18. Multimode model for projective photon-counting measurements

    SciTech Connect

    Tualle-Brouri, Rosa; Ourjoumtsev, Alexei; Dantan, Aurelien; Grangier, Philippe; Wubs, Martijn; Soerensen, Anders S.

    2009-07-15

    We present a general model to account for the multimode nature of the quantum electromagnetic field in projective photon-counting measurements. We focus on photon-subtraction experiments, where non-Gaussian states are produced conditionally. These are useful states for continuous-variable quantum-information processing. We present a general method called mode reduction that reduces the multimode model to an effective two-mode problem. We apply this method to a multimode model describing broadband parametric down-conversion, thereby improving the analysis of existing experimental results. The main improvement is that spatial and frequency filters before the photon detector are taken into account explicitly. We find excellent agreement with previously published experimental results, using fewer free parameters than before, and discuss the implications of our analysis for the optimized production of states with negative Wigner functions.

  19. Photon-counting technique for rapid fluorescence-decay measurement.

    PubMed

    Pack, S D; Renfro, M W; King, G B; Laurendeau, N M

    1998-08-01

    We report on a novel laser-induced fluorescence triple-integration method (LIFTIME) that is capable of making rapid, continuous fluorescence lifetime measurements by a unique photon-counting technique. The LIFTIME has been convolved with picosecond time-resolved laser-induced fluorescence, which employs a high-repetition-rate mode-locked laser, permitting the eventual monitoring of instantaneous species concentrations in turbulent flames. We verify the technique by application of the LIFTIME to two known fluorescence media, diphenyloxazole (PPO) and quinine sulfate monohydrate (QSM). PPO has a fluorescence lifetime of 1.28 ns, whereas QSM has a fluorescence lifetime that can be varied from 1.0 to 3.0 ns. From these liquid samples we demonstrate that fluorescence lifetime can currently be monitored at a sampling rate of up to 500 Hz with less than 10% uncertainty (1 sigma) . PMID:18087478

  20. Breakdown of the cross-Kerr scheme for photon counting.

    PubMed

    Fan, Bixuan; Kockum, Anton F; Combes, Joshua; Johansson, Göran; Hoi, Io-chun; Wilson, C M; Delsing, Per; Milburn, G J; Stace, Thomas M

    2013-02-01

    We show, in the context of single-photon detection, that an atomic three-level model for a transmon in a transmission line does not support the predictions of the nonlinear polarizability model known as the cross-Kerr effect. We show that the induced displacement of a probe in the presence or absence of a single photon in the signal field, cannot be resolved above the quantum noise in the probe. This strongly suggests that cross-Kerr media are not suitable for photon counting or related single-photon applications. Our results are presented in the context of a transmon in a one-dimensional microwave waveguide, but the conclusions also apply to optical systems. PMID:23414018

  1. Time-averaged photon-counting digital holography.

    PubMed

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario

    2015-09-15

    Time-averaged holography has been using photo-emulsions (early stage) and digital photo-sensitive arrays (later) to record holograms. We extend the recording possibilities by utilizing a photon-counting camera, and we further investigate the possibility of obtaining accurate hologram reconstructions in rather severe experimental conditions. To achieve this, we derived an expression for fringe function comprising the main parameters affecting the hologram recording. Influence of the main parameters, namely the exposure time and the number of averaged holograms, is analyzed by simulations and experiments. It is demonstrated that taking long exposure times can be avoided by averaging over many holograms with the exposure times much shorter than the vibration cycle. Conditions in which signal-to-noise ratio in reconstructed holograms can be substantially increased are provided. PMID:26371907

  2. Optimal selection of thresholds for photon counting CT

    NASA Astrophysics Data System (ADS)

    O'Donnell, Thomas; Schoeck, Friederike; Cheheltani, Rabee; Cormode, David; Fayad, Zahi A.

    2016-03-01

    Recent advances in Photon Counting CT (PCCT) have facilitated the simultaneous acquisition of multiple image volumes with differing energy thresholds. This presents the user with several choices for energy threshold combinations. As compared to standard clinical Dual kVp CT , where the user typically has only three choices of kVp pairings (e.g., 80/150Sn, 90/150Sn, 100/150Sn), a "quad" PCCT system with 14 threshold settings has Choose(14,4)= 1001 possible threshold combinations (assuming no restrictions). In this paper we describe a computationally tractable means to order, from best (most accurate) to worst (least accurate), threshold combinations for the task of discriminating pure materials of assumed approximate concentrations using the Bhattacharyya Coefficient. We observe that this ordering is not necessarily identical to the ordering for the task of decomposing material mixtures into their components. We demonstrate our approach on phantom data.

  3. Maturing CCD photon-counting technology for space flight

    NASA Astrophysics Data System (ADS)

    Mallik, Udayan; Lyon, Richard; Petrone, Peter; McElwain, Michael; Benford, Dominic; Clampin, Mark; HIcks, Brian

    2015-09-01

    This paper discusses charge blooming and starlight saturation - two potential technical problems - when using an Electron Multiplying Charge Coupled Device (EMCCD) type detector in a high-contrast instrument for imaging exoplanets. These problems especially affect an interferometric type coronagraph - coronagraphs that do not use a mask to physically block starlight in the science channel of the instrument. These problems are presented using images taken with a commercial Princeton Instrument EMCCD camera in the Goddard Space Flight Center's (GSFC), Interferometric Coronagraph facility. In addition, this paper discusses techniques to overcome such problems. This paper also discusses the development and architecture of a Field Programmable Gate Array and Digital-to-Analog Converter based shaped clock controller for a photon-counting EMCCD camera. The discussion contained here will inform high-contrast imaging groups in their work with EMCCD detectors.

  4. Investigation of a photon counting avalanche photodiode from Hamamatsu photonics

    NASA Astrophysics Data System (ADS)

    Britvitch, I.; Musienko, Y.; Renker, D.

    2006-11-01

    Multi-cell avalanche photodiodes (APDs) operating in Geiger mode have been shown to be a very promising alternative to photomultiplier tubes for the detection of single photons at room temperature. Like a photomultiplier they have high gain and a fast rise time and they are insensitive to pickup. Beyond it they operate in high magnetic fields, are compact and need a relatively low bias voltage. It is expected that the MOS production technique makes them cheap. Recently PSI and Hamamatsu Photonics worked together for the development of a radiation-hard APD for CMS ECAL and had very good success. The development continued based on a similar design for a photon counting multielement Geiger-mode APD with an area of 1×1 mm 2. The properties of this device have been measured and will be reported.

  5. Photon counting photodiode array detector for far ultraviolet (FUV) astronomy

    NASA Technical Reports Server (NTRS)

    Hartig, G. F.; Moos, H. W.; Pembroke, R.; Bowers, C.

    1982-01-01

    A compact, stable, single-stage intensified photodiode array detector designed for photon-counting, far ultraviolet astronomy applications employs a saturable, 'C'-type MCP (Galileo S. MCP 25-25) to produce high gain pulses with a narrowly peaked pulse height distribution. The P-20 output phosphor exhibits a very short decay time, due to the high current density of the electron pulses. This intensifier is being coupled to a self-scanning linear photodiode array which has a fiber optic input window which allows direct, rigid mechanical coupling with minimal light loss. The array was scanned at a 250 KHz pixel rate. The detector exhibits more than adequate signal-to-noise ratio for pulse counting and event location. Previously announced in STAR as N82-19118

  6. OPTIMA: A Photon Counting High-Speed Photometer

    NASA Astrophysics Data System (ADS)

    Straubmeier, C.; Kanbach, G.; Schrey, F.

    OPTIMA is a small, versatile high-speed photometer which is primarily intended for time resolved observations of young high energy pulsars at optical wavelengths. The detector system consists of eight fiber fed photon counters based on avalanche photodiodes, a GPS timing receiver, an integrating CCD camera to ensure the correct pointing of the telescope and a computerized control unit. Since January 1999 OPTIMA proves its scientific potential by measuring a very detailed lightcurve of the Crab Pulsar as well as by observing cataclysmic variable stars on very short timescales. In this article we describe the design of the detector system focussing on the photon counting units and the software control which correlates the detected photons with the GPS timing signal.

  7. Single photon counting pixel detectors for synchrotron radiation experiments

    NASA Astrophysics Data System (ADS)

    Toyokawa, H.; Broennimann, Ch.; Eikenberry, E. F.; Henrich, B.; Kawase, M.; Kobas, M.; Kraft, P.; Sato, M.; Schmitt, B.; Suzuki, M.; Tanida, H.; Uruga, T.

    2010-11-01

    At the Paul Scherrer Institute PSI an X-ray single photon counting pixel detector (PILATUS) based on the hybrid-pixel detector technology was developed in collaboration with SPring-8. The detection element is a 320 or 450 μm thick silicon sensor forming pixelated pn-diodes with a pitch of 172 μm×172 μm. An array of 2×8 custom CMOS readout chips are indium bump-bonded to the sensor, which leads to 33.5 mm×83.8 mm detective area. Each pixel contains a charge-sensitive amplifier, a single level discriminator and a 20 bit counter. This design realizes a high dynamic range, short readout time of less than 3 ms, a high framing rate of over 200 images per second and an excellent point-spread function. The maximum counting rate achieves more than 2×10 6 X-rays/s/pixel.

  8. Performance of single-photon-counting PILATUS detector modules

    PubMed Central

    Kraft, P.; Bergamaschi, A.; Broennimann, Ch.; Dinapoli, R.; Eikenberry, E. F.; Henrich, B.; Johnson, I.; Mozzanica, A.; Schlepütz, C. M.; Willmott, P. R.; Schmitt, B.

    2009-01-01

    PILATUS is a silicon hybrid pixel detector system, operating in single-photon-counting mode, that has been developed at the Paul Scherrer Institut for the needs of macromolecular crystallography at the Swiss Light Source (SLS). A calibrated PILATUS module has been characterized with monochromatic synchrotron radiation. The influence of charge sharing on the count rate and the overall energy resolution of the detector were investigated. The dead-time of the system was determined using the attenuated direct synchrotron beam. A single module detector was also tested in surface diffraction experiments at the SLS, whereby its performance regarding fluorescence suppression and saturation tolerance were evaluated, and have shown to greatly improve the sensitivity, reliability and speed of surface diffraction data acquisition. PMID:19395800

  9. Novel Photon-Counting Detectors for Free-Space Communication

    NASA Technical Reports Server (NTRS)

    Krainak, M. A.; Yang, G.; Sun, X.; Lu, W.; Merritt, S.; Beck, J.

    2016-01-01

    We present performance data for novel photon-counting detectors for free space optical communication. NASA GSFC is testing the performance of two types of novel photon-counting detectors 1) a 2x8 mercury cadmium telluride (HgCdTe) avalanche array made by DRS Inc., and a 2) a commercial 2880-element silicon avalanche photodiode (APD) array. We present and compare dark count, photon-detection efficiency, wavelength response and communication performance data for these detectors. We successfully measured real-time communication performance using both the 2 detected-photon threshold and AND-gate coincidence methods. Use of these methods allows mitigation of dark count, after-pulsing and background noise effects. The HgCdTe APD array routinely demonstrated photon detection efficiencies of greater than 50% across 5 arrays, with one array reaching a maximum PDE of 70%. We performed high-resolution pixel-surface spot scans and measured the junction diameters of its diodes. We found that decreasing the junction diameter from 31 micrometers to 25 micrometers doubled the e- APD gain from 470 for an array produced in the year 2010 to a gain of 1100 on an array delivered to NASA GSFC recently. The mean single-photon SNR was over 12 and the excess noise factors measurements were 1.2-1.3. The commercial silicon APD array exhibited a fast output with rise times of 300 ps and pulse widths of 600 ps. On-chip individually filtered signals from the entire array were multiplexed onto a single fast output.

  10. Phasor imaging with a widefield photon-counting detector

    PubMed Central

    Siegmund, Oswald H. W.; Tremsin, Anton S.; Vallerga, John V.; Weiss, Shimon

    2012-01-01

    Abstract. Fluorescence lifetime can be used as a contrast mechanism to distinguish fluorophores for localization or tracking, for studying molecular interactions, binding, assembly, and aggregation, or for observing conformational changes via Förster resonance energy transfer (FRET) between donor and acceptor molecules. Fluorescence lifetime imaging microscopy (FLIM) is thus a powerful technique but its widespread use has been hampered by demanding hardware and software requirements. FLIM data is often analyzed in terms of multicomponent fluorescence lifetime decays, which requires large signals for a good signal-to-noise ratio. This confines the approach to very low frame rates and limits the number of frames which can be acquired before bleaching the sample. Recently, a computationally efficient and intuitive graphical representation, the phasor approach, has been proposed as an alternative method for FLIM data analysis at the ensemble and single-molecule level. In this article, we illustrate the advantages of combining phasor analysis with a widefield time-resolved single photon-counting detector (the H33D detector) for FLIM applications. In particular we show that phasor analysis allows real-time subsecond identification of species by their lifetimes and rapid representation of their spatial distribution, thanks to the parallel acquisition of FLIM information over a wide field of view by the H33D detector. We also discuss possible improvements of the H33D detector’s performance made possible by the simplicity of phasor analysis and its relaxed timing accuracy requirements compared to standard time-correlated single-photon counting (TCSPC) methods. PMID:22352658