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Sample records for large detector arrays

  1. Large Format Detector Arrays for Astrophysics

    NASA Technical Reports Server (NTRS)

    Moseley, Harvey

    2006-01-01

    Improvements in detector design and advances in fabrication techniques has resulted in devices which can reach fundamental sensitivity limits in many cases. Many pressing astrophysical questions require large arrays of such sensitive detectors. I will describe the state of far infrared through millimeter detector development at NASA/GSFC, the design and production of large format arrays, and the initial deployment of these powerful new tools.

  2. Indium antimonide large-format detector arrays

    NASA Astrophysics Data System (ADS)

    Davis, Mike; Greiner, Mark

    2011-06-01

    Large format infrared imaging sensors are required to achieve simultaneously high resolution and wide field of view image data. Infrared sensors are generally required to be cooled from room temperature to cryogenic temperatures in less than 10 min thousands of times during their lifetime. The challenge is to remove mechanical stress, which is due to different materials with different coefficients of expansion, over a very wide temperature range and at the same time, provide a high sensitivity and high resolution image data. These challenges are met by developing a hybrid where the indium antimonide detector elements (pixels) are unconnected islands that essentially float on a silicon substrate and form a near perfect match to the silicon read-out circuit. Since the pixels are unconnected and isolated from each other, the array is reticulated. This paper shows that the front side illuminated and reticulated element indium antimonide focal plane developed at L-3 Cincinnati Electronics are robust, approach background limited sensitivity limit, and provide the resolution expected of the reticulated pixel array.

  3. A broadband superconducting detector suitable for use in large arrays.

    PubMed

    Day, Peter K; LeDuc, Henry G; Mazin, Benjamin A; Vayonakis, Anastasios; Zmuidzinas, Jonas

    2003-10-23

    Cryogenic detectors are extremely sensitive and have a wide variety of applications (particularly in astronomy), but are difficult to integrate into large arrays like a modern CCD (charge-coupled device) camera. As current detectors of the cosmic microwave background (CMB) already have sensitivities comparable to the noise arising from the random arrival of CMB photons, the further gains in sensitivity needed to probe the very early Universe will have to arise from large arrays. A similar situation is encountered at other wavelengths. Single-pixel X-ray detectors now have a resolving power of DeltaE < 5 eV for single 6-keV photons, and future X-ray astronomy missions anticipate the need for 1,000-pixel arrays. Here we report the demonstration of a superconducting detector that is easily fabricated and can readily be incorporated into such an array. Its sensitivity is already within an order of magnitude of that needed for CMB observations, and its energy resolution is similarly close to the targets required for future X-ray astronomy missions. PMID:14574407

  4. A readout for large arrays of microwave kinetic inductance detectors.

    PubMed

    McHugh, Sean; Mazin, Benjamin A; Serfass, Bruno; Meeker, Seth; O'Brien, Kieran; Duan, Ran; Raffanti, Rick; Werthimer, Dan

    2012-04-01

    Microwave kinetic inductance detectors (MKIDs) are superconducting detectors capable of counting single photons and measuring their energy in the UV, optical, and near-IR. MKIDs feature intrinsic frequency domain multiplexing (FDM) at microwave frequencies, allowing the construction and readout of large arrays. Due to the microwave FDM, MKIDs do not require the complex cryogenic multiplexing electronics used for similar detectors, such as transition edge sensors, but instead transfer this complexity to room temperature electronics where they present a formidable signal processing challenge. In this paper, we describe the first successful effort to build a readout for a photon counting optical/near-IR astronomical instrument, the ARray Camera for Optical to Near-infrared Spectrophotometry. This readout is based on open source hardware developed by the Collaboration for Astronomy Signal Processing and Electronics Research. Designed principally for radio telescope backends, it is flexible enough to be used for a variety of signal processing applications. PMID:22559560

  5. LAMBDA — Large Area Medipix3-Based Detector Array

    NASA Astrophysics Data System (ADS)

    Pennicard, D.; Lange, S.; Smoljanin, S.; Hirsemann, H.; Graafsma, H.

    2012-11-01

    Medipix3 is a photon-counting readout chip for X-ray detection. It has a small pixel size (55 μm) and a high frame rate with zero dead time, which makes it attractive for experiments at synchrotrons. Using Medipix3, DESY are developing the LAMBDA (Large Area Medipix3-Based Detector Array) system. A single LAMBDA module carries either a single large silicon sensor of 1536 by 512 pixels, or two smaller high-Z sensors. The sensor is bonded to 12 Medipix3 chips, and mounted on a ceramic carrier board. The readout system for the module then provides a fast FPGA, a large RAM and four 10 Gigabit Ethernet links to allow operation at high frame rates. Multiple modules may then be tiled together a larger area. Currently, the first large silicon modules have been constructed and tested at low speed, and the firmware for fast readout is being developed.

  6. Development of LAMBDA: Large Area Medipix-Based Detector Array

    NASA Astrophysics Data System (ADS)

    Pennicard, David; Lange, Sabine; Smoljanin, Sergej; Becker, Julian; Hirsemann, Helmut; Epple, Michael; Graafsma, Heinz

    2011-11-01

    The Medipix3 photon counting readout chip has a range of features — small pixel size, high readout rate and inter-pixel communication — which make it attractive for X-ray scattering and imaging at synchrotrons. DESY have produced a prototype large-area detector module that can carry a 6 by 2 array of Medipix3 chips (1536 by 512 pixels), which can be used with a single large silicon sensor (85mm by 28mm) or two ``hexa'' high-Z sensors. The detector head is designed to be tilable and compatible with low temperatures, and will allow high speed parallel readout of the Medipix3 chips. It consists of a ceramic board, on which the sensor assembly is mounted, and a secondary board for signal routing and voltage regulators. A prototype DAQ board using USB2 readout has also been produced. A ``quad'' Medipix3 sensor assembly has been mounted on the detector head, and successfully configured and read out by the DAQ board. Development has begun on a high-speed readout board, and large-area silicon assemblies are in production.

  7. Digital readouts for large microwave low-temperature detector arrays

    NASA Astrophysics Data System (ADS)

    Mazin, Benjamin A.; Day, Peter K.; Irwin, Kent D.; Reintsema, Carl D.; Zmuidzinas, Jonas

    2006-04-01

    Over the last several years many different types of low-temperature detectors (LTDs) have been developed that use a microwave resonant circuit as part of their readout. These devices include microwave kinetic inductance detectors (MKID), microwave SQUID readouts for transition edge sensors (TES), and NIS bolometers. Current readout techniques for these devices use analog frequency synthesizers and IQ mixers. While these components are available as microwave integrated circuits, one set is required for each resonator. We are exploring a new readout technique for this class of detectors based on a commercial-off-the-shelf technology called software defined radio (SDR). In this method a fast digital to analog (D/A) converter creates as many tones as desired in the available bandwidth. Our prototype system employs a 100 MS/s 16-bit D/A to generate an arbitrary number of tones in 50 MHz of bandwidth. This signal is then mixed up to the desired detector resonant frequency (˜10 GHz), sent through the detector, then mixed back down to baseband. The baseband signal is then digitized with a series of fast analog to digital converters (80 MS/s, 14-bit). Next, a numerical mixer in a dedicated integrated circuit or FPGA mixes the resonant frequency of a specified detector to 0 Hz, and sends the complex detector output over a computer bus for processing and storage. In this paper we will report on our results in using a prototype system to readout a MKID array, including system noise performance, X-ray pulse response, and cross-talk measurements. We will also discuss how this technique can be scaled to read out many thousands of detectors.

  8. Remote alignment of large mirror array for RICH detectors

    NASA Astrophysics Data System (ADS)

    Dalla Torre, S.; Levorato, S.; Menon, G.; Polak, J.; Steiger, L.; Sulc, M.; Tessarotto, F.

    2008-09-01

    Image focusing in large RICH detectors is obtained by composite systems of mirror elements. Monitoring and adjusting the alignment of the mirror elements during data taking are important handles to improve the detector resolution. Mirror adjustment via piezoelectric actuators can combine unprecedented accuracy and match some fundamental requirements: the detector material budget can be kept low and the high purity of the gas radiator can be preserved, a prerequisite when UV photons are detected. A system based on this principle, well suited for COMPASS RICH-1 mirrors, is proposed.

  9. The development and test of ultra-large-format multi-anode microchannel array detector systems

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1984-01-01

    The specific tasks that were accomplished with each of the key elements of the multi-anode microchannel array detector system are described. The modes of operation of position-sensitive electronic readout systems for use with high-gain microchannel plates are described and their performance characteristics compared and contrasted. Multi-anode microchannel array detector systems with formats as large as 256 x 1024 pixels are currently under evaluation. Preliminary performance data for sealed ultraviolet and visible-light detector tubes show that the detector systems have unique characteristics which make them complementary to photoconductive array detectors, such as CCDs, and superior to alternative pulse-counting detector systems employing high-gain MCPs.

  10. Large-format electrographic and array detectors for a space Schmidt imaging telescope

    NASA Technical Reports Server (NTRS)

    Carruthers, George R.; Fischer, Jacqueline; Wray, James D.; Lowrance, John L.

    1990-01-01

    Possible optical designs of imaging detectors for the spaceborne Schmidt telescope proposed by Carruthers et al. (1990) are discussed, surveying the currently or potentially available technology. Consideration is given to FUV electrographic detectors of large format (e.g., 120 mm with 10-micron resolution) using CsI photocathodes, the possible extension of the same technology to the mid-UV using Cs2Te instead of CsI, large CCD arrays for the visible and NIR, electron-bombarded CCDs for the FUV and mid-UV, and the data handling and processing requirements of these detectors.

  11. Assembly, characterization, and operation of large-scale TES detector arrays for ACTPol

    NASA Astrophysics Data System (ADS)

    Pappas, Christine Goodwin

    2016-01-01

    The Polarization-sensitive Receiver for the Atacama Cosmology Telescope (ACTPol) is designed to measure the Cosmic Microwave Background (CMB) temperature and polarization anisotropies on small angular scales. Measurements of the CMB temperature and polarization anisotropies have produced arguably the most important cosmological data to date, establishing the LambdaCDM model and providing the best constraints on most of its parameters. To detect the very small fluctuations in the CMB signal across the sky, ACTPol uses feedhorn-coupled Transition-Edge Sensor (TES) detectors. A TES is a superconducting thin film operated in the transition region between the superconducting and normal states, where it functions as a highly sensitive resistive thermometer. In this thesis, aspects of the assembly, characterization, and in-field operation of the ACTPol TES detector arrays are discussed. First, a novel microfabrication process for producing high-density superconducting aluminum/polyimide flexible circuitry (flex) designed to connect large-scale detector arrays to the first stage of readout is presented. The flex is used in parts of the third ACTPol array and is currently being produced for use in the AdvACT detector arrays, which will begin to replace the ACTPol arrays in 2016. Next, we describe methods and results for the in-lab and on-telescope characterization of the detectors in the third ACTPol array. Finally, we describe the ACTPol TES R(T,I) transition shapes and how they affect the detector calibration and operation. Methods for measuring the exact detector calibration and re-biasing functions, taking into account the R(T,I) transition shape, are presented.

  12. Force spectroscopy with a large dynamic range using small cantilevers and an array detector

    NASA Astrophysics Data System (ADS)

    Schäffer, Tilman E.

    2002-04-01

    The important characteristics of a detector for force spectroscopy measurements are sensitivity, linearity and dynamic range. The commonly used two-segment detector that measures the position of a light beam reflected from the force-sensing cantilever in an atomic force microscope becomes nonlinear when the beam shifts significantly onto one of the segments. For a detection setup optimized for high sensitivity, such as needed for the use with small cantilevers, it is shown both experimentally and theoretically that the dynamic range extends to an upper detection limit of only about 115 nm in cantilever deflection if <10% nonlinearity is required. A detector is presented that circumvents that limitation. This detector is based on a linear arrangement of multiple photodiode segments that are read out individually. With such an array detector, the irradiance distribution of the reflected beam is measured. The reflected beam not only shifts in position but also deforms when the cantilever deflects because the bent cantilever acts as a curved mirror. The mean of the distribution, however, is a linear function of cantilever deflection in both theory and experiment. An array detector is consequently well suited for force measurements for which both high sensitivity and a large dynamic range are required.

  13. The Cosmology Large Angular Scale Surveyor (CLASS): 38 GHz Detector Array of Bolometric Polarimeters

    NASA Technical Reports Server (NTRS)

    Appel, John W.; Ali, Aamir; Amiri, Mandana; Araujo, Derek; Bennett, Charles L.; Boone, Fletcher; Chan, Manwei; Cho, Hsiao-Mei; Chuss, David T.; Colazo, Felipe; Crowe, Erik; Denis, Kevin; Dunner, Rolando; Eimer, Joseph; Essinger-Hileman, Thomas; Gothe, Dominik; Halpern, Mark; Harrington, Kathleen; Kogut, Alan J..; Miller, Nathan; Moseley, Samuel H.; Stevenson, Thomas; Towner, Deborah; U-Yen, Kongpop; Wollack, Edward

    2014-01-01

    The Cosmology Large Angular Scale Surveyor (CLASS) experiment aims to map the polarization of the Cosmic Microwave Background (CMB) at angular scales larger than a few degrees. Operating from Cerro Toco in the Atacama Desert of Chile, it will observe over 65% of the sky at 38, 93, 148, and 217 GHz. In this paper we discuss the design, construction, and characterization of the CLASS 38 GHz detector focal plane, the first ever Q-band bolometric polarimeter array.

  14. Design considerations for large detector arrays on submillimeter-wave telescopes

    NASA Astrophysics Data System (ADS)

    Stark, Antony A.

    2000-07-01

    The emerging technology of large (approximately 10,000 pixel) submillimeter-wave bolometer arrays presents a novel optical design problem -- how can such arrays be fed by diffraction- limited telescope optics where the primary mirror is less than 100,000 wavelengths in diameter? Standard Cassegrain designs for radiotelescope optics exhibit focal surface curvature so large that detectors cannot be placed more than 25 beam diameters from the central ray. The problem is worse for Ritchey-Chretien designs, because these minimize coma while increasing field curvature. Classical aberrations, including coma, are usually dominated by diffraction in submillimeter- wave single dish telescopes. The telescope designer must consider (1) diffraction, (2) aberration, (3) curvature of field, (4) cross-polarization, (5) internal reflections, (6) the effect of blockages, (7) means of beam chopping on- and off-source, (8) gravitational and thermal deformations of the primary mirror, (9) the physical mounting of large detector packages, and (10) the effect of gravity and (11) vibration on those detectors. Simultaneous optimization of these considerations in the case of large detector arrays leads to telescopes that differ considerably from standard radiotelescope designs. Offset optics provide flexibility for mounting detectors, while eliminating blockage and internal reflections. Aberrations and cross-polarization can be the same as on-axis designs having the same diameter and focal length. Trade-offs include the complication of primary mirror homology and an increase in overall cost. A dramatic increase in usable field of view can be achieved using shaped optics. Solutions having one to six mirrors will be discussed, including possible six-mirror design for the proposed South Pole 10 m telescope.

  15. Large-scale numerical simulation of reduced-pitch HgCdTe infrared detector arrays

    NASA Astrophysics Data System (ADS)

    Pinkie, Benjamin; Bellotti, Enrico

    2013-06-01

    Numerical simulations play an important role in the development of large-format infrared detector array tech- nologies, especially when considering devices whose sizes are comparable to the wavelength of the radiation they are detecting. Computational models can be used to predict the optical and electrical response of such devices and evaluate designs prior to fabrication. We have developed a simulation framework which solves Maxwell's equations to determine the electromagnetic properties of a detector and subsequently uses a drift-diffusion ap- proach to asses the electrical response. We apply these techniques to gauge the effects of cathode placement on the inter- and intra-pixel attributes of compositionally graded and constant Hg1-xCdxTe mid-wavelength infrared detectors. In particular, the quantum efficiency, nearest-neighbor crosstalk, and modulation transfer function are evaluated for several device architectures.

  16. Quantum efficiency performances of the NIR European Large Format Array detectors tested at ESTEC

    NASA Astrophysics Data System (ADS)

    Crouzet, P.-E.; Duvet, L.; de Wit, F.; Beaufort, T.; Blommaert, S.; Butler, B.; Van Duinkerken, G.; ter Haar, J.; Heijnen, J.; van der Luijt, K.; Smit, H.

    2015-10-01

    Publisher's Note: This paper, originally published on 10/12/2015, was replaced with a corrected/revised version on 10/23/2015. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance. The Payload Technology Validation Section (SRE-FV) at ESTEC has the goal to validate new technology for future or on-going mission. In this framework, a test set up to characterize the quantum efficiency of near-infrared (NIR) detectors has been created. In the context of the NIR European Large Format Array ("LFA"), 3 deliverables detectors coming from SELEX-UK/ATC (UK) on one side, and CEA/LETI- CEA/IRFU-SOFRADIR (FR) on the other side were characterized. The quantum efficiency of an HAWAII-2RG detector from Teledyne was as well measured. The capability to compare on the same setup detectors from different manufacturers is a unique asset for the future mission preparation office. This publication will present the quantum efficiency results of a HAWAII-2RG detector from Teledyne with a 2.5um cut off compared to the LFA European detectors prototypes developed independently by SELEX-UK/ATC (UK) on one side, and CEA/LETI- CEA/IRFU-SOFRADIR (FR) on the other side.

  17. Calibration Scheme for Large Kinetic Inductance Detector Arrays Based on Readout Frequency Response

    NASA Astrophysics Data System (ADS)

    Bisigello, L.; Yates, S. J. C.; Murugesan, V.; Baselmans, J. J. A.; Baryshev, A. M.

    2016-02-01

    Microwave kinetic inductance detector (MKID) provides a way to build large ground-based sub-mm instruments such as NIKA and A-MKID. For such instruments, therefore, it is important to understand and characterize the response to ensure good linearity and calibration over a wide dynamic range. We propose to use the MKID readout frequency response to determine the MKID responsivity to an input optical source power. A signal can be measured in a KID as a change in the phase of the readout signal with respect to the KID resonant circle. Fundamentally, this phase change is due to a shift in the KID resonance frequency, in turn due to a radiation induced change in the quasiparticle number in the superconducting resonator. We show that the shift in resonant frequency can be determined from the phase shift by using KID phase versus frequency dependence using a previously measured resonant frequency. Working in this calculated resonant frequency, we gain near linearity and constant calibration to a constant optical signal applied in a wide range of operating points on the resonance and readout powers. This calibration method has three particular advantages: first, it is fast enough to be used to calibrate large arrays, with pixel counts in the thousands of pixels; second, it is based on data that are already necessary to determine KID positions; third, it can be done without applying any optical source in front of the array.

  18. Calibration Scheme for Large Kinetic Inductance Detector Arrays Based on Readout Frequency Response

    NASA Astrophysics Data System (ADS)

    Bisigello, L.; Yates, S. J. C.; Murugesan, V.; Baselmans, J. J. A.; Baryshev, A. M.

    2016-07-01

    Microwave kinetic inductance detector (MKID) provides a way to build large ground-based sub-mm instruments such as NIKA and A-MKID. For such instruments, therefore, it is important to understand and characterize the response to ensure good linearity and calibration over a wide dynamic range. We propose to use the MKID readout frequency response to determine the MKID responsivity to an input optical source power. A signal can be measured in a KID as a change in the phase of the readout signal with respect to the KID resonant circle. Fundamentally, this phase change is due to a shift in the KID resonance frequency, in turn due to a radiation induced change in the quasiparticle number in the superconducting resonator. We show that the shift in resonant frequency can be determined from the phase shift by using KID phase versus frequency dependence using a previously measured resonant frequency. Working in this calculated resonant frequency, we gain near linearity and constant calibration to a constant optical signal applied in a wide range of operating points on the resonance and readout powers. This calibration method has three particular advantages: first, it is fast enough to be used to calibrate large arrays, with pixel counts in the thousands of pixels; second, it is based on data that are already necessary to determine KID positions; third, it can be done without applying any optical source in front of the array.

  19. LAMBDA: Large Area Modular BaF2 Detector Array for the measurement of high energy γ rays

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, S.; Bhattacharya, Srijit; Pandit, Deepak; Ray, A.; Pal, Surajit; Banerjee, K.; Kundu, S.; Rana, T. K.; Bhattacharya, S.; Bhattacharya, C.; De, A.; Banerjee, S. R.

    2007-11-01

    A large BaF 2 detector array along with its dedicated CAMAC electronics and VME based data acquisition system has been designed, constructed and installed successfully at VECC, Kolkata for studying high energy γ rays ( >8 MeV). The array consists of 162 detector elements. The detectors were fabricated from bare barium fluoride crystals (each measuring 35 cm in length and having cross-sectional area of 3.5×3.5 cm2). The basic properties of the detectors (energy resolution, time resolution, efficiency, uniformity, fast to slow ratio, etc.) were studied exhaustively. Complete GEANT3 Monte Carlo simulations were performed to optimize the detector design and also to generate the response function. The detector system has been used successfully to measure high energy photons from 113Sb, formed by bombarding 145 and 160 MeV 20Ne beams on a 93Nb target. The measured experimental spectra are in good agreement with those from a modified version of the statistical model code CASCADE. In this paper, we present the complete description of this detector array along with its in-beam performance.

  20. Pyroelectric detector arrays

    NASA Technical Reports Server (NTRS)

    Fripp, A. L.; Robertson, J. B.; Breckenridge, R. (Inventor)

    1982-01-01

    A pyroelectric detector array and the method for using it are described. A series of holes formed through a silicon dioxide layer on the surface of a silicon substrate forms the mounting fixture for the pyroelectric detector array. A series of nontouching strips of indium are formed around the holes to make contact with the backside electrodes and form the output terminals for individual detectors. A pyroelectric detector strip with front and back electrodes, respectively, is mounted over the strips. Biasing resistors are formed on the surface of the silicon dioxide layer and connected to the strips. A metallized pad formed on the surface of layer is connected to each of the biasing resistors and to the film to provide the ground for the pyroelectric detector array.

  1. Pyroelectric detector arrays

    NASA Technical Reports Server (NTRS)

    Fripp, A. L.; Robertson, J. B.; Breckenridge, R. A. (Inventor)

    1982-01-01

    A pryoelectric detector array and the method for making it are described. A series of holes formed through a silicon dioxide layer on the surface of a silicon substrate forms the mounting fixture for the pyroelectric detector array. A series of nontouching strips of indium are formed around the holes to make contact with the backside electrodes and form the output terminals for individual detectors. A pyroelectric detector strip with front and back electrodes, respectively, is mounted over the strip. Biasing resistors are formed on the surface of the silicon dioxide layer and connected to the strips. A metallized pad formed on the surface of the layer is connected to each of the biasing resistors and to the film to provide the ground for the pyroelectric detector array.

  2. Students using large muon detectors to investigate an array of cosmic ray phenomena

    NASA Astrophysics Data System (ADS)

    Sedita, Paul; McFarland, Kevin

    2012-03-01

    During the summers of 2004 to 2008 high school students were given the opportunity to refurbish, characterize and ultimately experiment with large muon detectors at the University of Rochester. The 2.3 m^2 panels used for the cosmic ray investigations were remnants of the NuTeV experiment conducted at Fermilab in the late 1990's, and provided a means for measuring surface cosmic ray muon rates with high precision over many years of time. The first set of experiments carried out by students used data from two stacked paddles running in coincidence mode to detect significant muon fluctuations due to solar events, model an indirect relationship between muon frequency and atmospheric pressure, and determine if muon rates were dependent of the time of day. Current and archived data can be accessed at http://muon2.pas.rochester.edu/data/. In subsequent summers, students and teachers utilized four panel arrays to characterize directionality, angular distribution and frequency of atmospheric muon shower events. For all investigations students presented their findings to their peers and mentors via weekly seminars, e-logs, and poster sessions.

  3. Arrays of Segmented, Tapered Light Guides for Use with Large, Planar Scintillation Detectors

    PubMed Central

    Raylman, Raymond R.; Vaigneur, Keith; Stolin, Alexander V.; Jaliparthi, Gangadhar

    2015-01-01

    Metabolic imaging techniques can potentially improve detection and diagnosis of cancer in women with radiodense and/or fibrocystic breasts. Our group has previously developed a high-resolution positron emission tomography imaging and biopsy device (PEM-PET) to detect and guide the biopsy of suspicious breast lesions. Initial testing revealed that the imaging field-of-view (FOV) of the scanner was smaller than the physical size of the detector’s active area, which could hinder sampling of breast areas close to the chest wall. The purpose of this work was to utilize segmented, tapered light guides for optically coupling the scintillator arrays to arrays of position-sensitive photomultipliers to increase both the active FOV and identification of individual scintillator elements. Testing of the new system revealed that the optics of these structures made it possible to discern detector elements from the complete active area of the detector face. In the previous system the top and bottom rows and left and right columns were not identifiable. Additionally, use of the new light guides increased the contrast of individual detector elements by up to 129%. Improved element identification led to a spatial resolution increase by approximately 12%. Due to attenuation of light in the light guides the detector energy resolution decreased from 18.5% to 19.1%. Overall, these improvements should increase the field-of-view and spatial resolution of the dedicated breast-PET system. PMID:26538685

  4. Modeling and stress analysis of large format InSb focal plane arrays detector under thermal shock

    NASA Astrophysics Data System (ADS)

    Zhang, Li-Wen; Meng, Qing-Duan; Zhang, Xiao-Ling; Yu, Qian; Lv, Yan-Qiu; Si, Jun-Jie

    2013-09-01

    Higher fracture probability, appearing in large format InSb infrared focal plane arrays detector under thermal shock loadings, limits its applicability and suitability for large format equipment, and has been an urgent problem to be solved. In order to understand the fracture mechanism and improve the reliability, three dimensional modeling and stress analysis of large format InSb detector is necessary. However, there are few reports on three dimensional modeling and simulation of large format InSb detector, due to huge meshing numbers and time-consuming operation to solve. To solve the problems, basing on the thermal mismatch displacement formula, an equivalent modeling method is proposed in this paper. With the proposed equivalent modeling method, employing the ANSYS software, three dimensional large format InSb detector is modeled, and the maximum Von Mises stress appearing in InSb chip dependent on array format is researched. According to the maximum Von Mises stress location shift and stress increasing tendency, the adaptability range of the proposed equivalent method is also derived, that is, for 16 × 16, 32 × 32 and 64 × 64 format, its adaptability ranges are not larger than 64 × 64, 256 × 256 and 1024 × 1024 format, respectively. Taking 1024 × 1024 InSb detector as an example, the Von Mises stress distribution appearing in InSb chip, Si readout integrated circuits and indium bump arrays are described, and the causes are discussed in detail. All these will provide a feasible research plan to identify the fracture origins of InSb chip and reduce fracture probability for large format InSb detector.

  5. Detector array design

    SciTech Connect

    Lari, S.

    1996-02-01

    Neutron scattering facility at Oak-Ridge National is used to measure residual stresses in many different materials. Neutron beam from the reactor can be used to penetrate the inner atomic distances of metals which then can be diffracted to a detector to measure the strain. The strain data later can be converted to stresses. The facility currently uses only one detector to carry the measurement. By designing an array of detectors data can be obtained at a much faster rate and or having a much better and improved resolution. The purpose of this report is to show design of such array of detectors and their movements (rotation) for possible maximum data collection at a faster rate.

  6. Development of an array of cooled large area Si(Li) detectors

    SciTech Connect

    Pehl, R.H.; Madden, N.W.; Walton, J.T.; Malone, D.F.; Landis, D.A.; Goulding, F.S.; Cork, C.P.; Wong, Y.K.; Strauss, M.G.; Sherman, I.S.

    1985-10-01

    A system containing six cooled, 34 mm diam by 7 mm thick, high-resolution Si(Li) detectors designed to maximize the sensitivity for counting x rays in the 10-30 keV range to measure trace radionuclides in soil samples has been successfully fabricated. The detectors were mounted in a paddle-shaped cryostat with a single large beryllium window on each side. This configuration provides for efficient anticoincidence background suppression and effectively doubles the sensitive detector area because x rays can impinge on the detectors from both sides. To maximize detection efficiency, the thickness of the cryostat was held to a bare minimum (25 mm); this caused severe difficulties during fabrication of the system. Cutting down the rim of the detectors reduced to an acceptable level the microphony caused by movement of the beryllium window that faces the lithium-diffused contact of the detectors. Since this system will be used for low level counting. careful testing was performed to select materials having the lowest radioactivity.

  7. Final Scientific/Technical Report: Electronics for Large Superconducting Tunnel Junction Detector Arrays for Synchrotron Soft X-ray Research

    SciTech Connect

    Warburton, William K

    2009-03-06

    Superconducting tunnel junction (STJ) detectors offer a an approach to detecting soft x-rays with energy resolutions 4-5 times better and at rates 10 faster than traditions semiconductor detectors. To make such detectors feasible, however, then need to be deployed in large arrays of order 1000 detectors, which in turn implies that their processing electronics must be compact, fully computer controlled, and low cost per channel while still delivering ultra-low noise performance so as to not degrade the STJ's performance. We report on our progress in designing a compact, low cost preamplifier intended for this application. In particular, we were able to produce a prototype preamplifier of 2 sq-cm area and a parts cost of less than $30 that matched the energy resolution of the best conventional system to date and demonstrated its ability to acquire an STJ I-V curve under computer control, the critical step for determining and setting the detectors' operating points under software control.

  8. Map-making for Large-Format Detector Arrays on CCAT

    NASA Astrophysics Data System (ADS)

    Marsden, G.; Jenness, T.; Scott, D.

    2015-09-01

    CCAT is a large submillimetre telescope to be built near the ALMA site in northern Chile. A large-format KID camera, with up to 48,000 detectors at a single waveband sampled at ˜1 kHz, will have a data rate ˜50 times larger than SCUBA-2, the largest existing submillimetre camera. Creating a map from this volume of data will be a challenge, both in terms of memory and processing time required. We investigate how to extend SMURF, the iterative map-maker used for reducing SCUBA-2 observations, to a distributed-node parallel system, and estimate how the processing time scales with the number of nodes in the system.

  9. Very low noise AC/DC power supply systems for large detector arrays

    NASA Astrophysics Data System (ADS)

    Arnaboldi, C.; Baù, A.; Carniti, P.; Cassina, L.; Giachero, A.; Gotti, C.; Maino, M.; Passerini, A.; Pessina, G.

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μVRMS (CUORE setup) and 90 μVRMS (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled).

  10. Very low noise AC/DC power supply systems for large detector arrays.

    PubMed

    Arnaboldi, C; Baù, A; Carniti, P; Cassina, L; Giachero, A; Gotti, C; Maino, M; Passerini, A; Pessina, G

    2015-12-01

    In this work, we present the first part of the power supply system for the CUORE and LUCIFER arrays of bolometric detectors. For CUORE, it consists of AC/DC commercial power supplies (0-60 V output) followed by custom DC/DC modules (48 V input, ±5 V to ±13.5 V outputs). Each module has 3 floating and independently configurable output voltages. In LUCIFER, the AC/DC + DC/DC stages are combined into a commercial medium-power AC/DC source. At the outputs of both setups, we introduced filters with the aim of lowering the noise and to protect the following stages from high voltage spikes that can be generated by the energy stored in the cables after the release of accidental short circuits. Output noise is very low, as required: in the 100 MHz bandwidth the RMS level is about 37 μV(RMS) (CUORE setup) and 90 μV(RMS) (LUCIFER setup) at a load of 7 A, with a negligible dependence on the load current. Even more importantly, high frequency switching disturbances are almost completely suppressed. The efficiency of both systems is above 85%. Both systems are completely programmable and monitored via CAN bus (optically coupled). PMID:26724052

  11. Solid state neutron detector array

    DOEpatents

    Seidel, J.G.; Ruddy, F.H.; Brandt, C.D.; Dulloo, A.R.; Lott, R.G.; Sirianni, E.; Wilson, R.O.

    1999-08-17

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors. 7 figs.

  12. Solid state neutron detector array

    DOEpatents

    Seidel, John G.; Ruddy, Frank H.; Brandt, Charles D.; Dulloo, Abdul R.; Lott, Randy G.; Sirianni, Ernest; Wilson, Randall O.

    1999-01-01

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

  13. Efficiency calibration and coincidence summing correction for large arrays of NaI(Tl) detectors in soccer-ball and castle geometries

    NASA Astrophysics Data System (ADS)

    Anil Kumar, G.; Mazumdar, I.; Gothe, D. A.

    2009-11-01

    Efficiency calibration and coincidence summing correction have been performed for two large arrays of NaI(Tl) detectors in two different configurations. They are, a compact array of 32 conical detectors of pentagonal and hexagonal shapes in soccer-ball geometry and an array of 14 straight hexagonal NaI(Tl) detectors in castle geometry. Both of these arrays provide a large solid angle of detection, leading to considerable coincidence summing of gamma rays. The present work aims to understand the effect of coincidence summing of gamma rays while determining the energy dependence of efficiencies of these two arrays. We have carried out extensive GEANT4 simulations with radio-nuclides that decay with a two-step cascade, considering both arrays in their realistic geometries. The absolute efficiencies have been simulated for gamma energies from 700 to 2800 keV using four different double-photon emitters, namely, 60Co, 46Sc, 94Nb and 24Na. The efficiencies so obtained have been corrected for coincidence summing using the method proposed by Vidmar et al. [11]. The simulations have also been carried out for the same energies assuming mono-energetic point sources, for comparison. Experimental measurements have also been carried out using calibrated point sources of 137Cs and 60Co. The simulated and the experimental results are found to be in good agreement. This demonstrates the reliability of the correction method [11] for efficiency calibration of two large arrays in very different configurations.

  14. Development of an ASIC for the readout and control of near-infrared large array detectors

    NASA Astrophysics Data System (ADS)

    Meier, Dirk; Berge, Hans Kristian Otnes; Hasanbegovic, Amir; Altan, Mehmet A.; Najafiuchevler, Bahram; Azman, Suleyman; Talebi, Jahanzad; Olsen, Alf; Øya, Petter; Paahlsson, Philip; Gheorghe, Codin; Maehlum, Gunnar

    2014-07-01

    The article describes the near infrared readout and controller ASIC (NIRCA) developed by Integrated Detector Electronics AS (IDEAS). The project aims at future astronomical science and Earth observation missions, where the ASIC will be used with image sensors based on mercury cadmium telluride (HgCdTe, or MCT). NIRCA is designed to operate from cryogenic temperatures (77 K) to higher than room temperature (328 K) and in a high radiation environment (LET > 60 MeVcm2/mg). The ASIC connects to the readout integrated circuit (ROIC) and delivers fully digitized data via serial digital output. The ASIC contains an analogue front-end (AFE) with 4 analogue-to-digital converters (ADCs) and programmable gain amplifiers with offset adjustment. The ADCs have a differential input swing of +/-2 V, 12-bit resolution, and a maximum sample rate of 3 MSps. The ASIC contains a programmable sequencer (microcontroller) to generate up to 40 digital signals for the ROIC and to control the analogue front-end and DACs on the chip. The ASIC has two power supply voltage regulators that provide the ROIC with 1.8 V and 3.3 V, and programmable 10-bit DACs to generate 16 independent reference and bias voltages from 0.3 V to 3 V. In addition NIRCA allows one to read 8 external digital signals, and monitor external and internal analogue signals including onchip temperature. NIRCA can be programmed and controlled via SPI interface for all internal functions and allows data forwarding from and to the ROIC SPI interface.

  15. Detector Arrays For Infrared Astronomy

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Mckelvey, M. E.; Goebel, J. H.; Anderson, G. M.; Lee, J. H.

    1988-01-01

    Paper describes status of program for developing integrated infrared detectors for astronomy. Program covers variety of detectors, including extrinsic silicon, extrinsic germanium, and indium antimonide devices with hybrid silicon multiplexers. Paper notes for arrays to reach background noise limit in cryogenic telescope, continued reductions in readout noise and dark current needed.

  16. Massively parallel MRI detector arrays

    NASA Astrophysics Data System (ADS)

    Keil, Boris; Wald, Lawrence L.

    2013-04-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas via reception, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays.

  17. Massively Parallel MRI Detector Arrays

    PubMed Central

    Keil, Boris; Wald, Lawrence L

    2013-01-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  18. Massively parallel MRI detector arrays.

    PubMed

    Keil, Boris; Wald, Lawrence L

    2013-04-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas via reception, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called "ultimate" SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  19. The CHROMA focal plane array: a large-format, low-noise detector optimized for imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Demers, Richard T.; Bailey, Robert; Beletic, James W.; Bernd, Steve; Bhargava, Sidharth; Herring, Jason; Kobrin, Paul; Lee, Donald; Pan, Jianmei; Petersen, Anders; Piquette, Eric; Starr, Brian; Yamamoto, Matthew; Zandian, Majid

    2013-09-01

    The CHROMA (Configurable Hyperspectral Readout for Multiple Applications) is an advanced Focal Plane Array (FPA) designed for visible-infrared imaging spectroscopy. Using Teledyne's latest substrateremoved HgCdTe detector, the CHROMA FPA has very low dark current, low readout noise and high, stable quantum efficiency from the deep blue (390nm) to the cutoff wavelength. CHROMA has a pixel pitch of 30 microns and is available in array formats ranging from 320×480 to 1600×480 pixels. Users generally disperse spectra over the 480 pixel-length columns and image spatially over the n×160 pixellength rows, where n=2, 4, 8, 10. The CHROMA Readout Integrated Circuit (ROIC) has Correlated Double Sampling (CDS) in pixel and generates its own internal bias signals and clocks. This paper presents the measured performance of the CHROMA FPA with 2.5 micron cutoff wavelength including the characterization of noise versus pixel gain, power dissipation and quantum efficiency.

  20. High Performance Measurement System of Large Area Solid-State Track Detector Array for Ultra Heavy Cosmic Rays

    NASA Astrophysics Data System (ADS)

    Kodaira, S.; Doke, T.; Hareyama, M.; Hasebe, N.; Sakurai, K.; Ota, S.; Sato, M.; Yasuda, N.; Nakamura, S.; Kamei, T.; Tawara, H.; Ogura, K.

    The handling of solid-state track detector (SSTD) has been historically required for a long period and many human powers to scan and analyze etch-pits produced on the detector. Because a large area greater than a few m2 detector is required to observe ultraheavy nuclei in galactic cosmic rays, a high speed scanning system is practically important to realize our observation. We have developed the fast automated digital imaging optical microscope (HSP-1000) to scan and analyze the etch-pit produced on the detector, whose image acquisition speed is 50-100 times faster than conventional microscope system. Furthermore, analyzing massive cosmic ray track data produced in extremely large exposed area requires a completely automated multi-sample scanning system. The developed automated system consists of a modified HSP-1000 microscope for image acquisition, a robot arm to replace the sample trays, a magazine station for storing sample trays, and a scanning and analyzing computer to control the whole system. Moreover, since the improvement of thickness measurement accuracy in local area of SSTD will allow us to achieve higher charge and mass resolutions, the new system to measure the SSTD thickness located adjacent to etch-pit in SSTD with an excellent resolution of +/- 0.2 um has been developed.

  1. Synchronizing large systolic arrays

    SciTech Connect

    Fisher, A.L.; Kung, H.T.

    1982-04-01

    Parallel computing structures consist of many processors operating simultaneously. If a concurrent structure is regular, as in the case of systolic array, it may be convenient to think of all processors as operating in lock step. Totally synchronized systems controlled by central clocks are difficult to implement because of the inevitable problem of clock skews and delays. An alternate means of enforcing necessary synchronization is the use of self-timed, asynchronous schemes, at the cost of increased design complexity and hardware cost. Realizing that different circumstances call for different synchronization methods, this paper provides a spectrum of synchronization models; based on the assumptions made for each model, theoretical lower bounds on clock skew are derived, and appropriate or best-possible synchronization schemes for systolic arrays are proposed. This paper represents a first step towards a systematic study of synchronization problems for large systolic arrays.

  2. Encapsulated thermopile detector array for IR microspectrometer

    NASA Astrophysics Data System (ADS)

    Wu, Huaiwen; Emadi, Arvin; de Graaf, Ger; Wolffenbuttel, Reinoud F.

    2010-04-01

    The miniaturized IR spectrometer discussed in this paper is comprised of: slit, planar imaging diffraction grating and Thermo-Electric (TE) detector array, which is fabricated using CMOS compatible MEMS technology. The resolving power is maximized by spacing the TE elements at an as narrow as possible pitch, which is limited by processing constraints. The large aspect ratio of the TE elements implies a large cross-sectional area between adjacent elements within the array and results in a relatively large lateral heat exchange between micromachined elements by thermal diffusion. This thermal cross-talk is about 10% in case of a gap spacing of 10 μm between elements. Therefore, the detector array should be packaged (and operated) in vacuum in order to reduce the cross-talk due to the air conduction through the gap. Thin film packaging is a solution to achieve an operating air pressure at1.3 mBar, which reduces the cross-talk to 0.4%. An absorber based on an optical interference filter design is also designed and fabricated as an IC compatible post-process on top the detector array. The combination of the use of CMOS compatible materials and processing with high absorbance in 1.5 - 5 μm wavelength range makes a complete on-chip microspectrometer possible.

  3. Stressed detector arrays for airborne astronomy

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Beeman, J. W.; Haller, E. E.; Geis, N.; Poglitsch, A.; Rumitz, M.

    1989-01-01

    The development of stressed Ge:Ga detector arrays for far-infrared astronomy from the Kuiper Airborne Observatory (KAO) is discussed. Researchers successfully constructed and used a three channel detector array on five flights from the KAO, and have conducted laboratory tests of a two-dimensional, 25 elements (5x5) detector array. Each element of the three element array performs as well as the researchers' best single channel detector, as do the tested elements of the 25 channel system. Some of the exciting new science possible with far-infrared detector arrays is also discussed.

  4. The FPGA Pixel Array Detector

    NASA Astrophysics Data System (ADS)

    Hromalik, Marianne S.; Green, Katherine S.; Philipp, Hugh T.; Tate, Mark W.; Gruner, Sol M.

    2013-02-01

    A proposed design for a reconfigurable x-ray Pixel Array Detector (PAD) is described. It operates by integrating a high-end commercial field programmable gate array (FPGA) into a 3-layer device along with a high-resistivity diode detection layer and a custom, application-specific integrated circuit (ASIC) layer. The ASIC layer contains an energy-discriminating photon-counting front end with photon hits streamed directly to the FPGA via a massively parallel, high-speed data connection. FPGA resources can be allocated to perform user defined tasks on the pixel data streams, including the implementation of a direct time autocorrelation function (ACF) with time resolution down to 100 ns. Using the FPGA at the front end to calculate the ACF reduces the required data transfer rate by several orders of magnitude when compared to a fast framing detector. The FPGA-ASIC high-speed interface, as well as the in-FPGA implementation of a real-time ACF for x-ray photon correlation spectroscopy experiments has been designed and simulated. A 16×16 pixel prototype of the ASIC has been fabricated and is being tested.

  5. Why compton-suppressed germanium detector arrays?

    SciTech Connect

    Diamond, R.M.

    1993-10-01

    Nuclear spectroscopic studies have provided a strong incentive to obtain {gamma}-ray detectors with increasingly better energy resolution, higher full-energy peak efficiencies, and greater sensitivity or resolving power. A major step was the introduction of Ge detectors in the early 60`s. But because of the low atomic number of Ge they have a poor response function; a majority of interacting gamma rays of moderate energy Compton scatter out of the detector leaving a large low-energy background. The remedy was to add a Compton-suppression shield made of NaI around the Ge crystal, and if interactions occurred simultaneously in the NaI scintillator and in the Ge detector to veto that event. Efficiencies also increased greatly when an English-Danish collaboration assembled five Ge detectors, each with a NaI suppressor, into the first array at the end of 1980. Obviously, a system of five such detectors gave much better statistics than the usual two bare detectors used for obtaining coincidence data (by a factor of 10). A few years later, another major improvement came with replacement of the NaI suppressors with shields made of the much denser bismuth germanate (BGO) as scintillator, as these could be thinner leading to arrays with of order 20 detectors. Use of such a large number of detectors led to the realization that for cascades of coincident gamma rays, as in going down a band, the improvement in the peak/background ratio observed and already appreciated in going from singles spectra to gated (double-) coincidence spectra continued when doubly-gated triple-coincidence data were compared for the first time to singly-gated double-coincidence ones. The higher-gated spectra were much cleaner and more selective, though with poorer statistics, and the advantages of higher folds and efficiencies led to the proposals for the larger 4{pi} arrays of today, Eurogam and GASP in Europe and Gammasphere in the U.S.

  6. Preliminary validation results of an ASIC for the readout and control of near-infrared large array detectors

    NASA Astrophysics Data System (ADS)

    Pâhlsson, Philip; Meier, Dirk; Otnes Berge, Hans Kristian; Øya, Petter; Steenari, David; Olsen, Alf; Hasanbegovic, Amir; Altan, Mehmet A.; Najafiuchevler, Bahram; Talebi, Jahanzad; Azman, Suleyman; Gheorghe, Codin; Ackermann, Jörg; Mæhlum, Gunnar

    2015-06-01

    In this paper we present initial test results of the Near Infrared Readout and Controller ASIC (NIRCA), designed for large area image sensors under contract from the European Space Agency (ESA) and the Norwegian Space Center. The ASIC is designed to read out image sensors based on mercury cadmium telluride (HgCdTe, or MCT) operating down to 77 K. IDEAS has developed, designed and initiated testing of NIRCA with promising results, showing complete functionality of all ASIC sub-components. The ASIC generates programmable digital signals to clock out the contents of an image array and to amplify, digitize and transfer the resulting pixel charge. The digital signals can be programmed into the ASIC during run-time and allows for windowing and custom readout schemes. The clocked out voltages are amplified by programmable gain amplifiers and digitized by 12-bit, 3-Msps successive approximation register (SAR) analogue-to-digital converters (ADC). Digitized data is encoded using 8-bit to 10-bit encoding and transferred over LVDS to the readout system. The ASIC will give European researchers access to high spectral sensitivity, very low noise and radiation hardened readout electronics for astronomy and Earth observation missions operating at 77 K and room temperature. The versatility of the chip makes the architecture a possible candidate for other research areas, or defense or industrial applications that require analog and digital acquisition, voltage regulation, and digital signal generation.

  7. Coherent Detector Arrays for Continuum and Spectral Line Applications

    NASA Technical Reports Server (NTRS)

    Gaier, Todd C.

    2006-01-01

    This viewgraph presentation reviews the requirements for improved coherent detector arrays for use in continuum and spectral line applications. With detectors approaching fundamental limits, large arrays offer the only path to sensitivity improvement. Monolithic Microwave Integrated Circuit (MMIC) technology offers a straightforward path to massive focal plane millimeter wave arrays: The technology will readily support continuum imagers, polarimeters and spectral line receivers from 30-110 GHz. Science programs, particularly large field blind surveys will benefit from simultaneous observations of hundreds or thousands of pixels 1000 element array is competitive with a cost less than $2M.

  8. Multianode microchannel array detectors for Space Shuttle imaging applications

    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, photoncounting array detectors that have been developed and qualified specifically for use in space. MAMA detectors with formats as large as 256 x 1024 pixels are now in use or under construction for a variety of imaging and tracking applications. These photo-emissive detectors can be operated in a windowless configuration at extreme ultraviolet and soft X-ray wavelengths or in a sealed configuration at ultraviolet and visible wavelengths. The construction and modes-of-operation of the MAMA detectors are briefly described and the scientific objectives of a number of sounding rocket and Space Shuttle instruments utilizing these detectors are outlined. Performance characteristics of the MAMA detectors that are of fundamental importance for operation in the Space Shuttle environment are described and compared with those of the photo-conductive array detectors such as the CCDs and CIDs.

  9. Multi-Channel Detector Arrays for Heavy Ion Beam Probes

    NASA Astrophysics Data System (ADS)

    Aceto, Steven; Beckstead, Jeffrey; Castracane, James; Iguchi, H.; Fujisawa, A.; Demers, Diane; Schatz, John

    1997-11-01

    InterScience, Inc. has developed a multiple slit detector array for use with heavy ion beam probes. The first array was a twenty element array installed on the TEXT tokamak. An initial set of data was obtained with this array prior to the shutdown on the TEXT tokamak in December of 1995. More recently, a smaller detector array has been developed for use in the CHS torsatron in Nagoya. This array is smaller than the TEXT array, with ten elements, but contains two prototype sets of detector plates to determine the beam position. The operating conditions in CHS are expected to be much harsher than in TEXT, with ECH and NBI plasmas. Trajectory simulations allowed for the design of a tilted detector array in the CHS vacuum vessel. First tests of the CHS array will begin in the late summer of 1997. Other candidate machines for detector arrays are the MST reversed field pinch, in which a beam probe is expected to be installed in late 1997 or early 1998 and the Large Helical Device (LHD) which is expected to be operational in 1998. Design issues, trajectory simulations and array test results will be presented. Supported in part by the U.S. Department of Energy under Grant #DE-FG02-94ER81788

  10. Si:As BIB detector arrays

    NASA Technical Reports Server (NTRS)

    Bharat, R.; Petroff, M. D.; Speer, J. J.; Stapelbroek, M. G.

    1986-01-01

    Highlights of the results obtained on arsenic-doped silicon blocked impurity band (BIB) detectors and arrays since the invention of the BIB concept a few years ago are presented. After a brief introduction and a description of the BIB concept, data will be given on single detector performance. Then different arrays that were fabricated will be described and test data presented.

  11. Junction-side illuminated silicon detector arrays

    DOEpatents

    Iwanczyk, Jan S.; Patt, Bradley E.; Tull, Carolyn

    2004-03-30

    A junction-side illuminated detector array of pixelated detectors is constructed on a silicon wafer. A junction contact on the front-side may cover the whole detector array, and may be used as an entrance window for light, x-ray, gamma ray and/or other particles. The back-side has an array of individual ohmic contact pixels. Each of the ohmic contact pixels on the back-side may be surrounded by a grid or a ring of junction separation implants. Effective pixel size may be changed by separately biasing different sections of the grid. A scintillator may be coupled directly to the entrance window while readout electronics may be coupled directly to the ohmic contact pixels. The detector array may be used as a radiation hardened detector for high-energy physics research or as avalanche imaging arrays.

  12. Thermopile Detector Arrays for Space Science Applications

    NASA Technical Reports Server (NTRS)

    Foote, M. C.; Kenyon, M.; Krueger, T. R.; McCann, T. A.; Chacon, R.; Jones, E. W.; Dickie, M. R.; Schofield, J. T.; McCleese, D. J.; Gaalema, S.

    2004-01-01

    Thermopile detectors are widely used in uncooled applications where small numbers of detectors are required, particularly in low-cost commercial applications or applications requiring accurate radiometry. Arrays of thermopile detectors, however, have not been developed to the extent of uncooled bolometer and pyroelectric/ferroelectric arrays. Efforts at JPL seek to remedy this deficiency by developing high performance thin-film thermopile detectors in both linear and two-dimensional formats. The linear thermopile arrays are produced by bulk micromachining and wire bonded to separate CMOS readout electronic chips. Such arrays are currently being fabricated for the Mars Climate Sounder instrument, scheduled for launch in 2005. Progress is also described towards realizing a two-dimensional thermopile array built over CMOS readout circuitry in the substrate.

  13. Characterization of Large Volume 3.5″ x 8″ LaBr3:Ce Detectors for the HECTOR+ array

    NASA Astrophysics Data System (ADS)

    Camera, F.; Giaz, A.; Pellegri, L.; Riboldi, S.; Blasi, N.; Boiano, C.; Bracco, A.; Brambilla, S.; Ceruti, S.; Coelli, S.; Crespi, F. C. L.; Csatlòs, M.; Krasznahorkay, A.; Gulyàs, J.; Lodetti, S.; Frega, S.; Miani, A.; Million, B.; Stuhl, L.; Wieland, O.

    2014-03-01

    A selection of the properties of large volume, cylindrical 3.5" x 8" LaBr3:Ce scintillation detectors coupled to a 3.5" PMT (model R10233-1000SEL from HAMAMATSU) and a special designed Voltage Divider (LABRVD) will be discussed. A number of 10 of such detectors constitute the HECTOR+ array which, in fall 2012, measured at GSI coupled to the AGATA DEMOSTRATOR at the PRESPEC experimental setup. These crystals are among the largest ever produced and needed to be characterized. We have performed several tests and here we discuss, in particular, the energy resolution measured using monochromatic γ-ray sources and in-beam reactions producing γ-rays up to 22.6 MeV. As already measured in two previous works a saturation in the energy resolution was observed in case of high energy gamma rays. Crystal non-homogeneities and PMT gain drifts can affect the resolution of measurements especially in case of high energy γ-rays.

  14. Microparticle impact calibration of the Arrayed Large-Area Dust Detectors in INterplanetary space (ALADDIN) onboard the solar power sail demonstrator IKAROS

    NASA Astrophysics Data System (ADS)

    Hirai, Takayuki; Cole, Michael J.; Fujii, Masayuki; Hasegawa, Sunao; Iwai, Takeo; Kobayashi, Masanori; Srama, Ralf; Yano, Hajime

    2014-10-01

    The Arrayed Large-Area Dust Detectors in INterplanetary space (ALADDIN) is an array of polyvinylidene fluoride (PVDF) based dust detectors aboard the solar power sail demonstrator named IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). The total sensor area of ALADDIN (0.54 m2) is the world's largest among the past PVDF-based dust detectors. IKAROS was launched in May 2010 and then ALADDIN measured cosmic dust impacts for 16 months while orbiting around between 0.7 and 1.1 AU. The main scientific objective of ALADDIN is to reveal number density of ≥10-μm-sized dust in the zodiacal cloud with much higher time-space resolution than that achieved by any past in-situ measurements. The distribution of ≥10-μm-sized dust can be also observed mainly with the light scattering by optical instruments. This paper gives the scientific objectives, the instrumental description, and the results of microparticle impact calibration of ALADDIN conducted in ground laboratories. For the calibration tests we used Van de Graaf accelerators (VdG), two-stage light gas guns (LGG), and a nano-second pulsed Nd:YAG laser (nsPL). Through these experiments, we obtained depolarization charge signal caused by hypervelocity impacts or laser irradiation using the flight spare of 20-μm-thick PVDF sensor and the electronics box of ALADDIN. In the VdG experiment we accelerated iron, carbon, and silver microparticles at 1-30 km/s, while in the LGG experiment we performed to shoot 100's-μm-sized particles of soda-lime glass and stainless steel at 3-7 km/s as single projectile. For interpolation to ≥10-μm size, we irradiated infrared laser at the energy of 15-20 mJ directly onto the PVDF sensor. From the signal analysis, we developed a calibration law for estimation of masses of impacted dust particles. The dynamic range of ALADDIN corresponds from 9×10-14 kg to 2×10-10 kg (4-56 μm in diameter at density of 2.0 g/cm3) at the expected impact velocity of 10 km/s at 1 AU

  15. High-resolution ionization detector and array of such detectors

    DOEpatents

    McGregor, Douglas S.; Rojeski, Ronald A.

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  16. Next generation microwave multiplexers for low-temperature detector arrays

    NASA Astrophysics Data System (ADS)

    Irwin, Kent

    We propose to continue our successful program for the development of breakthrough readout technology for low-temperature detectors. The next generation of larger arrays requires multiplexed readout at microwave frequencies. Multiplexing at microwave frequencies with superconducting microwave resonators shows great promise for the instrumentation of very large arrays of transition-edge sensors (TES) and microwave kinetic inductance detectors (MKID). Applications include the detection of the cosmic microwave background (CMB), submillimeter and far-infrared astronomy, optical astronomy, and x-ray astronomy. These arrays will play a critical role in answering questions about the origins and evolution of galaxies, stars, and planetary systems, the physics of the cosmos, and the physics of the inflationary epoch in the early universe. We propose an integrated program to develop quantum-limited amplifiers to enable the readout of both large TES and MKID arrays. These amplifiers include microwave SQUIDs for TES readout and wideband parametric amplifiers for MKID arrays.

  17. Monolithic short wave infrared (SWIR) detector array

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A monolithic self-scanned linear detector array was developed for remote sensing in the 1.1- 2.4-micron spectral region. A high-density IRCCD test chip was fabricated to verify new design approaches required for the detector array. The driving factors in the Schottky barrier IRCCD (Pdsub2Si) process development are the attainment of detector yield, uniformity, adequate quantum efficiency, and lowest possible dark current consistent with radiometric accuracy. A dual-band module was designed that consists of two linear detector arrays. The sensor architecture places the floating diffusion output structure in the middle of the chip, away from the butt edges. A focal plane package was conceptualized and includes a polycrystalline silicon substrate carrying a two-layer, thick-film interconnecting conductor pattern and five epoxy-mounted modules. A polycrystalline silicon cover encloses the modules and bond wires, and serves as a radiation and EMI shield, thermal conductor, and contamination seal.

  18. Modeling Charge Collection in Detector Arrays

    NASA Technical Reports Server (NTRS)

    Hardage, Donna (Technical Monitor); Pickel, J. C.

    2003-01-01

    A detector array charge collection model has been developed for use as an engineering tool to aid in the design of optical sensor missions for operation in the space radiation environment. This model is an enhancement of the prototype array charge collection model that was developed for the Next Generation Space Telescope (NGST) program. The primary enhancements were accounting for drift-assisted diffusion by Monte Carlo modeling techniques and implementing the modeling approaches in a windows-based code. The modeling is concerned with integrated charge collection within discrete pixels in the focal plane array (FPA), with high fidelity spatial resolution. It is applicable to all detector geometries including monolithc charge coupled devices (CCDs), Active Pixel Sensors (APS) and hybrid FPA geometries based on a detector array bump-bonded to a readout integrated circuit (ROIC).

  19. Chunking of Large Multidimensional Arrays

    SciTech Connect

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  20. Integration of an amorphous silicon passive pixel sensor array with a lateral amorphous selenium detector for large area indirect conversion x-ray imaging applications

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Yazdandoost, Mohammad Y.; Keshavarzi, Rasoul; Shin, Kyung-Wook; Hristovski, Christos; Abbaszadeh, Shiva; Chen, Feng; Majid, Shaikh Hasibul; Karim, Karim S.

    2011-03-01

    Previously, we reported on a single-pixel detector based on a lateral a-Se metal-semiconductor-metal structure, intended for indirect conversion X-ray imaging. This work is the continuous effort leading to the first prototype of an indirect conversion X-ray imaging sensor array utilizing lateral amorphous selenium. To replace a structurally-sophisticated vertical multilayer amorphous silicon photodiode, a lateral a-Se MSM photodetector is employed which can be easily integrated with an amorphous silicon thin film transistor passive pixel sensor array. In this work, both 2×2 macro-pixel and 32×32 micro-pixel arrays were fabricated and tested along with discussion of the results.

  1. Technology developments toward large format long wavelength bolometer arrays

    NASA Astrophysics Data System (ADS)

    Allen, Christine A.; Benford, Dominic J.; Miller, Timothy M.; Moseley, S. Harvey; Staguhn, Johannes G.; Wollack, Edward J.

    2007-09-01

    We are developing a kilopixel, filled bolometer array for infrared astronomy. The array consists of three individual components, to be merged into a single, working unit; 1) a transition edge sensor (TES) bolometer array, operating in the milliKelvin regime, 2) quarter-wave resonance backshorts, and 3) superconducting quantum interference device (SQUID) multiplexer readout. The detector array is a filled, square-grid of suspended, silicon membrane bolometers with superconducting thermistors. The spacing of the backshort beneath the detector grid can be set from ~30-300 microns by adjusting two process parameters during fabrication. We have produced prototype, monolithic arrays having 1 mm and 2 mm pitch detectors. The key technologies required for kilopixel arrays of detectors to be hybridized to SQUID multiplexer readout circuits have been demonstrated. Mechanical models of large-format detector grids have been indium bump-bonded to dummy multiplexer readouts to study electrical continuity. A monolithic array of 1 mm pitch detectors has been mated to a backshort grid optimized for a 350 micron resonant wavelength. Through-wafer microvias, for electroplated, low-resistance electrical connection of detector elements, have been prototyped using deep reactive ion etching. The ultimate goal of this work is to develop large-format (thousands of pixels) bolometer array architecture with background-limited sensitivity, suitable for a wide range of long wavelengths and a wide range of astronomical applications such as imaging, spectroscopy, and polarimetry and applicable for ground-based, suborbital, and space-based instruments.

  2. The neutron detector array DESCANT

    NASA Astrophysics Data System (ADS)

    Bildstein, Vinzenz; Garrett, P. E.; Bandyopadhay, D.; Bangay, J.; Bianco, L.; Demand, G.; Hadinia, B.; Leach, K. G.; Sumithrarachchi, C.; Wong, J.; Ashley, S. F.; Crider, B. P.; McEllistrem, M. T.; Peters, E. E.; Prados-Estévez, F. M.; Yates, S. W.; Vanhoy, J. R.; Garnsworthy, A. B.; Pearson, C. J.

    2013-10-01

    The DESCANT array at TRIUMF is designed to track neutrons from RIB experiments. DESCANT is comprised of 70 close-packed deuterated liquid organic scintillators coupled to digital fast read-out ADC modules. This configuration will permit online pulse-shape discrimination between neutron and γ-ray events. The anisotropy of the n-d scattering will allow to distinguish higher neutron multiplicities from scattering within the array and to determine the neutron energy spectrum directly from the pulse-height spectrum without using TOF. Comparative type-testing of candidate small deuterated scintillators to non-deuterated scintillators have been performed at the University of Kentucky. Results of these type-testing measurements will be presented together with first designs of the firmware written for the fast sampling ADC modules.

  3. Optimal design of a generalized compound eye particle detector array

    NASA Astrophysics Data System (ADS)

    Nehorai, Arye; Liu, Zhi; Paldi, Eytan

    2006-05-01

    We analyze the performance of a novel detector array for detecting and localizing particle emitting sources. The array is spherically shaped and consists of multiple "eyelets," each having a conical shape with a lens on top and a particle detectors subarray inside. The array's configuration is inspired by and generalizes the biological compound eye: it has a global spherical shape and allows a large number of detectors in each eyelet. The array can be used to detect particles including photons (e.g. visible light, X or γ rays), electrons, protons, neutrons, or α particles. We analyze the performance of the array by computing statistical Cramer-Rao bounds on the errors in estimating the direction of arrival (DOA) of the incident particles. In numerical examples, we first show the influence of the array parameters on its performance bound on the mean-square angular error (MSAE). Then we optimize the array's configuration according to a min-max criterion, i.e. minimize the worst case lower bound of the MSAE. Finally we introduce two estimators of the source direction using the proposed array and analyze their performance, thereby showing that the performance bound is attainable in practice. Potential applications include artificial vision, astronomy, and security.

  4. Centroid tracking with area array detectors

    NASA Technical Reports Server (NTRS)

    Glavich, T. A.

    1986-01-01

    A computer program (ALGEVAL) has been developed to simulate the position estimating behavior of a centroid estimator algorithm using data typical of optical point spread function data recorded by an area array detector. Typical results are shown of varying detector properties and optical point spread function types. The detector parameters currently available for study include read noise mean value, dark current mean value and spatial variation, charge transfer efficiency and point spread function location, saturation level, signal level and pixel size. The program is capable of calculating any order centroid using an array size from 2 x 2 to 15 x 15 pixels. The output of the program is either a performance map, histogram data or tabluar data. A number of further developments are recommended.

  5. High-contrast X-ray micro-tomography of low attenuation samples using large area hybrid semiconductor pixel detector array of 10 × 5 Timepix chips

    NASA Astrophysics Data System (ADS)

    Karch, J.; Krejci, F.; Bartl, B.; Dudak, J.; Kuba, J.; Kvacek, J.; Zemlicka, J.

    2016-01-01

    State-of-the-art hybrid pixel semiconductor detectors provide excellent imaging properties such as unlimited dynamic range, high spatial resolution, high frame rate and energy sensitivity. Nevertheless, a limitation in the use of these devices for imaging has been the small sensitive area of a few square centimetres. In the field of microtomography we make use of a large area pixel detector assembled from 50 Timepix edgeless chips providing fully sensitive area of 14.3 × 7.15 cm2. We have successfully demonstrated that the enlargement of the sensitive area enables high-quality tomographic measurements of whole objects with high geometrical magnification without any significant degradation in resulting reconstructions related to the chip tilling and edgeless sensor technology properties. The technique of micro-tomography with the newly developed large area detector is applied for samples formed by low attenuation, low contrast materials such a seed from Phacelia tanacetifolia, a charcoalified wood sample and a beeswax seal sample.

  6. Terahertz detectors and focal plane arrays

    NASA Astrophysics Data System (ADS)

    Rogalski, A.; Sizov, F.

    2011-09-01

    Terahertz (THz) technology is one of emerging technologies that will change our life. A lot of attractive applications in security, medicine, biology, astronomy, and non-destructive materials testing have been demonstrated already. However, the realization of THz emitters and receivers is a challenge because the frequencies are too high for conventional electronics and the photon energies are too small for classical optics. As a result, THz radiation is resistant to the techniques commonly employed in these well established neighbouring bands. In the paper, issues associated with the development and exploitation of THz radiation detectors and focal plane arrays are discussed. Historical impressive progress in THz detector sensitivity in a period of more than half century is analyzed. More attention is put on the basic physical phenomena and the recent progress in both direct and heterodyne detectors. After short description of general classification of THz detectors, more details concern Schottky barrier diodes, pair braking detectors, hot electron mixers and field-effect transistor detectors, where links between THz devices and modern technologies such as micromachining are underlined. Also, the operational conditions of THz detectors and their upper performance limits are reviewed. Finally, recent advances in novel nanoelectronic materials and technologies are described. It is expected that applications of nanoscale materials and devices will open the door for further performance improvement in THz detectors.

  7. Interference effects in Reticon photodiode array detectors

    NASA Astrophysics Data System (ADS)

    Mount, George H.; Sanders, Ryan W.; Brault, James W.

    1992-03-01

    A detector system incorporating the Reticon RL1024S photodiode array has been constructed as part of a double spectrograph to be used to study the earth's atmosphere from ground-based and aircraft-based platforms. To determine accurately the abundances of atmospheric trace gases, this new system must be able to measure spectral absorptions as small as 0.02 percent. The detector exhibits superior signal-to-noise characteristics at the light levels characteristic of scattered skylights, but interference in the passivating layer causes problems in achieving the required precision. The mechanism of the problems and the solution implemented are described in detail.

  8. Development of the ORRUBA Silicon Detector Array

    SciTech Connect

    Pain, S. D.; Bardayan, Daniel W; Blackmon, Jeff C; Chae, K. Y.; Chipps, K.; Cizewski, J. A.; Hatarik, Robert; Johnson, M. S.; Jones, K. L.; Kapler, R.; Kozub, R. L.; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D; O'Malley, Patrick; Smith, Michael Scott; Thomas, J. S.

    2009-01-01

    High quality radioactive beams have recently made possible the measurement of (d,p) reactions on unstable nuclei in inverse kinematics, which can yield information on the development of single-neutron structure away from stability, and are of astrophysical interest due to the proximity to suggested r-process paths. The Oak Ridge Rutgers University Barrel Array (ORRUBA) is a new high solid-angular coverage array, composed of two rings of silicon detectors, optimized for measuring (d,p) reactions. A partial implementation has been used to measure (d,p) reactions on nuclei around the N = 82 shell closure.

  9. The SORDS trimodal imager detector arrays

    NASA Astrophysics Data System (ADS)

    Wakeford, Daniel; Andrews, H. R.; Clifford, E. T. H.; Li, Liqian; Bray, Nick; Locklin, Darren; Hynes, Michael V.; Toolin, Maurice; Harris, Bernard; McElroy, John; Wallace, Mark; Lanza, Richard

    2009-05-01

    The Raytheon Trimodal Imager (TMI) uses coded aperture and Compton imaging technologies as well as the nonimaging shadow technology to locate an SNM or radiological threat in the presence of background. The heart of the TMI is two arrays of NaI crystals. The front array serves as both a coded aperture and the first scatterer for Compton imaging. It is made of 35 5x5x2" crystals with specially designed low profile PMTs. The back array is made of 30 2.5x3x24" position-sensitive crystals which are read out at both ends. These crystals are specially treated to provide the required position resolution at the best possible energy resolution. Both arrays of detectors are supported by aluminum superstructures. These have been efficiently designed to allow a wide field of view and to provide adequate support to the crystals to permit use of the TMI as a vehicle-mounted, field-deployable system. Each PMT has a locally mounted high-voltage supply that is remotely controlled. Each detector is connected to a dedicated FPGA which performs automated gain alignment and energy calibration, event timing and diagnostic health checking. Data are streamed, eventby- event, from each of the 65 detector FPGAs to one master FPGA. The master FPGA acts both as a synchronization clock, and as an event sorting unit. Event sorting involves stamping events as singles or as coincidences, based on the approximately instantaneous detector hit pattern. Coincidence determination by the master FPGA provides a pre-sorting for the events that will ultimately be used in the Compton imaging and coded aperture imaging algorithms. All data acquisition electronics have been custom designed for the TMI.

  10. Large Format Arrays for Far Infrared and Millimeter Astronomy

    NASA Technical Reports Server (NTRS)

    Moseley, Harvey

    2004-01-01

    Some of the most compelling questions in modem astronomy are best addressed with submillimeter and millimeter observations. The question of the role of inflation in the early evolution of the universe is best addressed with large sensitive arrays of millimeter polarimeters. The study of the first generations of galaxies requires sensitive submillimeter imaging, which can help us to understand the history of energy release and nucleosynthesis in the universe. Our ability to address these questions is dramatically increasing, driven by dramatic steps in the sensitivity and size of available detector arrays. While the MIPS instrument on the SIRTF mission will revolutionize far infrared astronomy with its 1024 element array of photoconductors, thermal detectors remain the dominant technology for submillimeter and millimeter imaging and polarimetry. The last decade has seen the deployment of increasingly large arrays of bolometers, ranging from the 48 element arrays deployed on the KAO in the late 198Os, to the SHARC and SCUBA arrays in the 1990s. The past years have seen the deployment of a new generation of larger detector arrays in SHARC II (384 channels) and Bolocam (144 channels). These detectors are in operation and are beginning to make significant impacts on the field. Arrays of sensitive submillimeter bolometers on the SPIRE instrument on Herschel will allow the first large areas surveys of the sky, providing important insight into the evolution of galaxies. The next generation of detectors, led by SCUBA II, will increase the focal scale of these instruments by an order of magnitude. Two major missions are being planned by NASA for which further development of long wavelength detectors is essential, The SAFlR mission, a 10-m class telescope with large arrays of background limited detectors, will extend our reach into the epoch of initial galaxy formation. A major goal of modem cosmology is to test the inflationary paradigm in the early evolution of the universe

  11. Adaptive Detector Arrays for Optical Communications Receivers

    NASA Technical Reports Server (NTRS)

    Vilnrotter, V.; Srinivasan, M.

    2000-01-01

    The structure of an optimal adaptive array receiver for ground-based optical communications is described and its performance investigated. Kolmogorov phase screen simulations are used to model the sample functions of the focal-plane signal distribution due to turbulence and to generate realistic spatial distributions of the received optical field. This novel array detector concept reduces interference from background radiation by effectively assigning higher confidence levels at each instant of time to those detector elements that contain significant signal energy and suppressing those that do not. A simpler suboptimum structure that replaces the continuous weighting function of the optimal receiver by a hard decision on the selection of the signal detector elements also is described and evaluated. Approximations and bounds to the error probability are derived and compared with the exact calculations and receiver simulation results. It is shown that, for photon-counting receivers observing Poisson-distributed signals, performance improvements of approximately 5 dB can be obtained over conventional single-detector photon-counting receivers, when operating in high background environments.

  12. SQUID Multiplexers for Cryogenic Detector Arrays

    NASA Technical Reports Server (NTRS)

    Irwin, Kent; Beall, James; Deiker, Steve; Doriese, Randy; Duncan, William; Hilton, Gene; Moseley, S. Harvey; Reintsema, Carl; Stahle, Caroline; Ullom, Joel; Vale, Leila

    2004-01-01

    SQUID multiplexers make it possible to build arrays of thousands of cryogenic detectors with a manageable number of readout channels. We are developing time-division SQUID multiplexers based on Nb trilayer SQUIDs to read arrays of superconducting transition-edge sensors. Our first-generation, 8-channel SQUID multiplexer was used in FIBRE, a one-dimensional TES array for submillimeter astronomy. Our second-generation 32-pixel multiplexer, based on an improved architecture, has been developed for instruments including Constellation-X, SCUBA-2, and solar x-ray astronomy missions. SCUBA-2, which is being developed for the James Clerk Maxwell Telescope, will have more than 10,000 pixels. We are now developing a third-generation architecture based on superconducting hot-electron switches. The use of SQUID multiplexers in instruments operating at above 2 K will also be discussed.

  13. Conceptual design of a hybrid Ge:Ga detector array

    NASA Technical Reports Server (NTRS)

    Parry, C. M.

    1984-01-01

    For potential applications in space infrared astronomy missions such as the Space Infrared Telescope Facility and the Large Deployable Reflector, integrated arrays of long-wavelength detectors are desired. The results of a feasibility study which developed a design for applying integrated array techniques to a long-wavelength (gallium-doped germanium) material to achieve spectral coverage between 30 and 200 microns are presented. An approach which builds up a two-dimensional array by stacking linear detector modules is presented. The spectral response of the Ge:Ga detectors is extended to 200 microns by application of uniaxial stress to the stack of modules. The detectors are assembled with 1 mm spacing between the elements. Multiplexed readout of each module is accomplished with integration sampling of a metal-oxide-semiconductor (MOS) switch chip. Aspects of the overall design, including the anticipated level of particle effects on the array in the space environment, a transparent electrode design for 200 microns response, estimates of optical crosstalk, and mechanical stress design calculations are included.

  14. Spiral biasing adaptor for use in Si drift detectors and Si drift detector arrays

    DOEpatents

    Li, Zheng; Chen, Wei

    2016-07-05

    A drift detector array, preferably a silicon drift detector (SDD) array, that uses a low current biasing adaptor is disclosed. The biasing adaptor is customizable for any desired geometry of the drift detector single cell with minimum drift time of carriers. The biasing adaptor has spiral shaped ion-implants that generate the desired voltage profile. The biasing adaptor can be processed on the same wafer as the drift detector array and only one biasing adaptor chip/side is needed for one drift detector array to generate the voltage profiles on the front side and back side of the detector array.

  15. Large Aperture Electrostatic Dust Detector

    SciTech Connect

    C.H. Skinner, R. Hensley, and A.L Roquemore

    2007-10-09

    Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 ν has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

  16. Plans for CHICOS a detector array in California High Schools

    NASA Astrophysics Data System (ADS)

    McKeown, R. D.; Carr, R.; Gao, J.; Guerrera, T.; Horton-Smith, S.; Ito, T.; Seki, R.; Li, S.-P.; Shoup, A.; Yodh, G.

    The California HIgh school Cosmic ray ObServatory, CHICOS, is a collabora-tive project involving Caltech, Cal State Northridge, UC Irvine, and local high school physics teachers to site a large array of particle detectors at high schools in the Los Angeles area. The Los Angeles basin is quite unique in that there is a very large area (> 5000 km2 ) of uniformly dense population with available high school infrastructure. We have obtained 164 scintillation detectors from the decommissioned CYGNUS experiment in New Mexico, and are presently working to instrument these detectors in an array with area of more than 400 km2 . Each site will have a detection system with a computer to acquire data, and will operate in an autonomous mode using GPS time-stamping of events. The data from each site will be transmitted via internet to a central computer at Caltech where the data will be logged, processed, and accessible to the high schools. The availability of existing infrastructure in the Los Angeles school system with internet connections, power, and shelter provides an excellent op-portunity to develop such a large array. In the future we would like to expand the scope of this project to cover a larger fraction of the Los Angeles area and include a much larger percentage of the high schools, hopefully increasing the area to over 1000 km2 .

  17. Astronomical imaging with infrared array detectors.

    PubMed

    Gatley, I; Depoy, D L; Fowler, A M

    1988-12-01

    History shows that progress in astronomy often stems directly from technological innovation and that each portion of the electromagnetic spectrum offers unique insights into the nature of the universe. Most recently, the widespread availability of infrared-sensitive two-dimensional array detectors has led to dramatic improvements in the capabilities of conventional ground-based observatories. The impact of this new technology on our understanding of a wide variety of phenomena is illustrated here by infrared pictures of star-forming regions, of nebulae produced by the late stages of stellar evolution, of the nucleus of our own galaxy(the Milky Way), and of activity in other galaxies. PMID:17817072

  18. Detector Arrays for an Airborne Infrared Echelle Spectrometer

    NASA Technical Reports Server (NTRS)

    Erickson, E. F.; Haas, M. R.; Baltz, J. A.; McKelvey, M. E.; Colgan, S. W. J.; Lynch, D. H.; Wolf, J.; Witteborn, Fred (Technical Monitor)

    1996-01-01

    The design of a long-slit echelle spectrograph covering the 16 - 210 micron range for use on the Stratospheric Observatory for Infrared Astronomy (SOFIA) is under study at NASA-Ames. This wavelength range is selected for its content of important astrophysical spectral lines accessible from an airborne platform, and availability of suitable detectors. Two dimensional arrays will be used to simultaneously provide spectral coverage in the dispersion direction and imaging in the cross-dispersion direction. Major goals are: (1) to reach sensitivities limited primarily by the background from the residual atmosphere and the telescope; (2) to provide imaging not far from the diffraction limit of the 2.5 meter (effective) aperture of the telescope; and (3) to obtain diffraction-limited spectral resolution from the large echelle grating, which means that the resolving power increases with decreasing wavelength. To meet these requirements, three detector types are forseen: a commercially available monolithic Si:Sb IBC array to cover the wavelength range from 16 to 40 microns, a Ge:Sb photoconductor array to cover the range from 40 to 125 microns, and a stressed Ge:Ga photoconductor array covering the range from 125 to 210 microns. The paper discusses details of the studies and plans for the field optics, detectors, and readouts.

  19. Ultralow-Background Large-Format Bolometer Arrays

    NASA Technical Reports Server (NTRS)

    Benford, Dominic; Chervenak, Jay; Irwin, Kent; Moseley, S. Harvey; Oegerle, William (Technical Monitor)

    2002-01-01

    In the coming decade, work will commence in earnest on large cryogenic far-infrared telescopes and interferometers. All such observatories - for example, SAFIR, SPIRIT, and SPECS - require large format, two dimensional arrays of close-packed detectors capable of reaching the fundamental limits imposed by the very low photon backgrounds present in deep space. In the near term, bolometer array architectures which permit 1000 pixels - perhaps sufficient for the next generation of space-based instruments - can be arrayed efficiently. Demonstrating the necessary performance, with Noise Equivalent Powers (NEPs) of order 10-20 W/square root of Hz, will be a hurdle in the coming years. Superconducting bolometer arrays are a promising technology for providing both the performance and the array size necessary. We discuss the requirements for future detector arrays in the far-infrared and submillimeter, describe the parameters of superconducting bolometer arrays able to meet these requirements, and detail the present and near future technology of superconducting bolometer arrays. Of particular note is the coming development of large format planar arrays with absorber-coupled and antenna-coupled bolometers.

  20. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Astrophysics Data System (ADS)

    Henderson, S. W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Calabrese, E.; Choi, S. K.; Coughlin, K. P.; Crowley, K. T.; Datta, R.; Devlin, M. J.; Duff, S. M.; Dunkley, J.; Dünner, R.; van Engelen, A.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Hills, F.; Hilton, G. C.; Hincks, A. D.; Hloẑek, R.; Ho, S. P.; Hubmayr, J.; Huffenberger, K.; Hughes, J. P.; Irwin, K. D.; Koopman, B. J.; Kosowsky, A. B.; Li, D.; McMahon, J.; Munson, C.; Nati, F.; Newburgh, L.; Niemack, M. D.; Niraula, P.; Page, L. A.; Pappas, C. G.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Sehgal, N.; Sherwin, B. D.; Sievers, J. L.; Simon, S. M.; Spergel, D. N.; Staggs, S. T.; Stevens, J. R.; Thornton, R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-03-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies—imaged in intensity and polarization at few arcminute-scale resolution—will enable precision cosmological constraints and also a wide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the Advanced ACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the Advanced ACTPol cryogenic detector arrays.

  1. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Astrophysics Data System (ADS)

    Henderson, S. W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Calabrese, E.; Choi, S. K.; Coughlin, K. P.; Crowley, K. T.; Datta, R.; Devlin, M. J.; Duff, S. M.; Dunkley, J.; Dünner, R.; van Engelen, A.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Hills, F.; Hilton, G. C.; Hincks, A. D.; Hloẑek, R.; Ho, S. P.; Hubmayr, J.; Huffenberger, K.; Hughes, J. P.; Irwin, K. D.; Koopman, B. J.; Kosowsky, A. B.; Li, D.; McMahon, J.; Munson, C.; Nati, F.; Newburgh, L.; Niemack, M. D.; Niraula, P.; Page, L. A.; Pappas, C. G.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Sehgal, N.; Sherwin, B. D.; Sievers, J. L.; Simon, S. M.; Spergel, D. N.; Staggs, S. T.; Stevens, J. R.; Thornton, R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-08-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies—imaged in intensity and polarization at few arcminute-scale resolution—will enable precision cosmological constraints and also a wide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the Advanced ACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the Advanced ACTPol cryogenic detector arrays.

  2. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Technical Reports Server (NTRS)

    Henderson, S.W.; Battaglia, N.; Wollack, E. J.; Allison, R.; Austermann, J.; Baildon, T.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.

    2016-01-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies-imaged in intensity and polarization at few arcminute-scale resolution-will enable precision cosmological constraints and also awide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the AdvancedACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the AdvancedACTPol cryogenic detector arrays.

  3. Large phased-array radars

    SciTech Connect

    Brookner, D.E.

    1988-12-15

    Large phased-array radars can play a very important part in arms control. They can be used to determine the number of RVs being deployed, the type of targeting of the RVs (the same or different targets), the shape of the deployed objects, and possibly the weight and yields of the deployed RVs. They can provide this information at night as well as during the day and during rain and cloud covered conditions. The radar can be on the ground, on a ship, in an airplane, or space-borne. Airborne and space-borne radars can provide high resolution map images of the ground for reconnaissance, of anti-ballistic missile (ABM) ground radar installations, missile launch sites, and tactical targets such as trucks and tanks. The large ground based radars can have microwave carrier frequencies or be at HF (high frequency). For a ground-based HF radar the signal is reflected off the ionosphere so as to provide over-the-horizon (OTH) viewing of targets. OTH radars can potentially be used to monitor stealth targets and missile traffic.

  4. Low dark current InGaAs detector arrays for night vision and astronomy

    NASA Astrophysics Data System (ADS)

    MacDougal, Michael; Geske, Jon; Wang, Chad; Liao, Shirong; Getty, Jonathan; Holmes, Alan

    2009-05-01

    Aerius Photonics has developed large InGaAs arrays (1K x 1K and greater) with low dark currents for use in night vision applications in the SWIR regime. Aerius will present results of experiments to reduce the dark current density of their InGaAs detector arrays. By varying device designs and passivations, Aerius has achieved a dark current density below 1.0 nA/cm2 at 280K on small-pixel, detector arrays. Data is shown for both test structures and focal plane arrays. In addition, data from cryogenically cooled InGaAs arrays will be shown for astronomy applications.

  5. Demonstration of a passive, low-noise, millimeter-wave detector array for imaging

    NASA Astrophysics Data System (ADS)

    Wikner, David; Grossman, Erich

    2009-05-01

    The design of a millimeter-wave (MMW) camera is presented. The camera is meant to serve as a demonstration platform for a new 32-channel MMW detector array that requires no pre-amplification prior to detection. The Army Research Laboratory (ARL) and National Institute of Standards and Technology (NIST) have worked with the Defense Advanced Research Projects Agency and several contractors for four years to develop an affordable MMW detector array technology suitable for use in a large staring array. The camera described uses one particular embodiment of detector array that resulted from the program. This paper reviews the design of the MMW optics that will be used to form imagery with the linear array and the tradeoffs made in that design. Also presented are the results of laboratory tests of the detector array that were made at both ARL and NIST.

  6. Indium Hybridization of Large Format TES Bolometer Arrays to Readout Multiplexers for Far-Infrared Astronomy

    NASA Technical Reports Server (NTRS)

    Miller, Timothy M.; Costen, Nick; Allen, Christine

    2007-01-01

    This conference poster reviews the Indium hybridization of the large format TES bolometer arrays. We are developing a key technology to enable the next generation of detectors. That is the Hybridization of Large Format Arrays using Indium bonded detector arrays containing 32x40 elements which conforms to the NIST multiplexer readout architecture of 1135 micron pitch. We have fabricated and hybridized mechanical models with the detector chips bonded after being fully back-etched. The mechanical support consists of 30 micron walls between elements Demonstrated electrical continuity for each element. The goal is to hybridize fully functional array of TES detectors to NIST readout.

  7. Multiwavelength infrared focal plane array detector

    NASA Technical Reports Server (NTRS)

    Forrest, Stephen R. (Inventor); Olsen, Gregory H. (Inventor); Kim, Dong-Su (Inventor); Lange, Michael J. (Inventor)

    1995-01-01

    A multiwavelength focal plane array infrared detector is included on a common substrate having formed on its top face a plurality of In.sub.x Ga.sub.1-x As (x.ltoreq.0.53) absorption layers, between each pair of which a plurality of InAs.sub.y P.sub.1-y (y<1) buffer layers are formed having substantially increasing lattice parameters, respectively, relative to said substrate, for preventing lattice mismatch dislocations from propagating through successive ones of the absorption layers of decreasing bandgap relative to said substrate, whereby a plurality of detectors for detecting different wavelengths of light for a given pixel are provided by removing material above given areas of successive ones of the absorption layers, which areas are doped to form a pn junction with the surrounding unexposed portions of associated absorption layers, respectively, with metal contacts being formed on a portion of each of the exposed areas, and on the bottom of the substrate for facilitating electrical connections thereto.

  8. Novel Multiplexing Technique for Detector and Mixer Arrays

    NASA Technical Reports Server (NTRS)

    Karasik, Boris S.; McGrath, William R.

    2001-01-01

    Future submillimeter and far-infrared space telescopes will require large-format (many 1000's of elements) imaging detector arrays to perform state-of-the-art astronomical observations. A crucial issue related to a focal plane array is a readout scheme which is compatible with large numbers of cryogenically-cooled (typically < 1 K) detectors elements. When the number of elements becomes of the order of thousands, the physical layout for individual readout amplifiers becomes nearly impossible to realize for practical systems. Another important concern is the large number of wires leading to a 0.1-0.3 K platform. In the case of superconducting transition edge sensors (TES), a scheme for time-division multiplexing of SQUID read-out amplifiers has been recently demonstrated. In this scheme the number of SQUIDs is equal to the number (N) of the detectors, but only one SQUID is turned on at a time. The SQUIDs are connected in series in each column of the array, so the number of wires leading to the amplifiers can be reduced, but it is still of the order of N. Another approach uses a frequency domain multiplexing scheme of the bolometer array. The bolometers are biased with ac currents whose frequencies are individual for each element and are much higher than the bolometer bandwidth. The output signals are connected in series in a summing loop which is coupled to a single SQUID amplifier. The total number of channels depends on the ratio between the SQUID bandwidth and the bolometer bandwidth and can be at least 100 according to the authors. An important concern about this technique is a contribution of the out-of-band Johnson noise which multiplies by factor N(exp 1/2) for each frequency channel. We propose a novel solution for large format arrays based on the Hadamard transform coding technique which requires only one amplifier to read out the entire array of potentially many 1000's of elements and uses approximately 10 wires between the cold stage and room temperature

  9. High resolution 64-element pyroelectric linear array IR detector

    NASA Astrophysics Data System (ADS)

    Turnbull, Andrew A.; Cooke, Martin E.

    1987-01-01

    A 64-element pyroelectric linear array detector has been developed. Included within the detector is a corresponding array of source followers together with a multiplexer and amplifier. High responsivity and high detectivity have been achieved, together with a low level of microphony.

  10. Position sensitivity of MAMA detectors. [Multi-Anode Microchannel Array

    NASA Technical Reports Server (NTRS)

    Morgan, J. S.; Slater, D. S.; Timothy, J. G.; Jenkins, E. B.

    1988-01-01

    The results of laboratory and telescopic measurements of the position sensitivity of a visible MAMA detector utilizing a 'coarse-fine' array are presented. The photometric accuracy of this detector was determined under point source illumination. It was found that computed centroid positions are accurate across the entire array to within 0.04 pixels.

  11. Detector arrays for low-background space infrared astronomy

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Mckelvey, M. E.; Goebel, J. H.; Anderson, G. M.; Lee, J. H.

    1986-01-01

    The status of development and characterization tests of integrated infrared detector array technology for astronomy applications is described. The devices under development include intrinsic, extrinsic silicon, and extrinsic germanium detectors, with hybrid silicon multiplexers. Laboratary test results and successful astronomy imagery have established the usefulness of integrated arrays in low-background astronomy applications.

  12. Detector arrays for low-background space infrared astronomy

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Mckelvey, M. E.; Goebel, J. H.; Anderson, G. M.; Lee, J. H.

    1986-01-01

    The status of development and characterization tests of integrated infrared detector array technology for astronomy applications is described. The devices under development include intrinsic, extrinsic silicon, and extrinsic germanium detectors, with hybrid silicon multiplexers. Laboratory test results and successful astronomy imagery have established the usefulness of integrated arrays in low-background astronomy applications.

  13. The Impact of Array Detectors on Raman Spectroscopy

    ERIC Educational Resources Information Center

    Denson, Stephen C.; Pommier, Carolyn J. S.; Denton, M. Bonner

    2007-01-01

    The impact of array detectors in the field of Raman spectroscopy and all low-light-level spectroscopic techniques is examined. The high sensitivity of array detectors has allowed Raman spectroscopy to be used to detect compounds at part per million concentrations and to perform Raman analyses at advantageous wavelengths.

  14. Fabrication of Pop-up Detector Arrays on Si Wafers

    NASA Technical Reports Server (NTRS)

    Li, Mary J.; Allen, Christine A.; Gordon, Scott A.; Kuhn, Jonathan L.; Mott, David B.; Stahle, Caroline K.; Wang, Liqin L.

    1999-01-01

    High sensitivity is a basic requirement for a new generation of thermal detectors. To meet the requirement, close-packed, two-dimensional silicon detector arrays have been developed in NASA Goddard Space Flight Center. The goal of the task is to fabricate detector arrays configured with thermal detectors such as infrared bolometers and x-ray calorimeters to use in space fliGht missions. This paper focuses on the fabrication and the mechanical testing of detector arrays in a 0.2 mm pixel size, the smallest pop-up detectors being developed so far. These array structures, nicknamed "PUDS" for "Pop-Up Detectors", are fabricated on I pm thick, single-crystal, silicon membranes. Their designs have been refined so we can utilize the flexibility of thin silicon films by actually folding the silicon membranes to 90 degrees in order to obtain close-packed two-dimensional arrays. The PUD elements consist of a detector platform and two legs for mechanical support while also serving as electrical and thermal paths. Torsion bars and cantilevers connecting the detector platform to the legs provide additional flexures for strain relief. Using micro-electromechanical structure (MEMS) fabrication techniques, including photolithography, anisotropic chemical etching, reactive-ion etching, and laser dicing, we have fabricated PLTD detector arrays of fourteen designs with a variation of four parameters including cantilever length, torsion bar length and width, and leg length. Folding tests were conducted to test mechanical stress distribution for the array structures. We obtained folding yields and selected optimum design parameters to reach minimal stress levels. Computer simulation was also employed to verify mechanical behaviors of PUDs in the folding process. In addition, scanning electron microscopy was utilized to examine the flatness of detectors and the alignment of detector pixels in arrays. The fabrication of thermistors and heaters on the pop-up detectors is under way

  15. Modulation transfer function of a trapezoidal pixel array detector

    NASA Astrophysics Data System (ADS)

    Wang, Fan; Guo, Rongli; Ni, Jinping; Dong, Tao

    2016-01-01

    The modulation transfer function (MTF) is the tool most commonly used for quantifying the performance of an electro-optical imaging system. Recently, trapezoid-shaped pixels were designed and used in a retina-like sensor in place of rectangular-shaped pixels. The MTF of a detector with a trapezoidal pixel array is determined according to its definition. Additionally, the MTFs of detectors with differently shaped pixels, but the same pixel areas, are compared. The results show that the MTF values of the trapezoidal pixel array detector are obviously larger than those of rectangular and triangular pixel array detectors at the same frequencies.

  16. Performance characteristics of multi-anode microchannel array detector systems

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1984-01-01

    The multi-anode microchannel arrays (MAMAs) are state-of-the-art, pulse-counting, photoelectric array detectors designed specifically for use in space astrophysics instruments. The present paper provides a description of recent progress related to the development of ultraviolet and visible-light versions of the MAMA detectors, taking into account a comparison of the operating characteristics of these devices with those of photoconductive array detectors, such as the CCDs. Attention is given to MAMA detector system design parameters, the operating characteristics of MAMAs and CCDs, MAMA performance characteristics, and future developments.

  17. A 16 x 16 element extrinsic silicon detector array

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Two bismuth-doped silicon accumulation-mode charge-injection device (AMCID) infrared detector arrays are studied. The geometry and composition of the arrays, and a description of the cold and warm electronics components of the system are described. Instructions for setting up and operating the array system, plus results of a functional test, are included.

  18. Large Imaging X-ray MKID Arrays for Astrophysics

    NASA Astrophysics Data System (ADS)

    Mazin, Benjamin

    Microwave Kinetic Inductance Detectors, or MKIDs, are a relatively new type of superconducting detector with built-in frequency domain multiplexing (FDM). Like Transition Edge Sensors (TESs), MKIDs can count single X-ray photons over a wide energy range and determine their energy and arrival time. Unlike TESs, MKIDs allow very large pixel counts with a fairly simple room temperature readout. MKIDs currently are being used for submillimeter/millimeter and optical/UV astronomy. They are a mature technology, and our group has recently demonstrated very promising X-ray MKIDs. The uncertain state of future NASA X-ray missions makes fundamental detector research even more important. New detector capabilities are one of the best ways to increase mission performance without increasing cost. We propose to continue our existing ROSES-funded program to develop X-ray MKIDs with the ultimate goal of developing large, sensitive focal plane arrays for future X-ray missions. In particular, we will focus on making a hybrid array with a core of high count rate, high energy resolution single pixels, and a very large (up to 50 mm x 50 mm, megapixel or larger) extended array with a moderate 5-15 eV energy resolution R=E/FWHM(E) at 6 keV. For the single pixel core of the array we propose a new type of "calorimetric" MKID that uses the temperature rise of a membrane suspended MKID and absorber, very similar in design to the TES detectors that have achieved an energy resolution of 1.8 eV at 5.9 keV. For the outer array the ability of absorber-coupled MKIDs to trap quasiparticles in a lower gap material allows the separation of the function of photon absorption from detection, and also allows distributed "strip detector/DROID" configurations that can drastically increase the size of the arrays. MKID arrays using rectangular 2-D detectors could quickly reach megapixel pixel counts and cover 25 cm^2. The science potential of a CCD-scale array but with 10-20 times better energy resolution is

  19. Bolometric Array Detectors for Space-Borne Astronomy

    NASA Technical Reports Server (NTRS)

    Lange, Andrew E.

    2000-01-01

    Funding from the NASA Innovative Research Grant was used to develop bolometric detectors. As described in the proposal, silicon nitride micromesh ('spider-web') absorbers had been demonstrated at U.C. Berkeley but not developed to be flight-worthy devices. We proceeded to first fabricate bolometers with Neutron Transmutation Doped (NTD) Ge thermistors that demonstrated high optical coupling (Church et al. 1996) and were developed for a ground-based millimeter-wave receiver (Mauskopf et al. 1997). The next generation of devices used In bump-bonded thermistors to achieve devices with performance product NEP*sqrt(tau) = 3e - 18 j at 300 mK, demonstrating a full order of magnitude improvement over pervious devices. These devices achieved an NEP = 1e-18 W/rtHz (Murray et al. 1996) as promised in the proposal. Sensitivities as good as 1e - 19 W/rtHz appear achievable with the silicon nitride architecture (Bock et al. 1997). Finally, arrays of micromesh bolometers were shown to be feasible in the last year of the program by etching a large number of devices on a single silicon wafer (75 mm). Full arrays were subsequently demonstrated for selection on the ESA/NASA Far-Infrared Space Telescope (FIRST) in competition with detectors provided by CEA in France and GSFC in the US Micromesh bolometer arrays are now baselined for both the ESA/NASA Planck and FIRST missions.

  20. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras.

    PubMed

    Bolotnikov, A E; Ackley, K; Camarda, G S; Cherches, C; Cui, Y; De Geronimo, G; Fried, J; Hodges, D; Hossain, A; Lee, W; Mahler, G; Maritato, M; Petryk, M; Roy, U; Salwen, C; Vernon, E; Yang, G; James, R B

    2015-07-01

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm(3) detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays' performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects. PMID:26233363

  1. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

    NASA Astrophysics Data System (ADS)

    Bolotnikov, A. E.; Ackley, K.; Camarda, G. S.; Cherches, C.; Cui, Y.; De Geronimo, G.; Fried, J.; Hodges, D.; Hossain, A.; Lee, W.; Mahler, G.; Maritato, M.; Petryk, M.; Roy, U.; Salwen, C.; Vernon, E.; Yang, G.; James, R. B.

    2015-07-01

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm3 detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays' performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  2. Big Data Challenges for Large Radio Arrays

    NASA Technical Reports Server (NTRS)

    Jones, Dayton L.; Wagstaff, Kiri; Thompson, David; D'Addario, Larry; Navarro, Robert; Mattmann, Chris; Majid, Walid; Lazio, Joseph; Preston, Robert; Rebbapragada, Umaa

    2012-01-01

    Future large radio astronomy arrays, particularly the Square Kilometre Array (SKA), will be able to generate data at rates far higher than can be analyzed or stored affordably with current practices. This is, by definition, a "big data" problem, and requires an end-to-end solution if future radio arrays are to reach their full scientific potential. Similar data processing, transport, storage, and management challenges face next-generation facilities in many other fields.

  3. A possible EAS array above the Soudan 2 detector

    NASA Technical Reports Server (NTRS)

    Sivaprasad, K.

    1985-01-01

    Multiple high energy muons, when studied with a large area detector, can be useful in the study of the composition of cosmic rays at energies approx. 10 14 eV. The Soudan II detector, primarily designed to detect nucleon decay, is located approx. 600 m deep underground and has dimensions of 16m x 8m x 5m (height), and is made up of drift tubes. The minimum muon energy needed to penetrate that depth is approximately 500 GeV. A set of simulated cosmic ray showers was set up to calculate the rate of muon associated events, using a trigger array with the number of detectors varying from 37 to 127 (the radius of acceptance varying from 50m to 100m). The number used in the calculations is given. The association rate is seen to be a strong function of the multiplicity of muons in the detector. The difference in the rates of association of proton and nuclei induced showers rises rapidly with multiplicity.

  4. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

    DOE PAGESBeta

    Bolotnikov, A. E.; Ackley, K.; Camarda, G. S.; Cherches, C.; Cui, Y.; De Geronimo, G.; Fried, J.; Hodges, D.; Hossain, A.; Lee, W.; et al

    2015-07-28

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe (CZT) detectors coupled to a front-end readout ASIC for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6x6x15 mm3 detectors grouped into 3x3 sub-arrays of 2x2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics.more » The further enhancement of the arrays’ performance and reduction of their cost are made possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.« less

  5. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

    SciTech Connect

    Bolotnikov, A. E.; Ackley, K.; Camarda, G. S.; Cherches, C.; Cui, Y.; De Geronimo, G.; Fried, J.; Hodges, D.; Hossain, A.; Lee, W.; Mahler, G.; Maritato, M.; Petryk, M.; Roy, U.; Salwen, C.; Vernon, E.; Yang, G.; James, R. B.

    2015-07-28

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe (CZT) detectors coupled to a front-end readout ASIC for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6x6x15 mm3 detectors grouped into 3x3 sub-arrays of 2x2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays’ performance and reduction of their cost are made possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  6. An array of virtual Frisch-grid CdZnTe detectors and a front-end application-specific integrated circuit for large-area position-sensitive gamma-ray cameras

    SciTech Connect

    Bolotnikov, A. E. Ackley, K.; Camarda, G. S.; Cherches, C.; Cui, Y.; De Geronimo, G.; Fried, J.; Hossain, A.; Mahler, G.; Maritato, M.; Roy, U.; Salwen, C.; Vernon, E.; Yang, G.; James, R. B.; Hodges, D.; Lee, W.; Petryk, M.

    2015-07-15

    We developed a robust and low-cost array of virtual Frisch-grid CdZnTe detectors coupled to a front-end readout application-specific integrated circuit (ASIC) for spectroscopy and imaging of gamma rays. The array operates as a self-reliant detector module. It is comprised of 36 close-packed 6 × 6 × 15 mm{sup 3} detectors grouped into 3 × 3 sub-arrays of 2 × 2 detectors with the common cathodes. The front-end analog ASIC accommodates up to 36 anode and 9 cathode inputs. Several detector modules can be integrated into a single- or multi-layer unit operating as a Compton or a coded-aperture camera. We present the results from testing two fully assembled modules and readout electronics. The further enhancement of the arrays’ performance and reduction of their cost are possible by using position-sensitive virtual Frisch-grid detectors, which allow for accurate corrections of the response of material non-uniformities caused by crystal defects.

  7. Scientific Applications and Promise of Cryogenic Detector Arrays

    NASA Astrophysics Data System (ADS)

    Moseley, Samuel Harvey

    2009-12-01

    During the past year, the first results from a new generation of instruments based on kilopixel-scale arrays of cryogenic detectors have been released. I will review the history of low temperature detector arrays which has enabled this development, the science which has driven this rapid progress, describe the instruments now in operation and their initial scientific results, and speculate on the developments we may see in the next decade.

  8. Particle Identification in the NIMROD-ISiS Detector Array

    SciTech Connect

    Wuenschel, S.; Hagel, K.; May, L. W.; Wada, R.; Yennello, S. J.

    2009-03-10

    Interest in the influence of the neutron-to-proton (N/Z) ratio on multifragmenting nuclei has demanded an improvement in the capabilities of multi-detector arrays as well as the companion analysis methods. The particle identification method used in the NIMROD-ISiS 4{pi} array is described. Performance of the detectors and the analysis method are presented for the reaction of {sup 86}Kr+{sup 64}Ni at 35 MeV/u.

  9. Scientific Applications and Promise of Cryogenic Detector Arrays

    SciTech Connect

    Moseley, Samuel Harvey

    2009-12-16

    During the past year, the first results from a new generation of instruments based on kilopixel-scale arrays of cryogenic detectors have been released. I will review the history of low temperature detector arrays which has enabled this development, the science which has driven this rapid progress, describe the instruments now in operation and their initial scientific results, and speculate on the developments we may see in the next decade.

  10. A Research on CdZnTe Array Detector

    NASA Astrophysics Data System (ADS)

    Cai, M. S.; Guo, J. H.; Xie, M. G.; Zheng, C. X.

    2013-09-01

    The CdZnTe array detector is a new type of semiconductor detector, and it has been developing rapidly in recent years. It has some characteristics of high spatial resolution, high energy resolution, and it can work at room temperature. This article describes the physical characteristics and the working principle of the CdZnTe detector. It also introduces the production process of the CdZnTe array detector, including the pretreatment of the chips, passivation, ohmic electrode production, array template selection, and array package process selection (micro-interconnect). For evaluating the performance of the detector, the authors produced a 4 pixel × 4 pixel CdZnTe array and an 8 pixel × 8 pixel CdZnTe array (The thicknesses are 5 mm and 2 mm, respectively.The pixel size is 2 mm × 2 mm. The gaps are 0.15 mm and 0.2 mm, respectively.) with cooperation partner successfully. A multi-channel electronic readout system based on the ASIC (Application Specific Integrated Circuit) chip is used for the charge measurement of the 4 pixel × 4 pixel array of CdZnTe. The 16-pixel spectrum and the corresponding energy resolution are obtained with the ^{137}Cs radiation source. Among the results of each pixel, the best resolution is 4.8%@662 keV.

  11. High-resolution pulse-counting array detectors for imaging and spectroscopy at ultraviolet wavelengths

    NASA Technical Reports Server (NTRS)

    Timothy, J. Gethyn; Bybee, Richard L.

    1986-01-01

    The performance characteristics of multianode microchannel array (MAMA) detector systems which have formats as large as 256 x 1024 pixels and which have application to imaging and spectroscopy at UV wavelengths are evaluated. Sealed and open-structure MAMA detector tubes with opaque CsI photocathodes can determine the arrival time of the detected photon to an accuracy of 100 ns or better. Very large format MAMA detectors with CsI and Cs2Te photocathodes and active areas of 52 x 52 mm (2048 x 2048 pixels) will be used as the UV solar blind detectors for the NASA STIS.

  12. Low-background detector arrays for infrared astronomy

    NASA Technical Reports Server (NTRS)

    Mccreight, C. R.; Estrada, J. A.; Goebel, J. H.; Mckelvey, M. E.; Mckibbin, D. D.; Mcmurray, R. E., Jr.; Weber, T. T.

    1989-01-01

    The status of a program which develops and characterizes integrated infrared (IR) detector array technology for space astronomical applications is described. The devices under development include intrinsic, extrinsic silicon, and extrinsic germanium detectors, coupled to silicon readout electronics. Low-background laboratory test results include measurements of responsivity, noise, dark current, temporal response, and the effects of gamma-radiation. In addition, successful astronomical imagery has been obtained on some arrays from this program. These two aspects of the development combine to demonstrate the strong potential for integrated array technology for IR space astronomy.

  13. Superconducting-nanowire single-photon-detector linear array

    NASA Astrophysics Data System (ADS)

    Zhao, Qingyuan; McCaughan, Adam; Bellei, Francesco; Najafi, Faraz; De Fazio, Domenico; Dane, Andrew; Ivry, Yachin; Berggren, Karl K.

    2013-09-01

    We designed, fabricated, and tested a one-dimensional array of superconducting-nanowire single-photon detectors, integrated with on-chip inductors and resistors. The architecture is suitable for monolithic integration on a single chip operated in a cryogenic environment, and inherits the characteristics of individual superconducting-nanowire single-photon detectors. We demonstrated a working array with four pixels showing position discrimination and a timing jitter of 124 ps. The electronic crosstalk between the pixels in the array was negligible.

  14. Advanced Antenna-Coupled Superconducting Detector Arrays for CMB Polarimetry

    NASA Astrophysics Data System (ADS)

    Bock, James

    2014-01-01

    We are developing high-sensitivity millimeter-wave detector arrays for measuring the polarization of the cosmic microwave background (CMB). This development is directed to advance the technology readiness of the Inflation Probe mission in NASA's Physics of the Cosmos program. The Inflation Probe is a fourth-generation CMB satellite that will measure the polarization of the CMB to astrophysical limits, characterizing the inflationary polarization signal, mapping large-scale structure based on polarization induced by gravitational lensing, and mapping Galactic magnetic fields through measurements of polarized dust emission. The inflationary polarization signal is produced by a background of gravitational waves from the epoch of inflation, an exponential expansion of space-time in the early universe, with an amplitude that depends on the physical mechanism producing inflation. The inflationary polarization signal may be distinguished by its unique 'B-mode' vector properties from polarization from the density variations that predominantly source CMB temperature anisotropy. Mission concepts for the Inflation Probe are being developed in the US, Europe and Japan. The arrays are based on planar antennas that provide integral beam collimation, polarization analysis, and spectral band definition in a compact lithographed format that eliminates discrete fore-optics such as lenses and feedhorns. The antennas are coupled to transition-edge superconducting bolometers, read out with multiplexed SQUID current amplifiers. The superconducting sensors and readouts developed in this program share common technologies with NASA X-ray and FIR detector applications. Our program targets developments required for space observations, and we discuss our technical progress over the past two years and plans for future development. We are incorporating arrays into active sub-orbital and ground-based experiments, which advance technology readiness while producing state of the art CMB

  15. Hybrid Array of Gamma Ray Detectors (HAGRiD)

    NASA Astrophysics Data System (ADS)

    Smith, Karl; Grzywacz, R.; Jones, K. L.; Munoz, S.; Baugher, T.; Cizewski, J. A.; Ratkiewicz, A.; Pain, S. D.

    2015-10-01

    Transfer reactions and beta-decay studies are powerful tools to study nuclear structure and to provide insight into astrophysically important reactions that may be difficult to measure directly. Both types of studies are enhanced immensely by measuring a particle-gamma coincidence. For transfer reactions, gamma-ray measurements improve the resolution, aid in channel selection and lifetime measurements. To achieve these coincidences the Hybrid Array of Gamma Ray Detectors (HAGRiD) is being designed and constructed. This array would be coupled with the Oak Ridge Rutgers Barrel Array (ORRUBA) of silicon detectors, the Versatile Array of Neutron Detectors at Low Energy (VANDLE) and beta detection scintillators. Detector systems providing a particle-gamma coincidence have previously compromised the charged-particle angular resolution due to compact geometries used to increase the gamma efficiency. HAGRiD will be coupled with ORRUBA such that resolution is not sacrificed, requiring the new array to provide improved resolution and efficiency over NaI and increased portability and flexibility over germanium detectors; therefore, we have chosen to use LaBr3(Ce) crystals. We demonstrate the advantages of a coupled detector system and discuss the current status of the project.

  16. A Study on the CdZnTe Array Detector

    NASA Astrophysics Data System (ADS)

    Cai, Ming-sheng; Guo, Jian-hua; Xie, Ming-gang; Zheng, Chun-xiao

    2014-04-01

    The CdZnTe array detector is a new type of semiconductor detector being rapidly developed in recent years. It possesses a high spatial resolution and a high energy resolution, and it can work at room temperatures. This paper describes the physical properties and working principle of the CdZnTe array detector, as well as the manufacturing technology, including the chip pretreatment, passivation, ohmic electrode preparation, array template selection, and array packaging technology (micro-interconnection). For evaluating the perfor-mance of the detector, the authors have developed successfully a 4 pixel×4 pixel CdZnTe array and an 8 pixel×8 pixel CdZnTe array (with the thicknesses of 5 mm and 2 mm, the pixel size of 2 mm×2 mm, and the gaps of 0.15 mm and 0.2 mm, respectively) in cooperation with the partner. A multi-channel electronic readout system based on the ASIC (Application Specific Integrated Circuit) chip is devel-oped independently for the charge measurement of the 4 pixel×4 pixel CdZnTe array. The energy spectra and corresponding energy resolutions of the 16 pixels are obtained with the 137Cs radiative source, among them the best resolution is 4.8%@662 kev.

  17. Bolometeric detector arrays for CMB polarimetry

    NASA Technical Reports Server (NTRS)

    Kuo, C. L.; Bock, J. J.; Day, P.; Goldin, A.; Golwala, S.; Holmes, W.; Irwin, K.; Kenyon, M.; Lange, A. E.; LeDuc, H. G.; Rossinot, P.; Sterb, J.; Vayonakis, A.; Wang, G.; Yun, M.; Zmuidzinas, J.

    2005-01-01

    We describe the development of antenna coupled bolometers for CMB polarization experiments. The necessary components of a bolometric CMB polarimeter - a beam forming element, a band defining filter, and detectors - are all fabricated on a silicon chip with photolithography.

  18. Detector architecture of the cosmology large angular scale surveyor

    NASA Astrophysics Data System (ADS)

    Rostem, K.; Bennett, C. L.; Chuss, D. T.; Costen, N.; Crowe, E.; Denis, K. L.; Eimer, J. R.; Lourie, N.; Essinger-Hileman, T.; Marriage, T. A.; Moseley, S. H.; Stevenson, T. R.; Towner, D. W.; Voellmer, G.; Wollack, E. J.; Zeng, L.

    2012-09-01

    The cosmic microwave background (CMB) provides a powerful tool for testing modern cosmology. In particular, if inflation has occurred, the associated gravitational waves would have imprinted a specific polarized pattern on the CMB. Measurement of this faint polarized signature requires large arrays of polarization-sensitive, background- limited detectors, and an unprecedented control over systematic effects associated with instrument design. To this end, the ground-based Cosmology Large Angular Scale Surveyor (CLASS) employs large-format, feedhorn- coupled, background-limited Transition-Edge Sensor (TES) bolometer arrays operating at 40, 90, and 150 GHz bands. The detector architecture has several enabling technologies. An on-chip symmetric planar orthomode transducer (OMT) is employed that allows for highly symmetric beams and low cross-polarization over a wide bandwidth. Furthermore, the quarter-wave backshort of the OMT is integrated using an innovative indium bump bonding process at the chip level that ensures minimum loss, maximum repeatability and performance uniformity across an array. Care has been taken to reduce stray light and on-chip leakage. In this paper, we report on the architecture and performance of the first prototype detectors for the 40 GHz focal plane.

  19. Low-cost uncooled infrared detector arrays in standard CMOS

    NASA Astrophysics Data System (ADS)

    Eminoglu, Selim; Tanrikulu, M. Y.; Akin, Tayfun

    2003-09-01

    This paper reports the development of a low-cost 128 x 128 uncooled infrared focal plane array (FPA) based on suspended and thermally isolated CMOS p+-active/n-well diodes. The FPA is fabricated using a standard 0.35 μm CMOS process followed by simple post-CMOS bulk micromachining that does not require any critical lithography or complicated deposition steps; and therefore, the cost of the uncooled FPA is almost equal to the cost of the CMOS chip. The post-CMOS fabrication steps include an RIE etching to reach the bulk silicon and an anisotropic silicon etching to obtain thermally isolated pixels. During the RIE etching, CMOS metal layers are used as masking layers, and therefore, narrow openings such as 2 μm can be defined between the support arms. This approach allows achieving small pixel size of 40 μm x 40 μm with a fill factor of 44%. The FPA is scanned at 30 fps by monolithically integrated multi-channel parallel readout circuitry which is composed of low-noise differential transconductance amplifiers, switched capacitor (SC) integrators, sample-and-hold circuits, and various other circuit blocks for reducing the effects of variations in detector voltage and operating temperature. The fabricated detector has a temperature coefficient of -2 mV/K, a thermal conductance value of 1.8 x 10-7 W/K, and a thermal time constant value of 36 msec, providing a measured DC responsivity (R) of 4970 V/W under continuous bias. Measured detector noise is 0.69 μV in 8 kHz bandwidth at 30 fps scanning rate, resulting a measured detectivity (D*) of 9.7 x 108 cm√HzW. Contribution of the 1/f noise component is found to be negligible due to the single crystal nature of the silicon n-well and its low value at low bias levels. The noise of the readout circuit is measured as 0.76 μV, resulting in an expected NETD value of 1 K when scanned at 30 fps using f=1 optics. This NETD value can be decreased below 350 mK by decreasing the electrical bandwidth with the help of increased

  20. Adaptive Waveform Correlation Detectors for Arrays: Algorithms for Autonomous Calibration

    SciTech Connect

    Ringdal, F; Harris, D B; Dodge, D; Gibbons, S J

    2009-07-23

    Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the individual channel correlation traces to achieve significant array gain. In previous years we have characterized the decrease in detection threshold afforded by correlation detection across an array or network when observations of a previous event provide an adequate template for signals from subsequent events located near the calibration event. Last year we examined two related issues: (1) the size of the source region calibration footprint afforded by a master event, and (2) the use of temporally incoherent detectors designed to detect the gross envelope structure of the signal to extend the footprint. In Case 1, results from the PETROBAR-1 marine refraction profile indicated that array correlation gain was usable at inter-source separations out to one or two wavelengths. In Case 2, we found that incoherent detectors developed from a magnitude 6 event near Svalbard were successful at detecting aftershocks where correlation detectors derived from individual aftershocks were not. Incoherent detectors might provide 'seed' events for correlation detectors that then could

  1. Large active retrodirective arrays for space applications

    NASA Technical Reports Server (NTRS)

    Chernoff, R. C.

    1979-01-01

    An active retrodirective array (ARA) transmits a beam toward the apparent source of an illuminating signal called the pilot. The term active implies that the array produces, not merely reflects, RF power. Retrodirectivity is achieved by retransmitting from each element of the array a signal whose phase is the conjugate of that received by the element. The problem of supplying the correct phase reference to the phase conjugation circuit (PCC) is solved by central phasing. A new form of central phasing suitable for very large arrays is outlined. ARAs may serve simultaneously as transmitting and receiving satellite antennas for space applications. Precision pointing and input-output isolation is provided by exact frequency-translating PCCs. A two-element ARA breadboard has been built and tested.

  2. Large area position sensitive β-detector

    NASA Astrophysics Data System (ADS)

    Vaintraub, S.; Hass, M.; Edri, H.; Morali, N.; Segal, T.

    2015-03-01

    A new conceptual design of a large area electron detector, which is position and energy sensitive, was developed. This detector is designed for beta decay energies up to 4 MeV, but in principle can be re-designed for higher energies. The detector incorporates one large plastic scintillator and, in general, a limited number of photomultipliers (7 presently). The current setup was designed and constructed after an extensive Geant4 simulation study. By comparison of a single hit light distribution between the various photomultipliers to a pre-measured accurate position-response map, the anticipated position resolution is around 5 mm. The first benchmark experiments have been conducted in order to calibrate and confirm the position resolution of the detector. The new method, results of the first test experiments and comparison to simulations are presented.

  3. Quantum Well and Quantum Dot Modeling for Advanced Infrared Detectors and Focal Plane Arrays

    NASA Technical Reports Server (NTRS)

    Ting, David; Gunapala, S. D.; Bandara, S. V.; Hill, C. J.

    2006-01-01

    This viewgraph presentation reviews the modeling of Quantum Well Infrared Detectors (QWIP) and Quantum Dot Infrared Detectors (QDIP) in the development of Focal Plane Arrays (FPA). The QWIP Detector being developed is a dual band detector. It is capable of running on two bands Long-Wave Infrared (LWIR) and Medium Wavelength Infrared (MWIR). The same large-format dual-band FPA technology can be applied to Quantum Dot Infrared Photodetector (QDIP) with no modification, once QDIP exceeds QWIP in single device performance. Details of the devices are reviewed.

  4. Research in large adaptive antenna arrays

    NASA Technical Reports Server (NTRS)

    Berkowitz, R. S.; Dzekov, T.

    1976-01-01

    The feasibility of microwave holographic imaging of targets near the earth using a large random conformal array on the earth's surface and illumination by a CW source on a geostationary satellite is investigated. A geometrical formulation for the illuminator-target-array relationship is applied to the calculation of signal levels resulting from L-band illumination supplied by a satellite similar to ATS-6. The relations between direct and reflected signals are analyzed and the composite resultant signal seen at each antenna element is described. Processing techniques for developing directional beam formation as well as SNR enhancement are developed. The angular resolution and focusing characteristics of a large array covering an approximately circular area on the ground are determined. The necessary relations are developed between the achievable SNR and the size and number of elements in the array. Numerical results are presented for possible air traffic surveillance system. Finally, a simple phase correlation experiment is defined that can establish how large an array may be constructed.

  5. Terahertz 3D printed diffractive lens matrices for field-effect transistor detector focal plane arrays.

    PubMed

    Szkudlarek, Krzesimir; Sypek, Maciej; Cywiński, Grzegorz; Suszek, Jarosław; Zagrajek, Przemysław; Feduniewicz-Żmuda, Anna; Yahniuk, Ivan; Yatsunenko, Sergey; Nowakowska-Siwińska, Anna; Coquillat, Dominique; But, Dmytro B; Rachoń, Martyna; Węgrzyńska, Karolina; Skierbiszewski, Czesław; Knap, Wojciech

    2016-09-01

    We present the concept, the fabrication processes and the experimental results for materials and optics that can be used for terahertz field-effect transistor detector focal plane arrays. More specifically, we propose 3D printed arrays of a new type - diffractive multi-zone lenses of which the performance is superior to that of previously used mono-zone diffractive or refractive elements and evaluate them with GaN/AlGaN field-effect transistor terahertz detectors. Experiments performed in the 300-GHz atmospheric window show that the lens arrays offer both a good efficiency and good uniformity, and may improve the signal-to-noise ratio of the terahertz field-effect transistor detectors by more than one order of magnitude. In practice, we tested 3 × 12 lens linear arrays with printed circuit board THz detector arrays used in postal security scanners and observed significant signal-to-noise improvements. Our results clearly show that the proposed technology provides a way to produce cost-effective, reproducible, flat optics for large-size field-effect transistor THz-detector focal plane arrays. PMID:27607620

  6. Detector array evaluation and figures of merit

    NASA Technical Reports Server (NTRS)

    Dereniak, Eustace L.

    1990-01-01

    The commonly used methods to evaluate the performance of a two-dimensional focal-plane array using charge transfer devices are reviewed. Two figures of merit that attempt to combine quantum efficiency, read noise and dark-current generation into a single parameter are discussed. The figures of merit are suggested as possible alternatives to the D asterisk.

  7. Large scale anisotropy of UHECRs for the Telescope Array

    SciTech Connect

    Kido, E.

    2011-09-22

    The origin of Ultra High Energy Cosmic Rays (UHECRs) is one of the most interesting questions in astroparticle physics. Despite of the efforts by other previous measurements, there is no consensus of both of the origin and the mechanism of UHECRs generation and propagation yet. In this context, Telescope Array (TA) experiment is expected to play an important role as the largest detector in the northern hemisphere which consists of an array of surface particle detectors (SDs) and fluorescence detectors (FDs) and other important calibration devices. We searched for large scale anisotropy using SD data of TA. UHECRs are expected to be restricted in GZK horizon when the composition of UHECRs is proton, so the observed arrival directions are expected to exhibit local large scale anisotropy if UHECR sources are some astrophysical objects. We used the SD data set from 11 May 2008 to 7 September 2010 to search for large-scale anisotropy. The discrimination power between LSS and isotropy is not enough yet, but the statistics in TA is expected to discriminate between those in about 95% confidence level on average in near future.

  8. Large Format Multicolor QWIP Focal Plane Arrays

    NASA Technical Reports Server (NTRS)

    Soibel, A.; Gunapala, S. D.; Bandara, S. V.; Liu, J. K.; Mumolo, J. M.; Ting, D. Z.; Hill, C. J.; Nguyen, J.

    2009-01-01

    Mid-wave infrared (MWIR) and long-wave infrared (LWIR) multicolor focal plane array (FPA) cameras are essential for many DoD and NASA applications including Earth and planetary remote sensing. In this paper we summarize our recent development of large format multicolor QWIP FPA that cover MWIR and LWIR bands.

  9. High-energy interactions in kinetic inductance detectors arrays

    NASA Astrophysics Data System (ADS)

    D'Addabbo, A.; Calvo, M.; Goupy, J.; Benoit, A.; Bourrion, O.; Catalano, A.; Macias-Perez, J. F.; Monfardini, A.

    2014-07-01

    The impacts of Cosmic Rays on the detectors are a key problem for space-based missions. We are studying the effects of such interactions on arrays of Kinetic Inductance Detectors (KID), in order to adapt this technology for use on board of satellites. Before proposing a new technology such as the Kinetic Inductance Detectors for a space-based mission, the problem of the Cosmic Rays that hit the detectors during in-flight operation has to be studied in detail. We present here several tests carried out with KID exposed to radioactive sources, which we use to reproduce the physical interactions induced by primary Cosmic Rays, and we report the results obtained adopting different solutions in terms of substrate materials and array geometries. We conclude by outlining the main guidelines to follow for fabricating KID for spacebased applications.

  10. 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.

  11. Large Active Retrodirective Arrays for Space Applications

    NASA Technical Reports Server (NTRS)

    Chernoff, R. C.

    1978-01-01

    An active retrodirective array (ARA) electronically points a microwave beam back at the apparent source of an incident pilot signal. Retrodirectivity is the result of phase conjugation of the pilot signal received by each element of the array. The problem of supplying the correct phase reference to the phase conjugation circuit (PCC) associated with each element of the array is solved by central phasing. By eliminating the need for structural rigidity, central phasing confers a decisive advantage on ARA's as large spaceborne antennas. A new form of central phasing suitable for very large arrays is described. ARA's may easily be modified to serve both as transmitting and receiving arrays simultaneously. Two new kinds of exact, frequency translating PCC's are described. Such PCC's provide the ARA with input-output isolation and freedom from squint. The pointing errors caused by the radial and transverse components of the ARA's velocity, by the propagation medium, and by multipath are discussed. A two element ARA breadboard was built and tested at JPL. Its performance is limited primarily by multipath induced errors.

  12. Beam profile shaping for laser radars that use detector arrays.

    PubMed

    Veldkamp, W B; Kastner, C J

    1982-01-15

    The beam shaper we developed shapes the transmit beam of a CO(2) laser radar that uses a linear detector array. It consists of a diffraction grating and an anamorphic prism beam compressor and produces a stretched profile that efficiently and uniformly illuminates the far-field footprint of the detector array. The diffraction grating phase modulates the near field or the laser beam to generate a far-field flattop intensity profile, whereas the compressor produces the necessary profile eccentricity. We have achieved conversion efficiencies in the 70-90% range. PMID:20372453

  13. SRAM As An Array Of Energetic-Ion Detectors

    NASA Technical Reports Server (NTRS)

    Buehler, Martin G.; Blaes, Brent R.; Lieneweg, Udo; Nixon, Robert H.

    1993-01-01

    Static random-access memory (SRAM) designed for use as array of energetic-ion detectors. Exploits well-known tendency of incident energetic ions to cause bit flips in cells of electronic memories. Design of ion-detector SRAM involves modifications of standard SRAM design to increase sensitivity to ions. Device fabricated by use of conventional complementary metal oxide/semiconductor (CMOS) processes. Potential uses include gas densimetry, position sensing, and measurement of cosmic-ray spectrum.

  14. The development and test of multi-anode microchannel array detector systems. Part 2: Soft X-ray detectors

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1986-01-01

    Multi-Anode Microchannel Array (MAMA) detector systems with formats of 256 x 1024 pixels and active areas of 6 x 26 square mm are now under evaluation at visible, ultraviolet and soft x-ray wavelengths. Very-large-format versions of the MAMA detectors with formats of 2048 x 2048 pixels and active areas of 52 x 52 square mm are under development for use in the NASA Goddard Space Flight Center's Space Telescope Imaging Spectrograph (STIS). Open-structure versions of these detectors with CsI photocathodes can provide a high-resolution imaging capability at extreme ultraviolet (EUV) and soft x-ray wavelengths and can deliver a maximum count rate from each array in excess of 1 million counts s-1. In addition, these detector systems have the unique capability to determine the arrival time of a detected photon to an accuracy of 100 ns or better. The construction, mode-of-operation and performance characteristics of the MAMA detectors are described and the program for the development of the very-large-format detectors is outlined.

  15. An Event Reconstruction Method for the Telescope Array Fluorescence Detectors

    SciTech Connect

    Fujii, T.; Ogio, S.; Yamazaki, K.; Fukushima, M.; Ikeda, D.; Sagawa, H.; Takahashi, Y.; Tameda, Y.; Hayashi, K.; Ishimori, R.; Kobayashi, Y.; Tokuno, H.; Tsunesada, Y.; Honda, K.; Tomida, T.; Udo, S.

    2011-09-22

    We measure arrival directions, energies and mass composition of ultra-high energy cosmic rays with air fluorescence detector telescopes. The longitudinal profile of the cosmic ray induced extensive air shower cascade is imaged on focal plane of the telescope camera. Here, we show an event reconstruction method to obtain the primary information from data collected by the Telescope Array Fluorescence Detectors. In particular, we report on an ''Inverse Monte Carlo (IMC)'' method in which the reconstruction process searches for an optimum solution via repeated Monte Carlo simulations including characteristics of all detectors, atmospheric conditions, photon emission and scattering processes.

  16. First Results from the Telescope Array RAdar (TARA) Detector

    NASA Astrophysics Data System (ADS)

    Myers, Isaac

    2014-03-01

    The TARA cosmic ray detector has been in operation for about a year and a half. This bi-static radar detector was designed with the goal of detecting cosmic rays in coincidence with Telescope Array (TA). A new high power (25 kW, 5 MW effective radiated power) transmitter and antenna array and 250 MHz fPGA-based DAQ have been operational since August 2013. The eight-Yagi antenna array broadcasts a 54.1 MHz tone across the TA surface detector array toward our receiver station 50 km away at the Long Ridge fluorescence detector. Receiving antennas feed an intelligent DAQ that self-adjusts to the fluctuating radio background and which employs a bank of matched filters that search in real-time for chirp radar echoes. Millions of triggers have been collected in this mode. A second mode is a forced trigger scheme that uses the trigger status of the fluorescence telescope. Of those triggers collected in FD-triggered mode, about 800 correspond with well-reconstructed TA events. I will describe recent advancements in calibrating key components in the transmitter and receiver RF chains and the analysis of FD-triggered data. Work supported by W.M. Keck Foundation and NSF.

  17. Si:Bi switched photoconducttor infrared detector array

    NASA Technical Reports Server (NTRS)

    Eakin, C. E.

    1983-01-01

    A multiplexed infrared detector array is described. The small demonstration prototype consisted of two cryogenically cooled, bismuth doped silicon, extrinsic photoconductor pixels multiplexed onto a single output channel using an on focal plane switch integration sampling technique. Noise levels of the order of 400 to 600 rms electrons per sample were demonstrated for this chip and wire hybrid version.

  18. Cold radiation shield design for a linear detector array. II

    NASA Astrophysics Data System (ADS)

    Dhar, Vikram; Gopal, Vishnu

    1986-11-01

    This communication reports the results of a calculation of cold-shield shading effects in the linear detector array described by Gopal and Dhar (1986), for an elliptical aperture geometry with varying major-to-minor axis ratio. The results suggest that an elliptical aperture geometry is a better design than a rectangular aperture.

  19. High resolution decoding of Multi-Anode Microchannel Array detectors

    NASA Technical Reports Server (NTRS)

    Kasle, David B.; Morgan, Jeffrey S.

    1991-01-01

    The Multi-Anode Microchannel Array (MAMA) is a photon counting detector which utilizes a photocathode for photon to electron conversion, a microchannel plate (MCP) for signal amplification and a proximity focused anode array for position sensitivity. The detector electronics decode the position of an event through coincidence discrimination. The decoding algorithm which associates a given event with the appropriate pixel is determined by the geometry of the array. A new algorithm incorporated into a CMOS Application Specific Integrated Circuit (ASIC) decoder which improves the pixel spatial resolution is described. The new algorithm does not degrade the detector throughput and does not require any modifications to the detector tube. The standard MAMA detector has a pixel size of 25 x 25 square microns, but with the new decoder circuit the pixel size is reduced to 12.5 x 12.5 square microns. We have built the first set of decode electronics utilizing the new ASIC chips and report here on the first imaging tests of this system.

  20. Keck array and BICEP3: spectral characterization of 5000+ detectors

    NASA Astrophysics Data System (ADS)

    Karkare, K. S.; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bonetti, J. A.; Brevik, J. A.; Buder, I.; Bullock, E. W.; Burger, B.; Connors, J.; Crill, B. P.; Davis, G.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S. T.; Golwala, S. R.; Gordon, M. S.; Grayson, J. A.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J. H.; Karpel, E.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Mason, P.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C. L.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Turner, A. D.; Vieregg, A.; Weber, A.; Wong, C. L.; Wu, W. L. K.; Yoon, K. W.

    2014-08-01

    The inflationary paradigm of the early universe predicts a stochastic background of gravitational waves which would generate a B-mode polarization pattern in the cosmic microwave background (CMB) at degree angular scales. Precise measurement of B-modes is one of the most compelling observational goals in modern cosmology. Since 2011, the Keck Array has deployed over 2500 transition edge sensor (TES) bolometer detectors at 100 and 150 GHz to the South Pole in pursuit of degree-scale B-modes, and Bicep3 will follow in 2015 with 2500 more at 100 GHz. Characterizing the spectral response of these detectors is important for controlling systematic effects that could lead to leakage from the temperature to polarization signal, and for understanding potential coupling to atmospheric and astrophysical emission lines. We present complete spectral characterization of the Keck Array detectors, made with a Martin-Puplett Fourier Transform Spectrometer at the South Pole, and preliminary spectra of Bicep3 detectors taken in lab. We show band centers and effective bandwidths for both Keck Array bands, and use models of the atmosphere at the South Pole to cross check our absolute calibration. Our procedure for obtaining interferograms in the field with automated 4-axis coupling to the focal plane represents an important step towards efficient and complete spectral characterization of next-generation instruments more than 10000 detectors.

  1. Antineutrino spectroscopy with large water Cerenkov detectors.

    PubMed

    Beacom, John F; Vagins, Mark R

    2004-10-22

    We propose modifying large water C erenkov detectors by the addition of 0.2% gadolinium trichloride, which is highly soluble, newly inexpensive, and transparent in solution. Since Gd has an enormous cross section for radiative neutron capture, with summation operatorE(gamma)=8 MeV, this would make neutrons visible for the first time in such detectors, allowing antineutrino tagging by the coincidence detection reaction nu (e)+p-->e(+)+n (similarly for nu (mu)). Taking Super-Kamiokande as a working example, dramatic consequences for reactor neutrino measurements, first observation of the diffuse supernova neutrino background, galactic supernova detection, and other topics are discussed. PMID:15525063

  2. Muon Detector R&D in Telescope Array Experiment

    NASA Astrophysics Data System (ADS)

    Nonaka, T.; Takamura, M.; Honda, K.; Matthews, J. N.; Ogio, S.; Sakurai, N.; Sagawa, H.; Stokes, B. T.; Tsujimoto, M.; Yashiro, K.

    The Telescope Array (TA) experiment, located in the western desert of Utah, U.S.A., at 39.38° north and 112.9° west, is collecting data of ultra high energy cosmic rays in the energy range 1018-1020 eV. The experiment has a Surface Detector (SD) array surrounded by three Fluorescence Detector (FD) stations to enable simultaneous detection of shower particles and fluorescence photons generated by the extensive air shower. Measurement of shower particles at the ground level, with different absorber thickness, enables a more detailed studies of the experiment's energy scale and of hadron interaction models. In this report, we present a design and the first observation result of a surface muon detector using lead plates and concrete as absorbers.

  3. 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

  4. ASIC Readout System for use with a Silicon Detector Array (SAND)

    NASA Astrophysics Data System (ADS)

    Marsh, Ian; Lesher, Shelly; Tan, Wanpeng; Smith, Mallory; Robbe, Mike; Aprahamian, Ani

    2012-10-01

    Silicon (Si) detectors are widely used throughout the scientific community, particularly in nuclear physics. Modern versions of Si detectors are getting larger and increasingly segmented, requiring many electronic channels to process the signals. NIM and VME modules have traditionally been used to process signals from various types of detectors. Applying this traditional method to a large array of Si-detectors, segmented or otherwise, would be very expensive and in most cases highly impractical. To handle this high density of signals from state-of-the-art Si detector arrays we have explored an Application Specific Integrated Circuit (ASIC) approach in collaboration with University of Washington in St. Louis. This involves ASIC chips developed for simultaneous signal processing with charge sensitive preamplifiers, shaping amplifiers, and constant fraction discriminators built in for 16 channels. One ASIC box is capable of housing 32 of these chips and thus processing signals directly from detectors through a total of 512 channels. Analog energy and timing signals are digitized through a pipeline ADC for the NSCL DAQ software to readout. I was a part of the ND effort to implement such an ASIC system. I conducted energy and timing calibrations as well as linearity, threshold, and resolution tests on the system. In collaboration with Indiana University at Bloomington the ASIC system will be applied to a silicon detector array (SAND) at ND for the study of nuclear astrophysics.

  5. Parasitic antenna effect in terahertz plasmon detector array for real-time imaging system

    NASA Astrophysics Data System (ADS)

    Yang, Jong-Ryul; Lee, Woo-Jae; Ryu, Min Woo; Rok Kim, Kyung; Han, Seong-Tae

    2015-10-01

    The performance uniformity of each pixel integrated with a patch antenna in a terahertz plasmon detector array is very important in building the large array necessary for a real-time imaging system. We found a parasitic antenna effect in the terahertz plasmon detector whose response is dependent on the position of the detector pixel in the illumination area of the terahertz beam. It was also demonstrated that the parasitic antenna effect is attributed to the physical structure consisting of signal pads, bonding wires, and interconnection lines on a chip and a printed circuit board. Experimental results show that the performance of the detector pixel is determined by the sum of the effects of each parasitic antenna and the on-chip integrated antenna designed to detect signals at the operating frequency. The parasitic antenna effect can be minimized by blocking the interconnections with a metallic shield.

  6. The CLAS12 large area RICH detector

    SciTech Connect

    M. Contalbrigo, E. Cisbani, P. Rossi

    2011-05-01

    A large area RICH detector is being designed for the CLAS12 spectrometer as part of the 12 GeV upgrade program of the Jefferson Lab Experimental Hall-B. This detector is intended to provide excellent hadron identification from 3 GeV/c up to momenta exceeding 8 GeV/c and to be able to work at the very high design luminosity-up to 1035 cm2 s-1. Detailed feasibility studies are presented for two types of radiators, aerogel and liquid C6F14 freon, in conjunction with a highly segmented light detector in the visible wavelength range. The basic parameters of the RICH are outlined and the resulting performances, as defined by preliminary simulation studies, are reported.

  7. LEAP: the Large European Array for Pulsars

    NASA Astrophysics Data System (ADS)

    Bassa, C. G.; Janssen, G. H.; Karuppusamy, R.; Kramer, M.; Lee, K. J.; Liu, K.; McKee, J.; Perrodin, D.; Purver, M.; Sanidas, S.; Smits, R.; Stappers, B. W.

    2016-02-01

    The Large European Array for Pulsars (LEAP) is an experiment that harvests the collective power of Europe's largest radio telescopes in order to increase the sensitivity of high-precision pulsar timing. As part of the ongoing effort of the European Pulsar Timing Array, LEAP aims to go beyond the sensitivity threshold needed to deliver the first direct detection of gravitational waves. The five telescopes presently included in LEAP are the Effelsberg Telescope, the Lovell Telescope at Jodrell Bank, the Nançay Radio Telescope, the Sardinia Radio Telescope and the Westerbork Synthesis Radio Telescope. Dual polarization, Nyquist-sampled time series of the incoming radio waves are recorded and processed offline to form the coherent sum, resulting in a tied-array telescope with an effective aperture equivalent to a 195-m diameter circular dish. All observations are performed using a bandwidth of 128 MHz centred at a frequency of 1396 MHz. In this paper, we present the design of the LEAP experiment, the instrumentation, the storage and transfer of data and the processing hardware and software. In particular, we present the software pipeline that was designed to process the Nyquist-sampled time series, measure the phase and time delays between each individual telescope and a reference telescope and apply these delays to form the tied-array coherent addition. The pipeline includes polarization calibration and interference mitigation. We also present the first results from LEAP and demonstrate the resulting increase in sensitivity, which leads to an improvement in the pulse arrival times.

  8. A Large Scale Virtual Gas Sensor Array

    NASA Astrophysics Data System (ADS)

    Ziyatdinov, Andrey; Fernández-Diaz, Eduard; Chaudry, A.; Marco, Santiago; Persaud, Krishna; Perera, Alexandre

    2011-09-01

    This paper depicts a virtual sensor array that allows the user to generate gas sensor synthetic data while controlling a wide variety of the characteristics of the sensor array response: arbitrary number of sensors, support for multi-component gas mixtures and full control of the noise in the system such as sensor drift or sensor aging. The artificial sensor array response is inspired on the response of 17 polymeric sensors for three analytes during 7 month. The main trends in the synthetic gas sensor array, such as sensitivity, diversity, drift and sensor noise, are user controlled. Sensor sensitivity is modeled by an optionally linear or nonlinear method (spline based). The toolbox on data generation is implemented in open source R language for statistical computing and can be freely accessed as an educational resource or benchmarking reference. The software package permits the design of scenarios with a very large number of sensors (over 10000 sensels), which are employed in the test and benchmarking of neuromorphic models in the Bio-ICT European project NEUROCHEM.

  9. A large area, silicon photomultiplier-based PET detector module

    PubMed Central

    Raylman, RR; Stolin, A; Majewski, S; Proffitt, J

    2013-01-01

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26 × 58 array of 1.5 × 1.5mm2 LYSO elements (spanning 41 × 91mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ∼45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (∼2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3T clinical magnetic resonance imaging scanner. PMID:24319305

  10. A large area, silicon photomultiplier-based PET detector module

    NASA Astrophysics Data System (ADS)

    Raylman, R. R.; Stolin, A.; Majewski, S.; Proffitt, J.

    2014-01-01

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26×58 array of 1.5×1.5 mm2 LYSO elements (spanning 41×91 mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ~45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (~2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3 T clinical magnetic resonance imaging scanner.

  11. Cd1-xZnxTe detector imaging array

    NASA Astrophysics Data System (ADS)

    Butler, Jack F.; Friesenhahn, Stan J.; Lingren, Clinton L.; Apotovsky, Boris A.; Doty, F. P.; Ashburn, William L.; Dillon, William P.

    1993-09-01

    A prototype portable gamma ray camera using 32 X 32 channels was developed. An experimental 3 X 3 sub-array of 5 mm X 5 mm CZT detectors was fabricated for use in system checkout and to investigate the applicability of CZT imaging arrays to nuclear medical imaging. Experiments were carried out to make a direct comparison of the imaging capabilities of the CZT sub-array with a state-of-the-art Anger camera. In a linespread study using a Tc-99m source embedded in a tissue equivalent absorber, contrasts of 9.5 for the CZT array and 3.4 for the Anger camera were observed. In a dynamic imaging experiment, the CZT imager appeared to have comparable resolution to and be somewhat more regular than the Anger camera.

  12. Detector telescope array: silicon--CsI(Tl)--photodiode

    NASA Astrophysics Data System (ADS)

    Norbeck, E.; Yang, L. B.; Pogodin, P.; Ingram, F. D.

    1999-10-01

    A closely packed array of 60 telescopes was developed for use at forward angles in the 4π Array at the National Superconducting Cyclotron Laboratory at Michigan State University. The telescopes resolve isotopes and cover nearly 100% of the solid angle assigned to the array. These requirements and limitations of space and funding resulted in a number of novel features, some of which will be useful in other applications. These features include: photodiodes of arbitrary shape with no frame around the edge, replacement of aluminized Mylar with aluminum leaf, an inexpensive silicon diode leakage current monitor that presents a graph of leakage current vs detector number, and a low noise but inexpensive preamplifier chip. Experience with the array showed that compounds in the outer insulation layer of some types of coax cable can seriously contaminate a vacuum system. The use of computer aided design and computer controlled machine tools reduced the cost of the structural parts by orders of magnitude.

  13. Order-sorting filter transmittance measured with an array detector

    NASA Technical Reports Server (NTRS)

    Heaney, James B.; Bradley, Scott E.; Bly, Vincent T.; Ewin, Audrey J.; La, Anh T.

    1993-01-01

    The simultaneous measurement of the spectrally and spatially variant transmittance of a linear variable order-sorting filter in a manner that closely resembles its conditions of actual use is described. The transmittance of a prototype order-sorting filter was measured in the 400- to 880-nm wavelength region by illuminating it with the output beam of a spectrophotometer while the filter was attached to the front of a 30 x 32 pixel silicon array detector. The filter was designed to be used in the output beam of a grating spectrometer to prevent the dispersal of higher diffracted orders onto an array detector. Areas of the filter that were spatially matched to the corresponding detector pixel column had measured peak transmittances of about 90 percent that were uniform to within +/- 1.5 percent along a given column. Transmittances for incident wavelengths shorter than the desired bandpass, corresponding to the order overlap region, were measured in the 0.003 range. Line spread function measurements made with the array detector indicated no significant beam spreading caused by inserting the filter into the beam.

  14. The Atacama Large Millimeter Array (ALMA)

    NASA Astrophysics Data System (ADS)

    1999-06-01

    . The road ahead The three-year design and development phase of the project is now underway as a collaboration between Europe and the U.S., and Japan may also join in this effort. Assuming the construction phase begins about two years from now, limited operations of the array may begin in 2005 and the full array may become operational by 2009. Notes [1] Press Releases about this event have also been issued by some of the other organisations participating in this project: * CNRS (in French) * MPG (in German) * NOVA (in Dutch) * NRAO * NSF (ASCII and HTML versions) * PPARC [2] "ALMA" means "soul" in Spanish. [3] Additional information about ALMA is available on the web: * Articles in the ESO Messenger - "The Large Southern Array" (March 1998), "European Site Testing at Chajnantor" (December 1998) and "The ALMA Project" (June 1999), cf. http://www.eso.org/gen-fac/pubs/messenger/ * ALMA website at ESO at http://www.eso.org/projects/alma/ * ALMA website at the U.S. National Radio Astronomy Observatory (NRAO) at http://www.mma.nrao.edu/ * ALMA website in The Netherlands about the detectors at http://www.sron.rug.nl/alma/ ALMA/Chajnantor Video Clip and Photos ESO PR Video Clip 03/99 [MPEG-version] ESO PR Video Clip 03/99 (2450 frames/1:38 min) [MPEG Video; 160x120 pix; 2.1Mb] [MPEG Video; 320x240 pix; 10.0Mb] [RealMedia; streaming; 700k] [RealMedia; streaming; 2.3M] About ESO Video Clip 03/99 : This video clip about the ALMA project contains two sequences. The first shows a panoramic scan of the Chajnantor plain from approx. north-east to north-west. The Chajnantor mountain passes through the field-of-view and the perfect cone of the Licancabur volcano (5900 m) on the Bolivian border is seen at the end (compare also with ESO PR 24e/99 below. The second is a 52-sec animation with a change of viewing perspective of the array and during which the antennas move in unison. For convenience, the clip is available in four versions: two MPEG files of different sizes and two streamer

  15. Development of an 8× 8 CPW Microwave Kinetic Inductance Detector (MKID) Array at 0.35 THz

    NASA Astrophysics Data System (ADS)

    Li, Jing; Yang, Jin-Ping; Lin, Zhen-Hui; Liu, Dong; Shi, Sheng-Cai; Mima, S.; Furukawa, N.; Otani, C.

    2015-12-01

    Microwave kinetic inductance detectors (MKIDs) are promising for THz direct detector arrays of large size, particularly with simple frequency-division multiplexing. Purple Mountain Observatory is developing a terahertz superconducting imaging array (TeSIA) for the DATE5 telescope to be constructed at Dome A, Antarctica. Here we report on the development of a prototype array for the TeSIA, namely an 8× 8 CPW MKID array at 0.35 THz. The resonance frequencies of the MKIDs span the 4-5.575 GHz band with an interval of 25 MHz. Each detector is integrated with a twin-slot antenna centered at 0.5 THz and with a relative bandwidth of 10 %, while the whole MKID array with a micro-lens array. Detailed design and measurement results will be presented.

  16. Development of an 8× 8 CPW Microwave Kinetic Inductance Detector (MKID) Array at 0.35 THz

    NASA Astrophysics Data System (ADS)

    Li, Jing; Yang, Jin-Ping; Lin, Zhen-Hui; Liu, Dong; Shi, Sheng-Cai; Mima, S.; Furukawa, N.; Otani, C.

    2016-07-01

    Microwave kinetic inductance detectors (MKIDs) are promising for THz direct detector arrays of large size, particularly with simple frequency-division multiplexing. Purple Mountain Observatory is developing a terahertz superconducting imaging array (TeSIA) for the DATE5 telescope to be constructed at Dome A, Antarctica. Here we report on the development of a prototype array for the TeSIA, namely an 8× 8 CPW MKID array at 0.35 THz. The resonance frequencies of the MKIDs span the 4-5.575 GHz band with an interval of 25 MHz. Each detector is integrated with a twin-slot antenna centered at 0.5 THz and with a relative bandwidth of 10 %, while the whole MKID array with a micro-lens array. Detailed design and measurement results will be presented.

  17. Superconducting infrared detector arrays with integrated processing circuitry

    SciTech Connect

    Osterman, D.P.; Marr, P.; Dang, H.; Yao, C.T.; Radparvar, M. )

    1991-03-01

    This paper reports on thin film Josephson junctions used as infrared detectors' which function by a thermal sensing mechanism. In addition to the potential for high sensitivity to a broad range of optical wavelengths, they are ideally suited for integration with superconducting electronics on a single wafer. A project at HYPRES to develop these arrays is directed along two avenues: maximizing the sensitivity of individual Josephson junction detector/SQUID amplifier units and development of superconducting on-chip processing circuitry - multiplexers and A to D converters.

  18. Conceptual design of the early implementation of the NEutron Detector Array (NEDA) with AGATA

    NASA Astrophysics Data System (ADS)

    Hüyük, Tayfun; Di Nitto, Antonio; Jaworski, Grzegorz; Gadea, Andrés; Javier Valiente-Dobón, José; Nyberg, Johan; Palacz, Marcin; Söderström, Pär-Anders; Jose Aliaga-Varea, Ramon; de Angelis, Giacomo; Ataç, Ayşe; Collado, Javier; Domingo-Pardo, Cesar; Egea, Francisco Javier; Erduran, Nizamettin; Ertürk, Sefa; de France, Gilles; Gadea, Rafael; González, Vicente; Herrero-Bosch, Vicente; Kaşkaş, Ayşe; Modamio, Victor; Moszynski, Marek; Sanchis, Enrique; Triossi, Andrea; Wadsworth, Robert

    2016-03-01

    The NEutron Detector Array (NEDA) project aims at the construction of a new high-efficiency compact neutron detector array to be coupled with large γ-ray arrays such as AGATA. The application of NEDA ranges from its use as selective neutron multiplicity filter for fusion-evaporation reaction to a large solid angle neutron tagging device. In the present work, possible configurations for the NEDA coupled with the Neutron Wall for the early implementation with AGATA has been simulated, using Monte Carlo techniques, in order to evaluate their performance figures. The goal of this early NEDA implementation is to improve, with respect to previous instruments, efficiency and capability to select multiplicity for fusion-evaporation reaction channels in which 1, 2 or 3 neutrons are emitted. Each NEDA detector unit has the shape of a regular hexagonal prism with a volume of about 3.23l and it is filled with the EJ301 liquid scintillator, that presents good neutron- γ discrimination properties. The simulations have been performed using a fusion-evaporation event generator that has been validated with a set of experimental data obtained in the 58Ni + 56Fe reaction measured with the Neutron Wall detector array.

  19. Large volume flow-through scintillating detector

    DOEpatents

    Gritzo, Russ E.; Fowler, Malcolm M.

    1995-01-01

    A large volume flow through radiation detector for use in large air flow situations such as incinerator stacks or building air systems comprises a plurality of flat plates made of a scintillating material arranged parallel to the air flow. Each scintillating plate has a light guide attached which transfers light generated inside the scintillating plate to an associated photomultiplier tube. The output of the photomultiplier tubes are connected to electronics which can record any radiation and provide an alarm if appropriate for the application.

  20. The Deep Space Network Large Array

    NASA Astrophysics Data System (ADS)

    Gatti, M. S.

    2004-05-01

    In recent years it has become evident that, if future science needs are to be met, the capacity of the telecommunications link between planetary spacecraft and the Earth must be increased by orders of magnitude. Both the number of spacecraft and higher data rates demand the increased capacity. Technologies to support the increased capacity include even larger antennas, optical receiving systems, or arrays of antennas. This article describes a large array of small antennas that would be implemented for a fraction of the cost of an equivalent 70-m aperture. Adding additional antennas can increase the sensitivity many fold over current capabilities. The array will consist of 400 parabolic reflector antennas, each of which will be 12 m in diameter. Each antenna will operate simultaneously at both X-band (8 to 8.8 GHz) and Ka-band (31 to 38 GHz) and will be configured with radio frequency (RF) electronics, including the feeds, low-noise amplifiers, and frequency converters, as well as the appropriate servo controls and drives. The array also includes the signal transmission and signal processing to enable the system to track from between 1 and 16 different signals. A significant feature of this system is that it will be done for relatively very low cost compared to the current antenna paradigms. This is made possible by the use of low-cost antenna reflector technology, the extensive use of monolithic microwave integrated circuits (MMICs), and, finally, by using commercially available equipment to the maximum extent possible. Cost can be further reduced by the acceptance of lower antenna element reliability. High system availability will be maintained by a design paradigm that provides for a marginal set of excess antenna elements for any particular tracking period. Thus, the same total system availability is achieved for lower element availability. The "plug-and-play" aspects of the assemblies will enhance maintainability and operability. The project plans include a

  1. Advanced numerical modeling and hybridization techniques for third-generation infrared detector pixel arrays

    NASA Astrophysics Data System (ADS)

    Schuster, Jonathan

    Infrared (IR) detectors are well established as a vital sensor technology for military, defense and commercial applications. Due to the expense and effort required to fabricate pixel arrays, it is imperative to develop numerical simulation models to perform predictive device simulations which assess device characteristics and design considerations. Towards this end, we have developed a robust three-dimensional (3D) numerical simulation model for IR detector pixel arrays. We used the finite-difference time-domain technique to compute the optical characteristics including the reflectance and the carrier generation rate in the device. Subsequently, we employ the finite element method to solve the drift-diffusion equations to compute the electrical characteristics including the I(V) characteristics, quantum efficiency, crosstalk and modulation transfer function. We use our 3D numerical model to study a new class of detector based on the nBn-architecture. This detector is a unipolar unity-gain barrier device consisting of a narrow-gap absorber layer, a wide-gap barrier layer, and a narrow-gap collector layer. We use our model to study the underlying physics of these devices and to explain the anomalously long lateral collection lengths for photocarriers measured experimentally. Next, we investigate the crosstalk in HgCdTe photovoltaic pixel arrays employing a photon-trapping (PT) structure realized with a periodic array of pillars intended to provide broadband operation. The PT region drastically reduces the crosstalk; making the use of the PT structures not only useful to obtain broadband operation, but also desirable for reducing crosstalk, especially in small pitch detector arrays. Then, the power and flexibility of the nBn architecture is coupled with a PT structure to engineer spectrally filtering detectors. Last, we developed a technique to reduce the cost of large-format, high performance HgCdTe detectors by nondestructively screen-testing detector arrays prior

  2. Heterodyne detection with mismatch correction based on array detector

    NASA Astrophysics Data System (ADS)

    Dong, Hongzhou; Li, Guoqiang; Yang, Ruofu; Yang, Chunping; Ao, Mingwu

    2016-07-01

    Based on an array detector, a new heterodyne detection system, which can correct the mismatches of amplitude and phase between signal and local oscillation (LO) beams, is presented in this paper. In the light of the fact that, for a heterodyne signal, there is a certain phase difference between the adjacent two samples of analog-to-digital converter (ADC), we propose to correct the spatial phase mismatch by use of the time-domain phase difference. The corrections can be realized by shifting the output sequences acquired from the detector elements in the array, and the steps of the shifting depend on the quantity of spatial phase mismatch. Numerical calculations of heterodyne efficiency are conducted to confirm the excellent performance of our system. Being different from previous works, our system needs not extra optical devices, so it provides probably an effective means to ease the problem resulted from the mismatches.

  3. Heterodyne detection with mismatch correction base on array detector

    NASA Astrophysics Data System (ADS)

    Hongzhou, Dong; Guoqiang, Li; Ruofu, Yang; Chunping, Yang; Mingwu, Ao

    2016-07-01

    Based on an array detector, a new heterodyne detection system, which can correct the mismatches of amplitude and phase between signal and local oscillation (LO) beams, is presented in this paper. In the light of the fact that, for a heterodyne signal, there is a certain phase difference between the adjacent two samples of analog-to-digital converter (ADC), we propose to correct the spatial phase mismatch by use of the time-domain phase difference. The corrections can be realized by shifting the output sequences acquired from the detector elements in the array, and the steps of the shifting depend on the quantity of spatial phase mismatch. Numerical calculations of heterodyne efficiency are conducted to confirm the excellent performance of our system. Being different from previous works, our system needs not extra optical devices, so it provides probably an effective means to ease the problem resulted from the mismatches.

  4. Microscopy using source and detector arrays

    NASA Astrophysics Data System (ADS)

    Sheppard, Colin J. R.; Castello, Marco; Vicidomini, Giuseppe; Duocastella, Martí; Diaspro, Alberto

    2016-03-01

    There are basically two types of microscope, which we call conventional and scanning. The former type is a full-field imaging system. In the latter type, the object is illuminated with a probe beam, and a signal detected. We can generalize the probe to a patterned illumination. Similarly we can generalize the detection to a patterned detection. Combining these we get a range of different modalities: confocal microscopy, structured illumination (with full-field imaging), spinning disk (with multiple illumination points), and so on. The combination allows the spatial frequency bandwidth of the system to be doubled. In general we can record a four dimensional (4D) image of a 2D object (or a 6D image from a 3D object, using an acoustic tuneable lens). The optimum way to directly reconstruct the resulting image is by image scanning microscopy (ISM). But the 4D image is highly redundant, so deconvolution-based approaches are also relevant. ISM can be performed in fluorescence, bright field or interference microscopy. Several different implementations have been described, with associated advantages and disadvantages. In two-photon microscopy, the illumination and detection point spread functions are very different. This is also the case when using pupil filters or when there is a large Stokes shift.

  5. Spectral line-diode registry effects with photodiode array detectors

    SciTech Connect

    Winge, R.K.; Fassel, V.A.; Eckels, D.E.

    1986-05-01

    A limitation of photodiode array detectors for spectroscopic intensity measurements relates to the spacing of the diodes and the errors generated when a spectral line is not in exact registry with the diode or diodes from which its intensity is being measured. These misregistry intensity errors, which may be as high as 25 to 30%, are documented for a range of spectral bandwidths and for single diode (pixel) intensities and multiple diode summations of intensities.

  6. Development of a Prototype for the Fluorescence Detector Array of Single-Pixel Telescopes

    NASA Astrophysics Data System (ADS)

    Fujii, T.; Malacari, M.; Bertaina, M.; Casolino, M.; Dawson, B.; Jiang, J.; Matalon, A.; Matthews, J. N.; Motloch, P.; Privitera, P.; Takizawa, Y.; Yamazaki, K.

    We present a concept for large-area, low-cost detection of ultra-high energy cosmic rays (UHECR) with a Fluorescence detector Array of Single-pixel Telescopes (FAST), addressing the requirements for the next generation of UHECR experiments. In the FAST design, a large field of view is covered by a few pixels at the focal plane of a mirror or Fresnel lens. We report preliminary results of a FAST prototype installed at the Telescope Array site, consisting of a single 200 mm photo-multiplier tube at the focal plane of a 1 m2 Fresnel lens system taken from the prototype of the JEM-EUSO experiment.

  7. Report of the large solenoid detector group

    SciTech Connect

    Hanson, G.G.; Mori, S.; Pondrom, L.G.; Williams, H.H.; Barnett, B.; Barnes, V.; Cashmore, R.; Chiba, M.; DeSalvo, R.; Devlin, T.

    1987-09-01

    This report presents a conceptual design of a large solenoid for studying physics at the SSC. The parameters and nature of the detector have been chosen based on present estimates of what is required to allow the study of heavy quarks, supersymmetry, heavy Higgs particles, WW scattering at large invariant masses, new W and Z bosons, and very large momentum transfer parton-parton scattering. Simply stated, the goal is to obtain optimum detection and identification of electrons, muons, neutrinos, jets, W's and Z's over a large rapidity region. The primary region of interest extends over +-3 units of rapidity, although the calorimetry must extend to +-5.5 units if optimal missing energy resolution is to be obtained. A magnetic field was incorporated because of the importance of identifying the signs of the charges for both electrons and muons and because of the added possibility of identifying tau leptons and secondary vertices. In addition, the existence of a magnetic field may prove useful for studying new physics processes about which we currently have no knowledge. Since hermeticity of the calorimetry is extremely important, the entire central and endcap calorimeters were located inside the solenoid. This does not at the moment seem to produce significant problems (although many issues remain to be resolved) and in fact leads to a very effective muon detector in the central region.

  8. Imaging MAMA detector systems. [Multi-Anode Microchannel Array

    NASA Technical Reports Server (NTRS)

    Slater, David C.; Timothy, J. G.; Morgan, Jeffrey S.; Kasle, David B.

    1990-01-01

    Imaging multianode microchannel array (MAMA) detector systems with 1024 x 1024 pixel formats have been produced for visible and UV wavelengths; the UV types employ 'solar blind' photocathodes whose detective quantum efficiencies are significantly higher than those of currently available CCDs operating at far-UV and EUV wavelengths. Attention is presently given to the configurations and performance capabilities of state-of-the-art MAMA detectors, with a view to the development requirements of the hybrid electronic circuits needed for forthcoming spacecraft-sensor applications. Gain, dark noise, uniformity, and dynamic range performance data are presented for the curved-channel 'chevron', 'Z-plate', and helical-channel high gain microchannel plate configurations that are currently under evaluation with MAMA detector systems.

  9. READOUT SYSTEM FOR ARRAYS OF FRISCH-RING CDZNTE DETECTORS.

    SciTech Connect

    CUI, Y.; BOLOTNIKOV, A.E.; CAMARDA, G.S.; DE GERONIMO, G.; O'CONNOR, P.; JAMES, R.B.; KARGAR, A.; HARRISON, M.J.; MCGREGOR, D.S.

    2006-10-29

    Frisch-ring CdZnTe detectors have demonstrated good energy resolution for identifying isotopes, <1% FWHM at 662 keV, and good efficiency for detecting gamma rays. We will fabricate and test at Brookhaven National Laboratory an integrated module of a 64-element array of 6 x 6 x 12 mm{sup 3} Frisch-ring detectors, coupled with a readout electronics system. It supports 64 readout channels, and includes front-end electronics, signal processing circuit, USB interface and high-voltage power supply. The data-acquisition software is used to process the data stream, which includes amplitude and timing information for each detected event. This paper describes the design and assembly of the detector modules, readout electronics, and a conceptual prototype system. Some test results are also reported.

  10. Distributed Antenna-Coupled TES for FIR Detectors Arrays

    NASA Technical Reports Server (NTRS)

    Day, Peter K.; Leduc, Henry G.; Dowell, C. Darren; Lee, Richard A.; Zmuidzinas, Jonas

    2007-01-01

    We describe a new architecture for a superconducting detector for the submillimeter and far-infrared. This detector uses a distributed hot-electron transition edge sensor (TES) to collect the power from a focal-plane-filling slot antenna array. The sensors lay directly across the slots of the antenna and match the antenna impedance of about 30 ohms. Each pixel contains many sensors that are wired in parallel as a single distributed TES, which results in a low impedance that readily matches to a multiplexed SQUID readout These detectors are inherently polarization sensitive, with very low cross-polarization response, but can also be configured to sum both polarizations. The dual-polarization design can have a bandwidth of 50The use of electron-phonon decoupling eliminates the need for micro-machining, making the focal plane much easier to fabricate than with absorber-coupled, mechanically isolated pixels. We discuss applications of these detectors and a hybridization scheme compatible with arrays of tens of thousands of pixels.

  11. Multiple detector focal plane array ultraviolet spectrometer for the AMPS laboratory

    NASA Technical Reports Server (NTRS)

    Feldman, P. D.

    1975-01-01

    The possibility of meeting the requirements of the amps spectroscopic instrumentation by using a multi-element focal plane detector array in a conventional spectrograph mount was examined. The requirements of the detector array were determined from the optical design of the spectrometer which in turn depends on the desired level of resolution and sensitivity required. The choice of available detectors and their associated electronics and controls was surveyed, bearing in mind that the data collection rate from this system is so great that on-board processing and reduction of data are absolutely essential. Finally, parallel developments in instrumentation for imaging in astronomy were examined, both in the ultraviolet (for the Large Space Telescope as well as other rocket and satellite programs) and in the visible, to determine what progress in that area can have direct bearing on atmospheric spectroscopy.

  12. Muon-hadron detector of the carpet-2 array

    NASA Astrophysics Data System (ADS)

    Dzhappuev, D. D.; Kudzhaev, A. U.; Klimenko, N. F.

    2016-05-01

    The 1-GeV muon-hadron detector of the Carpet-2 multipurpose shower array at the Baksan Neutrino Observatory, Institute for Nuclear Research, Russian Academy of Sciences (INR, Moscow, Russia) is able to record simultaneously muons and hadrons. The procedure developed for this device makes it possible to separate the muon and hadron components to a high degree of precision. The spatial and energy features of the muon and hadron extensive-air-shower components are presented. Experimental data from the Carpet-2 array are contrasted against data from the EAS-TOP and KASCADE arrays and against the results of the calculations based on the CORSIKA (GHEISHA + QGSJET01) code package and performed for primary protons and iron nuclei.

  13. ALMA - the Atacama large millimeter array

    NASA Astrophysics Data System (ADS)

    Brown, Robert L.; Wild, Wolfgang; Cunningham, Charles

    2004-01-01

    The Atacama Large Millimeter Array (ALMA) is a major ground-based telescope for millimeter and submillimeter astronomy to be realized during this decade. It is comprised of 64 antennas of 12 m diameter, each of which is equipped with receivers in ten frequency bands that cover the atmospheric windows from 30 to 950 GHz. All the antennas may be moved on a specially-designed antenna transporter so that the antenna array may be reconfigured: At the extremes, the antennas may all be grouped together in an area 150 m in diameter to provide arcsecond angular resolution, or they may be distributed over an area 14 km in extent to provide an angular resolution as high as 10 milli-arcsec. ALMA will be located in the Chilean Andes east of the Atacama Desert at an elevation of 5000 m above sea level. The ALMA Project is a joint venture of the European Southern Observatory and the U.S. National Science Foundation acting in partnership with the National Research Council of Canada. Interim science operations are expected to begin in 2007 with completion of ALMA scheduled for 2011.

  14. Fast, High-Precision Readout Circuit for Detector Arrays

    NASA Technical Reports Server (NTRS)

    Rider, David M.; Hancock, Bruce R.; Key, Richard W.; Cunningham, Thomas J.; Wrigley, Chris J.; Seshadri, Suresh; Sander, Stanley P.; Blavier, Jean-Francois L.

    2013-01-01

    The GEO-CAPE mission described in NASA's Earth Science and Applications Decadal Survey requires high spatial, temporal, and spectral resolution measurements to monitor and characterize the rapidly changing chemistry of the troposphere over North and South Americas. High-frame-rate focal plane arrays (FPAs) with many pixels are needed to enable such measurements. A high-throughput digital detector readout integrated circuit (ROIC) that meets the GEO-CAPE FPA needs has been developed, fabricated, and tested. The ROIC is based on an innovative charge integrating, fast, high-precision analog-to-digital circuit that is built into each pixel. The 128×128-pixel ROIC digitizes all 16,384 pixels simultaneously at frame rates up to 16 kHz to provide a completely digital output on a single integrated circuit at an unprecedented rate of 262 million pixels per second. The approach eliminates the need for off focal plane electronics, greatly reducing volume, mass, and power compared to conventional FPA implementations. A focal plane based on this ROIC will require less than 2 W of power on a 1×1-cm integrated circuit. The ROIC is fabricated of silicon using CMOS technology. It is designed to be indium bump bonded to a variety of detector materials including silicon PIN diodes, indium antimonide (InSb), indium gallium arsenide (In- GaAs), and mercury cadmium telluride (HgCdTe) detector arrays to provide coverage over a broad spectral range in the infrared, visible, and ultraviolet spectral ranges.

  15. Very-large-format pulse-counting UV detectors

    NASA Technical Reports Server (NTRS)

    Timothy, J. Gethyn

    1988-01-01

    Multi-anode microchannel array (MAMA) detector systems with formats of 2048 x 2048 pixels and pixel dimensions of 25 x 25 microns are being developed for use in the NASA Goddard Hubble Space Telescope Imaging Spectrograph. This paper describes the current state of development of these detector systems.

  16. Topological detector: measuring continuous dosimetric quantities with few-element detector array

    NASA Astrophysics Data System (ADS)

    Han, Zhaohui; Brivio, Davide; Sajo, Erno; Zygmanski, Piotr

    2016-08-01

    A prototype topological detector was fabricated and investigated for quality assurance of radiation producing medical devices. Unlike a typical array or flat panel detector, a topological detector, while capable of achieving a very high spatial resolution, consists of only a few elements and therefore is much simpler in construction and more cost effective. The key feature allowing this advancement is a geometry-driven design that is customized for a specific dosimetric application. In the current work, a topological detector of two elements was examined for the positioning verification of the radiation collimating devices (jaws, MLCs, and blades etc). The detector was diagonally segmented from a rectangular thin film strip (2.5 cm  ×  15 cm), giving two contiguous but independent detector elements. The segmented area was the central portion of the strip measuring 5 cm in length. Under irradiation, signals from each detector element were separately digitized using a commercial multichannel data acquisition system. The center and size of an x-ray field, which were uniquely determined by the collimator positions, were shown mathematically to relate to the difference and sum of the two signals. As a proof of concept, experiments were carried out using slit x-ray fields ranging from 2 mm to 20 mm in size. It was demonstrated that, the collimator positions can be accurately measured with sub-millimeter precisions.

  17. Topological detector: measuring continuous dosimetric quantities with few-element detector array.

    PubMed

    Han, Zhaohui; Brivio, Davide; Sajo, Erno; Zygmanski, Piotr

    2016-08-21

    A prototype topological detector was fabricated and investigated for quality assurance of radiation producing medical devices. Unlike a typical array or flat panel detector, a topological detector, while capable of achieving a very high spatial resolution, consists of only a few elements and therefore is much simpler in construction and more cost effective. The key feature allowing this advancement is a geometry-driven design that is customized for a specific dosimetric application. In the current work, a topological detector of two elements was examined for the positioning verification of the radiation collimating devices (jaws, MLCs, and blades etc). The detector was diagonally segmented from a rectangular thin film strip (2.5 cm  ×  15 cm), giving two contiguous but independent detector elements. The segmented area was the central portion of the strip measuring 5 cm in length. Under irradiation, signals from each detector element were separately digitized using a commercial multichannel data acquisition system. The center and size of an x-ray field, which were uniquely determined by the collimator positions, were shown mathematically to relate to the difference and sum of the two signals. As a proof of concept, experiments were carried out using slit x-ray fields ranging from 2 mm to 20 mm in size. It was demonstrated that, the collimator positions can be accurately measured with sub-millimeter precisions. PMID:27452789

  18. Large format 15μm pitch XBn detector

    NASA Astrophysics Data System (ADS)

    Karni, Yoram; Avnon, Eran; Ben Ezra, Michael; Berkowitz, Eyal; Cohen, Omer; Cohen, Yossef; Dobromislin, Roman; Hirsh, Itay; Klin, Olga; Klipstein, Philip; Lukomsky, Inna; Nitzani, Michal; Pivnik, Igor; Rozenberg, Omer; Shtrichman, Itay; Singer, Michael; Sulimani, Shay; Tuito, Avi; Weiss, Eliezer

    2014-06-01

    Over the past few years, a new type of High Operating Temperature (HOT) photon detector has been developed at SCD, which operates in the blue part of the MWIR atmospheric window (3.4 - 4.2 μm). This window is generally more transparent than the red part of the MWIR window (4.4 - 4.9 μm), and thus is especially useful for mid and long range applications. The detector has an InAsSb active layer and is based on the new "XBn" device concept, which eliminates Generation-Recombination dark current and enables operation at temperatures of 150K or higher, while maintaining excellent image quality. Such high operating temperatures reduce the cooling requirements of Focal Plane Array (FPA) detectors dramatically, and allow the use of a smaller closed-cycle Stirling cooler. As a result, the complete Integrated Detector Cooler Assembly (IDCA) has about 60% lower power consumption and a much longer lifetime compared with IDCAs based on standard InSb detectors and coolers operating at 77K. In this work we present a new large format IDCA designed for 150K operation. The 15 μm pitch 1280×1024 FPA is based on SCD's XBn technology and digital Hercules ROIC. The FPA is housed in a robust Dewar and is integrated with Ricor's K508N Stirling cryo-cooler. The IDCA has a weight of ~750 gram and its power consumption is ~ 5.5 W at a frame rate of 100Hz. The Mean Time to Failure (MTTF) of the IDCA is more than 20,000 hours, greatly facilitating 24/7 operation.

  19. 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.

  20. Infrared speckle interferometer with a linear array detector

    NASA Astrophysics Data System (ADS)

    Kataza, Hirokazu; Maihara, Toshinori

    1993-04-01

    We have developed a 1D near-IR speckle interferometer with a linear-array detector which can produce speckle images by means of a cylindrical lens. The detector with a Reticon multiplexer is operated at the kTC noise limit (approximately 2500 e-, rms). Using this instrument, we have obtained systematic data of the exposure time dependence of the modulation transfer function along with astronomical observations. The result indicates that the best exposure time of the speckle interferometry is longer than the exposure time chosen so that the fluctuations in the atmosphere are approximately frozen within an exposure. In the actual observations at the University of Hawaii 2.2-m telescope at Mauna Kea, the optimum exposure time is proved to be about 0.3 s.

  1. Undersampling Correction for Array Detector-Based Satellite Spectrometers

    NASA Technical Reports Server (NTRS)

    Chance, Kelly; Kurosu, Thomas P.; Sioris, Christopher E.

    2004-01-01

    Array detector-based instruments are now fundamental to measurements of ozone and other atmospheric trace gases from space in the ultraviolet, visible, and infrared. The present generation of such instruments suffers, to a greater or lesser degree, from undersampling of the spectra, leading to difficulties in the analysis of atmospheric radiances. We provide extended analysis of the undersampling suffered by modem satellite spectrometers, which include Global Ozone Monitoring Experiment (GOME), Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), Ozone Monitoring Instrument (OMI), and Ozone Mapping and Profiler Suite (OMPS). The analysis includes basic undersampling, the effects of binning into separate detector pixels, and the application of high-resolution Fraunhofer spectral data to correct for undersampling in many useful cases.

  2. Advances in array detectors for X-ray diffraction techniques.

    PubMed

    Hanley, Quentin S; Denton, M Bonner

    2005-09-01

    Improved focal plane array detector systems are described which can provide improved readout speeds, random addressing and even be employed to simultaneously measure position, intensity and energy. This latter capability promises to rekindle interests in Laue techniques. Simulations of three varieties of foil mask spectrometer in both on- and off-axis configurations indicate that systems of stacked silicon detectors can provide energy measurements within 1% of the true value based on the use of single 'foils' and approximately 10000 photons. An eight-detector hybrid design can provide energy coverage from 4 to 60 keV. Energy resolution can be improved by increased integration time or higher flux experiments. An off-axis spectrometer design in which the angle between the incident beam and the detector system is 45 degrees results in a shift in the optimum energy response of the spectrometer system. In the case of a 200 microm-thick silicon absorber, the energy optimum shifts from 8.7 keV to 10.3 keV as the angle of incidence goes from 0 to 45 degrees. These new designs make better use of incident photons, lower the impact of source flicker through simultaneous rather than sequential collection of intensities, and improve the energy range relative to previously reported systems. PMID:16120985

  3. An MLC calibration method using a detector array

    SciTech Connect

    Simon, Thomas A.; Kahler, Darren; Simon, William E.; Fox, Christopher; Li, Jonathan; Palta, Jatinder; Liu, Chihray

    2009-10-15

    Purpose: The authors have developed a quantitative calibration method for a multileaf collimator (MLC) which measures individual leaf positions relative to the MLC backup jaw on an Elekta Synergy linear accelerator. Methods: The method utilizes a commercially available two-axis detector array (Profiler 2; Sun Nuclear Corporation, Melbourne, FL). To calibrate the MLC bank, its backup jaw is positioned at the central axis and the opposing jaw is retracted to create a half-beam configuration. The position of the backup jaws field edge is then measured with the array to obtain what is termed the radiation defined reference line. The positions of the individual leaf ends relative to this reference line are then inferred by the detector response in the leaf end penumbra. Iteratively adjusting and remeasuring the leaf end positions to within specifications completes the calibration. Using the backup jaw as a reference for the leaf end positions is based on three assumptions: (1) The leading edge of an MLC leaf bank is parallel to its backup jaw's leading edge, (2) the backup jaw position is reproducible, and (3) the measured radiation field edge created by each leaf end is representative of that leaf's position. Data from an electronic portal imaging device (EPID) were used in a similar analysis to check the results obtained with the array. Results: The relative leaf end positions measured with the array differed from those measured with the EPID by an average of 0.11 {+-}0.09 mm per leaf. The maximum leaf positional change measured with the Profiler 2 over a 3 month period was 0.51 mm. A leaf positional accuracy of {+-}0.4 mm is easily attainable through the iterative calibration process. The method requires an average of 40 min to measure both leaf banks. Conclusions: This work demonstrates that the Profiler 2 is an effective tool for efficient and quantitative MLC quality assurance and calibration.

  4. Two detector arrays for fast neutrons at LANSCE

    NASA Astrophysics Data System (ADS)

    Haight, R. C.; Lee, H. Y.; Taddeucci, T. N.; O'Donnell, J. M.; Perdue, B. A.; Fotiades, N.; Devlin, M.; Ullmann, J. L.; Laptev, A.; Bredeweg, T.; Jandel, M.; Nelson, R. O.; Wender, S. A.; White, M. C.; Wu, C. Y.; Kwan, E.; Chyzh, A.; Henderson, R.; Gostic, J.

    2012-03-01

    The neutron spectrum from neutron-induced fission needs to be known in designing new fast reactors, predicting criticality for safety analyses, and developing techniques for global security application. The experimental data base of fission neutron spectra is very incomplete and most present evaluated libraries are based on the approach of the Los Alamos Model. To validate these models and to provide improved data for applications, a program is underway to measure the fission neutron spectrum for a wide range of incident neutron energies using the spallation source of fast neutrons at the Weapons Neutron Research (WNR) facility at the Los Alamos Neutron Science Center (LANSCE). In a double time-of-flight experiment, fission neutrons are detected by arrays of neutron detectors to increase the solid angle and also to investigate possible angular dependence of the fission neutrons. The challenge is to measure the spectrum from low energies, down to 100 keV or so, to energies over 10 MeV, where the evaporation-like spectrum decreases by 3 orders of magnitude from its peak around 1 MeV. For these measurements, we are developing two arrays of neutron detectors, one based on liquid organic scintillators and the other on 6Li-glass detectors. The range of fission neutrons detected by organic liquid scintillators extends from about 600 keV to well over 10 MeV, with the lower limit being defined by the limit of pulse-shape discrimination. The 6Li-glass detectors have a range from very low energies to about 1 MeV, where their efficiency then becomes small. Various considerations and tests are in progress to understand important contributing factors in designing these two arrays and they include selection and characterization of photomultiplier tubes (PM), the performance of relatively thin (1.8 cm) 6Li-glass scintillators on 12.5 cm diameter PM tubes, use of 17.5 cm diameter liquid scintillators with 12.5 cm PM tubes, measurements of detector efficiencies with tagged neutrons

  5. Large area x-ray detectors for cargo radiography

    NASA Astrophysics Data System (ADS)

    Bueno, C.; Albagli, D.; Bendahan, J.; Castleberry, D.; Gordon, C.; Hopkins, F.; Ross, W.

    2007-04-01

    Large area x-ray detectors based on phosphors coupled to flat panel amorphous silicon diode technology offer significant advances for cargo radiologic imaging. Flat panel area detectors provide large object coverage offering high throughput inspections to meet the high flow rate of container commerce. These detectors provide excellent spatial resolution when needed, and enhanced SNR through low noise electronics. If the resolution is reduced through pixel binning, further advances in SNR are achievable. Extended exposure imaging and frame averaging enables improved x-ray penetration of ultra-thick objects, or "select-your-own" contrast sensitivity at a rate many times faster than LDAs. The areal coverage of flat panel technology provides inherent volumetric imaging with the appropriate scanning methods. Flat panel area detectors have flexible designs in terms of electronic control, scintillator selection, pixel pitch, and frame rates. Their cost is becoming more competitive as production ramps up for the healthcare, nondestructive testing (NDT), and homeland protection industries. Typically used medical and industrial polycrystalline phosphor materials such as Gd2O2S:Tb (GOS) can be applied to megavolt applications if the phosphor layer is sufficiently thick to enhance x-ray absorption, and if a metal radiator is used to augment the quantum detection efficiency and reduce x-ray scatter. Phosphor layers ranging from 0.2-mm to 1-mm can be "sandwiched" between amorphous silicon flat panel diode arrays and metal radiators. Metal plates consisting of W, Pb or Cu, with thicknesses ranging from 0.25-mm to well over 1-mm can be used by covering the entire area of the phosphor plate. In some combinations of high density metal and phosphor layers, the metal plate provides an intensification of 25% in signal due to electron emission from the plate and subsequent excitation within the phosphor material. This further improves the SNR of the system.

  6. Jansky Very Large Array: technology advancing science

    NASA Astrophysics Data System (ADS)

    Carilli, Christopher

    2015-08-01

    Over the last decade, the NRAO has completed on time, and on budget, a major reconstruction of the Very Large Array. Building on existing infrastructure to maximize efficiency, the entire VLA electronics system, including correlator, receivers, data transmission, and monitor and control, have been replaced with state of the art systems. This complete rebuild establishes the new Jansky VLA, operating between 75MHz and 50GHz, as the most powerful radio telescope in the world for the coming decade.I will review the technical improvements of the array, including:- Correlator: Increased bandwidth from 100MHz to 8GHz, with thousands of spectral channels.- Receivers: replaced the previous narrow bands with receivers covering the full frequency range from 1 GHz to 50GHz. New systems are also being tested to cover from 50MHz to 400MHz.- Data transmission: 8GHz over optical fiber out to 30km.I will then highlight some of the science enabled by these improvements, including:- Large cosmic volume searches for atomic and molecular gas, from the nearby Universe to the most distant galaxies, plus kpc-scale imaging of the cool gas in distant starburst galaxies.- High resolution studies of star and planet formation.- Innovative interferometric searches for transient phenomena.- The first radio continuum deep fields with sensitivities < 1uJy, with full polarization for Faraday tomography.- Imaging radio-mode feedback in galaxies and clusters, and delineating the complex plasma physical processes involved on scales from a few kpc to hundreds of kpc.I will conclude with a few words about the major challenges facing such a new instrument. These challenges are all on the critical path toward any successful development of future facilities, such as the next generation VLA and SKA:- Big data: data volumes and post-processing are currently major bottlenecks in the turn-over from observation to science publication. NRAO is developing calibration and imaging pipelines to provide science

  7. Indium Hybridization of Large Format TES Bolometer Arrays to Readout Multiplexers for Far-Infrared Astronomy

    NASA Technical Reports Server (NTRS)

    Miller, Timothy M.; Costen, Nick; Allen, Christine

    2007-01-01

    The advance of new detector technologies combined with enhanced fabrication methods has resulted in an increase in development of large format arrays. The next generation of scientific instruments will utilize detectors containing hundreds to thousands of elements providing a more efficient means to conduct large area sky surveys. Some notable detectors include a 32x32 x-ray microcalorimeter for Constellation-X, an infrared bolometer called SAFIRE to fly on the airborne observatory SOFIA, and the sub-millimeter bolometer SCUBA-2 to be deployed at the JCMT which will use more than 10,000 elements for two colors, each color using four 32x40 arrays. Of these detectors, SCUBA-2 is farthest along in development and uses indium hybridization to multiplexers for readout of the large number of elements, a technology that will be required to enable the next generation of large format arrays. Our current efforts in working toward large format arrays have produced GISMO, the Goddard IRAM Superconducting 2-Millimeter observer. GISMO is a far infrared instrument to be field tested later this year at the IRAM 30 meter telescope in Spain. GISMO utilizes transition edge sensor (TES) technology in an 8x16 filled array format that allows for typical fan-out wiring and wire-bonding to four 1x32 NIST multiplexers. GISMO'S electrical wiring is routed along the tops of 30 micron walls which also serve as the mechanical framework for the array. This architecture works well for the 128 element array, but is approaching the limit for routing the necessary wires along the surface while maintaining a high fill factor. Larger format arrays will benefit greatly from making electrical connections through the wafer to the backside, where they can be hybridized to a read-out substrate tailored to handling the wiring scheme. The next generation array we are developing is a 32x40 element array on a pitch of 1135 microns that conforms to the NIST multiplexer, already developed for the SCUBA-2

  8. High density processing electronics for superconducting tunnel junction x-ray detector arrays

    NASA Astrophysics Data System (ADS)

    Warburton, W. K.; Harris, J. T.; Friedrich, S.

    2015-06-01

    Superconducting tunnel junctions (STJs) are excellent soft x-ray (100-2000 eV) detectors, particularly for synchrotron applications, because of their ability to obtain energy resolutions below 10 eV at count rates approaching 10 kcps. In order to achieve useful solid detection angles with these very small detectors, they are typically deployed in large arrays - currently with 100+ elements, but with 1000 elements being contemplated. In this paper we review a 5-year effort to develop compact, computer controlled low-noise processing electronics for STJ detector arrays, focusing on the major issues encountered and our solutions to them. Of particular interest are our preamplifier design, which can set the STJ operating points under computer control and achieve 2.7 eV energy resolution; our low noise power supply, which produces only 2 nV/√Hz noise at the preamplifier's critical cascode node; our digital processing card that digitizes and digitally processes 32 channels; and an STJ I-V curve scanning algorithm that computes noise as a function of offset voltage, allowing an optimum operating point to be easily selected. With 32 preamplifiers laid out on a custom 3U EuroCard, and the 32 channel digital card in a 3U PXI card format, electronics for a 128 channel array occupy only two small chassis, each the size of a National Instruments 5-slot PXI crate, and allow full array control with simple extensions of existing beam line data collection packages.

  9. The hybrid energy spectrum of Telescope Array's Middle Drum Detector and surface array

    NASA Astrophysics Data System (ADS)

    Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M. G.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, K.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

    2015-08-01

    The Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated when a primary cosmic ray particle interacts with the atmosphere. Meanwhile, scintillator detectors measure the lateral distribution of secondary shower particles that hit the ground. The Middle Drum (MD) fluorescence telescope station consists of 14 telescopes from the High Resolution Fly's Eye (HiRes) experiment, providing a direct link back to the HiRes measurements. Using the scintillator detector data in conjunction with the telescope data improves the geometrical reconstruction of the showers significantly, and hence, provides a more accurate reconstruction of the energy of the primary particle. The Middle Drum hybrid spectrum is presented and compared to that measured by the Middle Drum station in monocular mode. Further, the hybrid data establishes a link between the Middle Drum data and the surface array. A comparison between the Middle Drum hybrid energy spectrum and scintillator Surface Detector (SD) spectrum is also shown.

  10. 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.

  11. NORSAR Final Scientific Report Adaptive Waveform Correlation Detectors for Arrays: Algorithms for Autonomous Calibration

    SciTech Connect

    Gibbons, S J; Ringdal, F; Harris, D B

    2009-04-16

    Correlation detection is a relatively new approach in seismology that offers significant advantages in increased sensitivity and event screening over standard energy detection algorithms. The basic concept is that a representative event waveform is used as a template (i.e. matched filter) that is correlated against a continuous, possibly multichannel, data stream to detect new occurrences of that same signal. These algorithms are therefore effective at detecting repeating events, such as explosions and aftershocks at a specific location. This final report summarizes the results of a three-year cooperative project undertaken by NORSAR and Lawrence Livermore National Laboratory. The overall objective has been to develop and test a new advanced, automatic approach to seismic detection using waveform correlation. The principal goal is to develop an adaptive processing algorithm. By this we mean that the detector is initiated using a basic set of reference ('master') events to be used in the correlation process, and then an automatic algorithm is applied successively to provide improved performance by extending the set of master events selectively and strategically. These additional master events are generated by an independent, conventional detection system. A periodic analyst review will then be applied to verify the performance and, if necessary, adjust and consolidate the master event set. A primary focus of this project has been the application of waveform correlation techniques to seismic arrays. The basic procedure is to perform correlation on the individual channels, and then stack the correlation traces using zero-delay beam forming. Array methods such as frequency-wavenumber analysis can be applied to this set of correlation traces to help guarantee the validity of detections and lower the detection threshold. In principle, the deployment of correlation detectors against seismically active regions could involve very large numbers of very specific detectors. To

  12. JPL Large Advanced Antenna Station Array Study

    NASA Technical Reports Server (NTRS)

    1978-01-01

    In accordance with study requirements, two antennas are described: a 30 meter standard antenna and a 34 meter modified antenna, along with a candidate array configuration for each. Modified antenna trade analyses are summarized, risks analyzed, costs presented, and a final antenna array configuration recommendation made.

  13. The Atacama Large Millimeter Array (ALMA)

    NASA Astrophysics Data System (ADS)

    1999-06-01

    The Atacama Large Millimeter Array (ALMA) is the new name [2] for a giant millimeter-wavelength telescope project. As described in the accompanying joint press release by ESO and the U.S. National Science Foundation , the present design and development phase is now a Europe-U.S. collaboration, and may soon include Japan. ALMA may become the largest ground-based astronomy project of the next decade after VLT/VLTI, and one of the major new facilities for world astronomy. ALMA will make it possible to study the origins of galaxies, stars and planets. As presently envisaged, ALMA will be comprised of up to 64 12-meter diameter antennas distributed over an area 10 km across. ESO PR Photo 24a/99 shows an artist's concept of a portion of the array in a compact configuration. ESO PR Video Clip 03/99 illustrates how all the antennas will move in unison to point to a single astronomical object and follow it as it traverses the sky. In this way the combined telescope will produce astronomical images of great sharpness and sensitivity [3]. An exceptional site For such observations to be possible the atmosphere above the telescope must be transparent at millimeter and submillimeter wavelengths. This requires a site that is high and dry, and a high plateau in the Atacama desert of Chile, probably the world's driest, is ideal - the next best thing to outer space for these observations. ESO PR Photo 24b/99 shows the location of the chosen site at Chajnantor, at 5000 meters altitude and 60 kilometers east of the village of San Pedro de Atacama, as seen from the Space Shuttle during a servicing mission of the Hubble Space Telescope. ESO PR Photo 24c/99 and ESO PR Photo 24d/99 show a satellite image of the immediate vicinity and the site marked on a map of northern Chile. ALMA will be the highest continuously operated observatory in the world. The stark nature of this extreme site is well illustrated by the panoramic view in ESO PR Photo 24e/99. High sensitivity and sharp images ALMA

  14. Continuous-wave terahertz digital holographic tomography with a pyroelectric array detector

    NASA Astrophysics Data System (ADS)

    Li, Bin; Wang, Dayong; Zhou, Xun; Rong, Lu; Li, Zeyu; Li, Lei; Min, Wan; Huang, Haochong; Wang, Yunxin

    2016-05-01

    Terahertz computed tomography makes use of the penetrability of terahertz radiation and obtains three-dimensional (3-D) object projection data. Continuous-wave terahertz digital holographic tomography with a pyroelectric array detector is presented. Compared with scanning terahertz computed tomography, a pyroelectric array detector can obtain a large quantity of projection data in a short time. To obtain a 3-D image, in-line digital holograms of the object are recorded from various directions and reconstructed to obtain two-dimensional (2-D) projection data; then 2-D cross-sectional images and 3-D images of the internal structure of the object are obtained by the filtered back projection algorithm. The presented system can rapidly reconstruct the 3-D object and reveals the internal 3-D structure of the object. A 3-D reconstruction of a polyethylene straw is presented with a 6% error in retrieved diameter.

  15. Capillary Array Waveguide Amplified Fluorescence Detector for mHealth

    PubMed Central

    Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

    2013-01-01

    array can potentially be used for sensitive analysis of multiple fluorescent detection assays simultaneously. The simple phone based capillary array approach presented in this paper is capable of amplifying weak fluorescent signals thereby improving the sensitivity of optical detectors based on mobile phones. This may allow sensitive biological assays to be measured with low sensitivity detectors and may make mHealth practical for many diagnostics applications, especially in resource-poor and global health settings. PMID:24039345

  16. Antenna coupled detectors for 2D staring focal plane arrays

    NASA Astrophysics Data System (ADS)

    Gritz, Michael A.; Kolasa, Borys; Lail, Brian; Burkholder, Robert; Chen, Leonard

    2013-06-01

    Millimeter-wave (mmW)/sub-mmW/THz region of the electro-magnetic spectrum enables imaging thru clothing and other obscurants such as fog, clouds, smoke, sand, and dust. Therefore considerable interest exists in developing low cost millimeter-wave imaging (MMWI) systems. Previous MMWI systems have evolved from crude mechanically scanned, single element receiver systems into very complex multiple receiver camera systems. Initial systems required many expensive mmW integrated-circuit low-noise amplifiers. In order to reduce the cost and complexity of the existing systems, attempts have been made to develop new mmW imaging sensors employing direct detection arrays. In this paper, we report on Raytheon's recent development of a unique focal plane array technology, which operates broadly from the mmW through the sub-mmW/THz region. Raytheon's innovative nano-antenna based detector enables low cost production of 2D staring mmW focal plane arrays (mmW FPA), which not only have equivalent sensitivity and performance to existing MMWI systems, but require no mechanical scanning.

  17. Large Format Transition Edge Sensor Microcalorimeter Arrays

    NASA Technical Reports Server (NTRS)

    Chervenak, J. A.; Adams, J. A.; Bandler, S. b.; Busch, S. E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, J. P.; Porter, F. S.; Ray, C.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2012-01-01

    We have produced a variety of superconducting transition edge sensor array designs for microcalorimetric detection of x-rays. Designs include kilopixel scale arrays of relatively small sensors (approximately 75 micron pitch) atop a thick metal heat sinking layer as well as arrays of membrane-isolated devices on 250 micron and up to 600 micron pitch. We discuss fabrication and performance of microstripline wiring at the small scales achieved to date. We also address fabrication issues with reduction of absorber contact area in small devices.

  18. Materials Development for Auxiliary Components for Large Compact Mo/Au TES Arrays

    NASA Astrophysics Data System (ADS)

    Chervenak, J. A.; Finkbeiner, F. M.; Bandler, S. R.; Brekosky, R.; Brown, A. D.; Iyomoto, N.; Kelley, R. L.; Kilbourne, C. A.; Porter, F. S.; Sadleir, J.; Smith, S.

    2008-04-01

    Pursuing the feasibility of scaling conventionally-micromachined transition-edge-sensor (TES) arrays, we have undertaken a study of materials suitable for array integration. A potential limitation of increased pixel count is adequate heatsinking of each detector element to its base temperature. We describe technical approaches for heat sinking large compact TES microcalorimeter arrays and calculate the achievable heatsinking based on measured material parameters. Techniques include backside-deposited thick film copper on arrays with deep-etched wells in the substrates and electroplated gold and copper-filled micro-trenches on the substrate surface. Another limitation is the sensitivity of the thin film circuit elements to applied stress, which can arise in fabrication and mounting of arrays of increasing size. We have explored stress and deposition temperature sensitivity in our molybdenum-based bilayers. Such process parameters can impact options for array heat sinking and electrical interconnects.

  19. Performance of A Compact Multi-crystal High-purity Germanium Detector Array for Measuring Coincident Gamma-ray Emissions

    SciTech Connect

    Howard, Chris; Daigle, Stephen; Buckner, Matt; Erikson, Luke E.; Runkle, Robert C.; Stave, Sean C.; Champagne, Art; Cooper, Andrew; Downen, Lori; Glasgow, Brian D.; Kelly, Keegan; Sallaska, Anne

    2015-02-18

    The Multi-sensor Airborne Radiation Survey (MARS) detector is a 14-crystal array of high-purity germanium (HPGe) detectors housed in a single cryostat. The array was used to measure the astrophysical S-factor for the 14N(p,γ)15O* reaction for several transition energies at an effective center of mass energy of 163 keV. Owing to the segmented nature of the MARS detector, the effect of gamma-ray summing was greatly reduced in comparison to past experiments which utilized large, single-crystal detectors. The new S-factor values agree within the uncertainties with the past measurements. Details of the analysis and detector performance will be presented.

  20. Performance of a compact multi-crystal high-purity germanium detector array for measuring coincident gamma-ray emissions

    NASA Astrophysics Data System (ADS)

    Howard, Chris; Daigle, Stephen; Buckner, Matt; Erikson, Luke E.; Runkle, Robert C.; Stave, Sean C.; Champagne, Arthur E.; Cooper, Andrew; Downen, Lori; Glasgow, Brian D.; Kelly, Keegan; Sallaska, Anne

    2015-05-01

    The Multi-sensor Airborne Radiation Survey (MARS) detector is a 14-crystal array of high-purity germanium (HPGe) detectors housed in a single cryostat. The array was used to measure the astrophysical S-factor for the 14N(p,γ)15O* reaction for several transition energies at an effective center-of-mass energy of 163 keV. Owing to the granular nature of the MARS detector, the effect of gamma-ray summing was greatly reduced in comparison to past experiments which utilized large, single-crystal detectors. The new S-factor values agree within their uncertainties with the past measurements. Details of the analysis and detector performance are presented.

  1. Large Cryogenic Germanium Detector. Final Report

    SciTech Connect

    Mandic, Vuk

    2013-02-13

    The goal of this project was to investigate possible ways of increasing the size of cryogenic Ge detectors. This project identified two possible approaches to increasing the individual cryogenic Ge detector size. The first approach relies on using the existing technology for growing detector-grade (high-purity) germanium crystals of dislocation density 100-7000 cm{sup -2}. The second approach is to consider dislocation-free Ge crystals.

  2. Detection and localization of particle-emitting sources with compound-eye inspired detector arrays

    NASA Astrophysics Data System (ADS)

    Liu, Zhi

    2007-08-01

    We develop methods to detect and localize particle-emitting sources using detector arrays that are inspired by biological compound eyes. The sources of interest may be optical, nuclear, or cosmic; they emit particles such as visible photons, neutrons, protons, or charged particles. Our results may have wide applications to artificial vision, which can be important in robotics (robot vision) or medicine (e.g., artificial eyes for the blind); security, where the detection of nuclear materials is needed; or astronomy. This dissertation consists of three parts. First, we detect a far-field particle source using two directional detector arrays: cubic and spherical. We propose a mean-difference test (MDT) detector, analyze its statistical performance, and show that the MDT has a number of advantages over the generalized likelihood- ratio test (GLRT). Second, we localize the source by proposing a novel biologically inspired detector array, whose configuration generalizes the compound eye of insects. This array combines the advantages of compound eyes (e.g., large field-of-view) and human eyes (e.g., high angular resolution). Based on a statistical model of the array measurements, we analyze the array performance by computing the Cramérao bound (CRB) on the error in estimating the source direction. We also derive lower bounds on the mean-square angular error (MSAE) of the source localization and investigate the MSAE of two source- direction estimators. Numerical examples, including the optimal array design, are presented to further illustrate the array performance. Third, we derive a statistical angular resolution limit (ARL) on resolving two closely spaced point sources in a three-dimensional frame, which is applicable to various measurement models (e.g., radar, sonar, or astronomy). Using the asymptotic analysis of the GLRT, we derive the ARL with constraints on the probabilities of false alarm and detection. Our results give explicit analytical expression for the ARL

  3. ASIC Readout Circuit Architecture for Large Geiger Photodiode Arrays

    NASA Technical Reports Server (NTRS)

    Vasile, Stefan; Lipson, Jerold

    2012-01-01

    The objective of this work was to develop a new class of readout integrated circuit (ROIC) arrays to be operated with Geiger avalanche photodiode (GPD) arrays, by integrating multiple functions at the pixel level (smart-pixel or active pixel technology) in 250-nm CMOS (complementary metal oxide semiconductor) processes. In order to pack a maximum of functions within a minimum pixel size, the ROIC array is a full, custom application-specific integrated circuit (ASIC) design using a mixed-signal CMOS process with compact primitive layout cells. The ROIC array was processed to allow assembly in bump-bonding technology with photon-counting infrared detector arrays into 3-D imaging cameras (LADAR). The ROIC architecture was designed to work with either common- anode Si GPD arrays or common-cathode InGaAs GPD arrays. The current ROIC pixel design is hardwired prior to processing one of the two GPD array configurations, and it has the provision to allow soft reconfiguration to either array (to be implemented into the next ROIC array generation). The ROIC pixel architecture implements the Geiger avalanche quenching, bias, reset, and time to digital conversion (TDC) functions in full-digital design, and uses time domain over-sampling (vernier) to allow high temporal resolution at low clock rates, increased data yield, and improved utilization of the laser beam.

  4. Reducing the Read Noise of H2RG Detector Arrays by more Efficient use of Reference Signals

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Arendt, Richard G.; Fixen, D. J.; Lindler, Don; Loose, Markus; Moseley, S. H.; Wilson, D. V.

    2011-01-01

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

  5. Mechanical Design and Development of TES Bolometer Detector Arrays for the Advanced ACTPol Experiment

    NASA Technical Reports Server (NTRS)

    Ward, Jonathan T.; Austermann, Jason; Beall, James A.; Choi, Steve K.; Crowley, Kevin T.; Devlin, Mark J.; Duff, Shannon M.; Gallardo, Patricio M.; Henderson, Shawn W.; Ho, Shuay-Pwu Patty; Hilton, Gene; Hubmayr, Johannes; Khavari, Niloufar; Klein, Jeffrey; Koopman, Brian J.; Li, Dale; McMahon, Jeffrey; Mumby, Grace; Nati, Federico; Wollack, Edward J.

    2016-01-01

    The next generation Advanced ACTPol (AdvACT) experiment is currently underway and will consist of four Transition Edge Sensor (TES) bolometer arrays, with three operating together, totaling 5800 detectors on the sky. Building on experience gained with the ACTPol detector arrays, AdvACT will utilize various new technologies, including 150 mm detector wafers equipped with multichroic pixels, allowing for a more densely packed focal plane. Each set of detectors includes a feedhorn array of stacked silicon wafers which form a spline pro le leading to each pixel. This is then followed by a waveguide interface plate, detector wafer, back short cavity plate, and backshort cap. Each array is housed in a custom designed structure manufactured from high purity copper and then gold plated. In addition to the detector array assembly, the array package also encloses cryogenic readout electronics. We present the full mechanical design of the AdvACT high frequency (HF) detector array package along with a detailed look at the detector array stack assemblies. This experiment will also make use of extensive hardware and software previously developed for ACT, which will be modi ed to incorporate the new AdvACT instruments. Therefore, we discuss the integration of all AdvACT arrays with pre-existing ACTPol infrastructure.

  6. Modulation transfer function of antenna-coupled infrared detector arrays.

    PubMed

    Boreman, G D; Dogariu, A; Christodoulou, C; Kotter, D

    1996-11-01

    Individual antenna-coupled IR bolometers have recently been demonstrated at wavelengths near 10 μm. If focal-plane arrays (FPA's) of antenna-coupled detectors can be fabricated, enhancement of IR-imager performance is possible. A first step in the design process is to analyze the image-quality potential of antenna-coupled, FPA-based imagers in terms of the modulation transfer function (MTF). The key step in our analysis is development of a cross-talk MTF that accounts for the electromagnetic coupling between adjacent antennas in the FPA. We find that electromagnetic cross talk will not be a significant image-quality factor in antenna-coupled IR FPA's. PMID:21127627

  7. Electrical breakdown gas detector featuring carbon nanotube array electrodes.

    PubMed

    Kim, Seongyul; Pal, Sunil; Ajayan, Pulickel M; Borca-Tasciuc, Theodorian; Koratkar, Nikhil

    2008-01-01

    We demonstrate here detection of dichloro-difluoro-methane and oxygen in mixtures with helium using a carbon nanotube electrical breakdown sensor device. The sensor is comprised of an aligned array of multiwalled carbon nanotubes deposited on a nickel based super-alloy (Inconel 600) as the anode; the counter electrode is a planar nickel sheet. By monitoring the electrical breakdown characteristics of oxygen and dichloro-difluoro-methane in a background of helium, we find that the detection limit for dichloro-difluoro-methane is approximately 0.1% and the corresponding limit for oxygen is approximately 1%. A phenomenologigal model is proposed to describe the trends observed in detection of the two mixtures. These results indicate that carbon nanotube based electrical breakdown sensors show potential as end detectors in gas-chromatography devices. PMID:18468093

  8. Modulation transfer function of antenna-coupled infrared detector arrays

    NASA Astrophysics Data System (ADS)

    Boreman, Glenn D.; Dogariu, Aristide; Christodoulou, Christos; Kotter, Dale

    1996-11-01

    Individual antenna-coupled IR bolometers have recently been demonstrated at wavelengths near 10 mu m. If focal-plane arrays (FPA's) of antenna-coupled detectors can be fabricated, enhancement of IR-imager performance is possible. A first step in the design process is to analyze the image-quality potential of antenna-coupled, FPA-based imagers in terms of the modulation transfer function (MTF). The key step in our analysis is development of a cross-talk MTF that accounts for the electromagnetic coupling between adjacent antennas in the FPA. We find that electromagnetic cross talk will not be a significant image-quality factor in antenna-coupled IR FPA's.

  9. Thermal crosstalk simulation and measurement of linear terahertz detector arrays

    NASA Astrophysics Data System (ADS)

    Li, Weizhi; Huang, Zehua; Wang, Jun; Li, Mingyu; Gou, Jun; Jiang, Yadong

    2015-11-01

    Thermal simulation of differently structured linear terahertz detector arrays (TDAs) based on lithium tantalate was performed by finite element analysis (FEA). Simulation results revealed that a relatively simple TDA structure can have good thermal insulation, i.e., low thermal crosstalk effect (TCE), between adjacent pixels, which was thus selected for the real fabrication of TDA sample. Current responsivity (Ri) of the sample for a 2.52 THz source was measured to be 6.66 × 10-6 A/W and non-uniformity (NU) of Ri was 4.1%, showing good performance of the sample. TCE test result demonstrated that small TCE existed in the sample, which was in good agreement with the simulation results.

  10. Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector

    DOEpatents

    Strauss, Charlie E.

    1997-01-01

    Apparatus and method for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO.sub.2 laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart.

  11. Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector

    DOEpatents

    Strauss, C.E.

    1997-11-18

    Apparatus and method are disclosed for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO{sub 2} laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart. 4 figs.

  12. Automatic and robust calibration of optical detector arrays for biomedical diffuse optical spectroscopy

    PubMed Central

    Mastanduno, Michael A.; Jiang, Shudong; DiFlorio-Alexander, Roberta; Pogue, Brian W.; Paulsen, Keith D.

    2012-01-01

    The design and testing of a new, fully automated, calibration approach is described. The process was used to calibrate an image-guided diffuse optical spectroscopy system with 16 photomultiplier tubes (PMTs), but can be extended to any large array of optical detectors and associated imaging geometry. The design goals were accomplished by developing a routine for robust automated calibration of the multi-detector array within 45 minutes. Our process was able to characterize individual detectors to a median norm of the residuals of 0.03 V for amplitude and 4.4 degrees in phase and achieved less than 5% variation between all the detectors at the 95% confidence interval for equivalent measurements. Repeatability of the calibrated data from the imaging system was found to be within 0.05 V for amplitude and 0.2 degrees for phase, and was used to evaluate tissue-simulating phantoms in two separate imaging geometries. Spectroscopic imaging of total hemoglobin concentration was recovered to within 5% of the true value in both cases. Future work will focus on streamlining the technology for use in a clinical setting with expectations of achieving accurate quantification of suspicious lesions in the breast. PMID:23082277

  13. Automatic and robust calibration of optical detector arrays for biomedical diffuse optical spectroscopy.

    PubMed

    Mastanduno, Michael A; Jiang, Shudong; Diflorio-Alexander, Roberta; Pogue, Brian W; Paulsen, Keith D

    2012-10-01

    The design and testing of a new, fully automated, calibration approach is described. The process was used to calibrate an image-guided diffuse optical spectroscopy system with 16 photomultiplier tubes (PMTs), but can be extended to any large array of optical detectors and associated imaging geometry. The design goals were accomplished by developing a routine for robust automated calibration of the multi-detector array within 45 minutes. Our process was able to characterize individual detectors to a median norm of the residuals of 0.03 V for amplitude and 4.4 degrees in phase and achieved less than 5% variation between all the detectors at the 95% confidence interval for equivalent measurements. Repeatability of the calibrated data from the imaging system was found to be within 0.05 V for amplitude and 0.2 degrees for phase, and was used to evaluate tissue-simulating phantoms in two separate imaging geometries. Spectroscopic imaging of total hemoglobin concentration was recovered to within 5% of the true value in both cases. Future work will focus on streamlining the technology for use in a clinical setting with expectations of achieving accurate quantification of suspicious lesions in the breast. PMID:23082277

  14. Method of fabricating multiwavelength infrared focal plane array detector

    NASA Technical Reports Server (NTRS)

    Forrest, Stephen R. (Inventor); Olsen, Gregory H. (Inventor); Kim, Dong-Su (Inventor); Lange, Michael J. (Inventor)

    1996-01-01

    A multiwavelength local plane array infrared detector is included on a common substrate having formed on its top face a plurality of In.sub.x Ga.sub.1-x As (x.ltoreq.0.53) absorption layers, between each pair of which a plurality of InAs.sub.y P.sub.1-y (y.ltoreq.1) buffer layers are formed having substantially increasing lattice parameters, respectively, relative to said substrate, for preventing lattice mismatch dislocations from propagating through successive ones of the absorption layers of decreasing bandgap relative to said substrate, whereby a plurality of detectors for detecting different wavelengths of light for a given pixel are provided by removing material above given areas of successive ones of the absorption layers, which areas are doped to form a pn junction with the surrounding unexposed portions of associated absorption layers, respectively, with metal contacts being formed on a portion of each of the exposed areas, and on the bottom of the substrate for facilitating electrical connections thereto.

  15. Automated Hybridization of X-ray Absorber Elements-A Path to Large Format Microcalorimeter Arrays

    NASA Technical Reports Server (NTRS)

    Moseley, S.; Kelley, R.; Allen, C.; Kilbourne, C.; Costen, N.; Miller, T.

    2007-01-01

    In the design of microcalorimeters, it is often desirable to produce the X-ray absorber separately from the detector element. In this case, the attachment of the absorber to the detector element with the required thermal and mechanical characteristics is a major challenge. In such arrays, the attachment has been done by hand. This process is not easily extended to the large format arrays required for future X- ray astronomy missions such as the New x-ray Telescope or NeXT. In this paper we present an automated process for attaching absorber tiles to the surface of a large-scale X-ray detector array. The absorbers are attached with stycast epoxy to a thermally isolating polymer structure made of SU-8. SU-8 is a negative epoxy based photo resist produced by Microchem. We describe the fabrication of the X-ray absorbers and their suspension on a handle die in an adhesive matrix. We describe the production process for the polymer isolators on the detector elements. We have developed a new process for the alignment, and simultaneous bonding of the absorber tiles to an entire detector array. This process uses equipment and techniques used in the flip-chip bonding industry and approaches developed in the fabrication of the XRS-2 instrument. XRS-2 was an X-ray spectrometer that was launched on the Suzaku telescope in July 10, 2005. We describe the process and show examples of sample arrays produced by this process. Arrays with up to 300 elements have been bonded. The present tests have used dummy absorbers made of Si. In future work, we will demonstrate bonding of HgTe absorbers.

  16. Evolution of large format impurity band conductor focal plane arrays for astronomy applications

    NASA Astrophysics Data System (ADS)

    Mills, Robert; Beuville, Eric; Corrales, Elizabeth; Hoffman, Alan; Finger, Gert; Ives, Derek

    2011-09-01

    Raytheon Vision Systems (RVS) has developed a family of high performance large format infrared (IR) detector arrays whose detectors are most effective for the detection of long and very long wavelength IR energy. This paper describes the evolution of the present state of the art one mega-pixel Si: As Impurity Band Conduction (IBC) arrays toward a four mega-pixel array that is desired by the astronomy community. Raytheon's Aquarius-1k, developed in collaboration with ESO, is a 1024 × 1024 pixel high performance array with a 30 μm pitch that features high quantum efficiency IBC detectors, low noise, low dark current, and on-chip clocking for ease of operation. Since the Aquarius-1k array was designed primarily for ground-based astronomy applications, it incorporates selectable gains and a large well capacity among its other features. Raytheon, in collaboration with JAXA (Japan Aerospace Exploration Agency), is also designing a 2048 × 2048 pixel high performance array with a 25 μm pitch. This 2k × 2k readout circuit will be based on the successful design used for the on the Mid-Infrared Instrument (MIRI) aboard the James Webb Space Telescope (JWST). It will feature high quantum efficiency IBC detectors, low noise, low dark current, and on-chip clocking for ease of operation. This version will also incorporate flight qualified packaging to support space-based astronomy applications. Previous generations of RVS IBC detectors have flown on several platforms, including NASA's Spitzer Space Telescope and Japan's Akari Space Telescope.

  17. Terahertz spectroscopy with a holographic Fourier transform spectrometer plus array detector using coherent synchrotron radiation

    SciTech Connect

    Nikolay I. Agladz, John Klopf, Gwyn Williams, Albert J. Sievers

    2010-06-01

    By use of coherent terahertz synchrotron radiation, we experimentally tested a holographic Fourier transform spectrometer coupled to an array detector to determine its viability as a spectral device. Somewhat surprisingly, the overall performance strongly depends on the absorptivity of the birefringent lithium tantalate pixels in the array detector.

  18. Assessment study of infrared detector arrays for low-background astronomical research

    NASA Technical Reports Server (NTRS)

    Ando, K. J.

    1978-01-01

    The current state-of-the-art of infrared detector arrays employing charge coupled devices (CCD) or charge injection devices (CID) readout are assessed. The applicability, limitations and potentials of such arrays under the low-background astronomical observing conditions of interest for SIRFT (Shuttle Infrared Telescope Facility) are determined. The following are reviewed: (1) monolithic extrinsic arrays; (2) monolithic intrinsic arrays; (3) charge injection devices; and (4) hybrid arrays.

  19. Array detector for high energy laser based on diffuse transmission sampling.

    PubMed

    Pang, Miao; Rong, Jian; Zhou, Shan; Wu, Juan; Fan, Guobin; Zhang, Wei; Hu, Xiaoyang

    2014-01-01

    In order to improve the ability and accuracy of measuring the temporal-spatial distribution of the intensity of a large-size, high-energy laser beam, a novel array detecting method based on diffuse transmission sampling is proposed. The measurement principle and the design of the sampling and attenuating unit are presented. High-temperature-resistant diffuse transmission material is used to sample and attenuate a high energy laser beam. Pure copper, whose surface is first sand-blasted and then gold-plated, is applied to scatter the incident high-energy laser beam. The formula for the attenuation ratio was derived in detail. We developed two large-aperture array detectors with spatial resolution of 5 mm, spatial duty ratio of 20%, and useable angle range of ±30° without varying the responsivity, the non-uniformity in the laser profile measurement is below 1%, and the repeatability error in the laser power measurement is approximately 1%. The maximal energy density that the array detector can endure is more than 10 kJ/cm(2). PMID:24517743

  20. Array detector for high energy laser based on diffuse transmission sampling

    SciTech Connect

    Pang, Miao; Rong, Jian; Zhou, Shan; Wu, Juan; Zhang, Wei; Hu, Xiaoyang; Fan, Guobin

    2014-01-15

    In order to improve the ability and accuracy of measuring the temporal–spatial distribution of the intensity of a large-size, high-energy laser beam, a novel array detecting method based on diffuse transmission sampling is proposed. The measurement principle and the design of the sampling and attenuating unit are presented. High-temperature-resistant diffuse transmission material is used to sample and attenuate a high energy laser beam. Pure copper, whose surface is first sand-blasted and then gold-plated, is applied to scatter the incident high-energy laser beam. The formula for the attenuation ratio was derived in detail. We developed two large-aperture array detectors with spatial resolution of 5 mm, spatial duty ratio of 20%, and useable angle range of ±30° without varying the responsivity, the non-uniformity in the laser profile measurement is below 1%, and the repeatability error in the laser power measurement is approximately 1%. The maximal energy density that the array detector can endure is more than 10 kJ/cm{sup 2}.

  1. Status of uncooled focal plane detector arrays for smart IR sensors

    NASA Astrophysics Data System (ADS)

    Liddiard, Kevin C.; Ringh, Ulf; Jansson, Christer

    1996-06-01

    A cooperative research project between the Defense Science and Technology Organization, Australia, and the National Defense Research Establishment, Sweden, seeks to investigate concepts for smart IR focal plane detector arrays, whereby a monolithic Semiconductor Film Bolometer detector array is integrated with a CMOS signal conditioning circuit, analog- to-digital conversion and signal processing functions on the same silicon chip. Novel signal conditioning and on-chip digital readout techniques have been successfully demonstrated, and the supporting signal processing electronic design is being developed. This paper discusses the status of detector materials research and staring focal plane array development. The first experimental array has been delivered and is undergoing evaluation.

  2. Large Array Channel Capacity in the Presence of Interference

    NASA Technical Reports Server (NTRS)

    Vilnrotter, V.; Srinivasan, M.

    2006-01-01

    We develop a model for a large array ground receiver system for use in deep-space communications, and analyze the resulting array channel capacity. The model includes effects of array geometry, time-dependent spacecraft orbital trajectory, point and extended interference sources, and elevation-dependent noise and tropospheric channel variations. Channel capacity is expressed as the ratio of determinants of covariance matrices characterizing source, interference, and additive noise, and then reduced to a simpler quadratic form more amenable to analysis and numerical computation. This formulation facilitates inclusion of array and channel characteristics into the model, as well as comparison of optimal, suboptimal, and equivalent single antenna configurations on achievable throughput. Realistic examples of ground array channel capacity calculations are presented, demonstrating the impact of array geometry, planetary interference sources, and array combining algorithm design upon the achievable data throughput.

  3. Opto-electrical characterization and X-ray mapping of large-volume cadmium zinc telluride radiation detectors

    SciTech Connect

    Yang, G.; Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Hossain, A.; Yao, H.W.; Kim, K.; and James, R.B.

    2009-04-13

    Large-volume cadmium zinc telluride (CZT) radiation detectors would greatly improve radiation detection capabilities and, therefore, attract extensive scientific and commercial interests. CZT crystals with volumes as large as hundreds of centimeters can be achieved today due to improvements in the crystal growth technology. However, the poor performance of large-volume CZT detectors is still a challenging problem affecting the commercialization of CZT detectors and imaging arrays. We have employed Pockels effect measurements and synchrotron X-ray mapping techniques to investigate the performance-limiting factors for large-volume CZT detectors. Experimental results with the above characterization methods reveal the non-uniform distribution of internal electric field of large-volume CZT detectors, which help us to better understand the responsible mechanism for the insufficient carrier collection in large-volume CZT detectors.

  4. Silicon PIN diode hybrid arrays for charged particle detection: Building blocks for vertex detectors at the SSC

    SciTech Connect

    Kramer, G.; Gaalema, S.; Shapiro, S.L.; Dunwoodie, W.M.; Arens, J.F.; Jernigan, J.G.

    1989-05-01

    Two-dimensional arrays of solid state detectors have long been used in visible and infrared systems. Hybrid arrays with separately optimized detector and readout substrates have been extensively developed for infrared sensors. The characteristics and use of these infrared readout chips with silicon PIN diode arrays produced by MICRON SEMICONDUCTOR for detecting high-energy particles are reported. Some of these arrays have been produced in formats as large as 512 /times/ 512 pixels; others have been radiation hardened to total dose levels beyond 1 Mrad. Data generation rates of 380 megasamples/second have been achieved. Analog and digital signal transmission and processing techniques have also been developed to accept and reduce these high data rates. 9 refs., 15 figs., 2 tabs.

  5. Fill-factor improvement of Si CMOS single-photon avalanche diode detector arrays by integration of diffractive microlens arrays.

    PubMed

    Intermite, Giuseppe; McCarthy, Aongus; Warburton, Ryan E; Ren, Ximing; Villa, Federica; Lussana, Rudi; Waddie, Andrew J; Taghizadeh, Mohammad R; Tosi, Alberto; Zappa, Franco; Buller, Gerald S

    2015-12-28

    Single-photon avalanche diode (SPAD) detector arrays generally suffer from having a low fill-factor, in which the photo-sensitive area of each pixel is small compared to the overall area of the pixel. This paper describes the integration of different configurations of high efficiency diffractive optical microlens arrays onto a 32 × 32 SPAD array, fabricated using a 0.35 µm CMOS technology process. The characterization of SPAD arrays with integrated microlens arrays is reported over the spectral range of 500-900 nm, and a range of f-numbers from f/2 to f/22. We report an average concentration factor of 15 measured for the entire SPAD array with integrated microlens array. The integrated SPAD and microlens array demonstrated a very high uniformity in overall efficiency. PMID:26832039

  6. A two dimensional silicon detectors array for quality assurance in stereotactic radiotherapy: MagicPlate-512

    SciTech Connect

    Aldosari, A. H.; Petasecca, M. Espinoza, A.; Newall, M.; Fuduli, I.; Porumb, C.; Alshaikh, S.; Alrowaili, Z. A.; Weaver, M.; Metcalfe, P.; Lerch, M. L. F.; Rosenfeld, A. B.; Carolan, M.; Perevertaylo, V.

    2014-09-15

    Purpose: Silicon diode arrays are commonly implemented in radiation therapy quality assurance applications as they have a number of advantages including: real time operation (compared to the film) and high spatial resolution, large dynamic range and small size (compared to ionizing chambers). Most diode arrays have detector pitch that is too coarse for routine use in small field applications. The goal of this work is to characterize the two-dimensional monolithic silicon diode array named “MagicPlate-512” (MP512) designed for QA in stereotactic body radiation therapy (SBRT) and stereotactic radio surgery (SRS). Methods: MP512 is a silicon monolithic detector manufactured on ap-type substrate. An array contains of 512 pixels with size 0.5 × 0.5 mm{sup 2} and pitch 2 mm with an overall dimension of 52 × 52 mm{sup 2}. The MP512 monolithic detector is wire bonded on a printed circuit board 0.5 mm thick and covered by a thin layer of raisin to preserve the silicon detector from moisture and chemical contamination and to protect the bonding wires. Characterization of the silicon monolithic diode array response was performed, and included pixels response uniformity, dose linearity, percent depth dose, output factor, and beam profiling for beam sizes relevant to SBRT and SRS and depth dose response in comparison with ionization chamber. Results: MP512 shows a good dose linearity (R{sup 2} = 0.998) and repeatability within 0.2%. The measured depth dose response for field size of 10 × 10 cm{sup 2} agreed to within 1.3%, when compared to a CC13 ionization chamber for depths in PMMA up to 30 cm. The output factor of a 6 MV Varian 2100EX medical linac beam measured by MP512 at the isocenter agrees to within 2% when compared to PTW diamond, Scanditronix point EDD-2 diode and MOSkin detectors for field sizes down to 1 × 1 cm{sup 2}. An over response of 4% was observed for square beam size smaller than 1 cm when compared to EBT3 films, while the beam profiles (FWHM) of MP

  7. Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays

    NASA Technical Reports Server (NTRS)

    Jhabvala, Murzy; Franz, David E.; Ewin, Audrey J.; Jhabvala, Christine; Babu, Sachi; Snodgrass, Stephen; Costen, Nicholas; Zincke, Christian

    2009-01-01

    The silicon substrate carrier was created so that a large-area array (in this case 62,000+ elements of a microshutter array) and a variety of discrete passive and active devices could be mounted on a single board, similar to a printed circuit board. However, the density and number of interconnects far exceeds the capabilities of printed circuit board technology. To overcome this hurdle, a method was developed to fabricate this carrier out of silicon and implement silicon integrated circuit (IC) technology. This method achieves a large number of high-density metal interconnects; a 100-percent yield over a 6-in. (approximately equal to 15-cm) diameter wafer (one unit per wafer); a rigid, thermally compatible structure (all components and operating conditions) to cryogenic temperatures; re-workability and component replaceability, if required; and the ability to precisely cut large-area holes through the substrate. A method that would employ indium bump technology along with wafer-scale integration onto a silicon carrier was also developed. By establishing a silicon-based version of a printed circuit board, the objectives could be met with one solution. The silicon substrate would be 2 mm thick to survive the environmental loads of a launch. More than 2,300 metal traces and over 1,500 individual wire bonds are required. To mate the microshutter array to the silicon substrate, more than 10,000 indium bumps are required. A window was cut in the substrate to allow the light signal to pass through the substrate and reach the microshutter array. The substrate was also the receptacle for multiple unpackaged IC die wire-bonded directly to the substrate (thus conserving space over conventionally packaged die). Unique features of this technology include the implementation of a 2-mmthick silicon wafer to withstand extreme mechanical loads (from a rocket launch); integrated polysilicon resistor heaters directly on the substrate; the precise formation of an open aperture

  8. ISABELLE. Volume 3. Experimental areas, large detectors

    SciTech Connect

    Not Available

    1981-01-01

    This section presents the papers which resulted from work in the Experimental Areas portion of the Workshop. The immediate task of the group was to address three topics. The topics were dictated by the present state of ISABELLE experimental areas construction, the possibility of a phased ISABELLE and trends in physics and detectors.

  9. CMOS preamplifiers for detectors large and small

    SciTech Connect

    O`Connor, P.

    1997-12-31

    We describe four CMOS preamplifiers developed for multiwire proportional chambers (MWPC) and silicon drift detectors (SDD) covering a capacitance range from 150 pF to 0.15 pF. Circuit techniques to optimize noise performance, particularly in the low-capacitance regime, are discussed.

  10. Polycrystalline CVD diamond pixel array detector for nuclear particles monitoring

    NASA Astrophysics Data System (ADS)

    Pacilli, M.; Allegrini, P.; Girolami, M.; Conte, G.; Spiriti, E.; Ralchenko, V. G.; Komlenok, M. S.; Khomic, A. A.; Konov, V. I.

    2013-02-01

    We report the 90Sr beta response of a polycrystalline diamond pixel detector fabricated using metal-less graphitic ohmic contacts. Laser induced graphitization was used to realize multiple squared conductive contacts with 1mm × 1mm area, 0.2 mm apart, on one detector side while on the other side, for biasing, a 9mm × 9mm large graphite contact was realized. A proximity board was used to wire bonding nine pixels at a time and evaluate the charge collection homogeneity among the 36 detector pixels. Different configurations of biasing were experimented to test the charge collection and noise performance: connecting the pixel at the ground potential of the charge amplifier led to best results and minimum noise pedestal. The expected exponential trend typical of beta particles has been observed. Reversing the bias polarity the pulse height distribution (PHD) does not changes and signal saturation of any pixel was observed around ±200V (0.4 V/μm). Reasonable pixels response uniformity has been evidenced even if smaller pitch 50÷100 μm structures need to be tested.

  11. Large format MBE HgCdTe on silicon detector development for astronomy

    NASA Astrophysics Data System (ADS)

    Hanold, Brandon J.; Figer, Donald F.; Lee, Joong; Kolb, Kimberly; Marcuson, Iain; Corrales, Elizabeth; Getty, Jonathan; Mears, Lynn

    2015-08-01

    The Center for Detectors at Rochester Institute of Technology and Raytheon Vision Systems (RVS) are leveraging RVS capabilities to produce large format, short-wave infrared HgCdTe focal plane arrays on silicon (Si) substrate wafers. Molecular beam epitaxial (MBE) grown HgCdTe on Si can reduce detector fabrication costs dramatically, while keeping performance competitive with HgCdTe grown on CdZnTe. Reduction in detector costs will alleviate a dominant expense for observational astrophysics telescopes. This paper presents the characterization of 2.5μm cutoff MBE HgCdTe/Si detectors including pre- and post-thinning performance. Detector characteristics presented include dark current, read noise, spectral response, persistence, linearity, crosstalk probability, and analysis of material defects.

  12. Progress of Multicolor Single Detector to Detector Array Development for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Abedin, M. Nurul; Refaat, Tamer F.; Bhat, Ishwara; Xiao, Ye-Gao; Bandra, Sumith; Gunapala, Sarath D.

    2004-01-01

    Knowledge of the spatial and temporal distribution of atmospheric species such as CO2, O3, H2O, and CH4 is important for understanding the chemistry and physical cycles involving Earth s atmosphere. Although several remote sensing techniques are suitable for such measurements they are considered high cost techniques involving complicated instrumentation. Therefore, simultaneous measurement of atmospheric species using a single remote sensing instrument is significant for minimizing cost, size and complexity. While maintaining the instrument sensitivity and range, quality of multicolor detector, in terms of high quantum efficiency and low noise are vital for these missions. As the first step for developing multicolor focal plan array, the structure of a single element multicolor detector is presented in this paper. The detector consists of three p-n junction layers of Si, GaSb and InAs wafer bonded to cover the spectral range UV to 900 nm, 800 nm to 1.7 m, and 1.5 m to 3.4 m, respectively. Modeling of the absorption coefficient for each material was carried out for optimizing the layers thicknesses for maximum absorption. The resulted quantum efficiency of each layer has been determined except InAs layer. The optical and electrical characterization of each layer structure is reported including dark current and spectral response measurements of Si pin structure and of GaSb and InAs p-n junctions. The effect of the material processing is discussed.

  13. Infrared pushbroom camera breadboard using off-the-shelf 2D array of detector

    NASA Astrophysics Data System (ADS)

    Bernier, Joel; Plainchamp, Patrick; Bardon, Dominique

    1994-09-01

    Performances for nowadays optronic systems require focal plane arrays (FPA) with an increasing number of detectors. The `push- broom' technic is well adapted to earth observation in the visible range with the availability of long linear CCD'S offering thousands of pixels. In the infrared, line scan systems are preferred at the present time because technological difficulties have to be overcome in order to get long linear arrays. Among the most important, are: (1) Difficulties to have a large cold focal plane with a temperature uniformity of a few degrees. (2) Difficulties to get good detection material over large surface. Mechanical or optical butting technology can be used there but with dead pixels and/or side effects. (3) Very low cold shield efficiency due to the geometry of the long linear array. (4) Very high development costs. MATRA DEFENSE UAO has made the design of a new infrared FPA concept which has the advantage to overcome all drawbacks listed previously (patented design). The idea consists to transform the pixel arrangement geometry of a 2D array which is available off the shelf into a long linear FPA using a coherent infrared fiber optic reformatter. In order to demonstrate the feasibility of this new FPA concept, a camera breadboard has been built. This task has been supported by the French MOD (STTE). This paper describes this breadboard and gives main technical performances.

  14. Development of an ultra-low-power x-ray-photon-resolving imaging detector array

    NASA Astrophysics Data System (ADS)

    Sun, Shunming; Downey, Stephen; Gaalema, Stephen; Gates, James L.; Jernigan, J. Garrett; Kaaret, Philip; MacIntosh, Scott; Ramsey, Brian; Wall, Bruce

    2010-08-01

    We report on progress to develop and demonstrate CZT and Si hybrid detector arrays for future NASA missions in X-ray and Gamma-ray astronomy. The primary goal for these detectors is consistent with the design concept for the EXIST mission1 and will also be appropriate for other NASA applications and ground-based projects. In particular we target science instruments that have large aperture (multiple square meters) and therefore require a low power ROIC (readout integrated circuits) design (< 10 microwatt per pixel in quiescent mode). The design also must achieve good energy resolution for single photon detection for X rays in the range 5-600 keV with a CZT sense layer and 2-30 keV with a Si sense layer. The target CZT arrays are 2 cm × 2 cm with 600 micron square-shaped pixels. The low power smart pixel detects rare X-ray hits with an adjustable threshold setting. A test array of 7 × 5 pixels with a 5 mm thick CZT sense layer demonstrates that the low power pixel can successfully detect X-rays with {50 readout noise electrons RMS.

  15. Signal-Conditioning Block of a 1 × 200 CMOS Detector Array for a Terahertz Real-Time Imaging System.

    PubMed

    Yang, Jong-Ryul; Lee, Woo-Jae; Han, Seong-Tae

    2016-01-01

    A signal conditioning block of a 1 × 200 Complementary Metal-Oxide-Semiconductor (CMOS) detector array is proposed to be employed with a real-time 0.2 THz imaging system for inspecting large areas. The plasmonic CMOS detector array whose pixel size including an integrated antenna is comparable to the wavelength of the THz wave for the imaging system, inevitably carries wide pixel-to-pixel variation. To make the variant outputs from the array uniform, the proposed signal conditioning block calibrates the responsivity of each pixel by controlling the gate bias of each detector and the voltage gain of the lock-in amplifiers in the block. The gate bias of each detector is modulated to 1 MHz to improve the signal-to-noise ratio of the imaging system via the electrical modulation by the conditioning block. In addition, direct current (DC) offsets of the detectors in the array are cancelled by initializing the output voltage level from the block. Real-time imaging using the proposed signal conditioning block is demonstrated by obtaining images at the rate of 19.2 frame-per-sec of an object moving on the conveyor belt with a scan width of 20 cm and a scan speed of 25 cm/s. PMID:26950128

  16. Signal-Conditioning Block of a 1 × 200 CMOS Detector Array for a Terahertz Real-Time Imaging System

    PubMed Central

    Yang, Jong-Ryul; Lee, Woo-Jae; Han, Seong-Tae

    2016-01-01

    A signal conditioning block of a 1 × 200 Complementary Metal-Oxide-Semiconductor (CMOS) detector array is proposed to be employed with a real-time 0.2 THz imaging system for inspecting large areas. The plasmonic CMOS detector array whose pixel size including an integrated antenna is comparable to the wavelength of the THz wave for the imaging system, inevitably carries wide pixel-to-pixel variation. To make the variant outputs from the array uniform, the proposed signal conditioning block calibrates the responsivity of each pixel by controlling the gate bias of each detector and the voltage gain of the lock-in amplifiers in the block. The gate bias of each detector is modulated to 1 MHz to improve the signal-to-noise ratio of the imaging system via the electrical modulation by the conditioning block. In addition, direct current (DC) offsets of the detectors in the array are cancelled by initializing the output voltage level from the block. Real-time imaging using the proposed signal conditioning block is demonstrated by obtaining images at the rate of 19.2 frame-per-sec of an object moving on the conveyor belt with a scan width of 20 cm and a scan speed of 25 cm/s. PMID:26950128

  17. Delta-Doped CCDs as Detector Arrays in Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Nikzad, Shouleh; Jones, Todd; Jewell, April; Sinha, Mahadeva

    2007-01-01

    In a conventional mass spectrometer, charged particles (ions) are dispersed through a magnetic sector onto an MCP at an output (focal) plane. In the MCP, the impinging charged particles excite electron cascades that afford signal gain. Electrons leaving the MCP can be read out by any of a variety of means; most commonly, they are post-accelerated onto a solid-state detector array, wherein the electron pulses are converted to photons, which, in turn, are converted to measurable electric-current pulses by photodetectors. Each step in the conversion from the impinging charged particles to the output 26 NASA Tech Briefs, February 2007 current pulses reduces spatial resolution and increases noise, thereby reducing the overall sensitivity and performance of the mass spectrometer. Hence, it would be preferable to make a direct measurement of the spatial distribution of charged particles impinging on the focal plane. The utility of delta-doped CCDs as detectors of charged particles was reported in two articles in NASA Tech Briefs, Vol. 22, No. 7 (July 1998): "Delta-Doped CCDs as Low-Energy-Particle Detectors" (NPO-20178) on page 48 and "Delta- Doped CCDs for Measuring Energies of Positive Ions" (NPO-20253) on page 50. In the present developmental miniature mass spectrometers, the above mentioned miniaturization and performance advantages contributed by the use of delta-doped CCDs are combined with the advantages afforded by the Mattauch-Herzog design. The Mattauch- Herzog design is a double-focusing spectrometer design involving an electric and a magnetic sector, where the ions of different masses are spatially separated along the focal plane of magnetic sector. A delta-doped CCD at the focal plane measures the signals of all the charged-particle species simultaneously at high sensitivity and high resolution, thereby nearly instantaneously providing a complete, high-quality mass spectrum. The simultaneous nature of the measurement of ions stands in contrast to that of a

  18. Large beam deflection using cascaded prism array

    NASA Astrophysics Data System (ADS)

    Wang, Wei-Chih; Tsui, Chi-Leung

    2012-04-01

    Endoscopes have been utilize in the medical field to observe the internals of the human body to assist the diagnosis of diseases, such as breathing disorders, internal bleeding, stomach ulcers, and urinary tract infections. Endoscopy is also utilized in the procedure of biopsy for the diagnosis of cancer. Conventional endoscopes suffer from the compromise between overall size and image quality due to the required size of the sensor for acceptable image quality. To overcome the size constraint while maintaining the capture image quality, we propose an electro-optic beam steering device based on thermal-plastic polymer, which has a small foot-print (~5mmx5mm), and can be easily fabricated using conventional hot-embossing and micro-fabrication techniques. The proposed device can be implemented as an imaging device inside endoscopes to allow reduction in the overall system size. In our previous work, a single prism design has been used to amplify the deflection generated by the index change of the thermal-plastic polymer when a voltage is applied; it yields a result of 5.6° deflection. To further amplify the deflection, a new design utilizing a cascading three-prism array has been implemented and a deflection angle to 29.2° is observed. The new design amplifies the beam deflection, while keeping the advantage of simple fabrication made possible by thermal-plastic polymer. Also, a photo-resist based collimator lens array has been added to reduce and provide collimation of the beam for high quality imaging purposes. The collimator is able to collimate the exiting beam at 4 μm diameter for up to 25mm, which potentially allows high resolution image capturing.

  19. High luminosity operation of large solid angle scintillator arrays in Jefferson Lab Hall A

    SciTech Connect

    Ran Shneor

    2003-12-01

    This thesis describes selected aspects of high luminosity operation of large solid angle scintillator arrays in Hall A of the CEBAF (Central Electron Beam Accelerator Facility) at TJNAF (Thomas Jefferson National Accelerator Facility ). CEBAF is a high current, high duty factor electron accelerator with a maximum beam energy of about 6 GeV and a maximum current of 200 {micro}A. Operating large solid angle scintillator arrays in high luminosity environment presents several problems such as high singles rates, low signal to noise ratios and shielding requirements. To demonstrate the need for large solid angle and momentum acceptance detectors as a third arm in Hall A, we will give a brief overview of the physics motivating five approved experiments, which utilize scintillator arrays. We will then focus on the design and assembly of these scintillator arrays, with special focus on the two new detector packages built for the Short Range Correlation experiment E01-015. This thesis also contains the description and results of different tests and calibrations which where conducted for these arrays. We also present the description of a number of tests which were done in order to estimate the singles rates, data reconstruction, filtering techniques and shielding required for these counters.

  20. Synthesis arrangement and parity correction of linear array infrared detector

    NASA Astrophysics Data System (ADS)

    Wang, Qun; Hong, Pu; Wang, Bo; Wang, Chensheng

    2010-11-01

    According to the configuration and technical specification of the detector, which has multiple channels, channels mixing, high speed outputs and separate columns between odd and even, a real time digital processing unit based on the CPLD, FPGA and DSP has been developed to achieve the data synthesis and arrangement function and the parity correction algorithm. A special interface circuit with 4 CPLDs is designed to complete the first synthesis step where the 16 channels of data are combined into 4 channels. The second step is finished in FPGA and ROM address encoder where the 4 channels of data are combined into 1 channel. For output data synchronization, FIFO is adopted to achieve the delay of even channels in the parity correction. Data of odd channels enters the columns synthesis unit without any processing and even channels shall be processed in the columns synthesis unit after entering the FIFO unit first and experiencing the delay process. Thereby the pre-processing before image processing of the linear array thermal imager is accomplished.

  1. Bi-material resonant infrared thermal detector and array

    NASA Astrophysics Data System (ADS)

    Zhang, Xia; Zhang, Dacheng

    2014-10-01

    A resonant infrared thermal sensor with high sensitivity, whose sensing element is a bi-material structure with thermal expansion mismatch effect, is presented in this paper. The sensor detects infrared radiation by means of tracking the change in resonance frequency of the bi-material structure with temperature change attributed to the infrared radiation from targets. The bi-material structure can amplify the change in resonance frequency compared to a single material sensing structure. In accordance with the theory of vibration mechanics and design principle of infrared thermal detector, the bi-material resonant sensor by means of which an array can be achieved is designed. The simulation results, by ANSYS software analysis based on multi-layer shell finite element, demonstrate that the dependence of resonance frequency on temperature of the designed sensing structure achieves 1Hz/0.01°C. A microarray with 6×6 resonant infrared sensors is fabricated based on microelectronics processes being compatible with integrated circuit fabrication technology. The frequency variation corresponding to the temperature shift can be obtained by electrical measurement.

  2. A Prototype Three-Dimensional Position Sensitive CdZnTe Detector Array

    SciTech Connect

    Zhang, Feng; He, Zhong; Seifert, Carolyn E.

    2007-08-01

    A new CdZnTe gamma-ray spectrometer system that employs two layers of modular detector arrays is being developed under the collaboration between the University of Michigan and the Pacific Northwest National Labaratory (PNNL). Each layer can accommodate up to three by three 3-dimensional position sensitive CdZnTe gamma-ray spectrometers. This array system is based on the newly developed VAS_UM/TAT4 ASIC readout electronics. Each of the nine detector modules consists of a pixellated CdZnTe detector and a VAS_UM/TAT4 ASIC frontend board. Each 1.5´1.5´1.0 cm3 CdZnTe detector employs an array of 11 by 11 pixellated anodes and a planar cathode. The energy depositions and 3-dimensional positions of individual interactions of each incident gamma ray can be obtained from pulse amplitude, location of each pixel anode and the drift time of electrons. Ten detectors were tested individually and half of them achieved resolution of <1.0% FWHM at 662 keV for single-pixel events (~30% of all 662 keV full energy deposition events). Two of them were tested in a simple array to verify that the upgrade to an array system does not sacrifice the performance of individual detectors. Experimental results of individual detectors and a twodetector array system are presented, and possible causes for several worse performing detectors are discussed.

  3. Large Phased Array Radar Using Networked Small Parabolic Reflectors

    NASA Technical Reports Server (NTRS)

    Amoozegar, Farid

    2006-01-01

    Multifunction phased array systems with radar, telecom, and imaging applications have already been established for flat plate phased arrays of dipoles, or waveguides. In this paper the design trades and candidate options for combining the radar and telecom functions of the Deep Space Network (DSN) into a single large transmit array of small parabolic reflectors will be discussed. In particular the effect of combing the radar and telecom functions on the sizes of individual antenna apertures and the corresponding spacing between the antenna elements of the array will be analyzed. A heterogeneous architecture for the DSN large transmit array is proposed to meet the radar and telecom requirements while considering the budget, scheduling, and strategic planning constrains.

  4. Use of single photon counting detector arrays in combined PET/MR: Characterization of LYSO-SiPM detector modules and comparison with a LSO-APD detector

    NASA Astrophysics Data System (ADS)

    Spanoudaki, V. C.; Mann, A. B.; Otte, A. N.; Konorov, I.; Torres-Espallardo, I.; Paul, S.; Ziegler, S. I.

    2007-12-01

    We propose in this study a novel PET detector concept as insert for simultaneous PET/MR imaging, using arrays of Silicon Photomultipliers (SiPMs) as photodetectors, read out by a data acquisition system based on sampling ADCs. A 2 × 2 LSO-SiPM detector array and four single channel LYSO-SiPM detectors have been evaluated and compared to a LSO-APD detector. A 17.9% energy resolution and a 1.4 ns time resolution have been measured. No degradation of these values could be detected when simultaneous MR acquisitions were performed. The non-linear detector behaviour due to the limited dynamic range and recovery time effects has been studied. In addition, the contribution of dark counts and optical crosstalk for PET applications was also addressed. The feasibility for position localization of the incident light to a SiPM array using Anger logic has been investigated.

  5. The Design and Performance of the 384: Element Submillimeter Detector Array for SHARC II

    NASA Technical Reports Server (NTRS)

    Moseley, Samuel H.; Allen, Christine; Benford, Dominic; Silverberg, Robert; Staguhn, Johannes; Dowell, Darren; Phillips, Tom

    2003-01-01

    We report on the performance of the SHARC II detector, a 12 x 32 array of ion implanted Si pop-up bolometers. This 384 element detector array was built as a prototype for the High Angular Resolution Widefield Camera (HAWC) for the Stratospheric Observatory for Infrared Astronomy (SOFIA). We will discuss the design process, the characterization of the detectors, and the performance of the array in the SHARC II instrument. SHARC II is now a facility instrument on the Caltech Submillimeter Observatory, providing background-limited imaging at 350 and 450 microns.

  6. Large-Format AlGaN PIN Photodiode Arrays for UV Images

    NASA Technical Reports Server (NTRS)

    Aslam, Shahid; Franz, David

    2010-01-01

    A large-format hybridized AlGaN photodiode array with an adjustable bandwidth features stray-light control, ultralow dark-current noise to reduce cooling requirements, and much higher radiation tolerance than previous technologies. This technology reduces the size, mass, power, and cost of future ultraviolet (UV) detection instruments by using lightweight, low-voltage AlGaN detectors in a hybrid detector/multiplexer configuration. The solar-blind feature eliminates the need for additional visible light rejection and reduces the sensitivity of the system to stray light that can contaminate observations.

  7. A prototype avalanche photodiode array for scintillating-fiber tracking detectors

    NASA Astrophysics Data System (ADS)

    Yoshida, tracking detectors T.; Sora, T.

    2004-12-01

    We have evaluated the performance of a prototype 16-channel avalanche photodiode (APD) array developed primarily for scintillating-fiber (SCIFI) tracking detectors. The APD array was coupled to a 2.5 m long SCIFI array, and the detection efficiency was measured for minimum ionizing particles passing through the SCIFI array. The APD array was cooled to -50 °C to improve the S/N ratio. We have found that the APD array can read out each individual SCIFI with sufficiently high efficiency.

  8. Helium cooling systems for large superconducting physics detector magnets

    NASA Astrophysics Data System (ADS)

    Green, M. A.

    The large superconducting detector magnets used for high energy physics experiments are virtually all indirectly cooled. In general, these detector magnets are not cryogenically stabilized. Therefore, there are a number of choices for cooling large indirectly cooled detector magnets. These choices include; 1) forced two-phase helium cooling driven by the helium refrigerator J-T circuit, 2) forced two-phase helium cooling driven by a helium pump, and 3) a peculation gravity feed cooling system which uses liquid helium from a large storage dewar. The choices for the cooling of a large detector magnet are illustrated by applying these concepts to a 4.2 meter diameter 0.5 tesla thin superconducting solenoid for an experiment at the Relativistic Heavy Ion Collider (RHIC).

  9. Large format high-operability SWIR and MWIR focal plane array performance and capabilities

    NASA Astrophysics Data System (ADS)

    Bangs, James; Langell, Mark; Reddy, Madhu; Melkonian, Leon; Johnson, Scott; Elizondo, Lee; Rybnicek, Kimon; Norton, Elyse; Jaworski, Frank; Asbrock, James; Baur, Stefan

    2011-06-01

    High-performance large-format detector arrays responsive to the 1-5μm wavelength range of the infrared spectrum fabricated using large area HgCdTe layers grown on 6-inch diameter (211) silicon substrates are available for advanced imaging applications. This paper reviews performance and capabilities of Raytheon Vision Systems (RVS) HgCdTe/Si Focal Plane Arrays (FPA) and shows 2k x 2k format MWIR HgCdTe/Si FPA performance with NEdT operabilities better than 99.9%. SWIR and MWIR detector performance for HgCdTe/Si is comparable to established performance of HgCdTe/CdZnTe wafers. HgCdTe devices fabricated on both types of substrates have demonstrated very low dark current, high quantum efficiency and full spectral band fill factor characteristic of HgCdTe. HgCdTe has the advantage of being able to precisely tune the detector cutoff via adjustment of the Cd composition in the MBE growth. The HgCdTe/Si detectors described in this paper are p-on-n mesa delineated architecture and fabricated using the same mature etch, passivation, and metallization processes as our HgCdTe/CdZnTe line. Uniform device quality HgCdTe epitaxial layers and application of detector fabrication processes across the full area of 6-inch wafers routinely produces high performing detector pixels from edge to edge of the photolithographic limits across the wafer, offering 5 times the printable area as costly 6×6cm CdZnTe substrates. This 6-inch HgCdTe detector wafer technology can provide applications demanding very wide FOV high resolution coverage the capability to produce a very large single piece infrared detector array, up to a continuous image plane 10×10 cm in size. Alternatively, significant detector cost reduction through allowing more die of a given size to be printed on each wafer is possible, with further cost reduction achieved through transition towards automated detector fabrication and photolithographic processes for both increased yields and reduced touch labor costs. RVS continues

  10. Fabrication of Metallic Magnetic Calorimeter X-ray Detector Arrays

    NASA Astrophysics Data System (ADS)

    Hsieh, W.-T.; Adams, J. A.; Bandler, S. R.; Beyer, J.; Denis, K. L.; Eguchi, H.; Figueroa-Feliciano, E.; Rotzinger, H.; Schneider, G. H.; Seidel, G. M.; Stevenson, T. R.; Travers, D. E.

    2008-04-01

    Microcalorimeters with metallic magnetic sensors show great promise for use in astronomical X-ray spectroscopy. We describe the design and fabrication of a lithographically patterned magnetic microcalorimeter. A paramagnetic AuEr film is sputter-deposited as the sensor, which is coupled to a low noise SQUID via a meander superconducting pickup loop used as an inductor. This inductor also provides the magnetic field bias to the sensor. The AuEr film is deposited over this meander such that the field created by a large current flowing in the loop magnetizes the sensor material. The use of thin film techniques in the fabrication of these magnetic sensors not only allows strong magnetic coupling between the sensor and the inductor, it also is scalable for array fabrication.

  11. 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.

  12. Large-scale liquid scintillation detectors for solar neutrinos

    NASA Astrophysics Data System (ADS)

    Benziger, Jay B.; Calaprice, Frank P.

    2016-04-01

    Large-scale liquid scintillation detectors are capable of providing spectral yields of the low energy solar neutrinos. These detectors require > 100 tons of liquid scintillator with high optical and radiopurity. In this paper requirements for low-energy neutrino detection by liquid scintillation are specified and the procedures to achieve low backgrounds in large-scale liquid scintillation detectors for solar neutrinos are reviewed. The designs, operations and achievements of Borexino, KamLAND and SNO+ in measuring the low-energy solar neutrino fluxes are reviewed.

  13. Evaluation of selected detector arrays for space applications

    NASA Technical Reports Server (NTRS)

    Lowrance, J. L.

    1986-01-01

    The development of a high density Schottky barrier Infrared Charged Coupled Device (IRCCD) type image sensor for earth observation was initiated. A dual band 512 pixel linear array was developed, which was capable of being butted end to end to make an arbitrarily long linear array. Measurement made on palladium silicide IRCCDs that were two-dimensional 63 x 32 pixel arrays were summarized. The test data on a 512 pixel linear array is also summarized.

  14. Method for producing a hybridization of detector array and integrated circuit for readout

    NASA Technical Reports Server (NTRS)

    Fossum, Eric R. (Inventor); Grunthaner, Frank J. (Inventor)

    1993-01-01

    A process is explained for fabricating a detector array in a layer of semiconductor material on one substrate and an integrated readout circuit in a layer of semiconductor material on a separate substrate in order to select semiconductor material for optimum performance of each structure, such as GaAs for the detector array and Si for the integrated readout circuit. The detector array layer is lifted off its substrate, laminated on the metallized surface on the integrated surface, etched with reticulating channels to the surface of the integrated circuit, and provided with interconnections between the detector array pixels and the integrated readout circuit through the channels. The adhesive material for the lamination is selected to be chemically stable to provide electrical and thermal insulation and to provide stress release between the two structures fabricated in semiconductor materials that may have different coefficients of thermal expansion.

  15. Underground Prototype Water Cherenkov Muon Detector with the Tibet Air Shower Array

    SciTech Connect

    Amenomori, M.; Nanjo, H.; Bi, X. J.; Ding, L. K.; Feng, Zhaoyang; He, H. H.; Hu, H. B.; Lu, H.; Lu, S. L.; Ren, J. R.; Tan, Y. H.; Wang, B.; Wang, H.; Wang, Y.; Wu, H. R.; Zhang, H. M.; Zhang, J. L.; Zhang, Y.; Chen, D.; Kawata, K.

    2008-12-24

    We are planning to build a 10,000 m{sup 2} water-Cherenkov-type muon detector (MD) array under the Tibet air shower (AS) array. The Tibet AS+MD array will have the sensitivity to detect gamma rays in the 100 TeV region by an order of the magnitude better than any other previous existing detectors in the world. In the late fall of 2007, a prototype water Cherenkov muon detector of approximately 100 m{sup 2} was constructed under the existing Tibet AS array. The preliminary data analysis is in good agreement with our MC simulation. We are now ready for further expanding the underground water Cherenkov muon detector.

  16. Subarray partitions of large aperture planar towed arrays

    NASA Astrophysics Data System (ADS)

    Watson, Jennifer A.; Baggeroer, Arthur B.; Zurk, Lisa M.; Tracey, Brian H.

    2002-05-01

    The current focus of passive detection and localization is in littoral regions where acoustic propagation becomes complicated by severe bottom interaction. The resultant high-transmission loss motivates the need for high-array gain for effective performance over long ranges. Large planar seismic arrays, with aperture dimensions upwards of 3 km×0.5 km, have potential to achieve high gain and good resolution when using matched field processing. In realistic environments, however, large arrays are suceptible to signal gain degradation mechanisms, particularly due to spatial decorrelation of the signal and non-stationary environments. One approach to overcoming this is partitioning the array. Subarray processing reduces stationarity requirements and extracts optimum coherent gain, thus achieving higher gain than that of smaller arrays. This work examines criteria for partitioning planar arrays to perform localization using MFP. Trade-offs between spatial resolution, array gain, and resilience to motion will be quantified and discussed. Performance of different subarray geometries will be presented using adaptive and conventional MFP. [Work sponsored by DARPA under Air Force Contract No. F1962800-00-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense. AB's work was supported by ONR through the SECNAV CNO Chair.

  17. Large hexagonal arrays of aligned ZnO nanorods

    NASA Astrophysics Data System (ADS)

    Banerjee, D.; Rybczynski, J.; Huang, J. Y.; Wang, D. Z.; Kempa, K.; Ren, Z. F.

    2005-02-01

    Large-scale truly periodic arrays of vertically aligned zinc oxide nanorods were grown on pre-patterned and pre-annealed gold dots on a-plane sapphire substrates via the vapor liquid solid mechanism. Periodic arrays of triangular gold islands were first patterned on the a-plane sapphire substrates by the nanosphere self-assembly technique. Zinc has been found to be an effective interfacial modifier between gold and sapphire to form single catalytic dots from triangular islands. The successful fabrication of zinc oxide nanowires in truly periodic arrays opens up the possibility of achieving enhanced room-temperature ultraviolet lasing and photonic crystal based devices and sensors.

  18. Spectral X-Ray Diffraction using a 6 Megapixel Photon Counting Array Detector

    PubMed Central

    Muir, Ryan D.; Pogranichniy, Nicholas R.; Muir, J. Lewis; Sullivan, Shane Z.; Battaile, Kevin P.; Mulichak, Anne M.; Toth, Scott J.; Keefe, Lisa J.; Simpson, Garth J.

    2016-01-01

    Pixel-array array detectors allow single-photon counting to be performed on a massively parallel scale, with several million counting circuits and detectors in the array. Because the number of photoelectrons produced at the detector surface depends on the photon energy, these detectors offer the possibility of spectral imaging. In this work, a statistical model of the instrument response is used to calibrate the detector on a per-pixel basis. In turn, the calibrated sensor was used to perform separation of dual-energy diffraction measurements into two monochromatic images. Targeting applications include multi-wavelength diffraction to aid in protein structure determination and X-ray diffraction imaging. PMID:27041789

  19. Assessment of present and future large-scale semiconductor detector systems

    SciTech Connect

    Spieler, H.G.; Haller, E.E.

    1984-11-01

    The performance of large-scale semiconductor detector systems is assessed with respect to their theoretical potential and to the practical limitations imposed by processing techniques, readout electronics and radiation damage. In addition to devices which detect reaction products directly, the analysis includes photodetectors for scintillator arrays. Beyond present technology we also examine currently evolving structures and techniques which show potential for producing practical devices in the foreseeable future.

  20. Enhancement of concentration range of chromatographically detectable components with array detector mass spectrometry

    DOEpatents

    Enke, Christie

    2013-02-19

    Methods and instruments for high dynamic range analysis of sample components are described. A sample is subjected to time-dependent separation, ionized, and the ions dispersed with a constant integration time across an array of detectors according to the ions m/z values. Each of the detectors in the array has a dynamically adjustable gain or a logarithmic response function, producing an instrument capable of detecting a ratio of responses or 4 or more orders of magnitude.

  1. SNM Detection with a Large Water Cerenkov Detector

    SciTech Connect

    Dazeley, S; Bernstein, A; Bowden, N; Ouedraogo, S; Svoboda, R; Sweeny, M

    2009-06-04

    Special Nuclear Material (SNM) can either spontaneously fission, or be induced to do so. Either case results in neutron emission. Since neutrons are highly penetrating and difficult to shield, they could, potentially, be detected escaping even a well shielded cargo container. Obviously, if the shielding is sophisticated, detecting it would require a highly efficient detector with close to 4{pi} solid angle coverage. Water Cerenkov detectors may be a cost effective way to achieve that goal if it can be shown that the neutron capture signature is large enough and if sufficient background rejection can be employed as detectors get larger. In 2008 the LLNL Advanced Detector Group reported the successful detection of neutrons with a 1/4 ton gadolinium doped water Cerenkov prototype. We have now built a 4 ton version. This detector is not only bigger, it was designed with photon detection efficiency in mind from the beginning. We are employing increased photocathode coverage and more reflective walls, coated with PTFE. The increased efficiency should allow better energy resolution. We expect that the better diffusive wall reflectivity will reduce the overall dependence of the detector response on particle direction, again producing a more consistent response. We also believe that as detectors get larger, both uncorrelated and correlated backgrounds due to gamma-rays and cosmic ray interactions near the detector will increase. To prove the effectiveness of the technology we must develop new ways to reject these backgrounds while maintaining our sensitivity to SNM neutrons. Better energy resolution will enable us to reject more of the low energy gamma-ray backgrounds on this basis. Overcoming cosmic ray induced neutrons is perhaps an even larger concern as detectors get larger. Our detector is designed so that we can test various segmentation schemes - effectively dividing the detector up into smaller ones. In this presentation, we will describe our detector in detail.

  2. Fabrication of large arrays of plasmonic nanostructures via double casting

    NASA Astrophysics Data System (ADS)

    Lo, Joanne C.; Horsley, David A.; Skinner, Jack L.

    2012-03-01

    Large arrays of periodic nanostructures are widely used for plasmonic applications, including ultrasensitive particle sensing, optical nanoantennas, and optical computing; however, current fabrication processes (e.g., e-beam lithography and nanoimprint lithography) remain time consuming and expensive. Previously, researchers have utilized double casting methods to effectively fabricate large-scale arrays of microscale features. Despite significant progress, employing such techniques at the nanoscale has remained a challenge due to cracking and incomplete transfer of the nanofeatures. To overcome these issues, here we present a double casting methodology for fabricating large-scale arrays of nanostructures. We demonstrate this technique by creating large (0.5 cm × 1 cm) arrays of 150 nm nanoholes and 150 nm nanopillars from one silicon master template with nanopillars. To preclude cracking and incomplete transfer problems, a hard-PDMS/soft-PDMS (h-PDMS/s-PDMS) composite stamp was used to replicate the features from: (i) the silicon template, and (ii) the resulting PDMS template. Our double casting technique can be employed repeatedly to create positive and negative copies of the original silicon template as desired. By drastically reducing the cost, time, and labor associated with creating separate silicon templates for large arrays of different nanostructures, this methodology will enable rapid prototyping for diverse applications in nanotechnological fields.

  3. Factors affecting the performance of large-aperture microphone arrays.

    PubMed

    Silverman, Harvey F; Patterson, William R; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m x 8 m x 3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment. PMID:12051434

  4. Factors affecting the performance of large-aperture microphone arrays

    NASA Astrophysics Data System (ADS)

    Silverman, Harvey F.; Patterson, William R.; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m×8 m×3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment.

  5. Chemical imaging of cotton fibers using an infrared microscope and a focal-plane array detector

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this presentation, the chemical imaging of cotton fibers with an infrared microscope and a Focal-Plane Array (FPA) detector will be discussed. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In addition, FPA detectors allow for simultaneous spe...

  6. A near-infrared 64-pixel superconducting nanowire single photon detector array with integrated multiplexed readout

    SciTech Connect

    Allman, M. S. Verma, V. B.; Stevens, M.; Gerrits, T.; Horansky, R. D.; Lita, A. E.; Mirin, R.; Nam, S. W.; Marsili, F.; Beyer, A.; Shaw, M. D.; Kumor, D.

    2015-05-11

    We demonstrate a 64-pixel free-space-coupled array of superconducting nanowire single photon detectors optimized for high detection efficiency in the near-infrared range. An integrated, readily scalable, multiplexed readout scheme is employed to reduce the number of readout lines to 16. The cryogenic, optical, and electronic packaging to read out the array as well as characterization measurements are discussed.

  7. Modulation Transfer Function (MTF) measurement techniques for lenses and linear detector arrays

    NASA Technical Reports Server (NTRS)

    Schnabel, J. J., Jr.; Kaishoven, J. E., Jr.; Tom, D.

    1984-01-01

    Application is the determination of the Modulation Transfer Function (MTF) for linear detector arrays. A system set up requires knowledge of the MTF of the imaging lens. Procedure for this measurement is described for standard optical lab equipment. Given this information, various possible approaches to MTF measurement for linear arrays is described. The knife edge method is then described in detail.

  8. Enabling Large Focal Plane Arrays Through Mosaic Hybridization

    NASA Technical Reports Server (NTRS)

    Miller, Timothy M.; Jhabvala, Christine A.; Leong, Edward; Costen, Nick P.; Sharp, Elmer; Adachi, Tomoko; Benford, Dominic J.

    2012-01-01

    We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit patbs by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabric.ted parts were hybridized using a Suss FCI50 flip chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.

  9. Enabling Large Focal Plane Arrays Through Mosaic Hybridization

    NASA Technical Reports Server (NTRS)

    Miller, Timothy M.; Jhabvala, Christine A.; Leong, Edward; Costen, Nicholas P.; Sharp, Elmer; Adachi, Tomoko; Benford, Dominic J.

    2012-01-01

    We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit paths by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabricated parts were hybridized using a flip-chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.

  10. Integrated filter and detector array for spectral imaging

    NASA Technical Reports Server (NTRS)

    Labaw, Clayton C. (Inventor)

    1992-01-01

    A spectral imaging system having an integrated filter and photodetector array is disclosed. The filter has narrow transmission bands which vary in frequency along the photodetector array. The frequency variation of the transmission bands is matched to, and aligned with, the frequency variation of a received spectral image. The filter is deposited directly on the photodetector array by a low temperature deposition process. By depositing the filter directly on the photodetector array, permanent alignment is achieved for all temperatures, spectral crosstalk is substantially eliminated, and a high signal to noise ratio is achieved.

  11. Optimal Chunking of Large Multidimensional Arrays for Data Warehousing

    SciTech Connect

    Otoo, Ekow J; Otoo, Ekow J.; Rotem, Doron; Seshadri, Sridhar

    2008-02-15

    Very large multidimensional arrays are commonly used in data intensive scientific computations as well as on-line analytical processingapplications referred to as MOLAP. The storage organization of such arrays on disks is done by partitioning the large global array into fixed size sub-arrays called chunks or tiles that form the units of data transfer between disk and memory. Typical queries involve the retrieval of sub-arrays in a manner that access all chunks that overlap the query results. An important metric of the storage efficiency is the expected number of chunks retrieved over all such queries. The question that immediately arises is"what shapes of array chunks give the minimum expected number of chunks over a query workload?" The problem of optimal chunking was first introduced by Sarawagi and Stonebraker who gave an approximate solution. In this paper we develop exact mathematical models of the problem and provide exact solutions using steepest descent and geometric programming methods. Experimental results, using synthetic and real life workloads, show that our solutions are consistently within than 2.0percent of the true number of chunks retrieved for any number of dimensions. In contrast, the approximate solution of Sarawagi and Stonebraker can deviate considerably from the true result with increasing number of dimensions and also may lead to suboptimal chunk shapes.

  12. Study of large adaptive arrays for space technology applications

    NASA Technical Reports Server (NTRS)

    Berkowitz, R. S.; Steinberg, B.; Powers, E.; Lim, T.

    1977-01-01

    The research in large adaptive antenna arrays for space technology applications is reported. Specifically two tasks were considered. The first was a system design study for accurate determination of the positions and the frequencies of sources radiating from the earth's surface that could be used for the rapid location of people or vehicles in distress. This system design study led to a nonrigid array about 8 km in size with means for locating the array element positions, receiving signals from the earth and determining the source locations and frequencies of the transmitting sources. It is concluded that this system design is feasible, and satisfies the desired objectives. The second task was an experiment to determine the largest earthbound array which could simulate a spaceborne experiment. It was determined that an 800 ft array would perform indistinguishably in both locations and it is estimated that one several times larger also would serve satisfactorily. In addition the power density spectrum of the phase difference fluctuations across a large array was measured. It was found that the spectrum falls off approximately as f to the minus 5/2 power.

  13. Characterization of Large Area APDs for the EXO-200 Detector

    SciTech Connect

    Neilson, R.; LePort, F.; Pocar, A.; Kumar, K.; Odian, A.; Prescott, C.Y.; Tenev, V.; Ackerman, N.; Akimov, D.; Auger, M.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Conley, R.; Cook, S.; deVoe, R.; Dolinski, M.J.; Fairbank, W., Jr.; Farine, J.; Fierlinger, P.; Flatt, B.; /Stanford U., Phys. Dept. /Bern U., LHEP /Stanford U., Phys. Dept. /Maryland U. /Colorado State U. /Laurentian U. /Carleton U. /SLAC /Maryland U. /Moscow, ITEP /Alabama U. /SLAC /Colorado State U. /Stanford U., Phys. Dept. /Alabama U. /Stanford U., Phys. Dept. /Alabama U. /SLAC /Carleton U. /SLAC /Maryland U. /Moscow, ITEP /Carleton U. /Stanford U., Phys. Dept. /Bern U., LHEP /SLAC /Laurentian U. /SLAC /Maryland U.

    2011-12-02

    EXO-200 uses 468 large area avalanche photodiodes (LAAPDs) for detection of scintillation light in an ultra-low-background liquid xenon (LXe) detector. We describe initial measurements of dark noise, gain and response to xenon scintillation light of LAAPDs at temperatures from room temperature to 169 K - the temperature of liquid xenon. We also describe the individual characterization of more than 800 LAAPDs for selective installation in the EXO-200 detector.

  14. Large area, dense silicon nanowire array chemical sensors

    SciTech Connect

    Talin, A. Alec; Hunter, Luke L.; Leonard, Francois; Rokad, Bhavin

    2006-10-09

    The authors present a simple top-down approach based on nanoimprint lithography to create dense arrays of silicon nanowires over large areas. Metallic contacts to the nanowires and a bottom gate allow the operation of the array as a field-effect transistor with very large on/off ratios. When exposed to ammonia gas or cyclohexane solutions containing nitrobenzene or phenol, the threshold voltage of the field-effect transistor is shifted, a signature of charge transfer between the analytes and the nanowires. The threshold voltage shift is proportional to the Hammett parameter and the concentration of the nitrobenzene and phenol analytes.

  15. A slot-scanned photodiode-array/CCD hybrid detector for digital mammography.

    PubMed

    Mainprize, James G; Ford, Nancy L; Yin, Shi; Tümer, Türmay; Yaffe, Martin J

    2002-02-01

    We have developed a novel direct conversion detector for use in a slot-scanning digital mammography system. The slot-scan concept allows for dose efficient scatter rejection and the ability to use small detectors to produce a large-area image. The detector is a hybrid design with a 1.0 mm thick silicon PIN photodiode array (the x-ray absorber) indium-bump bonded to a CCD readout that is operated in time-delay integration (TDI) mode. Because the charge capacity requirement for good image quality exceeds the capabilities of standard CCDs, a novel CCD was developed. This CCD consists of 24 independent sections, each acting as a miniature CCD with eight rows for TDI. The signal from each section is combined off-chip to produce a full signal image. The MTF and DQE for the device was measured at several exposures and compared to a linear systems model of signal and noise propagation. Because of the scanning nature of TDI imaging, both the MTF(f) and DQE(f) are reduced along the direction of the scanning motion. For a 26 kVp spectrum, the DQE(0) was measured to be 0.75+/-0.02 for an exposure of 1.29 x 10(-5) C/kg (50 mR). PMID:11865992

  16. Development of large CCD arrays with enhanced UV performance

    NASA Technical Reports Server (NTRS)

    Varian, Richard H.; Schaefer, A. Russell; Cover, John; Janesick, James R.; Bredthauer, Richard

    1989-01-01

    A development status evaluation is presented for proprietary UV-range CCDs for military and scientific applications requiring pixel sizes in the 18-micron range. The most recent developments in UV/X-ray responsive detectors have their bases in the backside illumination of multipinned phase (MPP) 1024 x 1024 CCD arrays, as well as in the initial exploration of open-pinned phase (OPP) techniques. The frontside performance of both MPP and OPP devices is noted to be excellent as well, and pinouts and mounting techniques have been defined which allow easy front-back operation comparisons. Novel backside processing techniques are being refined.

  17. Parallel Processing of Large Scale Microphone Arrays for Sound Capture

    NASA Astrophysics Data System (ADS)

    Jan, Ea-Ee.

    1995-01-01

    consistent with the real room data. Localization of sound sources has been explored using cross-power spectrum time delay estimation and has been evaluated using real room data under slightly, moderately and highly reverberant conditions. To improve the accuracy and reliability of the source localization, an outlier detector that removes incorrect time delay estimation has been invented. To provide speaker selectivity for microphone array systems, a hands-free speaker identification system has been studied. A recently invented feature using selected spectrum information outperforms traditional recognition methods. Measured results demonstrate the capabilities of speaker selectivity from a matched-filtered array. In addition, simulation utilities, including matched -filtering processing of the array and hands-free speaker identification, have been implemented on the massively -parallel nCube super-computer. This parallel computation highlights the requirements for real-time processing of array signals.

  18. Detector Arrays for the James Webb Near Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.

    2009-01-01

    NASA Goddard Space Flight Center is delivering the detector subsystem for the James Webb Space Telescope (JWST) Near Infrared Spectrograph (NIRSpec). Of all JWST instruments, NIRSpec has the most stringent detector requirements. In this poster, we describe recent performance testing results and relate them to NIRSpec's science requirements.

  19. Self-guarding Schottky barrier infrared detector array

    NASA Astrophysics Data System (ADS)

    Shepherd, F. D., Jr.; Pellegrini, P. W.; Ludington, C. E.; Weeks, M. M.

    1985-07-01

    A two dimensional focal plane array of Schottky photodiodes on a silicon substrate for infrared imaging is presented. The array is designed for mating with multiplexing circuitry and has a self-guarding feature wherein adjacent Schottky electrodes act as guard electrodes. This feature allows a substantial increase of the focal plane area coverage ratio.

  20. A Medium-Format, Mixed-Mode Pixel Array Detector for Kilohertz X-ray Imaging

    NASA Astrophysics Data System (ADS)

    Tate, M. W.; Chamberlain, D.; Green, K. S.; Philipp, H. T.; Purohit, P.; Strohman, C.; Gruner, S. M.

    2013-03-01

    An x-ray pixel array detector (PAD) capable of framing up to 1 kHz is described. This hybrid detector is constructed from a 3-side buttable, 128×128 pixel module based upon the mixed-mode pixel array detector (MMPAD) chip developed jointly by Cornell and Area Detector Systems Corporation (Poway, CA). The chip uses a charge integrating front end for a high instantaneous count rate yet with single photon sensitivity. In-pixel circuitry utilizing a digital overflow counter extends the per frame dynamic range to >4×107 x-rays/pixel. Results are shown from a base configuration of a 2×3 module array (256×384 pixels).

  1. Development of uncooled focal plane detector arrays for smart IR sensors

    NASA Astrophysics Data System (ADS)

    Liddiard, Kevin C.; Reinhold, Olaf; Ringh, Ulf; Jansson, Christer

    1997-11-01

    This paper reports on the development of silicon microbolometer uncooled IR focal plane detector arrays at the Defence Science and Technology Organization (DSTO), in collaboration with the National Defence Research Establishment (FOA). The detector arrays were designed by Electro-optic Sensor Design, which also provided specialist scientific advice on array fabrication. Detector arrays are prepared by monolithic processing at DSTO, using surface micromachining to achieve thermal isolation, and are integrated on-chip with a CMOS signal conditioning and readout microcircuit designed by FOA. The CMOS circuit incorporates 16-bit analog-to-digital conversion, and is described in more detail in an accompanying paper presented. The ultimate objective is to develop 'smart' focal plane arrays which have on-chip signal processing functions, giving a capability for decision making such as automatic target detection. The silicon microbolometer technology described in the paper was invented at DSTO, and is representative of core technology employed in many initiatives world-wide. A brief overview will be given of theoretical considerations which influence detector array design, followed by an outline of recent developments in array processing.

  2. Characterization and Calibration of Large Area Resistive Strip Micromegas Detectors

    NASA Astrophysics Data System (ADS)

    Lösel, Philipp; ATLAS Muon Collaboration

    2016-07-01

    Resistive strip Micromegas detectors have been tested extensively as small detectors of about 10×10 cm2 in size and they work reliably at high rates of 100 kHz/cm2 and above. Tracking resolution well below 100 μm has been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3 m2 in size. To investigate possible differences between small and large detectors, a 1 m2 detector with 2048 resistive strips at a pitch of 450 μm was studied in the LMU Cosmic Ray Measurement Facility (CRMF) using two 4×2.2 m2 large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. A segmentation of the resistive strip anode plane in 57.6 mm×93 mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by eleven 93 mm broad trigger scintillators placed along the readout strips. This allows for mapping of homogeneity in pulse height and efficiency, determination of signal propagation along the 1 m long anode strips and calibration of the position of the anode strips.

  3. Large-format 17μm high-end VOx μ-bolometer infrared detector

    NASA Astrophysics Data System (ADS)

    Mizrahi, U.; Argaman, N.; Elkind, S.; Giladi, A.; Hirsh, Y.; Labilov, M.; Pivnik, I.; Shiloah, N.; Singer, M.; Tuito, A.; Ben-Ezra, M.; Shtrichman, I.

    2013-06-01

    Long range sights and targeting systems require a combination of high spatial resolution, low temporal NETD, and wide field of view. For practical electro-optical systems it is hard to support these constraints simultaneously. Moreover, achieving these needs with the relatively low-cost Uncooled μ-Bolometer technology is a major challenge in the design and implementation of both the bolometer pixel and the Readout Integrated Circuit (ROIC). In this work we present measured results from a new, large format (1024×768) detector array, with 17μm pitch. This detector meets the demands of a typical armored vehicle sight with its high resolution and large format, together with low NETD of better than 35mK (at F/1, 30Hz). We estimate a Recognition Range for a NATO target of better than 4 km at all relevant atmospheric conditions, which is better than standard 2nd generation scanning array cooled detector. A new design of the detector package enables improved stability of the Non-Uniformity Correction (NUC) to environmental temperature drifts.

  4. A mini-array for large air showers

    NASA Technical Reports Server (NTRS)

    Ng, L. K.; Chan, S. K.; Hazen, W. E.; Hazen, E. S.

    1985-01-01

    A mini-array that utilizes the Linsley effect is proposed for the measurement of large air showers. An estimate of the detectable shower rates for various shower sizes is made. Details of the detection and data collection systems are also described.

  5. The Liquid Argon Calorimeter system for the SLC Large Detector

    SciTech Connect

    Haller, G.M.; Fox, J.D.; Smith, S.R.

    1988-09-01

    In this paper the physical packaging and the logical organization of the Liquid Argon Calorimeter (LAC) electronics system for the Stanford Linear Collider Large Detector (SLD) at SLAC are described. This system processes signals from approximately 44,000 calorimeter towers and is unusual in that most electronic functions are packaged within the detector itself as opposed to an external electronics support rack. The signal path from the towers in the liquid argon through the vacuum to the outside of the detector is explained. The organization of the control logic, analog electronics, power regulation, analog-to-digital conversion circuits, and fiber optic drivers mounted directly on the detector are described. Redundancy considerations for the electronics and cooling issues are discussed. 12 refs., 5 figs.

  6. General MoM Solutions for Large Arrays

    SciTech Connect

    Fasenfest, B; Capolino, F; Wilton, D R; Jackson, D R; Champagne, N

    2003-07-22

    This paper focuses on a numerical procedure that addresses the difficulties of dealing with large, finite arrays while preserving the generality and robustness of full-wave methods. We present a fast method based on approximating interactions between sufficiently separated array elements via a relatively coarse interpolation of the Green's function on a uniform grid commensurate with the array's periodicity. The interaction between the basis and testing functions is reduced to a three-stage process. The first stage is a projection of standard (e.g., RWG) subdomain bases onto a set of interpolation functions that interpolate the Green's function on the array face. This projection, which is used in a matrix/vector product for each array cell in an iterative solution process, need only be carried out once for a single cell and results in a low-rank matrix. An intermediate stage matrix/vector product computation involving the uniformly sampled Green's function is of convolutional form in the lateral (transverse) directions so that a 2D FFT may be used. The final stage is a third matrix/vector product computation involving a matrix resulting from projecting testing functions onto the Green's function interpolation functions; the low-rank matrix is either identical to (using Galerkin's method) or similar to that for the bases projection. An effective MoM solution scheme is developed for large arrays using a modification of the AIM (Adaptive Integral Method) method. The method permits the analysis of arrays with arbitrary contours and nonplanar elements. Both fill and solve times within the MoM method are improved with respect to more standard MoM solvers.

  7. Imaging by time-tagging photons with the multi-anode microchannel array detector system

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Morgan, J. S.

    1986-01-01

    The capability and initial use of the Multi-Anode Microchannel Array (MAMA) detector in the time-tag mode is reported. The detector hardware currently in use consists of a visible-light detector tube with a semitransparent photocathode proximity-focused to a high-gain curved-channel microchannel plate MCP. The photoevents are detected by a (256 x 1024)-pixel coincidence-anode array with pixel dimensions of 25 x 25 microns connected to charge-sensitive amplifiers and event-detection circuitry. In the time-lag mode, the detector delivers the pixel address and the time of arrival for each detected photon to an accuracy of 10 microns. The maximum count rate is limited by the speed of data-acquisition hardware. The MAMA detector in the time-lag mode is currently being evaluated in programs of astrometry and speckle imaging.

  8. Terahertz detectors arrays based on orderly aligned InN nanowires

    PubMed Central

    Chen, Xuechen; Liu, Huiqiang; Li, Qiuguo; Chen, Hao; Peng, Rufang; Chu, Sheng; Cheng, Binbin

    2015-01-01

    Nanostructured terahertz detectors employing a single semiconducting nanowire or graphene sheet have recently generated considerable interest as an alternative to existing THz technologies, for their merit on the ease of fabrication and above-room-temperature operation. However, the lack of alignment in nanostructure device hindered their potential toward practical applications. The present work reports ordered terahertz detectors arrays based on neatly aligned InN nanowires. The InN nanostructures (nanowires and nano-necklaces) were achieved by chemical vapor deposition growth, and then InN nanowires were successfully transferred and aligned into micrometer-sized groups by a “transfer-printing” method. Field effect transistors on aligned nanowires were fabricated and tested for terahertz detection purpose. The detector showed good photoresponse as well as low noise level. Besides, dense arrays of such detectors were also fabricated, which rendered a peak responsivity of 1.1 V/W from 7 detectors connected in series. PMID:26289498

  9. 256×1 element linear InGaAs short wavelength near-infrared detector arrays

    NASA Astrophysics Data System (ADS)

    Li, Xue; Tang, Hengjing; Fan, Guangyu; Liu, Dafu; Shao, Xiumei; Zhang, Yonggang; Zhang, Haiyan; Chen, Xinyu; Zhu, Sangen; Gong, Haimei; Fang, Jiaxiong

    2008-03-01

    256×1 element linear InGaAs detector arrays assembly have been fabricated for the short wave infrared band(0.9~1.7μm), including the detector, CMOS readout circuits, thermoelectric cooler in a sealed package. The InGaAs detectors were achieved by mesa structure on the p-InP/i-InGaAs/n-InP double hetero-structure epitaxial material. 256×1 element linear InGaAs detectors were wire-bonded to 128×1 element odd and even ROIC, which were packaged in a dual-in-line package by parallel sealing. The characteristics of detectors and detector arrays module were investigated at the room temperature. The detector shows response peak at 1.62μm with 50% cutoff wavelength of 1.73μm and average R0A with 5.02KΩ•cm2. Response non-uniformity and average peak detectivity of 256×1 element linear InGaAs detector arrays are 3.10% and 1.38×10 12cmHz 1/2/W, respectively.

  10. Design and Performance of the Astro-E/XRS Microcalorimeter Array and Anti-Coincidence Detector

    NASA Technical Reports Server (NTRS)

    Stahle, C. K.; Audley, M. D.; Boyce, K. R.; Brekosky, R. P.; Fujimoto, R.; Gendreau, K. C.; Gygax, J. D.; Ishisaki, Y.; Kelley, R. L.; McClanahan, R. A.

    1999-01-01

    The XRS instrument has an array of 32 micro-calorimeters at the focal plane. These calorimeters consist of ion-implanted silicon thermistors and HgTe thermalizing x-ray absorbers. These devices have demonstrated a resolution of 9 eV at 3 keV and 11 eV at 6 keV. We will discuss the basic physical parameters of this array, including the array layout, thermal conductance of the link to the heat sink, operating temperature, thermistor size, absorber choice, and means of attaching the absorber to the thermistor bearing element. We will present representative performance data, though a more detailed presentation of the results of the instrument calibration is presented elsewhere in these proceedings. A silicon ionization detector is located behind the calorimeter array and serves to reject events due to cosmic rays. We will briefly describe this anti-coincidence detector and its performance in conjunction with the array.

  11. Waveguide biosensor with integrated detector array for tuberculosis testing

    NASA Astrophysics Data System (ADS)

    Yan, Rongjin; Lynn, N. Scott; Kingry, Luke C.; Yi, Zhangjing; Slayden, Richard A.; Dandy, David S.; Lear, Kevin L.

    2011-01-01

    A label-free immunoassay using a local evanescent array coupled (LEAC) biosensor is reported. Complementary metal oxide semiconductor chips with integrated photoconductor arrays are used to detect an antibody to a M. tuberculosis protein antigen, HspX. The metrology limits of the LEAC sensor using dc and ac measurement systems correspond to average film thicknesses of 28 and 14 pm, respectively. Limits of detection are 87 and 108 pm, respectively, for mouse immunoglobulin G antibody patterning and antigen detection.

  12. Source test of the prototype neutron detector for the large-acceptance multipurpose spectrometer at RAON

    NASA Astrophysics Data System (ADS)

    Lee, Kisoo; Lee, Kyong Sei; Mulilo, Benard; Hong, Byungsik

    2013-05-01

    A neutron detector array will be essential for the study of the nuclear symmetry energy in the large-acceptance multipurpose spectrometer (LAMPS) at the planned rare-isotope beam facility RAON in Korea. We have built the prototype neutron detector for LAMPS and examined its performance by using radiation sources. For data taking, we tested the voltage-threshold discriminator (VTD) and the constant-fraction discriminator (CFD) modules for the pulse process. The intrinsic time resolution of the prototype detector is estimated to be 723 ps for VTD and 488 ps for CFD. The fission neutrons and gammas emitted from 252Cf can be clearly separated in the time distribution. We reconstruct the energy spectrum of the spontaneous fission neutrons from 252Cf, which can be described well by using the empirical Watt spectrum.

  13. SiPM detectors for the ASTRI project in the framework of the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Billotta, Sergio; Marano, Davide; Bonanno, Giovanni; Belluso, Massimiliano; Grillo, Alessandro; Garozzo, Salvatore; Romeo, Giuseppe; Timpanaro, Maria Cristina; Maccarone, Maria Concetta C.; Catalano, Osvaldo; La Rosa, Giovanni; Sottile, Giuseppe; Impiombato, Domenico; Gargano, Carmelo; Giarrusso, Salavtore

    2014-07-01

    The Cherenkov Telescope Array (CTA) is a worldwide new generation project aimed at realizing an array of a hundred ground based gamma-ray telescopes. ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is the Italian project whose primary target is the development of an end-to-end prototype, named ASTRI SST-2M, of the CTA small size class of telescopes devoted to investigation of the highest energy region, from 1 to 100 TeV. Next target is the implementation of an ASTRI/CTA mini-array based on seven identical telescopes. Silicon Photo-Multipliers (SiPMs) are the semiconductor photosensor devices designated to constitute the camera detection system at the focal plane of the ASTRI telescopes. SiPM photosensors are suitable for the detection of the Cherenkov flashes, since they are very fast and sensitive to the light in the 300-700nm wavelength spectrum. Their drawbacks compared to the traditional photomultiplier tubes are high dark count rates, after-pulsing and optical cross-talk contributions, and intrinsic gains strongly dependent on temperature. Nonetheless, for a single pixel, the dark count rate is well below the Night Sky Background, the effects of cross-talk and afterpulses are typically lower than 20%, and the gain can be kept stable against temperature variations by means of adequate bias voltage compensation strategies. This work presents and discusses some experimental results from a large set of measurements performed on the SiPM sensors to be used for the ASTRI SST-2M prototype camera and on recently developed detectors demonstrating outstanding performance for the future evolution of the project in the ASTRI/CTA mini-array.

  14. Large area nanostructured arrays: optical properties of metallic nanotubes.

    PubMed

    Fröhlich, Katja; Hojati-Talemi, Pejman; Bishop, Matthew; Zuber, Kamil; Murphy, Peter; Evans, Drew

    2013-05-01

    In this study, large area metallic nanotube arrays on flexible plastic substrates are produced by templating the growth of a cosputtered alloy using anodized aluminum oxide membranes. These nanotube arrays are prepared over large areas (ca. squared centimeters) by reducing the residual stress within the thin multilayered structure. The nanotubes are approximately 20 nm in inner diameter, having walls of <10 nm in thickness, and are arranged in a close packed configuration. Optically the nanotube arrays exhibit light trapping behavior (not plasmonic), where the reflectivity is less than 15% across the visible spectra compared to >40% for a flat sample using the same alloy. When the nanotubes are exposed to high relative humidity, they spontaneously fill, with a concomitant change in their visual appearance. The filling of the nanotubes is confirmed using contact angle measurements, with the nanotubes displaying a strong hydrophilic character compared to the weak behavior of the flat sample. The ability to easily fabricate large area nanotube arrays which display exotic behavior paves the way for their uptake in real world applications such as sensors and solar energy devices. PMID:23582083

  15. Non-volatile resistive photo-switches for flexible image detector arrays

    NASA Astrophysics Data System (ADS)

    Nau, Sebastian; Wolf, Christoph; Sax, Stefan; List-Kratochvil, Emil J. W.

    2015-09-01

    The increasing quest to find lightweight, conformable or flexible image detectors for machine vision or medical imaging brings organic electronics into the spotlight for these fields of application. Here were we introduce a unique imaging device concept and its utilization in an organic, flexible detector array with simple passive matrix wiring. We present a flexible organic image detector array built up from non-volatile resistive multi-bit photo-switchable elements. This unique realization is based on an organic photodiode combined with an organic resistive memory device wired in a simple crossbar configuration. The presented concept exhibits significant advantages compared to present organic and inorganic detector array technologies, facilitating the detection and simultaneous storage of the image information in one detector pixel, yet also allowing for simple read-out of the information from a simple passive-matrix crossbar wiring. This concept is demonstrated for single photo-switchable pixels as well as for arrays with sizes up to 32 by 32 pixels (1024 bit). The presented results pave the way for a versatile flexible and easy-to-fabricate sensor array technology. In a final step, the concept was expanded to detection of x-rays.

  16. National Array of Neutron Detectors (NAND): A versatile tool for nuclear reaction studies

    NASA Astrophysics Data System (ADS)

    Golda, K. S.; Jhingan, A.; Sugathan, P.; Singh, Hardev; Singh, R. P.; Behera, B. R.; Mandal, S.; Kothari, A.; Gupta, Arti; Zacharias, J.; Archunan, M.; Barua, P.; Venkataramanan, S.; Bhowmik, R. K.; Govil, I. M.; Datta, S. K.; Chatterjee, M. B.

    2014-11-01

    The first phase of the National Array of Neutron Detectors (NAND) consisting of 26 neutron detectors has been commissioned at the Inter University Accelerator Centre (IUAC), New Delhi. The motivation behind setting up of such a detector system is the need for more accurate and efficient study of reaction mechanisms in the projectile energy range of 5-8 MeV/n using heavy ion beams from a 15 UD Pelletron and an upgraded LINAC booster facility at IUAC. The above detector array can be used for inclusive as well as exclusive measurements of reaction products of which at least one product is a neutron. While inclusive measurements can be made using only the neutron detectors along with the time of flight technique and a pulsed beam, exclusive measurements can be performed by detecting neutrons in coincidence with charged particles and/or fission fragments detected with ancillary detectors. The array can also be used for neutron tagged gamma-ray spectroscopy in (HI, xn) reactions by detecting gamma-rays in coincidence with the neutrons in a compact geometrical configuration. The various features and the performance of the different aspects of the array are described in the present paper.

  17. Coherent summation of spatially distorted Doppler lidar signals using a two-dimensional heterodyne detector array

    NASA Astrophysics Data System (ADS)

    Chan, Kin Pui; Killinger, Dennis K.

    1992-07-01

    We have investigated the improvement in the signal-to-noise ratio for a coherent Doppler lidar through the use of a multi-element heterodyne detector array. Such an array enables the spatial summation of atmospheric refractive turbulence induced speckles, and time varying target speckles. Our recent experiments have shown that the non-coherent summation of the lidar signals from a heterodyne detector array can enhance the heterodyne mixing efficiency and thus the signal-to-noise ratio. In this paper, we expand this work to include the coherent summation of array signals. The digitized heterodyne signals were stored in a personal computer. Fast Fourier transforms were performed on both the non-coherent and coherent summations of the detector array signals. It was found that the coherent summation greatly enhanced the accuracy in the Doppler frequency estimate. A theoretical analysis was performed and indicated good agreement with experimental results. We have also applied these results to the more general lidar applications including atmospheric wind sensing, and have found that in most lidar applications the Doppler frequency estimate is increased through the use of the heterodyne detector array.

  18. Large area magnetic micropallet arrays for cell colony sorting.

    PubMed

    Cox-Muranami, Wesley A; Nelson, Edward L; Li, G P; Bachman, Mark

    2016-01-01

    A new micropallet array platform for adherent cell colony sorting has been developed. The platform consisted of thousands of square plastic pallets, 270 μm by 270 μm on each side, large enough to hold a single colony of cells. Each pallet included a magnetic core, allowing them to be collected with a magnet after being released using a microscope mounted laser system. The micropallets were patterned from 1002F epoxy resist and were fabricated on translucent, gold coated microscope slides. The gold layer was used as seed for electroplating the ferromagnetic cores within every individual pallet. The gold layer also facilitated the release of each micropallet during laser release. This array allows for individual observation, sorting and collection of isolated cell colonies for biological cell colony research. In addition to consistent release and recovery of individual colonies, we demonstrated stable biocompatibility and minimal loss in imaging quality compared to previously developed micropallet arrays. PMID:26606460

  19. Interconnnect and bonding technologies for large flexible solar arrays

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Thermocompression bonding and conductive adhesive bonding are developed and evaluated as alternate methods of joining solar cells to their interconnect assemblies. Bonding materials and process controls applicable to fabrication of large, flexible substrate solar cell arrays are studied. The primary potential use of the techniques developed is on the solar array developed by NASA/MSFC and LMSC for solar electric propulsion (SEP) and shuttle payload applications. This array is made up of flexible panels approximately 0.7 by 3.4 meters. It is required to operate in space between 0.3 and 6 AU for 5 years with limited degradation. Materials selected must be capable of enduring this space environment, including outgassing and radiation.

  20. Very Large Chemical Sensor Array for Mimicking Biological Olfaction

    NASA Astrophysics Data System (ADS)

    Beccherelli, R.; Zampetti, E.; Pantalei, S.; Bernabei, M.; Persaud, K. C.

    2009-05-01

    Olfactory receptor neurons (ORN) in the mammalian olfactory system, transduce molecular properties of the odorants into electrical signals and project these into the olfactory bulb (OB). In the biological system several millions of receptor neurons of a few hundred types create redundancy and the massive convergence of the ORNs to the OB, is thought to enhance the sensitivity and selectivity of the system. To explore this concept, the NEUROCHEM project will build a polymeric chemical sensor array consisting of 216 (65536) sensors with tens of different types. To interface such a large sensor array, a topological array configuration with n rows and m columns, has been adopted, to reduce the total wiring connections to n+m. A method of addressing a single element in the array in isolation of the rest of the network has been developed. Over the array ten different conductive polymers with different sensing characteristics will be deposited by means of electrodeposition and inkjet printing. A smaller prototype of 64 elements has been investigated and the results are here reported and discussed.

  1. Performance of high resolution decoding with Multi-Anode Microchannel Array detectors

    NASA Technical Reports Server (NTRS)

    Kasle, David B.; Horch, Elliott P.

    1993-01-01

    The Multi-Anode Microchannel Array (MAMA) is a microchannel plate based photon counting detector with applications in ground-based and space-based astronomy. The detector electronics decode the position of each photon event, and the decoding algorithm that associates a given event with the appropriate pixel is determined by the geometry of the anode array. The standard MAMA detector has a spatial resolution set by the anode array of 25 microns, but the MCP pore resolution exceeds this. The performance of a new algorithm that halves the pixel spacing and improves the pixel spatial resolution is described. The new algorithm does not degrade the pulse-pair resolution of the detector and does not require any modifications to the detector tube. Measurements of the detector's response demonstrate that high resolution decoding yields a 60 percent enhancement in spatial resolution. Measurements of the performance of the high resolution algorithm with a 14 micron MAMA detector are also described. The parameters that control high resolution performance are discussed. Results of the application of high resolution decoding to speckle interferometry are presented.

  2. Indium Hybridization of Large Format TES Bolometer Arrays to Readout Multiplexers for Far-Infrared Astronomy

    NASA Astrophysics Data System (ADS)

    Miller, Timothy M.; Costen, Nick; Allen, Christine

    2008-04-01

    In our effort to develop large format kilo-pixel arrays of transition edge sensors, we are working toward demonstrating electrical connectivity of a hybridized 32×40 element detector to a NIST multiplexer. The geometry of large-scale arrays that attempt to maintain a high filling factor does not allow for typical fan-out wiring, thus the detector array is hybridized directly to the readout multiplexer. The two parts are bonded together with 10 micron tall indium bumps, which complete the electrical path and also provide mechanical strength. The indium hybridization was developed and performed at the Goddard Space Flight Center and has been shown to withstand tensile loading up to 0.26 gram-force per indium bump. A cavity is deep etched behind each pixel prior to bonding, leaving only 30 micron support walls, which maintains a high filling fraction. Electrical continuity has been shown through the indium path in room temperature measurements. We report on the fabrication process used to hybridize the parts and the subsequent electrical performance.

  3. A YSO/LSO phoswich array detector for single and coincidence photon imaging

    SciTech Connect

    Dahlbom, M.; MacDonald, L.R.; Schmand, M.; Eriksson, L.; Andreaco, M.; Williams, C.

    1998-06-01

    The performance of a phoswich array detector module for possible use in a combined single and coincidence photon imaging system has been evaluated. The assumption is that this detection module would allow the construction of a combined SPECT/PET imaging system with better count rate performance in the coincidence mode compared to current dual headed scintillation cameras. The detector consist of a linear array of discrete 4 x 4 x 15 mm{sup 3} YSO elements coupled to a combined detector array/light guide of LSO, 10 mm thick. Since the scintillation light decay time is different in YSO and LSO (70 and 40 ns, respectively), events originating from the two detector materials can be separated by pulse shape discrimination. The front layer of YSO could then be used for detection of low energy, single photon events and the LSO layer for coincidence detection of annihilation radiation. The light collection of the PMTs coupled to the detector was found to be adequate to accurately identify each detector element in the array using the same positioning logic used in conventional BGO block detectors. The average energy resolution of the YSO elements at 140 keV for the block detector was found to be 14.5% FWHM, ranging from 13.8 to 15.4%. Spatial resolution of the detector block in single photon mode, using a high resolution collimator (geometric resolution 6.5 mm at 10 cm) was measured by scanning a {sup 99m}Tc line source. The resolution at 5 and 10 cm from the collimator face was found to be 5.9 and 8.5 mm FWHM, respectively.

  4. Development of a Large-Area Ultracold Neutron Detector

    NASA Astrophysics Data System (ADS)

    Stoffel, Jenna; Liu, Chen-Yu; UCN Tau Collaboration

    2015-10-01

    To improve our knowledge in particle physics and cosmology, including big-bang nucleosynthesis, we need a more precise and accurate measurement of the lifetime of free neutrons. Though there have been many attempts to measure the neutron lifetime, discrepancies exist between the two major experimental techniques of the beam and the bottle methods. To resolve this discrepancy, the UCN τ experiment will trap ultracold neutrons (UCNs) to perform lifetime measurements to the 1-second level. To accomplish this goal, we are developing a large-area, high-efficiency UCN detector. We construct a scintillating UCN detector by evaporating a thin film of boron-10 onto an airbrushed layer of zinc sulfide (ZnS); the 10B-coated ZnS scintillating film is then glued to wavelength-shifting plastic, which acts as a light guide to direct photons into modern silicon photomultipliers. This new detector has similar efficiency and background noise as the previously-used ion gas detectors, but can be easily scaled up to cover large areas for many applications. The new detector opens up exciting new ways to study systematic effects, as they hold the key to the interpretation of neutron lifetime.

  5. Phonon Quasidiffusion in Cryogenic Dark Matter Search Large Germanium Detectors

    SciTech Connect

    Leman, S.W.; Cabrera, B.; McCarthy, K.A.; Pyle, M.; Resch, R.; Sadoulet, B.; Sundqvist, K.M.; Brink, P.L.; Cherry, M.; Do Couto E Silva, E.; Figueroa-Feliciano, E.; Mirabolfathi, N.; Serfass, B.; Tomada, A.; /Stanford U., Phys. Dept.

    2012-06-04

    We present results on quasidiffusion studies in large, 3 inch diameter, 1 inch thick [100] high purity germanium crystals, cooled to 50 mK in the vacuum of a dilution refrigerator, and exposed with 59.5 keV gamma-rays from an Am-241 calibration source. We compare data obtained in two different detector types, with different phonon sensor area coverage, with results from a Monte Carlo. The Monte Carlo includes phonon quasidiffusion and the generation of phonons created by charge carriers as they are drifted across the detector by ionization readout channels.

  6. Position reconstruction in large-area scintillating fibre detectors

    NASA Astrophysics Data System (ADS)

    Mahata, K.; Johansson, H. T.; Paschalis, S.; Simon, H.; Aumann, T.

    2009-09-01

    A new analysis procedure has been developed for the large-area scintillating fibre detectors with position-sensitive photomultiplier (PSPM) readout used for heavy ions in the LAND set-up at GSI. It includes gain matching of the PSPM, calibration of the PSPM fibre mask and hit reconstruction. This procedure allows for a quasi-online calibration of this tracking device. It also allows for a precise determination of the position close to the intrinsic detector resolution of 1 mm pitch together with careful treatment of individual event accuracies.

  7. Optical scattering lengths in large liquid-scintillator neutrino detectors

    SciTech Connect

    Wurm, M.; Feilitzsch, F. von; Goeger-Neff, M.; Hofmann, M.; Lewke, T.; Meindl, Q.; Moellenberg, R.; Oberauer, L.; Potzel, W.; Tippmann, M.; Todor, S.; Winter, J.; Lachenmaier, T.; Traunsteiner, C.; Undagoitia, T. Marrodan

    2010-05-15

    For liquid-scintillator neutrino detectors of kiloton scale, the transparency of the organic solvent is of central importance. The present paper reports on laboratory measurements of the optical scattering lengths of the organic solvents phenylxylylethane, linear alkylbenzene (LAB), and dodecane, which are under discussion for next-generation experiments such as SNO+ (Sudbury Neutrino Observatory), HanoHano, or LENA (Low Energy Neutrino Astronomy). Results comprise the wavelength range of 415-440 nm. The contributions from Rayleigh and Mie scattering as well as from absorption/re-emission processes are discussed. Based on the present results, LAB seems to be the preferred solvent for a large-volume detector.

  8. Application of neural networks to digital pulse shape analysis for an array of silicon strip detectors

    NASA Astrophysics Data System (ADS)

    Flores, J. L.; Martel, I.; Jiménez, R.; Galán, J.; Salmerón, P.

    2016-09-01

    The new generation of nuclear physics detectors that used to study nuclear reactions is considering the use of digital pulse shape analysis techniques (DPSA) to obtain the (A,Z) values of the reaction products impinging in solid state detectors. This technique can be an important tool for selecting the relevant reaction channels at the HYDE (HYbrid DEtector ball array) silicon array foreseen for the Low Energy Branch of the FAIR facility (Darmstadt, Germany). In this work we study the feasibility of using artificial neural networks (ANNs) for particle identification with silicon detectors. Multilayer Perceptron networks were trained and tested with recent experimental data, showing excellent identification capabilities with signals of several isotopes ranging from 12C up to 84Kr, yielding higher discrimination rates than any other previously reported.

  9. IR Imaging Using Arrays of SiO2 Micromechanical Detectors

    SciTech Connect

    Grbovic, Dragoslav; Lavrik, Nickolay V; Rajic, Slobodan; Datskos, Panos G; Hunter, Scott Robert

    2012-01-01

    In this letter, we describe the fabrication of an array of bimaterial detectors for infrared (IR) imaging that utilize SiO2 as a structural material. All the substrate material underneath the active area of each detector element was removed. Each detector element incorporates an optical resonant cavity layer in the IR absorbing region of the sensing element. The simplified microfabrication process requires only four photolithographic steps with no wet etching or sacrificial layers. The thermomechanical deflection sensitivity was 7.9 10-3 rad/K which corresponds to a noise equivalent temperature difference (NETD) of 2.9 mK. In the present work the array was used to capture IR images while operating at room temperature and atmospheric pressure and no need for vacuum packaging. The average measured NETD of our IR detector system was approximately 200 mK but some sensing elements exhibited an NETD of 50 mK.

  10. Large-Aperture Membrane Active Phased-Array Antennas

    NASA Technical Reports Server (NTRS)

    Karasik, Boris; McGrath, William; Leduc, Henry

    2009-01-01

    Large-aperture phased-array microwave antennas supported by membranes are being developed for use in spaceborne interferometric synthetic aperture radar systems. There may also be terrestrial uses for such antennas supported on stationary membranes, large balloons, and blimps. These antennas are expected to have areal mass densities of about 2 kg/sq m, satisfying a need for lightweight alternatives to conventional rigid phased-array antennas, which have typical areal mass densities between 8 and 15 kg/sq m. The differences in areal mass densities translate to substantial differences in total mass in contemplated applications involving aperture areas as large as 400 sq m. A membrane phased-array antenna includes patch antenna elements in a repeating pattern. All previously reported membrane antennas were passive antennas; this is the first active membrane antenna that includes transmitting/receiving (T/R) electronic circuits as integral parts. Other integral parts of the antenna include a network of radio-frequency (RF) feed lines (more specifically, a corporate feed network) and of bias and control lines, all in the form of flexible copper strip conductors on flexible polymeric membranes. Each unit cell of a prototype antenna (see Figure 1) contains a patch antenna element and a compact T/R module that is compatible with flexible membrane circuitry. There are two membrane layers separated by a 12.7-mm air gap. Each membrane layer is made from a commercially available flexible circuit material that, as supplied, comprises a 127-micron-thick polyimide dielectric layer clad on both sides with 17.5-micron-thick copper layers. The copper layers are patterned into RF, bias, and control conductors. The T/R module is located on the back side of the ground plane and is RF-coupled to the patch element via a slot. The T/R module is a hybrid multilayer module assembled and packaged independently and attached to the membrane array. At the time of reporting the information for

  11. Research of THz wave detector based on bi-material microcantilever arrays

    NASA Astrophysics Data System (ADS)

    Su, Bo; Duan, Guoteng; Zhang, Cunlin

    2011-11-01

    The paper describes a new THz wave detector. The bi-material of niobium nitride and aluminum, which has a large difference in thermal expansion coefficient, is used to fabricate the micro-cantilever arrays of substrate-free using MEMS technology. The niobium nitride is used to absorb THz, and aluminum is used as the deformation material. The method of software simulation is used to research the optimum thickness ratio of the bi-material for the best design of the micro-cantilever. In addition, in order to prevent the heat diffusion, the micro-cantilever arrays is placed in a vacuum chamber which has the function of vibration prevention using the mechanical pump and molecular pump to keep the high vacuum degree for improving the signal to noise ratio of the detection system. The reflection type visible light optical readout system is used to acquire the THz wave information indirectly. Furthermore, the method of difference processing is used to process image for improving systemic resolution. At last, a THz source with a power of 5mW and a frequency of 973GHz is used for detection experiment, and the data processing results show that the micro-cantilever has deformed.

  12. Research of THz wave detector based on bi-material microcantilever arrays

    NASA Astrophysics Data System (ADS)

    Su, Bo; Duan, Guoteng; Zhang, Cunlin

    2012-03-01

    The paper describes a new THz wave detector. The bi-material of niobium nitride and aluminum, which has a large difference in thermal expansion coefficient, is used to fabricate the micro-cantilever arrays of substrate-free using MEMS technology. The niobium nitride is used to absorb THz, and aluminum is used as the deformation material. The method of software simulation is used to research the optimum thickness ratio of the bi-material for the best design of the micro-cantilever. In addition, in order to prevent the heat diffusion, the micro-cantilever arrays is placed in a vacuum chamber which has the function of vibration prevention using the mechanical pump and molecular pump to keep the high vacuum degree for improving the signal to noise ratio of the detection system. The reflection type visible light optical readout system is used to acquire the THz wave information indirectly. Furthermore, the method of difference processing is used to process image for improving systemic resolution. At last, a THz source with a power of 5mW and a frequency of 973GHz is used for detection experiment, and the data processing results show that the micro-cantilever has deformed.

  13. Development of One-Dimensional Pyroelectric Infrared Array Detector with High Sensitivity

    NASA Astrophysics Data System (ADS)

    Hashimoto, Kazuhiko; Tsuruta, Tomohiro; Nishimura, Koji; Morinaka, Katsuya; Yoshiike, Nobuyuki

    1999-10-01

    A one-dimensional pyroelectric array detector for use as a multielement infrared sensor has been developed by using PbTiO3 bulk ceramics fabricated by a sheet-forming method. This one-dimensional infrared sensor consists of 16 elements. A pyroelectric detector responsivity of 3×104 V/W can be obtained at a 10 Hz chopping frequency, and a specific detectivity D* of 1.2×108 cm·Hz1/2/W has been achieved. The time constant of this pyroelectric detector is about 5.2 ms, so the detector has a shorter response time compared with a commercially available conventional pyroelectric detector. The crosstalk, which influences the output for the adjacent elements, is less than 10%. The output voltage for the detector gradually decreased as the atmospheric temperature increased. Pyroelectric detector responsivity increases with decreasing electrode size. By using this high-performance pyroelectric array detector, the thermal sources at lower temperatures than that of the environment can be detected with high sensitivity, as much as in the case of the thermal sources at higher temperatures.

  14. Determination of the conversion gain and the accuracy of its measurement for detector elements and arrays

    NASA Astrophysics Data System (ADS)

    Beecken, B. P.; Fossum, E. R.

    1996-07-01

    Standard statistical theory is used to calculate how the accuracy of a conversion-gain measurement depends on the number of samples. During the development of a theoretical basis for this calculation, a model is developed that predicts how the noise levels from different elements of an ideal detector array are distributed. The model can also be used to determine what dependence the accuracy of measured noise has on the size of the sample. These features have been confirmed by experiment, thus enhancing the credibility of the method for calculating the uncertainty of a measured conversion gain. detector-array uniformity, charge coupled device, active pixel sensor.

  15. The 20 element HgI2 energy dispersive x ray array detector system

    NASA Astrophysics Data System (ADS)

    Iwanczyk, J. A.; Dorri, N.; Wang, M.; Szczebiot, R. W.; Dabrowski, A. J.; Hedman, B.; Hodgson, K. O.; Patt, B. E.

    1991-11-01

    This paper describes recent progress in the development of HgI2 energy dispersive x-ray detector arrays and associated miniaturized processing electronics for synchrotron radiation research applications. The experimental results with a 20 element array detector were obtained under realistic synchrotron beam conditions at SSRL. An energy resolution of 250 eV (FWHM) at 5.9 keV (Mn-K(sub a)) was achieved. Energy resolution and throughput measurements versus input count rate and energy of incoming radiation have been measured. Extended X-ray Absorption Fine Structure (EXAFS) spectra were taken from diluted samples simulating proteins with nickel.

  16. An IR focal plane array employing superconducting Josephson junction thermal detectors

    NASA Astrophysics Data System (ADS)

    Osterman, D. P.; Yao, C.-T.; Dang, H.; Cohen, C.; Radparvar, M.

    1990-07-01

    Thin-film superconductors invite the single-process/single-substrate fabrication of IR detector arrays and their associated processing circuitry. In place of the bolometric thermal-detection principle typical of previous superconductor-employing schemes, the temperature-dependence of the current-voltage relation in a current-biased Josephson tunnel junction is used in the present device; this yields very low intrinsic detector noise, as well as clearly-defined 'on' and 'off' states. Superconducting processing circuitry encompassing addressing and decoding circuits, analog amplifiers, and ADC has been tested for an 8 x 8 prototype array.

  17. Characterization of a 15-mm-long virtual Frisch-grid CZT detector array

    NASA Astrophysics Data System (ADS)

    Bolotnikov, A. E.; Babalola, S.; Camarda, G. S.; Cui, Y.; Egarievwe, S. U.; Fochuk, P. M.; Hirt, M.; Hossain, A. M.; Kim, K.; Kopach, O. V.; Sferrazza, N. D.; Sturgess, J.; Polack, K.; Raghothamachar, B.; Yang, G.; James, R. B.

    2009-08-01

    We detail our new results from testing an array of 15-mm long virtual Frisch-grid CdZnTe detectors with a cathode signal readout-scheme intended to improve spectral response by correcting for electron trapping. We designed a novel electrode configuration for these long-drift detectors that ensures an energy resolution close to the statistical limit, and high detection efficiency. However, in reality, the quality of the crystals limits the performance of this type of device. Here, we describe the characterization of the array, show our preliminary results obtained with gamma-ray sources, and expound on their relation to our material-characterization data.

  18. Measurement of the proton-air cross section with Telescope Array's Middle Drum detector and surface array in hybrid mode

    NASA Astrophysics Data System (ADS)

    Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.; Telescope Array Collaboration

    2015-08-01

    In this work we are reporting on the measurement of the proton-air inelastic cross section σp-air inel using the Telescope Array detector. Based on the measurement of the σp-air inel, the proton-proton cross section σp -p value is also determined at √{s }=9 5-8+5 TeV . Detecting cosmic ray events at ultrahigh energies with the Telescope Array enables us to study this fundamental parameter that we are otherwise unable to access with particle accelerators. The data used in this report are the hybrid events observed by the Middle Drum fluorescence detector together with the surface array detector collected over five years. The value of the σp-air inel is found to be equal to 567.0 ±70.5 [Stat]-25+29[Sys] mb . The total proton-proton cross section is subsequently inferred from Glauber formalism and the Block, Halzen and Stanev QCD inspired fit and is found to be equal to 17 0-44+48[Stat]-17+19[Sys] mb .

  19. Large area nuclear particle detectors using ET materials, phase 2

    NASA Technical Reports Server (NTRS)

    Wrigley, Charles Y.; Storti, George M.; Walter, Lee; Mathews, Scott

    1990-01-01

    This report presents work done under a Phase 2 SBIR contract for demonstrating large area detector planes utilizing Quantex electron trapping materials as a film medium for storing high-energy nuclide impingement information. The detector planes utilize energy dissipated by passage of the high-energy nuclides to produce localized populations of electrons stored in traps. Readout of the localized trapped electron populations is effected by scanning the ET plane with near-infrared, which frees the trapped electrons and results in optical emission at visible wavelengths. The effort involved both optimizing fabrication technology for the detector planes and developing a readout system capable of high spatial resolution for displaying the recorded nuclide passage tracks.

  20. 3D imaging LADAR with linear array devices: laser, detector and ROIC

    NASA Astrophysics Data System (ADS)

    Kameyama, Shumpei; Imaki, Masaharu; Tamagawa, Yasuhisa; Akino, Yosuke; Hirai, Akihito; Ishimura, Eitaro; Hirano, Yoshihito

    2009-07-01

    This paper introduces the recent development of 3D imaging LADAR (LAser Detection And Ranging) in Mitsubishi Electric Corporation. The system consists of in-house-made key devices which are linear array: the laser, the detector and the ROIC (Read-Out Integrated Circuit). The laser transmitter is the high power and compact planar waveguide array laser at the wavelength of 1.5 micron. The detector array consists of the low excess noise Avalanche Photo Diode (APD) using the InAlAs multiplication layer. The analog ROIC array, which is fabricated in the SiGe- BiCMOS process, includes the Trans-Impedance Amplifiers (TIA), the peak intensity detectors, the Time-Of-Flight (TOF) detectors, and the multiplexers for read-out. This device has the feature in its detection ability for the small signal by optimizing the peak intensity detection circuit. By combining these devices with the one dimensional fast scanner, the real-time 3D range image can be obtained. After the explanations about the key devices, some 3D imaging results are demonstrated using the single element key devices. The imaging using the developed array devices is planned in the near future.

  1. Large arrays and properties of 3-terminal graphene nanoelectromechanical switches.

    PubMed

    Liu, Xinghui; Suk, Ji Won; Boddeti, Narasimha G; Cantley, Lauren; Wang, Luda; Gray, Jason M; Hall, Harris J; Bright, Victor M; Rogers, Charles T; Dunn, Martin L; Ruoff, Rodney S; Bunch, J Scott

    2014-03-12

    Large arrays of 3-terminal nanoelectromechanical graphene switches are fabricated. The switch is designed with a novel geometry that leads to low actuation voltages and improved mechanical integrity, while reducing adhesion forces, which improves the reliability of the switch. A finite element model including non-linear electromechanics is used to simulate the switching behavior and to deduce a scaling relation between the switching voltage and device dimensions. PMID:24339026

  2. Operational performance characteristics of the WISH detector array on the ISIS spallation neutron source

    NASA Astrophysics Data System (ADS)

    Duxbury, D.; Khalyavin, D.; Manuel, P.; Raspino, D.; Rhodes, N.; Schooneveld, E.; Spill, E.

    2014-12-01

    The performance of the position sensitive neutron detector array of the WISH diffractometer is discussed. WISH (Wide angle In a Single Histogram) is one of the seven instruments currently available for users on the second target station (TS2) of the ISIS spallation neutron source, and is used mainly for magnetic studies of materials. WISH is instrumented with an array of 10 detector panels, covering an angular range of 320o, orientated in two semi-cylindrical annuli around a central sample position at a radius of 2.2m. In total the 10 detector panels are composed of 1520 3He based position sensitive detector tubes. Each tube has an active length of one metre, a diameter of 8mm and is filled with 3He at 15 bar. The specification for the WISH detectors included a neutron detection efficiency of 50% at a neutron wavelength of 1Å with good gamma rejection. A position resolution better than 8 mm FWHM along the length of the tubes was also required which has been met experimentally. Results obtained from the detector arrays showing pulse height and positional information both prior to and post installation are shown. The first 5 of the 10 detector panels have been operational since 2009, and comparable diffraction data from powder and single crystal samples taken from the remaining 5 panels (installation completed in 2013) shows that we have a detector array with a highly stable performance which is easily assembled and maintained. Finally some real user data is shown, highlighting the excellent quality of data attainable with this instrument.

  3. Large-scale optimal sensor array management for target tracking

    NASA Astrophysics Data System (ADS)

    Tharmarasa, Ratnasingham; Kirubarajan, Thiagalingam; Hernandez, Marcel L.

    2004-01-01

    Large-scale sensor array management has applications in a number of target tracking problems. For example, in ground target tracking, hundreds or even thousands of unattended ground sensors (UGS) may be dropped over a large surveillance area. At any one time it may then only be possible to utilize a very small number of the available sensors at the fusion center because of bandwidth limitations. A similar situation may arise in tracking sea surface or underwater targets using a large number of sonobuoys. The general problem is then to select a subset of the available sensors in order to optimize tracking performance. The Posterior Cramer-Rao Lower Bound (PCRLB), which quantifies the obtainable accuracy of target state estimation, is used as the basis for network management. In a practical scenario with even hundreds of sensors, the number of possible sensor combinations would make it impossible to enumerate all possibilities in real-time. Efficient local (or greedy) search techniques must then be used to make the computational load manageable. In this paper we introduce an efficient search strategy for selecting a subset of the sensor array for use during each sensor change interval in multi-target tracking. Simulation results illustrating the performance of the sensor array manager are also presented.

  4. Large-scale optimal sensor array management for target tracking

    NASA Astrophysics Data System (ADS)

    Tharmarasa, Ratnasingham; Kirubarajan, Thiagalingam; Hernandez, Marcel L.

    2003-12-01

    Large-scale sensor array management has applications in a number of target tracking problems. For example, in ground target tracking, hundreds or even thousands of unattended ground sensors (UGS) may be dropped over a large surveillance area. At any one time it may then only be possible to utilize a very small number of the available sensors at the fusion center because of bandwidth limitations. A similar situation may arise in tracking sea surface or underwater targets using a large number of sonobuoys. The general problem is then to select a subset of the available sensors in order to optimize tracking performance. The Posterior Cramer-Rao Lower Bound (PCRLB), which quantifies the obtainable accuracy of target state estimation, is used as the basis for network management. In a practical scenario with even hundreds of sensors, the number of possible sensor combinations would make it impossible to enumerate all possibilities in real-time. Efficient local (or greedy) search techniques must then be used to make the computational load manageable. In this paper we introduce an efficient search strategy for selecting a subset of the sensor array for use during each sensor change interval in multi-target tracking. Simulation results illustrating the performance of the sensor array manager are also presented.

  5. Large area event counting detectors with high spatial and temporal resolution

    NASA Astrophysics Data System (ADS)

    Siegmund, O. H. W.; McPhate, J. B.; Vallerga, J. V.; Tremsin, A. S.; Frisch, H. E.; Elam, J. W.; Mane, A. U.; Wagner, R. G.

    2014-04-01

    Novel large area microchannel plates (MCPs) constructed using micro-capillary arrays functionalized by atomic layer deposition (ALD) have been successfully demonstrated in large format detectors (10 cm and 20 cm) with cross delay line and cross strip readouts. Borosilicate micro-capillary substrates allow robust MCPs to be made in sizes to 20 cm, the intrinsic background rates are low ( < 0.06 events cm-2 sec-1), the channel open area can be made as high as 85%, and the gain after preconditioning (vacuum bake and burn-in) shows virtually no change over > 7 C cm-2 extracted charge. We have constructed a number of detectors with these novel MCPs, including a 10 × 10 cm cross strip readout device and 20 × 20 cm delay line readout sensors. The cross strip detector has very high spatial resolution (the 20 μm MCP pores can be resolved, thus obtaining ~ 5k × 5k resolution elements), good time resolution ( < 1 ns), and high event rate ( > 5 million counts/s at 20% dead time), while operating at relatively low gain ( ~ 106). The 20 × 20 cm delay line detectors have achieved spatial resolutions of ~ 50 μm and event rates of several MHz, with good gain and background uniformity and < 200 ps event time tagging. Progress has also been made in construction of a 20 × 20 cm sealed tube optical imager, and we have achieved > 20% quantum efficiency and good uniformity for large area (20 cm) bialkali photocathodes.

  6. Development of membrane cryostats for large liquid argon neutrino detectors

    NASA Astrophysics Data System (ADS)

    Montanari, D.; Bremer, J.; Gendotti, A.; Geynisman, M.; Hentschel, S.; Loew, T.; Mladenov, D.; Montanari, C.; Murphy, S.; Nessi, M.; Norris, B.; Noto, F.; Rubbia, A.; Sharma, R.; Smargianaki, D.; Stewart, J.; Vignoli, C.; Wilson, P.; Wu, S.

    2015-12-01

    A new collaboration is being formed to develop a multi-kiloton Long-Baseline neutrino experiment that will be located at the Surf Underground Research Facility (SURF) in Lead, SD. In the present design, the detector will be located inside cryostats filled with 68,400 ton of ultrapure liquid argon (less than 100 parts per trillion of oxygen equivalent contamination). To qualify the membrane technology for future very large-scale and underground implementations, a strong prototyping effort is ongoing: several smaller detectors of growing size with associated cryostats and cryogenic systems will be designed and built at Fermilab and CERN. They will take physics data and test different detector elements, filtration systems, design options and installation procedures. In addition, a 35 ton prototype is already operational at Fermilab and will take data with single-phase detector in early 2016. After the prototyping phase, the multi-kton detector will be constructed. After commissioning, it will detect and study neutrinos from a new beam from Fermilab. These cryostats will be engineered, constructed, commissioned, and qualified by an international engineering team. This contribution presents the on-going effort on the development of the cryostats and details the requirements and the current status of the design.

  7. Application of a single area array detector for acquisition, tracking and point-ahead in space optical communications

    NASA Technical Reports Server (NTRS)

    Clark, D. L.; Cosgrove, M.; Van Vranken, R.; Park, H.; Fitzmaurice, M .

    1989-01-01

    Functions of acquisition, tracking, and point-ahead in space optical communications are being combined into a single system utilizing an area array detector. An analysis is presented of the feasibility concept. The key parameters are: optical power less than 1 pW at 0.86 micrometer, acquisition in less than 30 seconds in an acquisition field of view (FOV) of 1 mrad, tracking with 0.5 microrad rms noise at 1000 Hz update rate, and point ahead transfer function precision of 0.25 microrad over a region of 150 microrad. Currently available array detectors were examined. The most demanding specifications are low output noise, a high detection efficiency, a large number of pixels, and frame rates over 1kHz. A proof of concept (POC) demonstration system is currently being built utilizing the Kodak HS-40 detector (a 128 x 128 photodiode array with a 64 channel CCD readout architecture which can be operated at frame rates as high as 40,000/sec). The POC system implements a windowing scheme and special purpose digital signal processing electronic for matched filter acquisition and tracking algorithms.

  8. Application of a single area array detector for acquistion, tracking and point-ahead in space optical communications

    NASA Technical Reports Server (NTRS)

    Clark, D. L.; Cosgrove, M.; Vanvranken, R.; Park, H.; Fitzmaurice, M.

    1989-01-01

    Functions of acquisition, tracking, and point-ahead in space optical communications are being combined into a single system utilizing an area array detector. An analysis is presented of the feasibility concept. The key parameters are: optical power less than 1 pW at 0.86 micrometer, acquisition in less than 30 seconds in an acquisition field of view (FOV) of 1 mrad, tracking with 0.5 microrad rms noise at 1000 Hz update rate, and point ahead transfer function precision of 0.25 microrad over a region of 150 microrad. Currently available array detectors were examined. The most demanding specifications are low output noise, a high detection efficiency, a large number of pixels, and frame rates over 1kHz. A proof of concept (POC) demonstration system is currently being built utilizing the Kodak HS-40 detector (a 128 x 128 photodiode array with a 64 channel CCD readout architecture which can be operated at frame rates as high as 40,000/sec). The POC system implements a windowing scheme and special purpose digital signal processing electronic for matched filter acquisition and tracking algorithms.

  9. Spot centroid sensitivity to angle of intensity on image detector with lenslet array.

    PubMed

    Hui, Mei; Zhou, Ping; Su, Peng; Zhao, Zhu

    2015-05-20

    Lenslet array was introduced to an image detector to compensate for low sensitivity. These lenses deviate the light from different incident angles and potentially introduce errors when subpixel accuracy is needed. We investigated the spot centroid position because the angle of incidence changes on a Kodak KAI-16000 image detector with lenslet array. In our experiment, we noticed that there is a cubic dependency on the incident angle. The experimental results show that dependence on the angle of incidence is related to the lenslet array in the Kodak detector used for the pentaprism test. This situation caused an error in spherical aberration on the test surface after integration. The magnitude of the cubic component at incident angle of 14° (equivalent to F/2) is 11.6 μm, which corresponds to a 48 nm rms spherical aberration for the test surface and brings the scanning pentaprism test closer to the principal test while there is a 56 nm rms discrepancy. The discrepancy in spherical aberration between the two tests reduced to 8 nm after this calibration. It also showed the contrast measurement results for the Kodak detector and PointGrey detector. We performed experiments with two different detectors to quantify this effect. PMID:26192498

  10. Adaptive non-uniformity correction method based on temperature for infrared detector array

    NASA Astrophysics Data System (ADS)

    Zhang, Zhijie; Yue, Song; Hong, Pu; Jia, Guowei; Lei, Bo

    2013-09-01

    The existence of non-uniformities in the responsitivity of the element array is a severe problem typical to common infrared detector. These non-uniformities result in a "curtain'' like fixed pattern noises (FPN) that appear in the image. Some random noise can be restrained by the method kind of equalization method. But the fixed pattern noise can only be removed by .non uniformity correction method. The produce of non uniformities of detector array is the combined action of infrared detector array, readout circuit, semiconductor device performance, the amplifier circuit and optical system. Conventional linear correction techniques require costly recalibration due to the drift of the detector or changes in temperature. Therefore, an adaptive non-uniformity method is needed to solve this problem. A lot factors including detectors and environment conditions variety are considered to analyze and conduct the cause of detector drift. Several experiments are designed to verify the guess. Based on the experiments, an adaptive non-uniformity correction method is put forward in this paper. The strength of this method lies in its simplicity and low computational complexity. Extensive experimental results demonstrate the disadvantage of traditional non-uniformity correct method is conquered by the proposed scheme.

  11. The DUV Stability of Superlattice-Doped CMOS Detector Arrays

    NASA Technical Reports Server (NTRS)

    Hoenk, M. E.; Carver, A.; Jones, T.; Dickie, M.; Cheng, P.; Greer, H. F.; Nikzad, S.; Sgro, J.

    2013-01-01

    In this paper, we present experimental results and band structure calculations that illuminate the unique properties of superlattice-doped detectors. Numerical band structure calculations are presented to analyze the dependencies of surface passivation on dopant profiles and interface trap densities (Figure 3). Experiments and calculations show that quantum-engineered surfaces, grown at JPL by low temperature molecular beam epitaxy, achieve a qualitative as well as quantitative uniqueness in their near-immunity to high densities of surface and interface traps.

  12. Circuit for high resolution decoding of multi-anode microchannel array detectors

    NASA Technical Reports Server (NTRS)

    Kasle, David B. (Inventor)

    1995-01-01

    A circuit for high resolution decoding of multi-anode microchannel array detectors consisting of input registers accepting transient inputs from the anode array; anode encoding logic circuits connected to the input registers; midpoint pipeline registers connected to the anode encoding logic circuits; and pixel decoding logic circuits connected to the midpoint pipeline registers is described. A high resolution algorithm circuit operates in parallel with the pixel decoding logic circuit and computes a high resolution least significant bit to enhance the multianode microchannel array detector's spatial resolution by halving the pixel size and doubling the number of pixels in each axis of the anode array. A multiplexer is connected to the pixel decoding logic circuit and allows a user selectable pixel address output according to the actual multi-anode microchannel array detector anode array size. An output register concatenates the high resolution least significant bit onto the standard ten bit pixel address location to provide an eleven bit pixel address, and also stores the full eleven bit pixel address. A timing and control state machine is connected to the input registers, the anode encoding logic circuits, and the output register for managing the overall operation of the circuit.

  13. Low dark current small pixel large format InGaAs 2D photodetector array development at Teledyne Judson Technologies

    NASA Astrophysics Data System (ADS)

    Yuan, Henry; Meixell, Mike; Zhang, Jiawen; Bey, Philip; Kimchi, Joe; Kilmer, Louis C.

    2012-06-01

    Teledyne Judson Technologies (TJT) has been developing technology for small pixel, large format, low dark current, and low capacitance NIR/SWIR InGaAs detector arrays, aiming to produce <10μm pixels and >2Kx2K format arrays that can be operated at or near room temperature. Furthermore, TJT is now developing technology for sub-10μm pixel arrays in response to requirements for a variety of low light level (LLL) imaging applications. In this paper, we will review test data that demonstrates lower dark current density for 10-20μm pixel arrays. We will present preliminary results on the successful fabrication of test arrays with pixels as small as 5μm. In addition, a lot of effort has been made to control and reduce the detector pixel capacitance which can become another source of detector noise. TJT is also developing 4" InGaAs wafer process and now offers four different types of InGaAs 2D arrays/FPAs that are tailored to different customer requirements for dark current, capacitance, spectral response, and bias range.

  14. Progress with type-II superlattice IR detector arrays

    NASA Astrophysics Data System (ADS)

    Rhiger, David R.; Kvaas, Robert E.; Harris, Sean F.; Bornfreund, Richard E.; Thai, Yen N.; Hill, Cory J.; Li, Jian V.; Gunapala, Sarath D.; Mumolo, Jason M.

    2007-04-01

    We report progress in the development of long wavelength infrared (LWIR) focal plane arrays (FPAs) built on type-II strained layer InAs/GaSb superlattice materials. Work at Raytheon Vision Systems and Jet Propulsion Laboratory has led to successful devices with cutoff wavelengths in the 10 to 12 μm range. Pixels have been formed by wet etching and surface passivation by plasma-deposited silicon dioxide. We present test results on arrays hybridized with indium bump bonding to silicon readout integrated circuits, as well as analyses of current-voltage characteristics of individual diodes. In particular, we find that, at temperatures below about 70 K the leakage current is dominated by generation-recombination effects near zero bias and by trap-assisted tunneling in reverse bias. Although other authors have demonstrated imaging for SWIR and MWIR type-II superlattice devices, to our knowledge no one has done so prior to 2006 in the LWIR range. We have obtained both still and video imaging with 256×256 arrays with 30-μm pixels operating at 78 K, having high operability and a cutoff wavelength of 10.5 μm.

  15. Performance of new 8-inch photomultiplier tube used for the Tibet muon-detector array

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Huang, J.; Chen, D.; Zhai, L.-M.; Chen, X.; Hu, X.-B.; Lin, Y.-H.; Jin, H.-B.; Zhang, X.-Y.; Feng, C.-F.; Jia, H.-Y.; Zhou, X.-X.; Danzengluobu; Chen, T.-L.; Labaciren; Liu, M.-Y.; Gao, Q.; Zhaxiciren

    2016-06-01

    Since 2014, a new hybrid experiment consisting of a high-energy air-shower-core array (YAC-II), a high-density air-shower array (Tibet-III) and a large underground water-Cherenkov muon-detector array (MD) has been continued by the Tibet ASγ collaboration to measure the chemical composition of cosmic rays in the wide energy range including the ``knee''. In this experiment, YAC-II is used to select high energy core events induced by cosmic rays in the above energy region, while MD is used to estimate the type of nucleus of primary particles by measuring the number of muons contained in the air showers. However, the dynamic range of each MD cell is only 5 to 2000 photoelectrons (PEs) which is mainly designed for observation of high-energy celestial gamma rays. In order to obtain the primary proton, helium and iron spectra and their ``knee'' positions with energy up to 1016 eV, each of PMTs equipped to the MD cell is required to measure the number of photons capable of covering a wide dynamic range of 100–106 PEs according to Monte Carlo simulations. In this paper, we firstly compare the characteristic features between R5912-PMT made by Japan Hamamatsu and CR365-PMT made by Beijing Hamamatsu. If there exists no serious difference, we will then add two 8-inch-in-diameter PMTs to meet our requirements in each MD cell, which are responsible for the range of 100–10000 PEs and 2000–1000000 PEs, respectively. That is, MD cell is expected to be able to measure the number of muons over 6 orders of magnitudes.

  16. A Large Drift Detector Array Lunar Orbiter Spectrometer

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica A.; Ramsey, Brian; Rebak, Pavel; De Geronimo, Gianluigi; Chen, Wei; Li, Zheng; Carini, Gabriella; Keister, Jeffrey; Siddons, Peter D.; Pinelli, Donald

    2009-01-01

    Measurement of-rays from the surface of objects can tell us about the chemical composition. Absorption of radiation causes characteristic fluorescence from material being irradiated. By measuring the spectrum ofthe radiation and identifying lines in the spectrum, the emitting element (s) can be identified.

  17. THz Direct Detector and Heterodyne Receiver Arrays in Silicon Nanoscale Technologies

    NASA Astrophysics Data System (ADS)

    Grzyb, Janusz; Pfeiffer, Ullrich

    2015-10-01

    The main scope of this paper is to address various implementation aspects of THz detector arrays in the nanoscale silicon technologies operating at room temperatures. This includes the operation of single detectors, detectors operated in parallel (arrays), and arrays of detectors operated in a video-camera mode with an internal reset to support continuous-wave illumination without the need to synchronize the source with the camera (no lock-in receiver required). A systematic overview of the main advantages and limitations in using silicon technologies for THz applications is given. The on-chip antenna design challenges and co-design aspects with the active circuitry are thoroughly analyzed for broadband detector/receiver operation. A summary of the state-of-the-art arrays of broadband THz direct detectors based on two different operation principles is presented. The first is based on the non-quasistatic resistive mixing process in a MOSFET channel, whereas the other relies on the THz signal rectification by nonlinearity of the base-emitter junction in a high-speed SiGe heterojunction bipolar transistor (HBT). For the MOSFET detector arrays implemented in a 65 nm bulk CMOS technology, a state-of-the-art optical noise equivalent power (NEP) of 14 pW/ at 720 GHz was measured, whereas for the HBT detector arrays in a 0.25 μm SiGe process technology, an optical NEP of 47 pW/ at 700 GHz was found. Based on the implemented 1k-pixel CMOS camera with an average power consumption of 2.5 μW/pixel, various design aspects specific to video-mode operation are outlined and co-integration issues with the readout circuitry are analyzed. Furthermore, a single-chip 2 × 2 array of heterodyne receivers for multi-color active imaging in a 160-1000 GHz band is presented with a well-balanced NEP across the operation bandwidth ranging from 0.1 to 0.24 fW/Hz (44.1-47.8 dB single-sideband NF) and an instantaneous IF bandwidth of 10 GHz. In its present implementation, the receiver RF

  18. X-ray source considerations in operation of digital detector arrays

    SciTech Connect

    Jensen, Terrence; Wendt, Scott

    2014-02-18

    Digital Detector Arrays (DDA) are increasingly replacing film in radiography applications. Standards exist for characterizing the performance of these detectors, and for using them in specific inspections. We have observed that the selection of the x-ray source to use with these detectors can also have a significant influence on the performance. We look at differences between standard, and micro-focus x-ray tubes, and end-window vs. side-window micro-focus tubes. We find that for best results, one must calibrate the DDA for the source settings used during an inspection. This is particularly true for variable-focus sources.

  19. X-ray source considerations in operation of digital detector arrays

    NASA Astrophysics Data System (ADS)

    Jensen, Terrence; Wendt, Scott

    2014-02-01

    Digital Detector Arrays (DDA) are increasingly replacing film in radiography applications. Standards exist for characterizing the performance of these detectors, and for using them in specific inspections. We have observed that the selection of the x-ray source to use with these detectors can also have a significant influence on the performance. We look at differences between standard, and micro-focus x-ray tubes, and end-window vs. side-window micro-focus tubes. We find that for best results, one must calibrate the DDA for the source settings used during an inspection. This is particularly true for variable-focus sources.

  20. Detector Arrays for the James Webb Space Telescope Near-Infrared Spectrograph

    NASA Technical Reports Server (NTRS)

    Rauscher, Bernard J.; Alexander, David; Brambora, Clifford K.; Derro, Rebecca; Engler, Chuck; Fox, Ori; Garrison, Matthew B.; Henegar, Greg; Hill, robert J.; Johnson, Thomas; Lindler, Don J.; Manthripragada, Sridhar S.; Marshall, Ceryl; Mott, Brent; Parr, Thomas M.; Roher, Wayne D.; Shakoorzadeh, Kamdin B.; Smith, Miles; Waczynski, Augustyn; Wen, Yiting; Wilson, Donna; Xia-Serafino, Wei

    2007-01-01

    The James Webb Space Telescope's (JWST) Near Infrared Spectrograph (NIRSpec) incorporates two 5 micron cutoff (lambda(sub co) = 5 microns) 2048x2048 pixel Teledyne HgCdTe HAWAII-2RG sensor chip assemblies. These detector arrays, and the two Teledyne SIDECAR application specific integrated circuits that control them, are operated in space at T approx. 37 K. In this article, we provide a brief introduction to NIRSpec, its detector subsystem (DS), detector readout in the space radiation environment, and present a snapshot of the developmental status of the NIRSpec DS as integration and testing of the engineering test unit begins.

  1. A 4 π charged-particle detector array for light-ion-induced nuclear fragmentation studies

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, K.; Alexander, A.; Bracken, D. S.; Brzychczyk, J.; Dorsett, J.; Ensman, R.; Renshaw Foxford, E.; Hamilton, T.; Komisarcik, K.; McDonald, K. N.; Morley, K. B.; Poehlman, J.; Powell, C.; Viola, V. E.; Yoder, N. R.; Ottarson, J.; Madden, N.

    1994-12-01

    Operating characteristics of the Indiana Silicon Sphere 4 π detector array are outlined. The detector geometry is spherical, with 90 telescopes in the forward hemisphere and 72 at backward angles, covering a total solid angle of 74% of 4π. Each telescope consists of a simple gas-ion chamber, operated with C3F8 gas, followed by a 0.5 mm thick ion-implanted silicon detector and a 28 mm CsI(Tl) crystal, readout by a photodiode. Custom-built bias supplies and NIM preamp/shaper modules were used in conjunction with commercial CFD, TDC and ADC CAMAC units.

  2. Proposed applications of monolithic microlens array technology to enhance IR detector performance

    NASA Astrophysics Data System (ADS)

    Wilson, J. P.; Reardon, Patrick J.

    1994-10-01

    Gains in micro-optic technology may provide enhanced performance for IR sensing applications. The benefits in noise reduction and increase in signal-to-noise ratio on the detector arrays can off-set the increased cost of adding micro-lens structures to the detector assemblies. Additionally, new manufacturing techniques make it feasible to make micro-lens structures on the same substrate as the detector elements. One of the advantages of this technology growth is the shifting of alignment to the fabrication stage instead of the filter assembly stage. Important considerations include: fill factor, diffraction efficiency, optical and electronic crosstalk, optical power, and optical bandwidth.

  3. Laboratory characterization of direct readout Si:Sb and Si:Ga infrared detector arrays

    NASA Technical Reports Server (NTRS)

    Mckelvey, Mark E.; Moss, Nicolas N.; Mcmurray, R. E., Jr.; Estrada, John A.; Goebel, John H.; Mccreight, Craig R.; Savage, Maureen L.; Junga, Frank; Whittemore, Thomas

    1989-01-01

    Highlights of recent results obtained at Ames Research Center in performance evaluations of infrared detector arrays are presented. Antimony- and gallium-doped silicon direct readout 58x62 element hybrid devices from Ames' ongoing detector technology development program are described. The observed characteristics meet most of the performance goals specified by the Space Infrared Telescope Facility (SIRTF) instrument teams and compare favorably with the best performance reported for discrete non-integrating extrinsic silicon detectors. Initial results of radiation environment testing are reported, and non-ideal behavior demonstrated by these test devices is discussed.

  4. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  5. Using Java to visualize and manipulate large arrays of neutron scattering data

    SciTech Connect

    Mikkelson, D.; Worlton, T.; Chatterjee, A.; Hammonds, J.; Chen, D.

    2000-02-02

    The Intense Pulsed Neutron Source at Argonne National Laboratory is a world class pulsed neutron source with thirteen instruments designed to characterize materials using time-of-flight neutron scattering techniques. For each instrument, a collimated pulse of neutrons is directed to a material sample. The neutrons are scattered by the sample and detected by arrays of detectors. The type, number and arrangement of detectors vary widely from instrument to instrument, depending on which properties of materials are being studied. In all cases, the faster, higher energy neutrons reach the detectors sooner than the lower energy neutrons. This produces a time-of-flight spectrum at each detector element. The time-of-flight spectrum produced by each detector element records the scattering intensity at hundreds to thousands of discrete time intervals. Since there are typically between two hundred and ten thousand distinct detector elements, a single set of raw data can include millions of points. Often many such datasets are collected for a single sample to determine the effect of different conditions on the microscopic structure and dynamics of the sample. In this project, Java was used to construct a portable highly interactive system for viewing and operating on large collections of time-of-flight spectra. Java performed surprisingly well in handling large amounts of data quickly was fast enough even with standard PC hardware. Although Java may not be the choice at this time for applications where computational efficiency is the primary refinement, any disadvantages in this case were outweighed by the advantages of a clean object oriented language with a portable set of GUI components. The authors anticipate that Java will prove useful for scientific computing and data visualization in situations where portability, case of use and effective use of software development manpower are critical.

  6. Uniform Non-stoichiometric Titanium Nitride Thin Films for Improved Kinetic Inductance Detector Arrays

    NASA Astrophysics Data System (ADS)

    Coiffard, G.; Schuster, K.-F.; Driessen, E. F. C.; Pignard, S.; Calvo, M.; Catalano, A.; Goupy, J.; Monfardini, A.

    2016-08-01

    We describe the fabrication of homogeneous sub-stoichiometric titanium nitride films for microwave kinetic inductance detector (KID) arrays. Using a 6'' sputtering target and a homogeneous nitrogen inlet, the variation of the critical temperature over a 2'' wafer was reduced to {<}25 %. Measurements of a 132-pixel KID arrays from these films reveal a sensitivity of 16 kHz/pW in the 100 GHz band, comparable to the best aluminum KIDs. We measured a noise equivalent power of NEP = 3.6× 10^{-15} W/Hz^{1/2}. Finally, we describe possible routes to further improve the performance of these TiN KID arrays.

  7. Uniform Non-stoichiometric Titanium Nitride Thin Films for Improved Kinetic Inductance Detector Arrays

    NASA Astrophysics Data System (ADS)

    Coiffard, G.; Schuster, K.-F.; Driessen, E. F. C.; Pignard, S.; Calvo, M.; Catalano, A.; Goupy, J.; Monfardini, A.

    2016-01-01

    We describe the fabrication of homogeneous sub-stoichiometric titanium nitride films for microwave kinetic inductance detector (KID) arrays. Using a 6'' sputtering target and a homogeneous nitrogen inlet, the variation of the critical temperature over a 2'' wafer was reduced to {<} 25 %. Measurements of a 132-pixel KID arrays from these films reveal a sensitivity of 16 kHz/pW in the 100 GHz band, comparable to the best aluminum KIDs. We measured a noise equivalent power of NEP = 3.6× 10^{-15} W/Hz^{1/2} . Finally, we describe possible routes to further improve the performance of these TiN KID arrays.

  8. 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.

  9. Integrating Different Types of Nanowire Sensors in a Large Array

    NASA Astrophysics Data System (ADS)

    Dan, Yaping; Evoy, Stephane; Johnson, A. T. Charlie

    2008-03-01

    Biological olfactory systems have a key structural feature: different types of sensors in a large array. Humans, for example, possess several hundred distinct types of sensing cells, a level of sensor diversity not yet achieved in artificial olfactory systems. Here, we demonstrate a simple and low-cost electrochemical approach to integrate large numbers of different types of nanowire sensors in an array on the same silicon wafer. In our approach, nanowires are grown inside an on-chip nanochannel template by electrochemistry with each horizontal channel connected to a gold electrode. This design allows for addressable synthesis of a specific type of nanowire in specified channels by providing a voltage to the electrodes connecting to those channels. The process can be further repeated to produce different types of nanowires in other channels using different electroplating solutions. The scale and diversity of this array have a potential to compete with those of biological olfactory systems and the synthesis process is cost-effective enough for commercialization.

  10. Digital Radiography and Computed Tomography Project -- Fully Integrated Linear Detector ArrayStatus Report

    SciTech Connect

    Tim Roney; Robert Seifert; Bob Pink; Mike Smith

    2011-09-01

    The field-portable Digital Radiography and Computed Tomography (DRCT) x-ray inspection systems developed for the Project Manager for NonStockpile Chemical Materiel (PMNSCM) over the past 13 years have used linear diode detector arrays from two manufacturers; Thomson and Thales. These two manufacturers no longer produce this type of detector. In the interest of insuring the long term viability of the portable DRCT single munitions inspection systems and to improve the imaging capabilities, this project has been investigating improved, commercially available detectors. During FY-10, detectors were evaluated and one in particular, manufactured by Detection Technologies (DT), Inc, was acquired for possible integration into the DRCT systems. The remainder of this report describes the work performed in FY-11 to complete evaluations and fully integrate the detector onto a representative DRCT platform.

  11. Development of 256 x 256 Element Impurity Band Conduction Infrared Detector Arrays for Astronomy

    NASA Technical Reports Server (NTRS)

    Domingo, George

    1997-01-01

    This report describes the work performed on a one and a half year advance technology program to develop Impurity Band Conduction (IBC) detectors with very low dark current, high quantum efficiency, and with good repeatable processes. The program fabricated several epitaxial growths of Si:As detecting layers from 15 to 35 microns thick and analyzed the performance versus the thickness and the Arsenic concentration of these epitaxial layers. Some of the epitaxial runs did not yield because of excessive residual impurities. The thicker epitaxial layers and the ones with higher Arsenic concentration resulted in good detectors with low dark currents and good quantum efficiency. The program hybridized six detector die from the best detector wafers to a low noise, 256 x 256 readout array and delivered the hybrids to NASA Ames for a more detailed study of the performance of the detectors.

  12. Curved CCD detector devices and arrays for multispectral astrophysical applications and terrestrial stereo panoramic cameras

    NASA Astrophysics Data System (ADS)

    Swain, Pradyumna; Mark, David

    2004-09-01

    The emergence of curved CCD detectors as individual devices or as contoured mosaics assembled to match the curved focal planes of astronomical telescopes and terrestrial stereo panoramic cameras represents a major optical design advancement that greatly enhances the scientific potential of such instruments. In altering the primary detection surface within the telescope"s optical instrumentation system from flat to curved, and conforming the applied CCD"s shape precisely to the contour of the telescope"s curved focal plane, a major increase in the amount of transmittable light at various wavelengths through the system is achieved. This in turn enables multi-spectral ultra-sensitive imaging with much greater spatial resolution necessary for large and very large telescope applications, including those involving infrared image acquisition and spectroscopy, conducted over very wide fields of view. For earth-based and space-borne optical telescopes, the advent of curved CCD"s as the principle detectors provides a simplification of the telescope"s adjoining optics, reducing the number of optical elements and the occurrence of optical aberrations associated with large corrective optics used to conform to flat detectors. New astronomical experiments may be devised in the presence of curved CCD applications, in conjunction with large format cameras and curved mosaics, including three dimensional imaging spectroscopy conducted over multiple wavelengths simultaneously, wide field real-time stereoscopic tracking of remote objects within the solar system at high resolution, and deep field survey mapping of distant objects such as galaxies with much greater multi-band spatial precision over larger sky regions. Terrestrial stereo panoramic cameras equipped with arrays of curved CCD"s joined with associative wide field optics will require less optical glass and no mechanically moving parts to maintain continuous proper stereo convergence over wider perspective viewing fields than

  13. X-band system performance of the very large array

    NASA Technical Reports Server (NTRS)

    Ulvestad, J. S.; Resch, G. M.; Brundage, W. D.

    1988-01-01

    The Very Large Array (VLA) is being equipped to receive telemetry from Voyager 2 during the Neptune encounter in 1989. Cryogenically cooled amplifiers are being installed on each of the 27 antennas. These amplifiers are currently a mix of field effect transistors (FETs) and high electron mobility transistors (HEMTs) and exhibit zenith system temperatures that range from 30 to 52 K. The system temperatures and aperture efficiencies determined during the past year are summarized. The nominal values of the noise diode calibration are compared with derived values made under the assumption of a uniform atmosphere over the array. Gain values are determined from observations of unresolved radio sources whose flux densities are well known. The tests suggest that the completed VLA will have a ratio of gain to system temperature that is approximately 4.4 dB above that of a single 64 m antenna of the Deep Space Network.

  14. A decoupled coil detector array for fast image acquisition in magnetic resonance imaging.

    PubMed

    Kwiat, D; Einav, S; Navon, G

    1991-01-01

    A method for magnetic resonance imaging (MRI) is investigated here, whereby an object is put under a homogeneous magnetic field, and the image is obtained by applying inverse source procedures to the data collected in an array of coil detectors surrounding the object. The induced current in each coil due to the precession of the magnetic dipole in each voxel depends on the characteristics of both the magnetic dipole frequency and strength, together with its distance from the coil, the coil direction in space, and the electrical properties of the coils. By calculating the induced current signals over an array of coil detectors, a relationship is established between the set of signals and the structure of the body under investigation. The linear relation can then be represented in matrix notation, and inversion of this matrix will produce an image of the body. Important problems which must be considered in the proposed method are signal-to-noise ratio (SNR) and coupling between adjacent coils. Solutions to these problems will provide a new method for obtaining an instantaneous image by NMR, with no need for gradient switching for encoding. A general algorithm for decoupling of the coils is presented and fast sampling of the signal, instead of filtering, is used in order to reduce both noise and numerical roundoff errors at the same time. Sensitivity considerations are made with respect to the number of coils that is required and its connection with coil radius and SNR. A computer simulation demonstrates the feasibility of this new modality. Based on the solutions presented here for the problems involved in the use of a large number of coils for a simultaneous recording of the signal, an improved method of multicoil recording is suggested, whereby it is combined with the conventional zeugmatographic method with read and phase gradients, to result in a novel method of magnetic resonance imaging. In the combined method, there are no phase-encoding gradients. Only a

  15. Detector station and registering system of the NEVOD-EAS array cluster

    NASA Astrophysics Data System (ADS)

    Shulzhenko, I. A.; Ampilogov, N. V.; Astapov, I. I.; Chiavassa, A.; Khokhlov, S. S.; Kompaniets, K. G.; Kutovoy, V. Yu; Likiy, O. I.; Yashin, I. I.

    2016-02-01

    The design features of the detector stations of the cluster type shower array NEVOD-EAS which is now under construction on the basis of the Unique Scientific Facility ‘Experimental complex NEVOD’, as well as the operation principle of the cluster registering system are discussed.

  16. Search for ultra-high energy photons using Telescope Array surface detector

    SciTech Connect

    Rubtsov, G. I.; Troitsky, S. V.; Ivanov, D.; Stokes, B. T.; Thomson, G. B.

    2011-09-22

    We search for ultra-high energy photons by analyzing geometrical properties of shower fronts of events registered by the Telescope Array surface detector. By making use of an event-by-event statistical method, we derive an upper limit on the absolute flux of primary photons with energies above 10{sup 19} eV.

  17. Modulation transfer function testing of detector arrays using narrow-band laser speckle

    NASA Astrophysics Data System (ADS)

    Sensiper, Martin; Boreman, Glenn D.; Ducharme, Alfred D.; Snyder, Donald R.

    1993-02-01

    A method for measuring the modulation transfer function (MTF) of a detector array from zero spatial frequency to twice the Nyquist frequency is presented. Laser speckle with a tunable, narrow spatial-frequency bandpass is used. The MTF measured with this method is compared to the MTF measured using sine targets. The results of the two methods agree to within 2%.

  18. Carrier diffusion limited MTF of a back-illuminated pv detector array

    NASA Astrophysics Data System (ADS)

    Gupta, Sudha; Gopal, Vishnu; Chhabra, K. C.

    Carrier diffusion limited MTF of a back-illuminated HgCdTe-PV detector array has been calculated by including the multiple reflections within a CdTe-HgCdTe structure. Results of these calculations show that there is only a marginal improvement in MTF. The gain in quantum efficiency can however become substantial if the unilluminated surface is made strongly reflecting.

  19. Novel Large Area High Resolution Neutron Detector for the Spallation Neutron Source

    SciTech Connect

    Lacy, Jeffrey L

    2009-05-22

    Neutron scattering is a powerful technique that is critically important for materials science and structural biology applications. The knowledge gained from past developments has resulted in far-reaching advances in engineering, pharmaceutical and biotechnology industries, to name a few. New facilities for neutron generation at much higher flux, such as the SNS at Oak Ridge, TN, will greatly enhance the capabilities of neutron scattering, with benefits that extend to many fields and include, for example, development of improved drug therapies and materials that are stronger, longer-lasting, and more impact-resistant. In order to fully realize this enhanced potential, however, higher neutron rates must be met with improved detection capabilities, particularly higher count rate capability in large size detectors, while maintaining practicality. We have developed a neutron detector with the technical and economic advantages to accomplish this goal. This new detector has a large sensitive area, offers 3D spatial resolution, high sensitivity and high count rate capability, and it is economical and practical to produce. The proposed detector technology is based on B-10 thin film conversion of neutrons in long straw-like gas detectors. A stack of many such detectors, each 1 meter in length, and 4 mm in diameter, has a stopping power that exceeds that of He-3 gas, contained at practical pressures within an area detector. With simple electronic readout methods, straw detector arrays can provide spatial resolution of 4 mm FWHM or better, and since an array detector of such form consists of several thousand individual elements per square meter, count rates in a 1 m^2 detector can reach 2?10^7 cps. Moreover, each individual event can be timetagged with a time resolution of less than 0.1 ?sec, allowing accurate identification of neutron energy by time of flight. Considering basic elemental cost, this novel neutron imaging detector can be commercially produced economically

  20. High Dynamic Range Pixel Array Detector for Scanning Transmission Electron Microscopy.

    PubMed

    Tate, Mark W; Purohit, Prafull; Chamberlain, Darol; Nguyen, Kayla X; Hovden, Robert; Chang, Celesta S; Deb, Pratiti; Turgut, Emrah; Heron, John T; Schlom, Darrell G; Ralph, Daniel C; Fuchs, Gregory D; Shanks, Katherine S; Philipp, Hugh T; Muller, David A; Gruner, Sol M

    2016-02-01

    We describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500 µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80-200 keV electron beams. PMID:26750260

  1. Large format two-color CMOS ROIC for SLS detectors

    NASA Astrophysics Data System (ADS)

    Simolon, Brian; Aziz, Naseem; Barskey, Steve; Hansen, Randy; Kurth, Eric; Long, John; Petronio, Susan

    2013-07-01

    The ISC0905 is a 640 × 512, large format, two-color CMOS readout integrated circuit (ROIC) designed for strained-layer superlattice (SLS) detectors. The detector interface is supported through one input pad in each 30 μm pixel. One bit in the serial control word programs the chip to automatically adjust all biases and timing to allow for the integration of either electrons or holes. This feature allows users to easily operate this ROIC with a wide variety of p-on-n or n-on-p detectors. The ROIC has been specifically designed to allow for both polarities of detectors to be placed back-to-back and to connect to the ROIC through a single input pad to obtain a two-color image. The two-color image is achieved by switching the ROIC mode between the two colors on a per frame basis. This paper will describe the interface, design and features of the ISC0905 ROIC as well as a summary of the characterization test results.

  2. Cross-talk-free multiplexed immunoassay using a disposable electrochemiluminescent immunosensor array coupled with a non-array detector.

    PubMed

    Li, Cuifang; Fu, Zhifeng; Li, Zongyun; Wang, Zhenxing; Wei, Wei

    2011-09-15

    A disposable electrochemiluminescent (ECL) immunosensor array was fabricated on a screen-printed carbon electrode (SPCE) substrate to perform multiplexed immunoassay (MIA) for the first time. The SPCE substrate was composed of an array of four carbon working electrodes, one common Ag/AgCl reference electrode, and one common carbon counter electrode. The immunosensor array was constructed by site-selectively immobilizing multiple antigens on different working electrodes of the SPCE substrate. With a competitive immunoassay format, the immobilized antigens competed with antigens in the sample to capture their corresponding tri(2,2'-bipyridyl)ruthenium(II)-labeled antibodies. The ECL signals from the immunosensors in this array were sequentially detected by a photomultiplier with the aid of a homemade single-pore-four-throw switch. Due to the ECL readout mechanism and the sequential detection mode, it could avoid the cross-talk between the adjacent immunosensors, which was common in other reported immunosensor array. Human, rabbit and mouse immunoglobulin Gs were near-simultaneously assayed as the model analytes. The linear ranges for them were 10-400, 20-400, and 20-400 ng/mL, with detection limits of 2.9, 6.1 and 6.5 ng/mL (S/N=3), respectively. This novel ECL strategy based on immunosensor array coupled with non-array detector provided a simple, sensitive, low-cost and time-saving approach for MIA. It showed great application potential in point-of-care test and field analysis of bio-agents, with mass production potential and high throughput. PMID:21778047

  3. Mass composition sensitivity of combined arrays of water cherenkov and scintillation detectors in the EeV range

    NASA Astrophysics Data System (ADS)

    Gonzalez, Javier G.; Engel, Ralph; Roth, Markus

    2016-02-01

    We consider an array of scintillation detectors combined with an array of water Cherenkov detectors designed to simultaneously measure the cosmic-ray primary mass composition and energy spectrum at energies around 1EeV. In this work we investigate the sensitivity to primary mass composition of such combined arrays. The water Cherenkov detectors are arranged in a triangular grid with fixed 750m spacing and the configuration of the scintillation detectors is changed to study the impact of different configurations on the sensitivity to mass composition. We show that the performance for composition determination can be compared favorably to that of fluorescence measurements after the difference in duty cycles is considered.

  4. Acquisition and tracking performance measurements for a high speed area array detector system

    NASA Technical Reports Server (NTRS)

    Short, R. C.; Cosgrove, M.; Clark, D. L.; Martino, A.; Park, H.; Seery, B.

    1991-01-01

    A proof-of-concept (POC) demonstration system has been developed which demonstrates acquisition, tracking and point-ahead angle sensing for a space optical communications terminal utilizing a single high speed area array detector. The detector is the 128 x 128 pixel Kodak HS-40 photodiode array. It has 64 parallel readout channels and can operate at frames rates up to 40,000 frames/sec with rms readout noise of 20 photoelectrons. A windowing scheme and special purpose digital signal processing electronics are employed to implement acquisition and tracking algorithms. The system operates at greater than 1 kHz sample (frame) rates. Acquisition can be performed in as little as 30 milliseconds with less than 1 picowatt of 0.85 micron beacon power on the detector. At the same power level, the rms tracking accuracy is approximately 1/16 pixel. Results of system analysis and measurements using the POC system are presented.

  5. Measurement of the UHECR Energy Spectrum by the Telescope Array Fluorescence Detectors

    NASA Astrophysics Data System (ADS)

    Stroman, Thomas; Bergman, Douglas

    2013-04-01

    Ultra-high-energy cosmic rays (UHECRs), subatomic charged particles of extraterrestrial origin and with kinetic energies near or exceeding 10^18 eV, are very rare. The Telescope Array (TA) experiment in western Utah is the northern hemisphere's largest UHECR detector, and consists of three atmospheric fluorescence detectors (FDs) and a ground array of 507 scintillator detectors. In stand-alone ``monocular'' operation, the FDs can observe the widest range in primary UHECR energies. One FD employs refurbished hardware from the High-Resolution Fly's Eye experiment; the remaining two FDs were designed for TA and employ new hardware and analysis. We will present the UHECR energy spectrum measured by the FDs in monocular mode using data collected during the first four years of operation.

  6. Recent advances in the modulation transfer function testing of detector arrays

    NASA Astrophysics Data System (ADS)

    Ducharme, Alfred D.

    2008-08-01

    The increased complexity of imaging sensors and total number of discrete detector sites has challenged traditional testing methods. The importance of reliable modulation transfer function testing of imaging sensors with high uncertainty has consequently grown more difficult. In this paper we demonstrate the design of an aperture for the generation of laser speckle with a flat power spectrum covering a wide-band of the measurement spatial frequency range. This aperture allows for the measurement of modulation transfer function (MTF) from zero to twice the Nyquist frequency of a twodimensional detector array. This design mitigates many of the measurement issues inherent in other aperture designs. The MTF measurement of a charge-coupled device (CCD) detector array is used to demonstrate the measurement technique and illustrate the advantages of the new aperture design.

  7. Recent progress with multi-anode microchannel array detector systems. [for use in instruments on telescopes

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1982-01-01

    The construction and modes of operation of Multi-Anode Microchannel Arrays (MAMA's) are briefly reviewed. The MAMA detectors, which are a family of photoelectric, photon-counting array detectors being developed specifically for use in instruments on ground-based and space-borne telescopes, combine the high sensitivity and photometric stability of a conventional channel electron multiplier with a high-resolution imaging capability. The MAMA detectors feature low applied potential (less than 3 kV), high gain (greater than 10 to the 6th electrons/pulse), an absolute event timing accuracy of 100 ns or better, a very long count lifetime (greater than 2.5 x 10 to the 11th counts/sq mm), and a power consumption of less than 30 W for a complete system

  8. Charge Sharing and Charge Loss in a Cadmium-Zinc-Telluride Fine-Pixel Detector Array

    NASA Technical Reports Server (NTRS)

    Gaskin, J. A.; Sharma, D. P.; Ramsey, B. D.; Six, N. Frank (Technical Monitor)

    2002-01-01

    Because of its high atomic number, room temperature operation, low noise, and high spatial resolution a Cadmium-Zinc-Telluride (CZT) multi-pixel detector is ideal for hard x-ray astrophysical observation. As part of on-going research at MSFC (Marshall Space Flight Center) to develop multi-pixel CdZnTe detectors for this purpose, we have measured charge sharing and charge loss for a 4x4 (750micron pitch), lmm thick pixel array and modeled these results using a Monte-Carlo simulation. This model was then used to predict the amount of charge sharing for a much finer pixel array (with a 300micron pitch). Future work will enable us to compare the simulated results for the finer array to measured values.

  9. Novel Usage for a Cosmic Ray Detector: Study of Lightning at Telescope Array

    NASA Astrophysics Data System (ADS)

    Belz, John; Okuda, Takeshi

    We describe observations performed at the Telescope Array Observatory in which "bursts" of air shower triggers of the surface detector occur in close temporal and spatial coincidence with lighting. These events appear to be consistent with other observations of high-energy particle showers produced by lightning. Telescope Array has the ability to reconstruct these showers using modified UHECR air shower reconstruction techniques, and thus determine the source of particles in the atmospheric breakdown. We describe new efforts to deploy lightning mapping detectors at the Telescope Array site which will enable further study of this phenomenon, along with enabling us to search for evidence of lightning strikes being "seeded" under certain atmospheric conditions by the passage of a UHECR air shower.

  10. A 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.

  11. Large-area solid state detector for radiology using amorphous selenium

    NASA Astrophysics Data System (ADS)

    Zhao, Wei; Rowlands, John A.

    1992-06-01

    A large area self-scanned solid-state detector is being developed for digital radiology. It consists of an x-ray sensitive flat-panel employing amorphous selenium ((alpha) )-Se) as the x- ray transducer and active matrix integrated circuit for readout. In principle such detectors could be used for all the currently applied radiological modalities -- radiography, photofluorography, and fluoroscopy. Layers of (alpha) )-Se up to 500 micrometers thick are readout with an array of thin film field effect transistors. The whole structure is integrated onto a glass plate. For all practical purposes the resolution of the system is dictated by the pixel size and readout could be in real-time (i.e., 30 frames/sec).

  12. Fabrication and characterization of large arrays of mesoscopic gold rings on large-aspect-ratio cantilevers

    SciTech Connect

    Ngo, D. Q.; Petković, I. Lollo, A.; Castellanos-Beltran, M. A.; Harris, J. G. E.

    2014-10-15

    We have fabricated large arrays of mesoscopic metal rings on ultrasensitive cantilevers. The arrays are defined by electron beam lithography and contain up to 10{sup 5} rings. The rings have a circumference of 1 μm, and are made of ultrapure (6N) Au that is deposited onto a silicon-on-insulator wafer without an adhesion layer. Subsequent processing of the SOI wafer results in each array being supported at the end of a free-standing cantilever. To accommodate the large arrays while maintaining a low spring constant, the cantilevers are nearly 1 mm in both lateral dimensions and 100 nm thick. The extreme aspect ratio of the cantilevers, the large array size, and the absence of a sticking layer are intended to enable measurements of the rings' average persistent current in the presence of relatively small magnetic fields. We describe the motivation for these measurements, the fabrication of the devices, and the characterization of the cantilevers' mechanical properties. We also discuss the devices' expected performance in measurements of .

  13. Fabrication and characterization of large arrays of mesoscopic gold rings on large-aspect-ratio cantilevers.

    PubMed

    Ngo, D Q; Petković, I; Lollo, A; Castellanos-Beltran, M A; Harris, J G E

    2014-10-01

    We have fabricated large arrays of mesoscopic metal rings on ultrasensitive cantilevers. The arrays are defined by electron beam lithography and contain up to 10(5) rings. The rings have a circumference of 1 μm, and are made of ultrapure (6N) Au that is deposited onto a silicon-on-insulator wafer without an adhesion layer. Subsequent processing of the SOI wafer results in each array being supported at the end of a free-standing cantilever. To accommodate the large arrays while maintaining a low spring constant, the cantilevers are nearly 1 mm in both lateral dimensions and 100 nm thick. The extreme aspect ratio of the cantilevers, the large array size, and the absence of a sticking layer are intended to enable measurements of the rings' average persistent current ⟨I⟩ in the presence of relatively small magnetic fields. We describe the motivation for these measurements, the fabrication of the devices, and the characterization of the cantilevers' mechanical properties. We also discuss the devices' expected performance in measurements of ⟨I⟩. PMID:25362443

  14. Imaging Radio Photospheres with the Jansky Very Large Array

    NASA Astrophysics Data System (ADS)

    Matthews, L. D.; Reid, M. J.; Menten, K. M.

    2015-08-01

    Using the Jansky Very Large Array (JVLA), we have imaged the radio photosphere of the long-period variable star W Hya at 45 GHz (˜ 7 mm) with a resolution of ˜ 40 mas. Our data reveal a non-spherical photospheric shape, consistent with earlier measurements. We also find evidence for an elongation along PA ≍ -5°, the orientation of which is consistent with the previously measured projected magnetic field direction and an extension in the 18 μm dust emission, both at larger scales.

  15. Optical comparison of detector arrays from modulation transfer function measurements with laser speckle patterns

    NASA Astrophysics Data System (ADS)

    Fernández-Oliveras, Alicia; Pozo, Antonio M.; Rubiño, Manuel

    2012-04-01

    Charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) matrices offer excellent features in imaging systems. A suitability evaluation of either technology according to a specific application requires a complete characterization of the different detector types. A system is optically characterized by the modulation transfer function (MTF), which represents its response in spatial frequency of this system. One of the methods to measure the MTF uses a laser speckle pattern as the object. Here, we comparatively examine the results provided by the speckle method to determine the MTF for detectors of two types: CCD and CMOS. We generate the speckle pattern using a laser and an integrating sphere with an aperture at its exit port. The aperture determined the spatial-frequency content of the pattern registered in the detector. The precision in determining the MTF of the CCD was studied using two different apertures: a single-slit and a double-slit. For the single-slit, we propose a new procedure of fitting the experimental data which resolves the drawbacks of the conventional procedure. To study the CMOS detector, we used the single-slit because it offered lower uncertainty and better reproducibility. The differences between the MTF values of the CCD and the CMOS detectors proved significant for the spatial frequencies higher than 50 cycles/mm, which is half of the interval studied with both arrays. For these spatial frequencies, our results demonstrate that the CCD detector presented MTF values higher than those of the CMOS array.

  16. Prototype of a large neutron detector based on MWPC

    NASA Astrophysics Data System (ADS)

    Tian, LiChao; Qi, HuiRong; Sun, ZhiJia; Wang, YanFeng; Zhang, Jian; Liu, RongGuang; Zhao, YuBin; Zhang, HongYu; Zhao, DongXu; Dong, Jing; Xie, Wan; Yang, GuiAn; Ouyang, Qun; Chen, YuanBo

    2014-11-01

    A prototype of large-area position sensitive neutron detector was designed and constructed according to the requirements of the Small-Angle Scattering spectrometer of China Spallation Neutron Source (CSNS). The detector was based on the 3He neutron convertor and MWPC with an effective area of 650 mm×650 mm. A prototype was completed and tested with 55Fe X-ray.The high-pressure vessel was designed and constructed with high-strength aluminum alloy. A position resolution of about 4.6 mm×2.3 mm (FWHM) and efficiency > 65% for neutrons with wavelength of 1.8 Å was determined after the operational gas filled.

  17. 3D Dose Verification Using Tomotherapy CT Detector Array

    SciTech Connect

    Sheng Ke; Jones, Ryan; Yang Wensha; Saraiya, Siddharth; Schneider, Bernard; Chen Quan; Sobering, Geoff; Olivera, Gustavo; Read, Paul

    2012-02-01

    Purpose: To evaluate a three-dimensional dose verification method based on the exit dose using the onboard detector of tomotherapy. Methods and Materials: The study included 347 treatment fractions from 24 patients, including 10 prostate, 5 head and neck (HN), and 9 spinal stereotactic body radiation therapy (SBRT) cases. Detector sonograms were retrieved and back-projected to calculate entrance fluence, which was then forward-projected on the CT images to calculate the verification dose, which was compared with ion chamber and film measurement in the QA plans and with the planning dose in patient plans. Results: Root mean square (RMS) errors of 2.0%, 2.2%, and 2.0% were observed comparing the dose verification (DV) and the ion chamber measured point dose in the phantom plans for HN, prostate, and spinal SBRT patients, respectively. When cumulative dose in the entire treatment is considered, for HN patients, the error of the mean dose to the planning target volume (PTV) varied from 1.47% to 5.62% with a RMS error of 3.55%. For prostate patients, the error of the mean dose to the prostate target volume varied from -5.11% to 3.29%, with a RMS error of 2.49%. The RMS error of maximum doses to the bladder and the rectum were 2.34% (-4.17% to 2.61%) and 2.64% (-4.54% to 3.94%), respectively. For the nine spinal SBRT patients, the RMS error of the minimum dose to the PTV was 2.43% (-5.39% to 2.48%). The RMS error of maximum dose to the spinal cord was 1.05% (-2.86% to 0.89%). Conclusions: An excellent agreement was observed between the measurement and the verification dose. In the patient treatments, the agreement in doses to the majority of PTVs and organs at risk is within 5% for the cumulative treatment course doses. The dosimetric error strongly depends on the error in multileaf collimator leaf opening time with a sensitivity correlating to the gantry rotation period.

  18. Quantified, multi-scale X-ray fluorescence element mapping using the Maia detector array: application to mineral deposit studies

    NASA Astrophysics Data System (ADS)

    Fisher, Louise A.; Fougerouse, Denis; Cleverley, James S.; Ryan, Christopher G.; Micklethwaite, Steven; Halfpenny, Angela; Hough, Robert M.; Gee, Mary; Paterson, David; Howard, Daryl L.; Spiers, Kathryn

    2015-08-01

    The Maia large solid-angle detector array and imaging system is capable of collecting high-resolution images of up to ˜100 M pixels in size with dwell times of less than 0.2 ms per pixel and thus it is possible to document variation in textures associated with trace element chemistry by collecting quantified elemental maps of geological samples on the scale of entire thin sections in a short time frame (6-8 hr). The analysis is nondestructive and allows variation to be recognised on a centimetre scale while also recognising zonations at the micron scale.

  19. Characterization of flight detector arrays for the wide-field infrared survey explorer

    NASA Astrophysics Data System (ADS)

    Mainzer, Amy; Larsen, Mark; Stapelbroek, Maryn G.; Hogue, Henry; Garnett, James; Zandian, Majid; Mattson, Reed; Masterjohn, Stacy; Livingston, John; Lingner, Nicole; Alster, Natali; Ressler, Michael; Masci, Frank

    2008-07-01

    The Wide-field Infrared Survey Explorer is a NASA Midex mission launching in late 2009 that will survey the entire sky at 3.3, 4.7, 12, and 23 microns (PI: Ned Wright, UCLA). Its primary scientific goals are to find the nearest stars (actually most likely to be brown dwarfs) and the most luminous galaxies in the universe. WISE uses three dichroic beamsplitters to take simultaneous images in all four bands using four 1024×1024 detector arrays. The 3.3 and 4.7 micron channels use HgCdTe arrays, and the 12 and 23 micron bands employ Si:As arrays. In order to make a 1024×1024 Si:As array, a new multiplexer had to be designed and produced. The HgCdTe arrays were developed by Teledyne Imaging Systems, and the Si:As array were made by DRS. All four flight arrays have been delivered to the WISE payload contractor, Space Dynamics Laboratory. We present initial ground-based characterization results for the WISE arrays, including measurements of read noise, dark current, flat field and latent image performance, etc. These characterization data will be useful in producing the final WISE data product, an all-sky image atlas and source catalog.

  20. High-Energy Cutoff for Solar Cosmic Rays by the Data of Large Non-Standard Detectors

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, Leonty I.

    2003-07-01

    A problem of the upper energy limit for solar cosmic rays (SCR) is studied. Formerly, this limit has been estimated mostly by the data of world network of standard detectors of cosmic rays — neutron monitors, muon telescopes and ionization chambers. Recently, it became possible to use for this purpose also the data of some large non-standard detectors (Baksan Underground Scintillation telescope BUST, Extensive Air Shower (EAS) Arrays like Carp et and Andyrchy, project GRAND Array and others). Even though those detectors have been designed for resolving quite different nuclear and astrophysical problems, nevertheless, they proved to be sensible to the effects caused by powerful sporadic manifestations of the solar activity. These observations allow to advance into the energy range above 100 GeV and understand more distinctly the extreme potentialities of solar accelerators.

  1. Operation of a multiple cell array detector in plasma experiments with a heavy ion beam diagnostic

    SciTech Connect

    Goncalves, B.; Malaquias, A.; Nedzelskiy, I. S.; Pereira, L.; Silva, C.; Varandas, C.A.F.; Cabral, J.A.C.; Khrebtov, S.M.; Dreval, N.B.; Krupnik, L.I.; Hidalgo, C.; Depablos, J.

    2004-10-01

    A multiple cell array detector (MCAD) has been developed to investigate the spatial structure of plasma turbulence in fusion plasmas. This system is expected to provide simultaneous measurements of edge and core density fluctuations with both temporal and spatial resolution, extending the range and number of the sample volumes simultaneously recorded by a heavy ion beam diagnostic (HIBD). Since the detector (usually located close to the vessel wall of a plasma device) operates in a strong plasma radiation environment, the effective shielding of the detector presents a special problem. This article describes and compares the MCAD operation conditions on ISTTOK tokamak and TJ-II stellarator. Experimental results of the detector performance are presented together with the first measurements of n{sub e}{sigma}{sub eff} in the TJ-II plasmas.

  2. Speckle-based modulation transfer function measurements for comparative evaluation of CCD and CMOS detector arrays

    NASA Astrophysics Data System (ADS)

    Fernández-Oliveras, Alicia; Pozo, Antonio M.; Rubiño, Manuel

    2013-01-01

    Charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) matrices offer excellent features in imaging systems. For assessing the suitability of each technology according to the application, the complete characterization of the detector arrays becomes necessary. A system is optically characterized by the modulation transfer function (MTF). We have comparatively studied the results provided by the speckle method for detectors of two types: CCD and CMOS. To do so, we first analysed the precision in determining the MTF of the CCD using two apertures at the exit port of an integrating sphere: a single and a double-slit. For the single-slit, we propose a new procedure of fitting the experimental data which overcomes the drawbacks of the conventional procedure. Since it offered lower uncertainty and better reproducibility, the single-slit was used for the study with the CMOS detector. Significant differences were found between the MTF of the CCD and the CMOS detectors.

  3. Fabrication and characterization of cubic SrI2(Eu) scintillators for use in array detectors

    NASA Astrophysics Data System (ADS)

    Shimazoe, K.; Koyama, A.; Takahashi, H.; Sakuragi, S.; Yamasaki, Y.

    2016-02-01

    Strontium iodide (SrI2(Eu)) is a promising spectroscopic detector for use in both nuclear security and medical imaging owing to its excellent energy resolution and low internal background radiation. A cubic form is preferable when coupling with a silicon-based photosensor in order to build an array detector for use in applications such as Compton cameras. Here, cubic SrI2(Eu) crystals with 10 mm sides were fabricated and evaluated. The cubic SrI2(Eu) samples coupled to an avalanche photodiode exhibited an energy resolution of approximately 3.6% at 662 keV when using a shaping time of 3 μs. An increase in light output and an improvement of energy resolution were also observed at lower temperatures. The excellent energy resolution of these devices indicates that these crystals are promising potential detectors for use in Compton cameras and other imaging detectors.

  4. Dynamic range considerations for EUV MAMA detectors. [Extreme UV Multianode Microchannel Array

    NASA Technical Reports Server (NTRS)

    Illing, Rainer M. E.; Bybee, Richard L.; Timothy, J. G.

    1990-01-01

    The multianode microchannel array (MAMA) has been chosen as the detector for two instruments on the ESA/NASA Solar Heliospheric Observatory. The response of the MAMA to the two extreme types of solar spectra, disk and corona, have been modeled with a view toward evaluating dynamic range effects present. The method of MAMA operation is discussed, with emphasis given to modeling the effect of electron cloud charge spreading to several detector anodes and amplifiers (n-fold events). Representative synthetic EUV spectra have been created. The detector response to these spectra is modeled by dissecting the input photon radiation field across the detector array into contributions to the various amplifier channels. The results of this dissection are shown for spectral regions across the entire wavelength region of interest. These results are used to identify regions in which total array photon counting rate or individual amplifier rate may exceed the design limits. This allows the design or operational modes to be tailored to eliminate the problem areas.

  5. The performance of 2D array detectors for light sheet based fluorescence correlation spectroscopy.

    PubMed

    Singh, Anand Pratap; Krieger, Jan Wolfgang; Buchholz, Jan; Charbon, Edoardo; Langowski, Jörg; Wohland, Thorsten

    2013-04-01

    Single plane illumination microscopy based fluorescence correlation spectroscopy (SPIM-FCS) is a new method for imaging FCS in 3D samples, providing diffusion coefficients, transport, flow velocities and concentrations in an imaging mode. SPIM-FCS records correlation functions over a whole plane in a sample, which requires array detectors for recording the fluorescence signal. Several types of image sensors are suitable for FCS. They differ in properties such as effective area per pixel, quantum efficiency, noise level and read-out speed. Here we compare the performance of several low light array detectors based on three different technologies: (1) Single-photon avalanche diode (SPAD) arrays, (2) passive-pixel electron multiplying charge coupled device (EMCCD) and (3) active-pixel scientific-grade complementary metal oxide semiconductor cameras (sCMOS). We discuss the influence of the detector characteristics on the effective FCS observation volume, and demonstrate that light sheet based SPIM-FCS provides absolute diffusion coefficients. This is verified by parallel measurements with confocal FCS, single particle tracking (SPT), and the determination of concentration gradients in space and time. While EMCCD cameras have a temporal resolution in the millisecond range, sCMOS cameras and SPAD arrays can extend the time resolution of SPIM-FCS down to 10 μs or lower. PMID:23571955

  6. Characterization of Large Diameter PMTs for Kaon Cerenkov Detector

    NASA Astrophysics Data System (ADS)

    Boylan, Derek

    2014-09-01

    The 12 GeV upgrade at the Jefferson Laboratory allows for unique new opportunities to study hadron structure through kaon production in Hall C, a threshold aerogel detector was constructed at the Catholic University of America. It uses the emission of Cerenkov radiation at different indices of refraction ranging from 1.03 to 1.01 to distinguish pions, kaons, and protons. An important aspect of this detector is the collection of very small amounts of light, in particular as the aerogel refractive index decreases. The Hall C aerogel detector uses the Photonis XP4500 large-diameter photomultiplier tubes (PMT) in order to detect these small traces of light. The purpose of this project is to explore the performance of alternative large-diameter PMTs and compares them to that of the XP4500. The PMT uniformity across the photocathode was characterized through scans along the surface of the PMT with a low-intensity, focused LED, thereby creating a 3D image of the gain at each section. The method of scanning consists of a two axis step motor moving an LED light source on a 100 x 100 grid parallel to the face of the PMT, with 30 pulses of light from the LED at each step. The step motor scans with a resolution of 1.2 mm. Scans conducted in this manner result in high resolution images which pick up most sensitive/non-sensitive spots on the photocathode. In this presentation I will present the results of the characterization and performance test of the XP4500 and comparison to alternative large-diameter PMT models. The 12 GeV upgrade at the Jefferson Laboratory allows for unique new opportunities to study hadron structure through kaon production in Hall C, a threshold aerogel detector was constructed at the Catholic University of America. It uses the emission of Cerenkov radiation at different indices of refraction ranging from 1.03 to 1.01 to distinguish pions, kaons, and protons. An important aspect of this detector is the collection of very small amounts of light, in

  7. Performance of large pixelised Micromegas detectors in the COMPASS environment

    NASA Astrophysics Data System (ADS)

    Thibaud, F.; Abbon, P.; Andrieux, V.; Anfreville, M.; Bedfer, Y.; Burtin, E.; Capozza, L.; Coquelet, C.; Curiel, Q.; d'Hose, N.; Desforge, D.; Dupraz, K.; Durand, R.; Ferrero, A.; Giganon, A.; Jourde, D.; Kunne, F.; Magnon, A.; Makke, N.; Marchand, C.; Neyret, D.; Paul, B.; Platchkov, S.; Usseglio, M.; Vandenbroucke, M.

    2014-02-01

    New large-size Micromegas detectors are being developed for the future physics program of the COMPASS experiment at CERN. These detectors will have a pixelised readout in their center to detect particles in the beam region, where the particle flux can reach several MHz/cm2 in nominal conditions, and will have to handle high intensity hadron beams (up to a few 107 hadrons/s) with a discharge rate lower than 0.01 to 0.001 discharge/s. Several prototypes with two different discharge rate reduction technologies (preamplification stage with a GEM foil and resistive readout with buried resistors) have been studied in the COMPASS beam since 2010. Four of them have been included in the spectrometer since 2012, and have been used for the track reconstruction. Their performance (detection efficiency, space and time resolutions, and discharge rates) for different beam intensities and magnetic fields environments are presented. These detectors play an important role in the track reconstruction at very small angle; their impact is presented, with a particular emphasis on the effect of the background reduction due to an improved cluster selection.

  8. Compact dewar and electronics for large-format infrared detectors

    NASA Astrophysics Data System (ADS)

    Manissadjian, A.; Magli, S.; Mallet, E.; Cassaigne, P.

    2011-06-01

    Infrared systems cameras trend is to require higher performance (thanks to higher resolution) and in parallel higher compactness for easier integration in systems. The latest developments at SOFRADIR / France on HgCdTe (Mercury Cadmium Telluride / MCT) cooled IR staring detectors do show constant improvements regarding detector performances and compactness, by reducing the pixel pitch and optimizing their encapsulation. Among the latest introduced detectors, the 15μm pixel pitch JUPITER HD-TV format (1280×1024) has to deal with challenging specifications regarding dewar compactness, low power consumption and reliability. Initially introduced four years ago in a large dewar with a more than 2kg split Stirling cooler compressor, it is now available in a new versatile compact dewar that is vacuum-maintenance-free over typical 18 years mission profiles, and that can be integrated with the different available Stirling coolers: K548 microcooler for light solution (less than 0.7 kg), K549 or LSF9548 for split cooler and/or higher reliability solution. The IDDCAs are also required with simplified electrical interface enabling to shorten the system development time and to standardize the electronic boards definition with smaller volumes. Sofradir is therefore introducing MEGALINK, the new compact Command & Control Electronics compatible with most of the Sofradir IDDCAs. MEGALINK provides all necessary input biases and clocks to the FPAs, and digitizes and multiplexes the video outputs to provide a 14 bit output signal through a cameralink interface, in a surface smaller than a business card.

  9. Fabrication of Tunnel Junctions For Direct Detector Arrays With Single-Electron Transistor Readout Using Electron-Beam Lithography

    NASA Technical Reports Server (NTRS)

    Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Stahle, C. M.; Rhee, K. W.; Teufel, J.; Schoelkopf, R. J.

    2002-01-01

    This paper will describe the fabrication of small aluminum tunnel junctions for applications in astronomy. Antenna-coupled superconducting tunnel junctions with integrated single-electron transistor readout have the potential for photon-counting sensitivity at sub-millimeter wavelengths. The junctions for the detector and single-electron transistor can be made with electron-beam lithography and a standard self-aligned double-angle deposition process. However, high yield and uniformity of the junctions is required for large-format detector arrays. This paper will describe how measurement and modification of the sensitivity ratio in the resist bilayer was used to greatly improve the reliability of forming devices with uniform, sub-micron size, low-leakage junctions.

  10. Array of virtual Frisch-grid CZT detectors with common cathode readout and pulse-height correction

    SciTech Connect

    Bolotnikov, A.E.; Camarda, G.S.; Cui, Y.; Egarievwe, E.U.; Fochuk, P.M.; Fuerstnau, M.; Gul, R.; Hossain, A.; Jones, F.; Kim, K.; Kopach, O.V.; Taggart, R.; Yang, G.; Ye, Z.; Xu, L.; and James, R.B.

    2010-08-01

    We present our new results from testing 15-mm-long virtual Frisch-grid CdZnTe detectors with a common-cathode readout for correcting pulse-height distortions. The array employs parallelepiped-shaped CdZnTe (CZT) detectors of a large geometrical aspect ratio, with two planar contacts on the top and bottom surfaces (anode and cathode) and an additional shielding electrode on the crystal's sides to create the virtual Frisch-grid effect. We optimized the geometry of the device and improved its spectral response. We found that reducing to 5 mm the length of the shielding electrode placed next to the anode had no adverse effects on the device's performance. At the same time, this allowed corrections for electron loss by reading the cathode signals to obtain depth information.

  11. Lutetium oxyorthosilicate block detector readout by avalanche photodiode arrays for high resolution animal PET

    NASA Astrophysics Data System (ADS)

    Pichler, B. J.; Swann, B. K.; Rochelle, J.; Nutt, R. E.; Cherry, S. R.; Siegel, S. B.

    2004-09-01

    Avalanche photodiodes (APDs) have proven to be useful as light detectors for high resolution positron emission tomography (PET). Their compactness makes these devices excellent candidates for replacing bulky photomultiplier tubes (PMTs) in PET systems where space limitations are an issue. The readout of densely packed, 10 × 10 lutetium oxyorthosilicate (LSO) block detectors (crystal size 2.0 × 2.0 × 12 mm3) with custom-built monolithic 3 × 3 APD arrays was investigated. The APDs had a 5 × 5 mm2 active surface and were arranged on a 6.25 mm pitch. The dead space on the edges of the array was 1.25 mm. The APDs were operated at a bias voltage of approximately 380 V for a gain of 100 and a dark current of 10 nA per APD. The standard deviation in gain between the APDs in the array ranged from 1.8 to 6.5% as the gain was varied from 50 to 108. A fast, low-noise, multi-channel charge sensitive preamplifier application-specific integrated circuit (ASIC) was developed for the APD readout. The amplifier had a rise time of 8 ns, a noise floor of 515 e- rms and a 9 e- pF-1 noise slope. An acquired flood image showed that all 100 crystals from the block detector could be resolved. Timing measurements with single-channel LSO-APD detectors, as well as with the array, against a plastic scintillator and PMT assembly showed a time resolution of 1.2 ns and 2.5 ns, respectively. The energy resolution measured with a single 4.0 × 4.0 × 10 mm3 LSO crystal, wrapped in four-layer polytetrafluoroethylene (PTFE) tape and coupled with optical grease on a single APD of the array, yielded 15% (full width at half maximum, FWHM) at 511 keV. Stability tests over 9 months of operation showed that the APD arrays do not degrade appreciably. These results demonstrate the ability to decode densely packed LSO scintillation blocks with compact APD arrays. The good timing and energy resolution makes these detectors suitable for high resolution PET.

  12. A large detector for cosmic ray abundance and energy measurements

    NASA Astrophysics Data System (ADS)

    Alsop, C.

    A large aperture, balloon borne cosmic ray detector was designed to measure the energy spectra of individual cosmic ray species with Z greater than 8 in the energy range 0.3GeV/N to 400GeV/N. The energy dependence of the abundance spectrum extending up to such high energies will provide valuable data for determining the nature of the origin and propagation of cosmic rays in the Galaxy. The properties of cosmic ray nuclei and the interpretation of the energy dependence of the abundance spectrum are discussed. The design and response of the BUGS IV cosmic ray detector are described. The measurement techniques used are gas scintillation, gas proportional scintillation and Cerenkov radiation from both gases and solids. The light collection properties of the detector and several experimental investigations of the light collection efficiency of the drift chamber region are described. The expected signals from the gas scintillation and gas Cerenkov emissions are predicted and the choice of a suitable scintillating gas mixture for minimizing the uncertainty in the charge and energy measurements is considered. The theoretical aspects of electron drift and diffusion in gases and several experimental investigations on the electron drift in the BUGS IV drift chamber are given. Also some preliminary results from a uniform field drift chamber are included which demonstrate the sensitivity of the electron drift velocity in inert gas mixtures to water vapor contamination. The expected overall performance of BUGS IV and the results of an experimental simulation of the parachute landing of the detector are given.

  13. High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector

    PubMed Central

    Giewekemeyer, Klaus; Philipp, Hugh T.; Wilke, Robin N.; Aquila, Andrew; Osterhoff, Markus; Tate, Mark W.; Shanks, Katherine S.; Zozulya, Alexey V.; Salditt, Tim; Gruner, Sol M.; Mancuso, Adrian P.

    2014-01-01

    Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 108 8-keV photons pixel−1 s−1, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 1010 photons µm−2 s−1 within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while ‘still’ images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described. PMID:25178008

  14. X-ray characterization of a multichannel smart-pixel array detector.

    PubMed

    Ross, Steve; Haji-Sheikh, Michael; Huntington, Andrew; Kline, David; Lee, Adam; Li, Yuelin; Rhee, Jehyuk; Tarpley, Mary; Walko, Donald A; Westberg, Gregg; Williams, George; Zou, Haifeng; Landahl, Eric

    2016-01-01

    The Voxtel VX-798 is a prototype X-ray pixel array detector (PAD) featuring a silicon sensor photodiode array of 48 × 48 pixels, each 130 µm × 130 µm × 520 µm thick, coupled to a CMOS readout application specific integrated circuit (ASIC). The first synchrotron X-ray characterization of this detector is presented, and its ability to selectively count individual X-rays within two independent arrival time windows, a programmable energy range, and localized to a single pixel is demonstrated. During our first trial run at Argonne National Laboratory's Advance Photon Source, the detector achieved a 60 ns gating time and 700 eV full width at half-maximum energy resolution in agreement with design parameters. Each pixel of the PAD holds two independent digital counters, and the discriminator for X-ray energy features both an upper and lower threshold to window the energy of interest discarding unwanted background. This smart-pixel technology allows energy and time resolution to be set and optimized in software. It is found that the detector linearity follows an isolated dead-time model, implying that megahertz count rates should be possible in each pixel. Measurement of the line and point spread functions showed negligible spatial blurring. When combined with the timing structure of the synchrotron storage ring, it is demonstrated that the area detector can perform both picosecond time-resolved X-ray diffraction and fluorescence spectroscopy measurements. PMID:26698064

  15. Photoacoustic projection imaging using a 64-channel fiber optic detector array

    NASA Astrophysics Data System (ADS)

    Bauer-Marschallinger, Johannes; Felbermayer, Karoline; Bouchal, Klaus-Dieter; Veres, Istvan A.; Grün, Hubert; Burgholzer, Peter; Berer, Thomas

    2015-03-01

    In this work we present photoacoustic projection imaging with a 64-channel integrating line detector array, which average the pressure over cylindrical surfaces. For imaging, the line detectors are arranged parallel to each other on a cylindrical surface surrounding a specimen. Thereby, the three-dimensional imaging problem is reduced to a twodimensional problem, facilitating projection imaging. After acquisition of a dataset of pressure signals, a twodimensional photoacoustic projection image is reconstructed. The 64 channel line detector array is realized using optical fibers being part of interferometers. The parts of the interferometers used to detect the ultrasonic pressure waves consist of graded-index polymer-optical fibers (POFs), which exhibit better sensitivity than standard glass-optical fibers. Ultrasonic waves impinging on the POFs change the phase of light in the fiber-core due to the strain-optic effect. This phase shifts, representing the pressure signals, are demodulated using high-bandwidth balanced photo-detectors. The 64 detectors are optically multiplexed to 16 detection channels, thereby allowing fast imaging. Results are shown on a Rhodamine B dyed microsphere.

  16. X-ray Characterization of a Multichannel Smart-Pixel Array Detector

    SciTech Connect

    Ross, Steve; Haji-Sheikh, Michael; Huntington, Andrew; Kline, David; Lee, Adam; Li, Yuelin; Rhee, Jehyuk; Tarpley, Mary; Walko, Donald A.; Westberg, Gregg; Williams, George; Zou, Haifeng; Landahl, Eric

    2016-01-01

    The Voxtel VX-798 is a prototype X-ray pixel array detector (PAD) featuring a silicon sensor photodiode array of 48 x 48 pixels, each 130 mu m x 130 mu m x 520 mu m thick, coupled to a CMOS readout application specific integrated circuit (ASIC). The first synchrotron X-ray characterization of this detector is presented, and its ability to selectively count individual X-rays within two independent arrival time windows, a programmable energy range, and localized to a single pixel is demonstrated. During our first trial run at Argonne National Laboratory's Advance Photon Source, the detector achieved a 60 ns gating time and 700 eV full width at half-maximum energy resolution in agreement with design parameters. Each pixel of the PAD holds two independent digital counters, and the discriminator for X-ray energy features both an upper and lower threshold to window the energy of interest discarding unwanted background. This smart-pixel technology allows energy and time resolution to be set and optimized in software. It is found that the detector linearity follows an isolated dead-time model, implying that megahertz count rates should be possible in each pixel. Measurement of the line and point spread functions showed negligible spatial blurring. When combined with the timing structure of the synchrotron storage ring, it is demonstrated that the area detector can perform both picosecond time-resolved X-ray diffraction and fluorescence spectroscopy measurements.

  17. Large format focal plane array integration with precision alignment, metrology and accuracy capabilities

    NASA Astrophysics Data System (ADS)

    Neumann, Jay; Parlato, Russell; Tracy, Gregory; Randolph, Max

    2015-09-01

    Focal plane alignment for large format arrays and faster optical systems require enhanced precision methodology and stability over temperature. The increase in focal plane array size continues to drive the alignment capability. Depending on the optical system, the focal plane flatness of less than 25μm (.001") is required over transition temperatures from ambient to cooled operating temperatures. The focal plane flatness requirement must also be maintained in airborne or launch vibration environments. This paper addresses the challenge of the detector integration into the focal plane module and housing assemblies, the methodology to reduce error terms during integration and the evaluation of thermal effects. The driving factors influencing the alignment accuracy include: datum transfers, material effects over temperature, alignment stability over test, adjustment precision and traceability to NIST standard. The FPA module design and alignment methodology reduces the error terms by minimizing the measurement transfers to the housing. In the design, the proper material selection requires matched coefficient of expansion materials minimizes both the physical shift over temperature as well as lowering the stress induced into the detector. When required, the co-registration of focal planes and filters can achieve submicron relative positioning by applying precision equipment, interferometry and piezoelectric positioning stages. All measurements and characterizations maintain traceability to NIST standards. The metrology characterizes the equipment's accuracy, repeatability and precision of the measurements.

  18. Evolution of miniature detectors and focal plane arrays for infrared sensors

    NASA Technical Reports Server (NTRS)

    Watts, Louis A.

    1993-01-01

    Sensors that are sensitive in the infrared spectral region have been under continuous development since the WW2 era. A quest for the military advantage of 'seeing in the dark' has pushed thermal imaging technology toward high spatial and temporal resolution for night vision equipment, fire control, search track, and seeker 'homing' guidance sensing devices. Similarly, scientific applications have pushed spectral resolution for chemical analysis, remote sensing of earth resources, and astronomical exploration applications. As a result of these developments, focal plane arrays (FPA) are now available with sufficient sensitivity for both high spatial and narrow bandwidth spectral resolution imaging over large fields of view. Such devices combined with emerging opto-electronic developments in integrated FPA data processing techniques can yield miniature sensors capable of imaging reflected sunlight in the near IR and emitted thermal energy in the Mid-wave (MWIR) and longwave (LWIR) IR spectral regions. Robotic space sensors equipped with advanced versions of these FPA's will provide high resolution 'pictures' of their surroundings, perform remote analysis of solid, liquid, and gas matter, or selectively look for 'signatures' of specific objects. Evolutionary trends and projections of future low power micro detector FPA developments for day/night operation or use in adverse viewing conditions are presented in the following test.

  19. Results of radiation tests performed on the ISOCAM infrared detector array

    NASA Astrophysics Data System (ADS)

    Agnese, P.; Engelmann, J. J.; Mottier, P.

    1991-08-01

    Extensive radiation tests have been performed on the long-wavelength IR detector array for the ISOCAM camera, to be launched on the European ISO satellite. Transient and memory effects, induced by gamma-rays, protons, and heavy ions have been investigated. Each time a pixel is traversed by a particle, an ionization pulse is generated. The results of different deglitching techniques have been compared. Among them, the half Gauss method seems to be the best. In addition to the transient effect, a memory effect is induced by the radiation: an increase of the photoconductive gain is observed. For 2 rad, the raise in responsivity is about 60 percent. The relaxation time is the order of 1 h. The relativistic Fe ions present in cosmic rays have been simulated by Argon ions of 70 MeV/nucleon energy. These very heavily ionizing particles induce a large responsivity change, not only in the pixels directly hit by the particles, but also in their neighbors.

  20. Evolution of miniature detectors and focal plane arrays for infrared sensors

    NASA Astrophysics Data System (ADS)

    Watts, Louis A.

    1993-06-01

    Sensors that are sensitive in the infrared spectral region have been under continuous development since the WW2 era. A quest for the military advantage of 'seeing in the dark' has pushed thermal imaging technology toward high spatial and temporal resolution for night vision equipment, fire control, search track, and seeker 'homing' guidance sensing devices. Similarly, scientific applications have pushed spectral resolution for chemical analysis, remote sensing of earth resources, and astronomical exploration applications. As a result of these developments, focal plane arrays (FPA) are now available with sufficient sensitivity for both high spatial and narrow bandwidth spectral resolution imaging over large fields of view. Such devices combined with emerging opto-electronic developments in integrated FPA data processing techniques can yield miniature sensors capable of imaging reflected sunlight in the near IR and emitted thermal energy in the Mid-wave (MWIR) and longwave (LWIR) IR spectral regions. Robotic space sensors equipped with advanced versions of these FPA's will provide high resolution 'pictures' of their surroundings, perform remote analysis of solid, liquid, and gas matter, or selectively look for 'signatures' of specific objects. Evolutionary trends and projections of future low power micro detector FPA developments for day/night operation or use in adverse viewing conditions are presented in the following test.

  1. Investigation of a clinical PET detector module design that employs large-area avalanche photodetectors

    NASA Astrophysics Data System (ADS)

    Peng, Hao; Olcott, Peter D.; Spanoudaki, Virginia; Levin, Craig S.

    2011-06-01

    We investigated the feasibility of designing an Anger-logic PET detector module using large-area high-gain avalanche photodiodes (APDs) for a brain-dedicated PET/MRI system. Using Monte Carlo simulations, we systematically optimized the detector design with regard to the scintillation crystal, optical diffuser, surface treatment, layout of large-area APDs, and signal-to-noise ratio (SNR, defined as the 511 keV photopeak position divided by the standard deviation of noise floor in an energy spectrum) of the APD devices. A detector prototype was built comprising an 8 × 8 array of 2.75 × 3.00 × 20.0 mm3 LYSO (lutetium-yttrium-oxyorthosilicate) crystals and a 22.0 × 24.0 × 9.0 mm3 optical diffuser. From the four designs of the optical diffuser tested, two designs employing a slotted diffuser are able to resolve all 64 crystals within the block with good uniformity and peak-to-valley ratio. Good agreement was found between the simulation and experimental results. For the detector employing a slotted optical diffuser, the energy resolution of the global energy spectrum after normalization is 13.4 ± 0.4%. The energy resolution of individual crystals varies between 11.3 ± 0.3% and 17.3 ± 0.4%. The time resolution varies between 4.85 ± 0.04 (center crystal), 5.17 ± 0.06 (edge crystal), and 5.18 ± 0.07 ns (corner crystal). The generalized framework proposed in this work helps to guide the design of detector modules for selected PET system configurations, including scaling the design down to a preclinical PET system, scaling up to a whole-body clinical scanner, as well as replacing APDs with other novel photodetectors that have higher gain or SNR such as silicon photomultipliers.

  2. High-resolution spectroscopy with the multi-anode microchannel array detector systems

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Joseph, C. L.; Wolf, S. C.

    1982-01-01

    The results of a series of high-resolution spectroscopic observations undertaken with a linear (1 x 1024)-pixel visible-light Multi-Anode Microchannel Array (MAMA) detector on the Coudespectrograph of the 2.2-meter telescope at the Mauna Kea Observatory and on the vacuum spectrograph of the McMath Solar telescope at the Kitt Peak National Observatory are described. In addition, the two-dimensional MAMA detector systems with (16 x 1024)-pixel, (24 x 1024)-pixel, and (256 x 1024)-pixel formats which are now being readied for use in a series of ground-based, balloon, and sounding-rocket observing programs are briefly described.

  3. Calibration and monitoring of the air fluorescence detector for the Telescope Array experiment

    NASA Astrophysics Data System (ADS)

    Tokuno, H.; Azuma, R.; Fukushima, M.; Higashide, Y.; Inoue, N.; Kadota, K.; Kakimoto, F.; Kawana, S.; Murano, Y.; Ogio, S.; Sakurai, N.; Sagawa, H.; Shibata, T.; Takeda, M.; Taketa, A.; Tameda, Y.; Tsunesada, Y.; Udo, S.; Yoshida, S.; Telescope Array Collaboration

    The air fluorescence detectors (FDs) of the Telescope Array (TA) experiment have been constructed in a dessert of Utah, USA. We can measure the longitudinal developments of EASs directly with the FDs by detecting air fluorescence lights and determine the primary energies of ultra-high energy cosmic rays. In order for accurate observation and measurements of EASs, elaborate detector calibrations and monitoring systems are required. We will present the result of calibration and monitoring systems for the reflectance and curvature radius of segment mirrors, the characteristics of PMT (absolute gain, linearity, temperature dependence of gain), and the uniformity of the camera surface, etc.

  4. Dosimetric characteristics of the novel 2D ionization chamber array OCTAVIUS Detector 1500

    SciTech Connect

    Stelljes, T. S. Looe, H. K.; Chofor, N.; Poppe, B.; Harmeyer, A.; Reuter, J.; Harder, D.

    2015-04-15

    Purpose: The dosimetric properties of the OCTAVIUS Detector 1500 (OD1500) ionization chamber array (PTW-Freiburg, Freiburg, Germany) have been investigated. A comparative study was carried out with the OCTAVIUS Detector 729 and OCTAVIUS Detector 1000 SRS arrays. Methods: The OD1500 array is an air vented ionization chamber array with 1405 detectors in a 27 × 27 cm{sup 2} measurement area arranged in a checkerboard pattern with a chamber-to-chamber distance of 10 mm in each row. A sampling step width of 5 mm can be achieved by merging two measurements shifted by 5 mm, thus fulfilling the Nyquist theorem for intensity modulated dose distributions. The stability, linearity, and dose per pulse dependence were investigated using a Semiflex 31013 chamber (PTW-Freiburg, Freiburg, Germany) as a reference detector. The effective depth of measurement was determined by measuring TPR curves with the array and a Roos chamber type 31004 (PTW-Freiburg, Freiburg, Germany). Comparative output factor measurements were performed with the array, the Semiflex 31010 ionization chamber and the Diode 60012 (both PTW-Freiburg, Freiburg, Germany). The energy dependence of the OD1500 was measured by comparing the array’s readings to those of a Semiflex 31010 ionization chamber for varying mean photon energies at the depth of measurement, applying to the Semiflex chamber readings the correction factor k{sub NR} for nonreference conditions. The Gaussian lateral dose response function of a single array detector was determined by searching the convolution kernel suitable to convert the slit beam profiles measured with a Diode 60012 into those measured with the array’s central chamber. An intensity modulated dose distribution measured with the array was verified by comparing a OD1500 measurement to TPS calculations and film measurements. Results: The stability and interchamber sensitivity variation of the OD1500 array were within ±0.2% and ±0.58%, respectively. Dose linearity was within 1

  5. Large-area nanogap plasmon resonator arrays for plasmonics applications

    NASA Astrophysics Data System (ADS)

    Jin, Mingliang; van Wolferen, Henk; Wormeester, Herbert; van den Berg, Albert; Carlen, Edwin T.

    2012-07-01

    Large-area (~8000 mm2) Au nanogap plasmon resonator array substrates manufactured using maskless laser interference lithography (LIL) with high uniformity are presented. The periodically spaced subwavelength nanogap arrays are formed between adjacent nanopyramid (NPy) structures with precisely defined pitch and high length density (~1 km cm-2), and are ideally suited as scattering sites for surface enhanced Raman scattering (SERS), as well as refractive index sensing. The two-dimensional grid arrangement of NPy structures renders the excitation of the plasmon resonators minimally dependent on the incident polarization. The SERS average enhancement factor (AEF) has been characterized using over 30 000 individual measurements of benzenethiol (BT) chemisorbed on the Au NPy surfaces. From the 1(a1), βCCC + νCS ring mode (1074 cm-1) of BT on surfaces with pitch λg = 200 nm, AEF = 0.8 × 106 and for surfaces with λg = 500 nm, AEF = 0.3 × 107 from over 99% of the imaged spots. Maximum AEFs > 108 have been measured in both cases.

  6. Weather response to a large wind turbine array

    NASA Astrophysics Data System (ADS)

    Barrie, D. B.; Kirk-Davidoff, D. B.

    2010-01-01

    Electrical generation by wind turbines is increasing rapidly, and has been projected to satisfy 15% of world electric demand by 2030. The extensive installation of wind farms would alter surface roughness and significantly impact the atmospheric circulation due to the additional surface roughness forcing. This forcing could be changed deliberately by adjusting the attitude of the turbine blades with respect to the wind, which would enable the "management" of a large array of wind turbines. Using a General Circulation Model (GCM), we represent a continent-scale wind farm as a distributed array of surface roughness elements. Here we show that initial disturbances caused by a step change in roughness grow within four and a half days such that the flow is altered at synoptic scales. The growth rate of the induced perturbations is largest in regions of high atmospheric instability. For a roughness change imposed over North America, the induced perturbations involve substantial changes in the track and development of cyclones over the North Atlantic, and the magnitude of the perturbations rises above the level of forecast uncertainty.

  7. Development of cryogenic installations for large liquid argon neutrino detectors

    NASA Astrophysics Data System (ADS)

    Adamowski, M.; Bremer, J.; Geynisman, M.; Hentschel, S.; Montanari, D.; Nessi, M.; Norris, B.

    2015-12-01

    A proposal for a very large liquid argon (68,000 kg) based neutrino detector is being studied. To validate the design principles and the detector technology, and to gain experience in the development of the cryostats and the cryogenic systems needed for such large experiments, several smaller scale installations will be developed and implemented, at Fermilab and CERN. The cryogenic systems for these installations will be developed, constructed, installed and commissioned by an international engineering team. These installations shall bring the required cooling power under specific conditions to the experiments for the initial cool-down and the long term operation, and shall also guarantee the correct distribution of the cooling power within the cryostats to ensure a homogeneous temperature distribution within the cryostat itself. The cryogenic systems shall also include gaseous and liquid phase argon purification devices to be used to reach and maintain the very stringent purity requirements needed for these installations (parts per trillion of oxygen equivalent contamination). This paper gives an overview of the installations involved in these cryogenic projects, describes the functional demands made to these cryogenic systems and presents the initial studies on which these future cryogenic systems will be based.

  8. Focal Plane Array Shutter Mechanism of the JWST NIRSpec Detector System

    NASA Technical Reports Server (NTRS)

    Hale, Kathleen; Sharma, Rajeev

    2006-01-01

    This viewgraph presentation reviews the requirements, chamber location, shutter system design, stepper motor specifications, dry lubrication, control system, the environmental cryogenic function testing and the test results of the Focal Plane Array Shutter mechanism for the James Webb Space Telescope Near Infrared Spectrum Detector system. Included are design views of the location for the Shutter Mechanism, lubricant (lubricated with Molybdenum Di Sulfide) thickness, and information gained from the cryogenic testing.

  9. Direct Assembly of Large Arrays of Oriented Conducting Polymer Nanowires

    SciTech Connect

    Liang, Liang; Liu, Jun; Windisch, Charles F.; Exarhos, Gregory J.; Lin, Yuehe

    2002-10-04

    Although oriented carbon nanotubes, oriented nanowires of metals, semiconductors and oxides have attracted wide attention, there have been few reports on oriented polymer nanostructures such as nanowires. In this paper we report the assembly of large arrays of oriented nanowires through controlled nucleation and growth during a stepwise electrochemical deposition process in which a large number of nuclei were first deposited on the substrate using a large current density. After the initial nucleation, the current density was reduced step by step to grow the oriented nanowires from the nucleation sites created in the first step. A very different morphology was also demonstrated by first depositing a monolayer of close-packed colloidal spheres using a similar step-wise deposition process. As a result, the polymer nanofibers grew from the spheres in a radial fashion and formed the continuous three-dimensional network of nanofibers in the film. The principles of control nucleation and growth in electrochemical deposition investigated in this paper should be applicable to other electrical conducting and electrochemical active materials, including metals and conducting oxides. We also hope the oriented electroactive polymer nanostructure will open the door for new applications, such as miniaturized biosensors.

  10. Super-resolution x-ray imaging by CdTe discrete detector arrays

    NASA Astrophysics Data System (ADS)

    Aoki, T.; Ishida, Y.; Morii, H.; Tomita, Y.; Ohashi, G.; Temmyo, J.; Hatanaka, Y.

    2005-08-01

    512-pixel CdTe super-liner imaging scanner was developed. This device was consist with 512 chips of M-π-n CdTe diode detector fabricated by excimer laser doping process, 8 chips of photon-counting mode 64ch ASIC with FPGA circuit, USB2.0 interface with 1-CPU. It has 5 discriminated levels and over 2Mcps count rate for X-ray penetration imaging. This imaging scanner has 512 discrete CdTe chips for detector arrays with the length of 2.0mm, width of 0.8mm and thickness of 0.5mm. These chips were mounted in four plover array rows for high-resolution imaging with 0.5mm-pitch, therefore the pixel pitch was over the pixel width. When images were taken with scanning system with this arrays, we could obtain over-resolution than pixel width. In this paper, this "over-resolution" imaging will be called "super resolution imaging". In high-resolution imaging device, the pixel devices on one substrate were formed by integrated process, or many discrete detector chips were installed on circuit board, usually. In the latter case, it is easer to make each detector chips than former case, and it are no need to consider charge sharing phenomena compare with one-chip pixel devices. However, a decrease in pixel pitch makes the mount to the detector chip to the ASIC board difficult because the handling will also be difficult The super-resolution technique in this scanner by pixel-shift method for X-ray imaging is shown in this paper

  11. A large area cosmic muon detector located at Ohya stone mine

    NASA Technical Reports Server (NTRS)

    Nii, N.; Mizutani, K.; Aoki, T.; Kitamura, T.; Mitsui, K.; Matsuno, S.; Muraki, Y.; Ohashi, Y.; Okada, A.; Kamiya, Y.

    1985-01-01

    The chemical composition of the primary cosmic rays between 10 to the 15th power eV and 10 to the 18th power eV were determined by a Large Area Cosmic Muon Detector located at Ohya stone mine. The experimental aims of Ohya project are; (1) search for the ultra high-energy gamma-rays; (2) search for the GUT monopole created by Big Bang; and (3) search for the muon bundle. A large number of muon chambers were installed at the shallow underground near Nikko (approx. 100 Km north of Tokyo, situated at Ohya-town, Utsunomiya-city). At the surface of the mine, very fast 100 channel scintillation counters were equipped in order to measure the direction of air showers. These air shower arrays were operated at the same time, together with the underground muon chamber.

  12. Investigation of Very Fast Light Detectors: Silicon Photomultiplier and Micro PMT for a Cosmic Ray Array

    NASA Astrophysics Data System (ADS)

    Cervantes, Omar; Reyes, Liliana; Hooks, Tyler; Perez, Luis; Ritt, Stefan

    2016-03-01

    To construct a cosmic detector array using 4 scintillation detectors, we investigated 2 recent light sensor technologies from Hamamatsu, as possible readout detectors. First, we investigated several homemade versions of the multipixel photon counter (MPPC) light sensors. These detectors were either biased with internal or external high voltage power supplies. We made extensive measurements to confirm for the coincidence of the MPPC devices. Each sensor is coupled to a wavelength shifting fiber (WSF) that is embedded along a plastic scintillator sheet (30cmx60cmx1/4''). Using energetic cosmic rays, we evaluated several of these homemade detector modules placed above one another in a light proof enclosure. Next, we assembled 2 miniaturized micro photomultiplier (micro PMT), a device recently marketed by Hamamatsu. These sensors showed very fast response times. With 3 WSF embedded in scintillator sheets, we performed coincidence experiments. The detector waveforms were captured using the 5GS/sec domino ring sampler, the DRS4 and our workflow using the CERN PAW package and data analysis results would be presented. Title V Grant.

  13. Lung counting: Comparison of a four detector array that has either metal or carbon fiber end caps, and the effect on array performance characteristics

    NASA Astrophysics Data System (ADS)

    Sabbir Ahmed, Asm; H. Kramer, Gary

    2011-12-01

    This study described the performance of an array of HPGe detectors, made by ORTEC. In the existing system, a metal end cap was used in the detector construction. In general, the natural metal contains some radioactive materials, create high background noises and signals during in vivo counting. ORTEC proposed a novel carbon fiber to be used in end cap, without any radio active content. This paper described the methodology of developing a model of the given HPGe array-detectors, comparing the detection efficiency and cross talk among the detectors using two end cap materials: either metal or carbon fiber and to provide a recommendation about the end cap material. The detector's counting efficiency were studied using point and plane sources. The cross talk among the array detectors were studied using a homogeneous attenuating medium made of tissue equivalent material. The cross talk was significant when single or multiple point sources (simulated to heterogeneous hot spots) were embedded inside the attenuating medium. With carbon fiber, the cross talk increased about 100% for photon energy at about 100 keV. For a uniform distribution of radioactive material, the cross talk increased about 5-10% when the end cap was made of carbon instead of steel. Metal end cap was recommended for the array of HPGe detectors.

  14. Numerical Simulation of the Modulation Transfer Function in HgCdTe Detector Arrays

    NASA Astrophysics Data System (ADS)

    Pinkie, Benjamin; Bellotti, Enrico

    2014-08-01

    In this work, we develop a method for simulating the modulation transfer function (MTF) of infrared detector arrays, which is based on numerical evaluation of the detector physics. The finite-difference time-domain and finite element methods are used to solve the electromagnetic and electrical equations for the device, respectively. We show how the total MTF can be deconvolved to examine the effects of specific physical processes. We introduce the MTF area difference and use it to quantify the effectiveness of several crosstalk mitigation techniques in improving the system MTF. We then apply our simulation methods to two-thirds generation mercury cadmium telluride (HgCdTe) detector architectures. The methodology is general, can be implemented with commercially available software, has experimentally realizable analogs, and is extendable to other material systems and device designs.

  15. Development of arrays of Silicon Drift Detectors and readout ASIC for the SIDDHARTA experiment

    NASA Astrophysics Data System (ADS)

    Quaglia, R.; Schembari, F.; Bellotti, G.; Butt, A. D.; Fiorini, C.; Bombelli, L.; Giacomini, G.; Ficorella, F.; Piemonte, C.; Zorzi, N.

    2016-07-01

    This work deals with the development of new Silicon Drift Detectors (SDDs) and readout electronics for the upgrade of the SIDDHARTA experiment. The detector is based on a SDDs array organized in a 4×2 format with each SDD square shaped with 64 mm2 (8×8) active area. The total active area of the array is therefore 32×16 mm2 while the total area of the detector (including 1 mm border dead area) is 34 × 18mm2. The SIDDHARTA apparatus requires 48 of these modules that are designed and manufactured by Fondazione Bruno Kessler (FBK). The readout electronics is composed by CMOS preamplifiers (CUBEs) and by the new SFERA (SDDs Front-End Readout ASIC) circuit. SFERA is a 16-channels readout ASIC designed in a 0.35 μm CMOS technology, which features in each single readout channel a high order shaping amplifier (9th order Semi-Gaussian complex-conjugate poles) and a high efficiency pile-up rejection logic. The outputs of the channels are connected to an analog multiplexer for the external analog to digital conversion. An on-chip 12-bit SAR ADC is also included. Preliminary measurements of the detectors in the single SDD format are reported. Also measurements of low X-ray energies are reported in order to prove the possible extension to the soft X-ray range.

  16. Mercuric iodide room-temperature array detectors for gamma-ray imaging

    SciTech Connect

    Patt, B.

    1994-11-15

    Significant progress has been made recently in the development of mercuric iodide detector arrays for gamma-ray imaging, making real the possibility of constructing high-performance small, light-weight, portable gamma-ray imaging systems. New techniques have been applied in detector fabrication and then low noise electronics which have produced pixel arrays with high-energy resolution, high spatial resolution, high gamma stopping efficiency. Measurements of the energy resolution capability have been made on a 19-element protypical array. Pixel energy resolutions of 2.98% fwhm and 3.88% fwhm were obtained at 59 keV (241-Am) and 140-keV (99m-Tc), respectively. The pixel spectra for a 14-element section of the data is shown together with the composition of the overlapped individual pixel spectra. These techniques are now being applied to fabricate much larger arrays with thousands of pixels. Extension of these principles to imaging scenarios involving gamma-ray energies up to several hundred keV is also possible. This would enable imaging of the 208 keV and 375-414 keV 239-Pu and 240-Pu structures, as well as the 186 keV line of 235-U.

  17. Gamma-ray multiplicity measurement of the spontaneous fission decay of 252Cf in a segmented HPGe/BGO detector array

    SciTech Connect

    Bleuel, D L; Bernstein, L A; Burke, J T; Gibelin, J; Heffner, M D; Mintz, J; Norman, E B; Phair, L; Scielzo, N D; Sheets, S A; Snyderman, N J; Stoyer, M A; Wiedeking, M

    2008-04-23

    Coincident {gamma} rays from a {sup 252}Cf source were measured using an array of six segmented high-purity germanium (HPGe) Clover detectors each enclosed by 16 bismuth-germanate (BGO) detectors. The detectors were arranged in a cubic pattern around a 1 {micro}Ci {sup 252}Cf source to cover a large solid angle for {gamma}-ray measurement with a reasonable reconstruction of the multiplicity. Neutron multiplicity was determined in certain cases by identifying the prompt {gamma} rays from individual fission fragment pairs. Multiplicity distributions from previous experiments and theoretical models were convolved with the response function of the array and compared to the present results. These results suggest a {gamma}-ray multiplicity spectrum broader than previous measurements and models, and provide no evidence of correlation with neutron multiplicity.

  18. Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

    NASA Technical Reports Server (NTRS)

    Chervenak, J. A.; Adams, J. A.; Bandler, S. B.; Busch, S. E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, J. P.; Porter, F. S.; Ray, C.; Sadleir, J. E.; Smith, S. J.; Wassell, E. J.

    2012-01-01

    We have produced a variety of superconducting transition edge sensor array designs for microcalorimetric detection of x-rays. Arrays are characterized with a time division SQUID multiplexer such that greater than 10 devices from an array can be measured in the same cooldown. Designs include kilo pixel scale arrays of relatively small sensors (-75 micron pitch) atop a thick metal heatsinking layer as well as arrays of membrane-isolated devices on 250 micron and up to 600 micron pitch. We discuss fabrication and performance of microstripline wiring at the small scales achieved to date. We also address fabrication issues with reduction of absorber contact area in small devices.

  19. Performance of charge-injection-device infrared detector arrays at low and moderate backgrounds

    NASA Technical Reports Server (NTRS)

    Mckelvey, M. E.; Mccreight, C. R.; Goebel, J. H.; Reeves, A. A.

    1985-01-01

    Three 2 x 64 element charge injection device infrared detector arrays were tested at low and moderate background to evaluate their usefulness for space based astronomical observations. Testing was conducted both in the laboratory and in ground based telescope observations. The devices showed an average readout noise level below 200 equivalent electrons, a peak responsivity of 4 A/W, and a noise equivalent power of 3x10 sq root of W/Hz. Array well capacity was measured to be significantly smaller than predicted. The measured sensitivity, which compares well with that of nonintegrating discrete extrinsic silicon photoconductors, shows these arrays to be useful for certain astronomical observations. However, the measured readout efficiency and frequency response represent serious limitations in low background applications.

  20. Experimental study of double-{beta} decay modes using a CdZnTe detector array

    SciTech Connect

    Dawson, J. V.; Goessling, C.; Koettig, T.; Muenstermann, D.; Rajek, S.; Schulz, O.; Janutta, B.; Zuber, K.; Junker, M.; Reeve, C.; Wilson, J. R.

    2009-08-15

    An array of sixteen 1 cm{sup 3} CdZnTe semiconductor detectors was operated at the Gran Sasso Underground Laboratory (LNGS) to further investigate the feasibility of double-{beta} decay searches with such devices. As one of the double-{beta} decay experiments with the highest granularity the 4x4 array accumulated an overall exposure of 18 kg days. The setup and performance of the array is described. Half-life limits for various double-{beta} decay modes of Cd, Zn, and Te isotopes are obtained. No signal has been found, but several limits beyond 10{sup 20} years have been performed. They are an order of magnitude better than those obtained with this technology before and comparable to most other experimental approaches for the isotopes under investigation. An improved limit for the {beta}{sup +}/EC decay of {sup 120}Te is given.

  1. Detector arrays for photometric measurements at soft X-ray, ultraviolet and visible wavelengths

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    The construction and modes of operation of the Multi-Anode Microchannel Array (MAMA) detectors are described, and the designs of spectrometers utilizing them are outlined. MAMA consists of a curved microchannel array plate, an opaque photocathode (peak quantum efficiency of 19% at 1216 A), and a multi-anode (either discrete- or coincidence-anode) readout array. Designed for use in instruments on spaceborne telescopes, MAMA can be operated in a windowless configuration in extreme-ultraviolet and soft X-ray wavelengths, or in a sealed configuration at UV and visible wavelengths. Advantages of MAMA include low applied potential (less than 3.0 kV), high gain (greater than 10 to the 6th electrons/pulse), low sensitivity to high-energy charged particles, and immunity to external magnetic fields of less than 500 Gauss

  2. Crown detectors arrays to observe horizontal and upward air-showers

    NASA Astrophysics Data System (ADS)

    Fargion, D.; Grossi, M.; De Santis, M.; De Sanctis Lucentini, P. G.; Iori, M.; Sergi, A.; Moscato, F.

    Terrestrial Cerenkov Telescopes at tens GeV gamma energy and Scintillators set on a Crown-like array facing the Horizons may reveal far Cosmic Rays Showers or nearer PeVs Neutrino ν-e→W- shower in air as well as up-going ντ + N → τ + X, τ → Earth-Skimming tau air-showers. Even UHE SUSY χo+e→e˜→χo+e at tens PeVs-EeV energy may blaze at Horizons, as ν-e→W- shower. We show first estimate on down- and up-going Horizontal Showers traces for present and future Magic-like Crown Arrays and their correlated Scintillator-like twin Crown Arrays. The one mono- or stereo-Magic elements facing the Horizons are already comparable to present Amanda underground neutrino detector.

  3. Design and Fabrication of Microwave Kinetic Inductance Detectors using NbN Symmetric Spiral Resonator Array

    NASA Astrophysics Data System (ADS)

    Hayashi, K.; Saito, A.; Ogawa, Y.; Murata, M.; Sawada, T.; Nakajima, K.; Yamada, H.; Ariyoshi, S.; Taino, T.; Tanoue, H.; Otani, C.; Ohshima, S.

    2014-05-01

    We designed and fabricated a microwave kinetic inductance detector (MKID) using a niobium nitride (NbN) symmetric spiral resonator array. Previously we revealed that a rewound spiral structure works as not only a high-Q half-wavelength resonator but also as a broadband terahertz antenna. We conducted simulations for a 9 resonator array assuming NbN as the superconducting material and sapphire as the dielectric substrate, and obtained a maximum attenuation of over 30 dB and unloaded quality factors of over 2×105 for frequencies between 4.4 and 4.9 GHz. We fabricated the 9 resonator array MKID using NbN thin film deposited on an m-sapphire substrate by using dc magnetron sputtering. We observed half-wavelength resonances of around 4.5 GHz at 4 K. We measured the optical response of the MKID. The frequency shift was 0.5 MHz when illuminated with 650 nm photons.

  4. Microelectrode Arrays with Overlapped Diffusion Layers as Electroanalytical Detectors: Theory and Basic Applications

    PubMed Central

    Tomčík, Peter

    2013-01-01

    This contribution contains a survey of basic literature dealing with arrays of microelectrodes with overlapping diffusion layers as prospective tools in contemporary electrochemistry. Photolithographic thin layer technology allows the fabrication of sensors of micrometric dimensions separated with a very small gap. This fact allows the diffusion layers of single microelectrodes to overlap as members of the array. Various basic types of microelectrode arrays with interacting diffusion layers are described and their analytical abilities are accented. Theoretical approaches to diffusion layer overlapping and the consequences of close constitution effects such as collection efficiency and redox cycling are discussed. Examples of basis applications in electroanalytical chemistry such as amperometric detectors in HPLC and substitutional stripping voltammetry are also given. PMID:24152927

  5. Defect density reduction in InAs/GaSb type II superlattice focal plane array infrared detectors

    NASA Astrophysics Data System (ADS)

    Walther, Martin; Rehm, Robert; Schmitz, Johannes; Niemasz, Jasmin; Rutz, Frank; Wörl, Andreas; Kirste, Lutz; Scheibner, Ralf; Wendler, Joachim; Ziegler, Johann

    2011-01-01

    InAs/GaSb short-period superlattices (SL) have proven their large potential for high performance focal plane array infrared detectors. Lots of interest is focused on the development of short-period InAs/GaSb SLs for mono- and bispectral infrared detectors between 3 - 30 μm. InAs/GaSb short-period superlattices can be fabricated with up to 1000 periods in the intrinsic region without revealing diffusion limited behavior. This enables the fabrication of InAs/GaSb SL camera systems with very high responsivity, comparable to state of the art CdHgTe and InSb detectors. The material system is also well suited for the fabrication of dual-color mid-wavelength infrared InAs/GaSb SL camera systems. These systems exhibit high quantum efficiency and offer simultaneous and spatially coincident detection in both spectral channels. An essential point for the performance of two-dimensional focal plane infrared detectors in camera systems is the number of defective pixel on the matrix detector. Sources for pixel outages are manifold and might be caused by the dislocation in the substrate, the epitaxial growth process or by imperfections during the focal plane array fabrication process. The goal is to grow defect-free epitaxial layers on a dislocation free large area GaSb substrate. Permanent improvement of the substrate quality and the development of techniques to monitor the substrate quality are of particular importance. To examine the crystalline quality of 3" and 4" GaSb substrates, synchrotron white beam X-ray topography (SWBXRT) was employed. In a comparative defect study of different 3" GaSb and 4" GaSb substrates, a significant reduction of the dislocation density caused by improvements in bulk crystal growth has been obtained. Optical characterization techniques for defect characterization after MBE growth are employed to correlate epitaxially grown defects with the detector performance after hybridization with the read-out integrated circuit.

  6. A large area detector for x-ray applications

    SciTech Connect

    Rodricks, B.; Huang, Qiang; Hopf, R.; Wang, Kemei

    1993-10-01

    A large area detector for x-ray synchrotron applications has been developed. The front end of this device consist of a scintillator coupled to a fiber-optic taper. The fiber-optic taper is comprised of 4 smaller (70 mm x 70 mm) tapers fused together in a square matrix giving an active area of 140 mm x 140 mm. Each taper has a demagnification of 5.5 resulting in four small ends that are 12 mm diagonally across. The small ends of each taper are coupled to four microchannel-plate-based image intensifiers. The output from each image intensifier is focused onto a Charge Coupled Device (CCD) detector. The four CCDs are read out in parallel and are independently controlled. The image intensifiers also act as fast (20 ns) electronic shutters. The system is capable of displaying images in real time. Additionally, with independent control on the readout of each row of data from the CCD, the system is capable of performing high speed imaging through novel readout manipulation.

  7. Low-flux measurements with Cornell's LCLS integrating pixel array detector

    NASA Astrophysics Data System (ADS)

    Philipp, Hugh T.; Tate, Mark W.; Gruner, Sol M.

    2011-11-01

    Next generation light sources are revolutionizing x-ray science by delivering ultra-intense, hard x-ray pulses many orders of magnitude brighter and shorter in duration than previously achievable. Maximizing the scientific potential of these light sources requires the development of suitable detectors. Experiments such as coherent x-ray imaging of single particles require detectors that can record extremely high instantaneous flux rates produced by femtosecond x-ray pulses (i.e. thousands of photons incident on a single pixel of an area detector in a few femtoseconds) while also being able to accurately distinguish single photon events so that many thousands of frames of data can be used to reconstruct extremely low flux information (e.g. less than 1/1000 photons per pixel per frame). This paper presents data from an integrating pixel array detector (PAD) possessing the ability to record high- and low-flux x-ray data at an X-ray Free Electron Laser (XFEL). Methods are presented to process extremely low-flux data (less than 1/10000 8-keV x-rays per pixel per frame) to accurately recover diffraction patterns from thousands of frames. The data were collected using a detector developed by Cornell for the Linac Coherent Light Source (LCLS) at SLAC National Lab. A copy of this detector was delivered to SLAC in the middle of 2008. The ASIC developed for this detector was used by SLAC as the basis for the CS-PAD (Cornell SLAC-PAD) being used on the Coherent X-ray Imaging beamline at the LCLS. These methods extend beyond XFEL applications because they allow for the suppression of dark accumulation noise which typically limits the low-flux capability of integrating detectors on conventional x-ray sources.

  8. Foreground Characterization for the Murchison Widefield Array Using the Jansky Very Large Array

    NASA Astrophysics Data System (ADS)

    Busch, Michael P.; Bowman, Judd D.; Kittiwisit, Piyanat; Jacobs, Danny

    2016-01-01

    One of the most compelling questions in astrophysics today is how the process of galaxy formation unfolded during the Epoch of Reionization (EoR). A new generation of radio telescopes, including the Murchison Widefield Array (MWA) and others, are attempting to capture the redshifted 21cm signal from neutral hydrogen during the EoR. Mapping the reionization of the intergalactic medium (IGM) is one of the core objectives of 21 cm observatories. A pressing concern of these observations is the bright foreground sources in the telescope's sidelobes outside the primary beam of the MWA. These sources, including AGN, radio galaxies and local Galactic sources, are numerous and difficult to deal with. These foreground contaminants are five orders of magnitude brighter than the redshifted 21 cm emission expected from the IGM during the EoR. The Jansky Very Large Array (JVLA) in New Mexico can provide sensitive characterization of these sources in the MWA's northern sidelobe. We observed 100 bright radio sources using the JVLA in P-band and characterized these sources by extracting the spectral fits and fluxes for each source. By creating a foreground model for these data, the MWA will be able to better subtract these sources from future EoR measurements. We report the current status of the creation of the foreground model.

  9. Progress Towards High-Sensitivity Arrays of Detectors of Sub-mm Radiation using Superconducting Tunnel Junctions with Radio-Frequency Single-Electron Transistors

    NASA Technical Reports Server (NTRS)

    Stevenson, T. R.; Hsieh, W.-T.; Li, M. J.; Stahle, C. M.; Wollack, E. J.; Schoelkopf, R. J.; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The science drivers for the SPIRIT/SPECS missions demand sensitive, fast, compact, low-power, large-format detector arrays for high resolution imaging and spectroscopy in the far infrared and submillimeter. Detector arrays with 10,000 pixels and sensitivity less than 10(exp 20)-20 W/Hz(exp 20)0.5 are needed. Antenna-coupled superconducting tunnel junction detectors with integrated rf single-electron transistor readout amplifiers have the potential for achieving this high level of sensitivity, and can take advantage of an rf multiplexing technique when forming arrays. The device consists of an antenna structure to couple radiation into a small superconducting volume and cause quasiparticle excitations, and a single-electron transistor to measure currents through tunnel junction contacts to the absorber volume. We will describe optimization of device parameters, and recent results on fabrication techniques for producing devices with high yield for detector arrays. We will also present modeling of expected saturation power levels, antenna coupling, and rf multiplexing schemes.

  10. Real-time scintillation array dosimetry for radiotherapy: The advantages of photomultiplier detectors

    SciTech Connect

    Liu, Paul Z. Y.; Suchowerska, Natalka; Abolfathi, Peter; McKenzie, David R.

    2012-04-15

    Purpose: In this paper, a photomultiplier tube (PMT) array dosimetry system has been developed and tested for the real-time readout of multiple scintillation signals from fiber optic dosimeters. It provides array dosimetry with the advantages in sensitivity provided by a PMT, but without the need for a separate PMT for each detector element. Methods: The PMT array system consisted of a multianode PMT, a multichannel data acquisition system, housing and optic fiber connections suitable for clinical use. The reproducibility, channel uniformity, channel crosstalk, acquisition speed, and sensitivity of the PMT array were quantified using a constant light source. Its performance was compared to other readout systems used in scintillation dosimetry. An in vivo HDR brachytherapy treatment was used as an example of a clinical application of the dosimetry system to the measurement of dose at multiple sites in the rectum. The PMT array system was also tested in the pulsed beam of a linear accelerator to test its response speed and its application with two separate methods of Cerenkov background removal. Results: The PMT array dosimetry system was highly reproducible with a measurement uncertainty of 0.13% for a 10 s acquisition period. Optical crosstalk between neighboring channels was accounted for by omitting every second channel. A mathematical procedure was used to account for the crosstalk in next-neighbor channels. The speed and sensitivity of the PMT array system were found be superior to CCD cameras, allowing for measurement of more rapid changes in dose rate. This was further demonstrated by measuring the dose delivered by individual photon pulses of a linear accelerator beam. Conclusions: The PMT array system has advantages over CCD camera-based systems for the readout of scintillation light. It provided a more sensitive, more accurate, and faster response to meet the demands of future developments in treatment delivery.

  11. Large area detector based computed tomography system for production nondestructive evaluation.

    SciTech Connect

    Keating, S. C.; Davis, A. A.; Claytor, T. N.

    2001-01-01

    We present a system for industrial x-ray computed tomography that has been optimized for all phases of nondestructive component inspection. Data acquisition is greatly enhanced by the use of high resolution, large area, flat-panel amorphous-silicon detectors. The detectors have proven, over several years, to be a robust alternative to CCD-optics and image intensifier CT systems. In addition to robustness, these detectors provide the advantage of area detection as compared with the single slice geometry of linear array systems. Parallel processing provides significant speed improvements for data reconstruction, and is implemented for parallel-beam, fan-beam and Feldkamp conebeam reconstruction algorithms. By clustering ten or more equal-speed computers, reconstruction times are reduced by an order of magnitude. We have also developed interactive software for visualization and interrogation of the full three-dimensional dataset. Inspection examples presented in this paper include an electro-mechanical device, nonliving biological specimens and a turbo-machinery component. We also present examples of everyday items for the benefit of the layperson.

  12. Early operating experience with large-area germanium detectors for detecting low-energy photons

    SciTech Connect

    Rieksts, G.A.; Lynch, T.P.; Olsen, P.C.

    1994-11-01

    Intrinsic germanium (Ge) planar detector arrays have been used at Hanford for lung counting since 1983. This paper describes a counting system using an array of only four detectors, larger than those used in the past, using larger dewars and a simplified detector-positioning system. Typical detector elements have been 51 mm in diameter and 20 mm thick, with a beryllium window thickness of 0.51 mm. The resolution of the detectors has been about 560 eV for 6.4-keV x-rays and 700 eV for 122-keV gamma rays. In the past, arrays of three, four, five, and six detectors have been employed. Six detectors have been the preferred configuration for lung counting. Up to 3,000 counts annually have been performed with these systems. When detectors fail and spares are not available, calibrations and calculational algorithms are maintained for four-detector configurations. For several years, both ``bucket`` and ``stovepipe`` designs have been used for the Dewars with the 15-liter dewars proving to be much more reliable than the ``stovepipe`` designs.

  13. A three dimensionally position sensitive large area detector

    NASA Astrophysics Data System (ADS)

    Pochodzalla, J.; Butsch, R.; Heck, B.; Hlawatsch, G.; Miczaika, A.; Rabe, H. J.; Rosner, G.

    1985-01-01

    A large area detector consisting of a parallel plate avalanche counter (PPAC) and a trapezohedral ionization chamber (TIC) is described. Its active area is 184 cm 2. The time resolution of the PPAC is 175 ps. The energy resolution of the TIC is 0.4%, the energy loss resolution 2.8%, the nuclear charge resolution 2.3%. The TIC is position sensitive in three dimensions. The position x is measured via a saw-tooth anode with a resolution of 0.7 mm; the drift time coordinate shows a resolution of δy ≅ mm. The range z is determined by a new technique, a graded density Frisch grid. It enlarges the dynamic range of the charge measurement down to the Bragg maximum at E/ A ˜ 1 MeV. The resolution is δZ/ Z ≅ 3.5%

  14. Development of a TES based Cryo-Anticoincidence for a large array of microcalorimeters

    SciTech Connect

    Colasanti, L.; Macculi, C.; Piro, L.; Natalucci, L.; Gatti, F.; Ferrari, L.; Mineo, T.; Perinati, E.; Torrioli, G.; Bastia, P.; Barbera, M.

    2009-12-16

    The employment of large arrays of microcalorimeters in space missions (IXO, EDGE/XENIA), requires the presence of an anticoincidence detector to remove the background due to the particles, with a rejection efficiency at least equal to Suzaku (98%). A new concept of anticoincidence is under development to match the very tight thermal requirements and to simplify the design of the electronic chain. The idea is to produce a Cryo-AntiCoincidence (Cryo-AC) based on a silicon absorber and read by a TES (Transition-Edge Sensor). This configuration would ensure very good performances in terms of efficiency, time response and signal to noise ratio. We present the results of estimations, simulations and preliminary measurement.

  15. The data array, a tool to interface the user to a large data base

    NASA Technical Reports Server (NTRS)

    Foster, G. H.

    1974-01-01

    Aspects of the processing of spacecraft data is considered. Use of the data array in a large address space as an intermediate form in data processing for a large scientific data base is advocated. Techniques for efficient indexing in data arrays are reviewed and the data array method for mapping an arbitrary structure onto linear address space is shown. A compromise between the two forms is given. The impact of the data array on the user interface are considered along with implementation.

  16. Two dimensional extensible array configuration for EMCCD-based solid state x-ray detectors

    NASA Astrophysics Data System (ADS)

    Sharma, P.; Swetadri Vasan, S. N.; Cartwright, A. N.; Titus, A. H.; Bednarek, D. R.; Rudin, S.

    2012-03-01

    We have designed and developed from the discrete component level a high resolution dynamic x-ray detector to be used for fluoroscopic and angiographic medical imaging. The heart of the detector is a 1024 ×1024 pixel electron multiplying charge coupled device (EMCCD) with a pixel size of 13 × 13 μm2 (Model CCD201-20, e2v Technologies, Inc.), bonded to a fiber optic plate (FOP), and optically coupled to a 350 μm thick micro-columnar CsI(TI) scintillator via a fiber optic taper (FOT). Our aim is to design an array of these detectors that could be extended to any arbitrary X × Y size in two dimensions to provide a larger field of view (FOV). A physical configuration for a 3×3 array is presented that includes two major sub-systems. First is an optical front end that includes (i) a phosphor to convert the x-ray photons into light photons, and (ii) a fused array of FOTs that focuses light photons from the phosphor onto an array of EMCCD's optically coupled using FOPs. Second is an electronic front end that includes (i) an FPGA board used for generating clocks and for data acquisition (ii) driver boards to drive and digitize the analog output from the EMCCDs, (iii) a power board, and (iv) headboards to hold the EMCCD's while they are connected to their respective driver board using flex cables. This configuration provides a larger FOV as well as region-of-interest (ROI) high-resolution imaging as required by modern neurovascular procedures.

  17. Two dimensional extensible array configuration for EMCCD-based solid state x-ray detectors

    PubMed Central

    Sharma, P.; Vasan, S.N. Swetadri; Cartwright, A. N.; Titus, A. H.; Bednarek, D.R.; Rudin, S.

    2012-01-01

    We have designed and developed from the discrete component level a high resolution dynamic x- ray detector to be used for fluoroscopic and angiographic medical imaging. The heart of the detector is a 1024 × 1024 pixel electron multiplying charge coupled device (EMCCD) with a pixel size of 13 × 13 μm2 (Model CCD201-20, e2v Technologies, Inc.), bonded to a fiber optic plate (FOP), and optically coupled to a 350 μm thick micro-columnar CsI(TI) scintillator via a fiber optic taper (FOT). Our aim is to design an array of these detectors that could be extended to any arbitrary X × Y size in two dimensions to provide a larger field of view (FOV). A physical configuration for a 3×3 array is presented that includes two major sub-systems. First is an optical front end that includes (i) a phosphor to convert the x-ray photons into light photons, and (ii) a fused array of FOTs that focuses light photons from the phosphor onto an array of EMCCD's optically coupled using FOPs. Second is an electronic front end that includes (i) an FPGA board used for generating clocks and for data acquisition (ii) driver boards to drive and digitize the analog output from the EMCCDs, (iii) a power board, and (iv) headboards to hold the EMCCD's while they are connected to their respective driver board using flex cables. This configuration provides a larger FOV as well as region-of- interest (ROI) high-resolution imaging as required by modern neurovascular procedures. PMID:22822419

  18. Solar Observations with the Atacama Large Millimeter/submillimeter Array

    NASA Astrophysics Data System (ADS)

    Wedemeyer, Sven

    2015-08-01

    The interferometric Atacama Large Millimeter/submillimeter Array (ALMA) has already demonstrated its impressive capabilities by observing a large variety of targets ranging from protoplanetary disks to galactic nuclei. ALMA is also capable of observing the Sun and has been used for five solar test campaigns so far. The technically challenging solar observing modes are currently under development and regular observations are expected to begin in late 2016.ALMA consists of 66 antennas located in the Chilean Andes at an altitude of 5000 m and is a true leap forward in terms of spatial resolution at millimeter wavelengths. The resolution of reconstructed interferometric images of the Sun is anticipated to be close to what current optical solar telescopes can achieve. In combination with the high temporal and spectral resolution, these new capabilities open up new parameter spaces for solar millimeter observations.The solar radiation at wavelengths observed by ALMA originates from the chromosphere, where the height of the sampled layer increases with selected wavelength. The continuum intensity is linearly correlated to the local gas temperature in the probed layer, which makes ALMA essentially a linear thermometer. During flares, ALMA can detect additional non-thermal emission contributions. Measurements of the polarization state facilitate the valuable determination of the chromospheric magnetic field. In addition, spectrally resolved observations of radio recombination and molecular lines may yield great diagnostic potential, which has yet to be investigated and developed.Many different scientific applications for a large range of targets from quiet Sun to active regions and prominences are possible, ranging from ultra-high cadence wave studies to flare observations. ALMA, in particular in combination with other ground-based and space-borne instruments, will certainly lead to fascinating new findings, which will advance our understanding of the atmosphere of our Sun

  19. High-speed X-ray imaging pixel array detector for synchrotron bunch isolation

    PubMed Central

    Philipp, Hugh T.; Tate, Mark W.; Purohit, Prafull; Shanks, Katherine S.; Weiss, Joel T.; Gruner, Sol M.

    2016-01-01

    A wide-dynamic-range imaging X-ray detector designed for recording successive frames at rates up to 10 MHz is described. X-ray imaging with frame rates of up to 6.5 MHz have been experimentally verified. The pixel design allows for up to 8–12 frames to be stored internally at high speed before readout, which occurs at a 1 kHz frame rate. An additional mode of operation allows the integration capacitors to be re-addressed repeatedly before readout which can enhance the signal-to-noise ratio of cyclical processes. This detector, along with modern storage ring sources which provide short (10–100 ps) and intense X-ray pulses at megahertz rates, opens new avenues for the study of rapid structural changes in materials. The detector consists of hybridized modules, each of which is comprised of a 500 µm-thick silicon X-ray sensor solder bump-bonded, pixel by pixel, to an application-specific integrated circuit. The format of each module is 128 × 128 pixels with a pixel pitch of 150 µm. In the prototype detector described here, the three-side buttable modules are tiled in a 3 × 2 array with a full format of 256 × 384 pixels. The characteristics, operation, testing and application of the detector are detailed. PMID:26917125

  20. High-speed X-ray imaging pixel array detector for synchrotron bunch isolation.

    PubMed

    Philipp, Hugh T; Tate, Mark W; Purohit, Prafull; Shanks, Katherine S; Weiss, Joel T; Gruner, Sol M

    2016-03-01

    A wide-dynamic-range imaging X-ray detector designed for recording successive frames at rates up to 10 MHz is described. X-ray imaging with frame rates of up to 6.5 MHz have been experimentally verified. The pixel design allows for up to 8-12 frames to be stored internally at high speed before readout, which occurs at a 1 kHz frame rate. An additional mode of operation allows the integration capacitors to be re-addressed repeatedly before readout which can enhance the signal-to-noise ratio of cyclical processes. This detector, along with modern storage ring sources which provide short (10-100 ps) and intense X-ray pulses at megahertz rates, opens new avenues for the study of rapid structural changes in materials. The detector consists of hybridized modules, each of which is comprised of a 500 µm-thick silicon X-ray sensor solder bump-bonded, pixel by pixel, to an application-specific integrated circuit. The format of each module is 128 × 128 pixels with a pixel pitch of 150 µm. In the prototype detector described here, the three-side buttable modules are tiled in a 3 × 2 array with a full format of 256 × 384 pixels. The characteristics, operation, testing and application of the detector are detailed. PMID:26917125

  1. A four-pixel single-photon pulse-position array fabricated from WSi superconducting nanowire single-photon detectors

    SciTech Connect

    Verma, V. B. Horansky, R.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Marsili, F.; Stern, J. A.; Shaw, M. D.

    2014-02-03

    We demonstrate a scalable readout scheme for an infrared single-photon pulse-position camera consisting of WSi superconducting nanowire single-photon detectors. For an N × N array, only 2 × N wires are required to obtain the position of a detection event. As a proof-of-principle, we show results from a 2 × 2 array.

  2. Polycrystalline CVD diamond detector: Fast response and high sensitivity with large area

    SciTech Connect

    Liu, Linyue Zhang, Xianpeng; Zhong, Yunhong; Ouyang, Xiaoping Zhang, Jianfu

    2014-01-15

    Polycrystalline diamond was successfully used to fabricate a large area (diameter up to 46 mm) radiation detector. It was proven that the developed detector shows a fast pulsed response time and a high sensitivity, therefore its rise time is lower than 5 ns, which is two times faster than that of a Si-PIN detector of the same size. And because of the large sensitive area, this detector shows good dominance in fast pulsed and low density radiation detection.

  3. The Indiana silicon sphere 4 π charged-particle detector array

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, K.; Bracken, D. S.; Morley, K. B.; Brzychczyk, J.; Foxford, E. Renshaw; Komisarcik, K.; Viola, V. E.; Yoder, N. R.; Dorsett, J.; Poehlman, J.; Madden, N.; Ottarson, J.

    1995-02-01

    A low threshold charged particle detector array for the study of fragmentation processes in light-ion-induced reactions has been constructed and successfully implemented at the IUCF and Saturne II accelerators. The array consists of 162-triple-element detector telescopes mounted in a spherical geometry and covering 74% of 4π in solid angle. Telescope elements are composed of (1) an axial-field gas ionization chamber operated with C3F8 gas; (2) a 0.5 mm thick passivated silicon detector, and (3) a 2.8 cm thick CsI(TI) scintillation crystal with photodiode readout. Discrete element identification is obtained for ejectiles up to Z ~ 16 over the dynamic range 0.7 <= E/A <= 95 MeV/nucleon. Isotopes are also distinguished for H, He, Li and Be ejectiles with 8 <~ E/A <~ 95 MeV. Custom-designed electronics are employed for bias supplies and linear signal processing. Data are acquired via a CAMAC/VME/Ethernet system.

  4. Population density estimated from locations of individuals on a passive detector array

    USGS Publications Warehouse

    Efford, Murray G.; Dawson, Deanna K.; Borchers, David L.

    2009-01-01

    The density of a closed population of animals occupying stable home ranges may be estimated from detections of individuals on an array of detectors, using newly developed methods for spatially explicit capture–recapture. Likelihood-based methods provide estimates for data from multi-catch traps or from devices that record presence without restricting animal movement ("proximity" detectors such as camera traps and hair snags). As originally proposed, these methods require multiple sampling intervals. We show that equally precise and unbiased estimates may be obtained from a single sampling interval, using only the spatial pattern of detections. This considerably extends the range of possible applications, and we illustrate the potential by estimating density from simulated detections of bird vocalizations on a microphone array. Acoustic detection can be defined as occurring when received signal strength exceeds a threshold. We suggest detection models for binary acoustic data, and for continuous data comprising measurements of all signals above the threshold. While binary data are often sufficient for density estimation, modeling signal strength improves precision when the microphone array is small.

  5. Optical cross-talk effect in a semiconductor photon-counting detector array

    NASA Astrophysics Data System (ADS)

    Prochazka, Ivan; Hamal, Karel; Kral, Lukas; Blazej, Josef

    2005-09-01

    Solid state single photon detectors are getting more and more attention in various areas of applied physics: optical sensors, communication, quantum key distribution, optical ranging and Lidar, time resolved spectroscopy, opaque media imaging and ballistic photon identification. Avalanche photodiodes specifically designed for single photon counting semiconductor avalanche structures have been developed on the basis of various materials: Si, Ge, GaP, GaAsP and InGaAs/InGaAsP at the Czech Technical University in Prague during the last 20 years. They have been tailored for numerous applications. Recently, there is a strong demand for the photon counting detector in a form of an array; even small arrays 10x1 or 3x3 are of great importance for users. Although the photon counting array can be manufactured, there exists a serious limitation for its performance: the optical cross-talk between individual detecting cells. This cross-talk is caused by the optical emission of the avalanche photon counting structure which accompanies the photon detection process. We have studied in detail the optical emission of the avalanche photon counting structure in the silicon shallow junction type photodiode. The timing properties, radiation pattern and spectral distribution of the emitted light have been measured for various detection structures and their different operating conditions. The ultimate limit for the cross-talk has been determined and the methods for its limitation have been proposed.

  6. Digital data acquisition for the Low Energy Neutron Detector Array (LENDA)

    NASA Astrophysics Data System (ADS)

    Lipschutz, S.; Zegers, R. G. T.; Hill, J.; Liddick, S. N.; Noji, S.; Prokop, C. J.; Scott, M.; Solt, M.; Sullivan, C.; Tompkins, J.

    2016-04-01

    A digital data acquisition system (DDAS) has been implemented for the Low Energy Neutron Detector Array (LENDA). LENDA is an array of 24 BC-408 plastic-scintillator bars designed to measure low-energy neutrons with kinetic energies in the range of 100 keV-10 MeV from (p,n)-type charge-exchange reactions. Compared to the previous data acquisition (DAQ) system for LENDA, DDAS offers the possibility to lower the neutron detection threshold, increase the overall neutron-detection efficiency, decrease the dead time of the system, and allow for easy expansion of the array. The system utilized in this work was XIA's Digital Gamma Finder Pixie-16 250 MHz digitizers. A detector-limited timing resolution of 400 ps was achieved for a single LENDA bar. Using DDAS, the neutron detection threshold of the system was reduced compared to the previous analog system, now reaching below 100 keV. The new DAQ system was successfully used in a recent charge-exchange experiment using the 16C(p,n) reaction at the National Superconducting Cyclotron Laboratory (NSCL).

  7. ICARUS: An Innovative Large LAR Detector for Neutrino Physics

    SciTech Connect

    Vignoli, C.; Barni, D.; Disdier, J. M.; Rampoldi, D.; Passardi, G.

    2006-04-27

    ICARUS is an international project that foresees the installation of very large LAr detectors inside the Gran Sasso underground laboratory in order to be sensitive to rare phenomena of particle physics. The detection technique is based on the collection of electrons produced by particle interactions in LAr by a matrix of thousands of thin wires. At the moment the project foresees the installation of a 600,000-kg vessel (T600). The total amount of LAr can be expanded in a modular way to masses of the order of 106 kg. The T600 houses two identical 300,000-kg Ar sub-cryostats that are aluminum boxes about 20-m long, 4-m high and 4-m wide. Safety requirements for the underground installation have led to a unique design for the vessels to prevent LAr spillages even in the case of inner cryostat failure. Electrons must drift over meters requiring the development of special gas and liquid Ar purification units to provide an extremely high LAr purity (better then 0.1 ppb). The cooling system has been designed to assure a high thermal uniformity in the detector volume (less than 1-K differential). The cryogenic system associated with the final ICARUS configuration is based on three N2 refrigerators, three 30-m3 tanks and pump driven two-phase N2 forced-flow cooling of the various sub-systems. The T600 was successfully tested in Pavia in 2001 and it is now under installation in Gran Sasso for final operation. The future mass expansion strategy is under investigation.

  8. A Comprehensive Study of the Large Underground Xenon Detector

    NASA Astrophysics Data System (ADS)

    Woods, Michael Austin

    The Large Underground Xenon (LUX) dark matter search experiment operates a time projection chamber constructed of 370 kg of xenon, currently installed in the Homestake gold mine. The goal of the experiment is to detect Weakly Interacting Massive Particles (WIMPs). Novel calibration methods for this uniquely large detector are discussed. Background events due to standard model physics processes including cosmogenically activated xenon, alpha emission, and neutron production are shown to be negligible in recent 85 day WIMP search data. The LUX Monte Carlo simulation includes a new physical model, the Nobel Element Simulation Technique (NEST), for scintillation and ionization. NEST describes energy-, particle-, field- and medium-dependent behavior of a charge recombination model. A simulated data acquisition chain that bridges the gap between simulation and data has been developed to permit full testing of the analysis tools employed by LUX. Signal generation by cumulative photon responses are described algorithmically. Computational optimization has been performed to decrease processing time by a factor of fifty. A new technique for event depth estimation using machine learning and image analysis is introduced. Variable length waveforms are converted to fixed dimension field maps for use in machine learning. A support vector machine trained against pulse shapes with known depth successfully regressed depth without direct measurement of highly variable pulse widths. The world's most stringent limits on spin-independent WIMP-nucleon scattering cross section are presented.

  9. The GLAST Large Area Telescope Detector Performance Monitoring

    SciTech Connect

    Borgland, A.W.; Charles, E.; /SLAC

    2007-10-16

    The Large Area Telescope (LAT) is one of two instruments on board the Gamma-ray Large Area Telescope (GLAST), the next generation high energy gamma-ray space telescope. The LAT contains sixteen identical towers in a four-by-four grid. Each tower contains a silicon-strip tracker and a CsI calorimeter that together will give the incident direction and energy of the pair-converting photon in the energy range 20 MeV - 300 GeV. In addition, the instrument is covered by a finely segmented Anti-Coincidence Detector (ACD) to reject charged particle background. Altogether, the LAT contains more than 864k channels in the trackers, 1536 CsI crystals and 97 ACD plastic scintillator tiles and ribbons. Here we detail some of the strategies and methods for how we are planning to monitor the instrument performance on orbit. It builds on the extensive experience gained from Integration & Test and Commissioning of the instrument on ground.

  10. Extra-large crystal emulsion detectors for future large-scale experiments

    NASA Astrophysics Data System (ADS)

    Ariga, T.; Ariga, A.; Kuwabara, K.; Morishima, K.; Moto, M.; Nishio, A.; Scampoli, P.; Vladymyrov, M.

    2016-03-01

    Photographic emulsion is a particle tracking device which features the best spatial resolution among particle detectors. For certain applications, for example muon radiography, large-scale detectors are required. Therefore, a huge surface has to be analyzed by means of automated optical microscopes. An improvement of the readout speed is then a crucial point to make these applications possible and the availability of a new type of photographic emulsions featuring crystals of larger size is a way to pursue this program. This would allow a lower magnification for the microscopes, a consequent larger field of view resulting in a faster data analysis. In this framework, we developed new kinds of emulsion detectors with a crystal size of 600-1000 nm, namely 3-5 times larger than conventional ones, allowing a 25 times faster data readout. The new photographic emulsions have shown a sufficient sensitivity and a good signal to noise ratio. The proposed development opens the way to future large-scale applications of the technology, e.g. 3D imaging of glacier bedrocks or future neutrino experiments.

  11. AIDA: A 16-channel amplifier ASIC to read out the advanced implantation detector array for experiments in nuclear decay spectroscopy

    SciTech Connect

    Braga, D.; Coleman-Smith, P. J.; Davinson, T.; Lazarus, I. H.; Page, R. D.; Thomas, S.

    2011-07-01

    We have designed a read-out ASIC for nuclear decay spectroscopy as part of the AIDA project - the Advanced Implantation Detector Array. AIDA will be installed in experiments at the Facility for Antiproton and Ion Research in GSI, Darmstadt. The AIDA ASIC will measure the signals when unstable nuclei are implanted into the detector, followed by the much smaller signals when the nuclei subsequently decay. Implant energies can be as high as 20 GeV; decay products need to be measured down to 25 keV within just a few microseconds of the initial implants. The ASIC uses two amplifiers per detector channel, one covering the 20 GeV dynamic range, the other selectable over a 20 MeV or 1 GeV range. The amplifiers are linked together by bypass transistors which are normally switched off. The arrival of a large signal causes saturation of the low-energy amplifier and a fluctuation of the input voltage, which activates the link to the high-energy amplifier. The bypass transistors switch on and the input charge is integrated by the high-energy amplifier. The signal is shaped and stored by a peak-hold, then read out on a multiplexed output. Control logic resets the amplifiers and bypass circuit, allowing the low-energy amplifier to measure the subsequent decay signal. We present simulations and test results, demonstrating the AIDA ASIC operation over a wide range of input signals. (authors)

  12. High-gain and low-excess noise near-infrared single-photon avalanche detector arrays

    NASA Astrophysics Data System (ADS)

    Linga, Krishna; Yevtukhov, Yuriy; Liang, Bing

    2010-04-01

    We have designed and developed a new family of photodetectors and arrays with Internal Discrete Amplification (IDA) mechanism for the realization of very high gain and low excess noise factor in the visible and near infrared spectral regions. These devices surpass many limitations of the Single Photon Avalanche Photodetectors such as ultra low excess noise factor, very high gain, lower reset time (< 200 ns). These devices are very simple to operate in the non-gated mode under a constant dc bias voltage. Because of its unique characteristics of self-quenching and self-recovery, no external quenching circuit is needed. This unique feature of self quenching and self-recovery makes it simple to less complex readout integrated circuit to realize large format detector arrays. In this paper, we present the discrete amplification design approach used for the development of self reset, high gain photodetector arrays in the near infrared wavelength region. The demonstrated device performance far exceeds any available solid state Photodetectors in the near infrared wavelength range. These devices are ideal for researchers in the field of spectroscopy, industrial and scientific instrumentation, Ladar, quantum cryptography, night vision and other military, defense and aerospace applications.

  13. Study of Ultra-High Energy Cosmic Ray composition using Telescope Array's Middle Drum detector and surface array in hybrid mode

    NASA Astrophysics Data System (ADS)

    Abbasi, R. U.; Abe, M.; Abu-Zayyad, T.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Chae, M. J.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, T.; Fukushima, M.; Goto, T.; Hanlon, W.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Honda, K.; Ikeda, D.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kawata, K.; Kido, E.; Kim, H. B.; Kim, J. H.; Kim, J. H.; Kitamura, S.; Kitamura, Y.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, K.; Martens, K.; Matsuda, T.; Matsuyama, T.; Matthews, J. N.; Minamino, M.; Mukai, Y.; Myers, I.; Nagasawa, K.; Nagataki, S.; Nakamura, T.; Nonaka, T.; Nozato, A.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Rubtsov, G.; Ryu, D.; Sagawa, H.; Sakurai, N.; Sampson, A. L.; Scott, L. M.; Shah, P. D.; Shibata, F.; Shibata, T.; Shimodaira, H.; Shin, B. K.; Shin, H. S.; Smith, J. D.; Sokolsky, P.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T.; Suzawa, T.; Takamura, M.; Takeda, M.; Takeishi, R.; Taketa, A.; Takita, M.; Tameda, Y.; Tanaka, H.; Tanaka, K.; Tanaka, M.; Thomas, S. B.; Thomson, G. B.; Tinyakov, P.; Tkachev, I.; Tokuno, H.; Tomida, T.; Troitsky, S.; Tsunesada, Y.; Tsutsumi, K.; Uchihori, Y.; Udo, S.; Urban, F.; Vasiloff, G.; Wong, T.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yashiro, K.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

    2015-04-01

    Previous measurements of the composition of Ultra-High Energy Cosmic Rays (UHECRs) made by the High Resolution Fly's Eye (HiRes) and Pierre Auger Observatory (PAO) are seemingly contradictory, but utilize different detection methods, as HiRes was a stereo detector and PAO is a hybrid detector. The five year Telescope Array (TA) Middle Drum hybrid composition measurement is similar in some, but not all, respects in methodology to PAO, and good agreement is evident between data and a light, largely protonic, composition when comparing the measurements to predictions obtained with the QGSJetII-03 and QGSJet-01c models. These models are also in agreement with previous HiRes stereo measurements, confirming the equivalence of the stereo and hybrid methods. The data is incompatible with a pure iron composition, for all models examined, over the available range of energies. The elongation rate and mean values of Xmax are in good agreement with Pierre Auger Observatory data. This analysis is presented using two methods: data cuts using simple geometrical variables and a new pattern recognition technique.

  14. Analysis of crosstalk in front-illuminated InGaAs PIN hetero-junction photovoltaic infrared detector arrays

    NASA Astrophysics Data System (ADS)

    Li, Yongfu; Tang, Hengjing; Zhang, Kefeng; Li, Tao; Ning, Jinhua; Li, Xue; Gong, Haimei

    2009-07-01

    Here presented an experimental study on crosstalk in front illuminated planar and mesa-type InP/ InGaAs/ InP PIN hetero-junction photovoltaic infrared detector arrays. A scanning laser beam with an optical wavelength of 1310 nm coupled in a single-mode optical fiber placed within a few microns of the detector array surface was used to measure the crosstalk between the detector pixels. The crosstalk in the detector array varying with the distance between the incident laser spot and the measured pixel was shown. It is suggested that for the deep mesa-type arrays the dominating source of crosstalk is the light reflected from the detector substrate. And the dominating source of crosstalk that occurs in the planar type and shallow mesa type photovoltaic arrays is associated with photo-induced carries generated in the InGaAs absorption layer that diffuse laterally between neighbor pixels. These results gave out the possibility to optimize the detectors structures in order to reduce crosstalk.

  15. Fabrication of large dual-polarized multichroic TES bolometer arrays for CMB measurements with the SPT-3G camera

    NASA Astrophysics Data System (ADS)

    Posada, C. M.; Ade, P. A. R.; Ahmed, Z.; Arnold, K.; Austermann, J. E.; Bender, A. N.; Bleem, L. E.; Benson, B. A.; Byrum, K.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Ciocys, S. T.; Cliche, J. F.; Crawford, T. M.; Cukierman, A.; Czaplewski, D.; Ding, J.; Divan, R.; de Haan, T.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Gilbert, A.; Halverson, N. W.; Harrington, N. L.; Hattori, K.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Hubmayr, J.; Irwin, K. D.; Jeong, O.; Keisler, R.; Kubik, D.; Kuo, C. L.; Lee, A. T.; Leitch, E. M.; Lendinez, S.; Meyer, S. S.; Miller, C. S.; Montgomery, J.; Myers, M.; Nadolski, A.; Natoli, T.; Nguyen, H.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Ruhl, J. E.; Saliwanchik, B. R.; Smecher, G.; Sayre, J. T.; Shirokoff, E.; Stan, L.; Stark, A. A.; Sobrin, J.; Story, K.; Suzuki, A.; Thompson, K. L.; Tucker, C.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.; Ziegler, K. E.

    2015-09-01

    This work presents the procedures used at Argonne National Laboratory to fabricate large arrays of multichroic transition-edge sensor (TES) bolometers for cosmic microwave background (CMB) measurements. These detectors will be assembled into the focal plane for the SPT-3G camera, the third generation CMB camera to be installed in the South Pole Telescope. The complete SPT-3G camera will have approximately 2690 pixels, for a total of 16 140 TES bolometric detectors. Each pixel is comprised of a broad-band sinuous antenna coupled to a Nb microstrip line. In-line filters are used to define the different bands before the millimeter-wavelength signal is fed to the respective Ti/Au TES bolometers. There are six TES bolometer detectors per pixel, which allow for measurements of three band-passes (95, 150 and 220 GHz) and two polarizations. The steps involved in the monolithic fabrication of these detector arrays are presented here in detail. Patterns are defined using a combination of stepper and contact lithography. The misalignment between layers is kept below 200 nm. The overall fabrication involves a total of 16 processes, including reactive and magnetron sputtering, reactive ion etching, inductively coupled plasma etching and chemical etching.

  16. Large active retrodirective arrays for solar power satellites

    NASA Technical Reports Server (NTRS)

    Chernoff, R.

    1978-01-01

    An active retrodirective array (ARA) transmits a beam toward the apparent source of an illuminating signal called the pilot. The array produces the RF power. Retrodirectivity is achieved by retransmitting from each element of the array a signal whose phase is the 'conjugate' of that received by the element. Application of the ARA to the solar power satellite concept has been proposed. A method of providing a reference phase is described, called 'central phasing', which eliminates the need for a rigid structure ordinarily needed in order to realize accurate retrodirectivity.

  17. Large dynamic range radiation detector and methods thereof

    DOEpatents

    Marrs, Roscoe E.; Madden, Norman W.

    2012-02-14

    According to one embodiment, a radiation detector comprises a scintillator and a photodiode optically coupled to the scintillator. The radiation detector also includes a bias voltage source electrically coupled to the photodiode, a first detector operatively electrically coupled to the photodiode for generating a signal indicative of a level of a charge at an output of the photodiode, and a second detector operatively electrically coupled to the bias voltage source for generating a signal indicative of an amount of current flowing through the photodiode.

  18. Engineering study of the module/array interface for large terrestrial photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Three major areas--structural, electrical, and maintenance--were evaluated. Efforts in the structural area included establishing acceptance criteria for materials and members, determining loading criteria, and analyzing glass modules in various framing system configurations. Array support structure design was addressed briefly. Electrical considerations included evaluation of module characteristics, intermodule connectors, array wiring, converters and lightning protection. Plant maintenance features such as array cleaning, failure detection, and module installation and replacement were addressed.

  19. Epitaxial InSb for elevated temperature operation of large IR focal plane arrays

    NASA Astrophysics Data System (ADS)

    Ashley, Tim; Burke, Theresa M.; Emeny, Martin T.; Gordon, Neil T.; Hall, David J.; Lees, David J.; Little, J. Chris; Milner, Daniel

    2003-09-01

    The use of epitaxially grown indium antimonide (InSb) has previously been demonstrated for the production of large 2D focal plane arrays. It confers several advantages over conventional, bulk InSb photo-voltaic detectors, such as reduced cross-talk, however here we focus on the improvement in operating temperature that can be achieved because more complex structures can be grown. Diode resistance, imaging, NETD and operability results are presented for a progression of structures that reduce the diode leakage current as the temperature is raised above 80K, compared with a basic p+-n-n+ structure presented previously. These include addition of a thin region of InAlSb to reduce p-contact leakage current, and construction of the whole device from InAlSb to reduce thermal generation in the active region of the detector. An increase in temperature to 110K, whilst maintaining full 80K performance, is achieved, and imaging up to 130K is demonstrated. This gives the prospect of significant benefits for the cooling systems, including, for example, use of argon in Joule-Thomson coolers or an increase in the life and/or decrease in the cost; power consumption and cool-down time of Stirling engines by several tens of per cent.

  20. Continuous emission monitoring system based on a PbSe detector array

    NASA Astrophysics Data System (ADS)

    Pujadas, Manuel; Oche, A.; Barcala, J. M.; Teres, J.

    1995-09-01

    PbSe is a very important photoconductive material extensively used as IR detector for military applications and may be considered one of the most useful materials for detection in the MIR range. In the last years the opening of its production for wide civil use has allowed the conception of new detection systems based on this semiconductor. Considering some possible applications of it in environmental control, PbSe can provide, for instance, good response band to monitor several gases of major importance (SO2, NO, CO, etc.), especially when their concentrations are high. In this paper, we present applications of this semiconductor for this purpose: the developemnt of a new continuous emission monitoring system (CEMS) using a PbSe detector array in a nondispersive configuration. The basics of this prototype and some experimental results related to the detection of different typical emission gases with this system are presented here.

  1. Development of the Plastic Scintillator Detector Array for the Prototype of the Dark Matter Particle Explorer

    NASA Astrophysics Data System (ADS)

    Zhang, Yongjie; Sun, Zhiyu; Yu, Yuhong; Zhou, Yong; Fang, Fang; Chen, Junling

    2016-07-01

    The scientific object of Dark Matter Particles Explorer(DAMPE) is the measurement of electrons and photons in the range of 5GeV~10TeV and the flux of nuclei up to 500TeV with excellent resolution , and the realization of measurements will identify possible Dark Matter(DM) signature and help deepen our understanding of the origin and propagation of high energy cosmic ray respectively. Plastic Scintillator Detector Array (PSD), which adopts perpendicular structure with two layers and each layer consists of 15 scintillator strips, is one sub-detector of DAMPE for detecting heavy ions and distinguishing photons and electrons. In this paper, the design and some test results of PSD are to be described.

  2. Fabrication and Characterization of Linear Terahertz Detector Arrays Based on Lithium Tantalate Crystal

    NASA Astrophysics Data System (ADS)

    Li, Weizhi; Wang, Jun; Gou, Jun; Huang, Zehua; Jiang, Yadong

    2015-01-01

    Two samples of 30-pixel linear terahertz detector arrays (TDAs) were fabricated based on lithium tantalate (LT) crystals. Pixel readout circuit (ROC) was designed to extract the weak current signal of TDAs. A test platform was established for performance evaluation of TDA+ROC components. By using a 2.52THz laser as radiation source, the test results reveal that average voltage responsivities of the components were larger than 7000V/W and non-uniformity no more than 2.1%. Average noise equivalent power ( NEP) of one sample was measured to be 1.5×10-9 W/Hz1/2, which is low enough and desirable for high performance THz detector.

  3. InAs/GaSb superlattice focal plane array infrared detectors: manufacturing aspects

    NASA Astrophysics Data System (ADS)

    Rutz, Frank; Rehm, Robert; Schmitz, Johannes; Fleissner, Joachim; Walther, Martin; Scheibner, Ralf; Ziegler, Johann

    2009-05-01

    InAs/GaSb type-II short-period superlattice (SL) photodiodes have been shown to be very promising for 2nd and 3rd generation thermal imaging systems with excellent detector performance. A multi-wafer molecular beam epitaxy (MBE) growth process on 3"-GaSb substrates, which allows simultaneous growth on five substrates with excellent homogeneity has been developed. A reliable III/V-process technology for badge processing of single-color and dual-color FPAs has been set up to facilitate fabrication of mono- and bi-spectral InAs/GaSb SL detector arrays for the mid-IR spectral range. Mono- and bispectral SL camera systems with different pitch and number of pixels have been fabricated. Those imaging systems show excellent electro-optical performance data with a noise equivalent temperature difference (NETD) around 10 mK.

  4. InGaAs Schottky barrier diode array detector for a real-time compact terahertz line scanner.

    PubMed

    Han, Sang-Pil; Ko, Hyunsung; Park, Jeong-Woo; Kim, Namje; Yoon, Young-Jong; Shin, Jun-Hwan; Kim, Dae Yong; Lee, Dong Hun; Park, Kyung Hyun

    2013-11-01

    We present a terahertz (THz) broadband antenna-integrated 1 × 20 InGaAs Schottky barrier diode (SBD) array detector with an average responsivity of 98.5 V/W at a frequency of 250 GHz, which is measured without attaching external amplifiers and Si lenses, and an average noise equivalent power (NEP) of 106.6 pW/√Hz. The 3-dB bandwidth of the SBD detector is also investigated at approximately 180 GHz. For implementing an array-type SBD detector by a simple fabrication process to achieve a high yield, a structure comprising an SiN(x) layer instead of an air bridge between the anode and the cathode is designed. THz line beam imaging using a Gunn diode emitter with a center frequency of 250 GHz and a 1 × 20 SBD array detector is successfully demonstrated. PMID:24216813

  5. The future of large format HgCdTe arrays for astronomy

    NASA Technical Reports Server (NTRS)

    Vural, K.

    1994-01-01

    Rockwell has developed the 256 x 256 Near Infrared Camera and Multi-Object Spectrometer 3 (NICMOS3) FPA for the Hubble Space Telescope under funding from NASA through the University of Arizona. Since 1989, dozens of science grade devices have been delivered to astronomers throughout the world for ground based infrared observations. These devices have excellent sensitivity at 77 K with mean dark currents of 0.1 e(-)/s, noise of 25 e(-), and quantum efficiency of 55-70%. Pixel yields as high as 99.9% have been achieved. Our present plans are to develop a 1024 x 1024 focal plane array (FPA) with 2.5 micron cutoff and make it available to astronomers. Such large arrays are made possible by the advances in detector material size (3 in. diameter producible alternative to CdTe for epitaxy (PACE-I) wafers), multiplexer advances (ability to verify the design in detail and availability of advanced foundries), and novel hybridization and reliability approaches.

  6. Micro Cantilever Movement Detection with an Amorphous Silicon Array of Position Sensitive Detectors

    PubMed Central

    Contreras, Javier; Costa, Daniel; Pereira, Sonia; Fortunato, Elvira; Martins, Rodrigo; Wierzbicki, Rafal; Heerlein, Holger; Ferreira, Isabel

    2010-01-01

    The movement of a micro cantilever was detected via a self constructed portable data acquisition prototype system which integrates a linear array of 32 1D amorphous silicon position sensitive detectors (PSD). The system was mounted on a microscope using a metal structure platform and the movement of the 30 μm wide by 400 μm long cantilever was tracked by analyzing the signals acquired by the 32 sensor array electronic readout system and the relevant data algorithm. The obtained results show a linear behavior of the photocurrent relating X and Y movement, with a non-linearity of about 3%, a spatial resolution of less than 2 μm along the lateral dimension of the sensor as well as of less than 3 μm along the perpendicular dimension of the sensor, when detecting just the micro-cantilever, and a spatial resolution of less than 1 μm when detecting the holding structure. PMID:22163648

  7. DENSITY: software for analysing capture-recapture data from passive detector arrays

    USGS Publications Warehouse

    Efford, M.G.; Dawson, D.K.; Robbins, C.S.

    2004-01-01

    A general computer-intensive method is described for fitting spatial detection functions to capture-recapture data from arrays of passive detectors such as live traps and mist nets. The method is used to estimate the population density of 10 species of breeding birds sampled by mist-netting in deciduous forest at Patuxent Research Refuge, Laurel, Maryland, U.S.A., from 1961 to 1972. Total density (9.9 ? 0.6 ha-1 mean ? SE) appeared to decline over time (slope -0.41 ? 0.15 ha-1y-1). The mean precision of annual estimates for all 10 species pooled was acceptable (CV(D) = 14%). Spatial analysis of closed-population capture-recapture data highlighted deficiencies in non-spatial methodologies. For example, effective trapping area cannot be assumed constant when detection probability is variable. Simulation may be used to evaluate alternative designs for mist net arrays where density estimation is a study goal.

  8. Observation of high energy atmospheric neutrinos with antarctic muon and neutrino detector array

    SciTech Connect

    Ahrens, J.; Andres, E.; Bai, X.; Barouch, G.; Barwick, S.W.; Bay, R.C.; Becka, T.; Becker, K.-H.; Bertrand, D.; Binon, F.; Biron, A.; Booth, J.; Botner, O.; Bouchta, A.; Bouhali, O.; Boyce, M.M.; Carius, S.; Chen, A.; Chirkin, D.; Conrad, J.; Cooley, J.; Costa, C.G.S.; Cowen, D.F.; Dalberg, E.; De Clercq, C.; DeYoung, T.; Desiati, P.; Dewulf, J.-P.; Doksus, P.; Edsjo, J.; Ekstrom, P.; Feser, T.; Frere, J.-M.; Gaisser, T.K.; Gaug, M.; Goldschmidt, A.; Hallgren, A.; Halzen, F.; Hanson, K.; Hardtke, R.; Hauschildt, T.; Hellwig, M.; Heukenkamp, H.; Hill, G.C.; Hulth, P.O.; Hundertmark, S.; Jacobsen, J.; Karle, A.; Kim, J.; Koci, B.; Kopke, L.; Kowalski, M.; Lamoureux, J.I.; Leich, H.; Leuthold, M.; Lindahl, P.; Liubarsky, I.; Loaiza, P.; Lowder, D.M.; Madsen, J.; Marciniewski, P.; Matis, H.S.; McParland, C.P.; Miller, T.C.; Minaeva, Y.; Miocinovic, P.; Mock, P.C.; Morse, R.; Neunhoffer, T.; Niessen, P.; Nygren, D.R.; Ogelman, H.; Olbrechts, Ph.; Perez de los Heros, C.; Pohl, A.C.; Porrata, R.; Price, P.B.; Przybylski, G.T.; Rawlins, K.; Reed, C.; Rhode, W.; Ribordy, M.; Richter, S.; Rodriguez Martino, J.; Romenesko, P.; Ross, D.; Sander, H.-G.; Schmidt, T.; Schneider, D.; Schwarz, R.; Silvestri, A.; Solarz, M.; Spiczak, G.M.; Spiering, C.; Starinsky, N.; Steele, D.; Steffen, P.; Stokstad, R.G.; Streicher, O.; Sudhoff, P.; Sulanke, K.-H.; Taboada, I.; Thollander, L.; Thon, T.; Tilav, S.; Vander Donckt, M.; Walck, C.; Weinheimer, C.; Wiebusch, C.H.; Wiedeman, C.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Wu, W.; Yodh, G.; Young, S.

    2002-05-07

    The Antarctic Muon and Neutrino Detector Array (AMANDA) began collecting data with ten strings in 1997. Results from the first year of operation are presented. Neutrinos coming through the Earth from the Northern Hemisphere are identified by secondary muons moving upward through the array. Cosmic rays in the atmosphere generate a background of downward moving muons, which are about 10{sup 6} times more abundant than the upward moving muons. Over 130 days of exposure, we observed a total of about 300 neutrino events. In the same period, a background of 1.05 x 10{sup 9} cosmic ray muon events was recorded. The observed neutrino flux is consistent with atmospheric neutrino predictions. Monte Carlo simulations indicate that 90 percent of these events lie in the energy range 66 GeV to 3.4 TeV. The observation of atmospheric neutrinos consistent with expectations establishes AMANDA-B10 as a working neutrino telescope.

  9. Graphical user interface for a dual-module EMCCD x-ray detector array

    NASA Astrophysics Data System (ADS)

    Wang, Weiyuan; Ionita, Ciprian; Kuhls-Gilcrist, Andrew; Huang, Ying; Qu, Bin; Gupta, Sandesh K.; Bednarek, Daniel R.; Rudin, Stephen

    2011-03-01

    A new Graphical User Interface (GUI) was developed using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) for a high-resolution, high-sensitivity Solid State X-ray Image Intensifier (SSXII), which is a new x-ray detector for radiographic and fluoroscopic imaging, consisting of an array of Electron-Multiplying CCDs (EMCCDs) each having a variable on-chip electron-multiplication gain of up to 2000x to reduce the effect of readout noise. To enlarge the field-of-view (FOV), each EMCCD sensor is coupled to an x-ray phosphor through a fiberoptic taper. Two EMCCD camera modules are used in our prototype to form a computer-controlled array; however, larger arrays are under development. The new GUI provides patient registration, EMCCD module control, image acquisition, and patient image review. Images from the array are stitched into a 2kx1k pixel image that can be acquired and saved at a rate of 17 Hz (faster with pixel binning). When reviewing the patient's data, the operator can select images from the patient's directory tree listed by the GUI and cycle through the images using a slider bar. Commonly used camera parameters including exposure time, trigger mode, and individual EMCCD gain can be easily adjusted using the GUI. The GUI is designed to accommodate expansion of the EMCCD array to even larger FOVs with more modules. The high-resolution, high-sensitivity EMCCD modular-array SSXII imager with the new user-friendly GUI should enable angiographers and interventionalists to visualize smaller vessels and endovascular devices, helping them to make more accurate diagnoses and to perform more precise image-guided interventions.

  10. THE COSMIC-RAY ENERGY SPECTRUM OBSERVED WITH THE SURFACE DETECTOR OF THE TELESCOPE ARRAY EXPERIMENT

    SciTech Connect

    Abu-Zayyad, T.; Allen, M.; Anderson, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Hanlon, W.; Aida, R.; Azuma, R.; Fukuda, T.; Cheon, B. G.; Cho, E. J.; Chiba, J.; Chikawa, M.; Cho, W. R.; Fujii, H.; Fujii, T.; Fukushima, M.; and others

    2013-05-01

    The Telescope Array (TA) collaboration has measured the energy spectrum of ultra-high energy cosmic rays (UHECRs) with primary energies above 1.6 Multiplication-Sign 10{sup 18} eV. This measurement is based upon four years of observation by the surface detector component of TA. The spectrum shows a dip at an energy of 4.6 Multiplication-Sign 10{sup 18} eV and a steepening at 5.4 Multiplication-Sign 10{sup 19} eV which is consistent with the expectation from the GZK cutoff. We present the results of a technique, new to the analysis of UHECR surface detector data, that involves generating a complete simulation of UHECRs striking the TA surface detector. The procedure starts with shower simulations using the CORSIKA Monte Carlo program where we have solved the problems caused by use of the ''thinning'' approximation. This simulation method allows us to make an accurate calculation of the acceptance of the detector for the energies concerned.

  11. A digital data acquisition framework for the Versatile Array of Neutron Detectors at Low Energy (VANDLE)

    NASA Astrophysics Data System (ADS)

    Paulauskas, S. V.; Madurga, M.; Grzywacz, R.; Miller, D.; Padgett, S.; Tan, H.

    2014-02-01

    Neutron energy measurements can be achieved using time-of-flight (ToF) techniques. A digital data acquisition system was developed for reliable ToF measurements with subnanosecond timing resolution based on digitizers with 10 ns and 4 ns sampling periods using pulse shape analysis algorithms. A validation procedure was developed to confirm the reliability. The response of the algorithm to photomultiplier signals was studied using a specially designed experimental system based on fast plastic scintillators. The presented developments enabled digital data acquisition systems to instrument the recently developed Versatile Array of Neutron Detectors at Low-Energy (VANDLE).

  12. Digital Electronics For The Versatile Array Of Neutron Detectors At Low Energies

    SciTech Connect

    Madurga, M.; Paulauskas, S.; Grzywacz, R.; Padgett, S. W.; Liddick, S. N.; Bardayan, D. W.; Batchelder, J. C.; Matei, C.; Peters, W. A.; Rasco, C.; Blackmon, J. C.; Cizewski, J. A.; O'Malley, P.; Goans, R. E.; Raiola, F.; Sarazin, F.

    2011-06-01

    A {chi}{sup 2} minimization algorithm has been developed to extract sub-sampling-time information from digitized waveforms, to be used to instrument the future Versatile Array of Neutron Detectors at Low energies. The algorithm performance has been characterized with a fast Arbitrary Function Generator, obtaining time resolution better than 1 ns for signals of amplitudes between 50 mV and 1V, with negligible walk in the whole range. The proof-of-principle measurement of the beta-delayed neutron emission from {sup 89}Br indicates a resolution of 1 ns can be achieved in realistic experimental conditions.

  13. Digital Electronics For The Versatile Array Of Neutron Detectors At Low Energies

    NASA Astrophysics Data System (ADS)

    Madurga, M.; Paulauskas, S.; Grzywacz, R.; Padgett, S. W.; Bardayan, D. W.; Batchelder, J. C.; Blackmon, J. C.; Cizewski, J. A.; Goans, R. E.; Liddick, S. N.; O'Malley, P.; Matei, C.; Peters, W. A.; Rasco, C.; Raiola, F.; Sarazin, F.

    2011-06-01

    A χ2 minimization algorithm has been developed to extract sub-sampling-time information from digitized waveforms, to be used to instrument the future Versatile Array of Neutron Detectors at Low energies. The algorithm performance has been characterized with a fast Arbitrary Function Generator, obtaining time resolution better than 1 ns for signals of amplitudes between 50 mV and 1V, with negligible walk in the whole range. The proof-of-principle measurement of the beta-delayed neutron emission from 89Br indicates a resolution of 1 ns can be achieved in realistic experimental conditions.

  14. Parallel Beam Approximation for Calculation of Detection Efficiency of Crystals in PET Detector Arrays

    PubMed Central

    Komarov, Sergey; Song, Tae Yong; Wu, Heyu; Tai, Yuan-Chuan

    2014-01-01

    In this work we propose a parallel beam approximation for the computation of the detection efficiency of crystals in a PET detector array. In this approximation the detection efficiency of a crystal is estimated using the distance between source and the crystal and the pre-calculated detection cross section of the crystal in a crystal array which is calculated for a uniform parallel beam of gammas. The pre-calculated detection cross sections for a few representative incident angles and gamma energies can be used to create a look-up table to be used in simulation studies or practical implementation of scatter or random correction algorithms. Utilizing the symmetries of the square crystal array, the pre-calculated look-up tables can be relatively small. The detection cross sections can be measured experimentally, calculated analytically or simulated using a Monte Carlo (MC) approach. In this work we used a MC simulation that takes into account the energy windowing, Compton scattering and factors in the “block effect”. The parallel beam approximation was validated by a separate MC simulation using point sources located at different positions around a crystal array. Experimentally measured detection efficiencies were compared with Monte Carlo simulated detection efficiencies. Results suggest that the parallel beam approximation provides an efficient and accurate way to compute the crystal detection efficiency, which can be used for estimation of random and scatter coincidences for PET data corrections. PMID:25400292

  15. A Failure Mode in Dense Infrared Detector Arrays Resulting in Increased Dark Current

    NASA Astrophysics Data System (ADS)

    Pinkie, Benjamin; Bellotti, Enrico

    2016-04-01

    In this paper, we investigate a failure mode that arises in dense infrared focal plane detector arrays as a consequence of the interactions of neighboring pixels through the minority carrier profiles in the common absorber layer. We consider the situation in which one pixel in a hexagonal array becomes de-biased relative to its neighbors and show that the dark current in the six neighboring pixels increases exponentially as a function of the difference between the nominal and anomalous biases. Moreover, we show that the current increase in the six nearest-neighbor pixels is in total larger than that by which the current in the affected pixel decreases, causing a net increase in the dark current. The physical origins of this effect are explained as being due to increased lateral diffusion currents that arise as a consequence of breaking the symmetry of the minority carrier profiles. We then perform a parametric study to quantify the magnitude of this effect for a number of detector geometric parameters, operating temperatures, and spectral bands. Particularly, numerical simulations are carried out for short-, mid-, and long-wavelength HgCdTe infrared detectors operating between 77 K and 210 K. We show that this effect is most prevalent in architectures for which the lateral diffusion current is the largest component of the total dark current—high operating temperature devices with narrow epitaxial absorber thicknesses and pitches small compared to the diffusion length of minority carriers. These results could prove significant particularly for short- and mid-wave infrared detectors, which are typically designed to fit these conditions.

  16. A Failure Mode in Dense Infrared Detector Arrays Resulting in Increased Dark Current

    NASA Astrophysics Data System (ADS)

    Pinkie, Benjamin; Bellotti, Enrico

    2016-09-01

    In this paper, we investigate a failure mode that arises in dense infrared focal plane detector arrays as a consequence of the interactions of neighboring pixels through the minority carrier profiles in the common absorber layer. We consider the situation in which one pixel in a hexagonal array becomes de-biased relative to its neighbors and show that the dark current in the six neighboring pixels increases exponentially as a function of the difference between the nominal and anomalous biases. Moreover, we show that the current increase in the six nearest-neighbor pixels is in total larger than that by which the current in the affected pixel decreases, causing a net increase in the dark current. The physical origins of this effect are explained as being due to increased lateral diffusion currents that arise as a consequence of breaking the symmetry of the minority carrier profiles. We then perform a parametric study to quantify the magnitude of this effect for a number of detector geometric parameters, operating temperatures, and spectral bands. Particularly, numerical simulations are carried out for short-, mid-, and long-wavelength HgCdTe infrared detectors operating between 77 K and 210 K. We show that this effect is most prevalent in architectures for which the lateral diffusion current is the largest component of the total dark current—high operating temperature devices with narrow epitaxial absorber thicknesses and pitches small compared to the diffusion length of minority carriers. These results could prove significant particularly for short- and mid-wave infrared detectors, which are typically designed to fit these conditions.

  17. A four-layer attenuation compensated PET detector based on APD arrays without discrete crystal elements.

    PubMed

    McCallum, Stephen; Clowes, Peter; Welch, Andrew

    2005-09-01

    Scintillation detectors developed for PET traditionally use relatively thick crystals coupled to photomultiplier tubes. To ensure good efficiency the crystals typically measure between 10 and 30 mm thick. Detectors also require good spatial resolution so the scintillator is normally made up of a densely packed array of long thin crystals. In this paper, we present a novel design in which the detection crystal is divided into a number of layers along its length with an avalanche photo diode (APD) inserted between each layer. With thin layers of crystal, it is possible to use a continuous rather than a pixelated crystal. The potential advantages of this design over a conventional PMT-based detector are: (i) improved light collection efficiency, (ii) reduced dependency on dense crystal to achieve good stopping power, (iii) ease of crystal manufacture, (iv) reduced detector dead-time and increased count rate, and (v) inherent depth of interaction. We have built a four-layer detector to test this design concept using Hamamatsu S8550 APD arrays and LYSO crystals. We used the centre 16 pixels of each of the arrays to give an active area of 9.5 mm x 9.5 mm. Four crystals 9.5 mm x 9.5 mm were used with thickness increasing from 2 mm at the front to 2.5 mm, 3.1 mm and 4.3 mm at the back, to ensure a similar count rate in each layer. Calculations for the thickness of the four layers were initially made using the linear attenuation coefficient for photons at 511 keV of LYSO. Experimental results and further simulation demonstrated that a correction to the thickness of each layer should be considered to take into account the scattered events. The energy resolution for each of the layers at 511 keV was around 15%, coincidence-timing resolution was 2.2 ns and the special resolution was less than 2 mm using a statistical-based positioning algorithm. PMID:16177539

  18. DESIGN OF A LARGE-AREA FAST NEUTRON DIRECTIONAL DETECTOR.

    SciTech Connect

    VANIER, P.E.

    2006-10-29

    A large-area fast-neutron double-scatter directional detector and spectrometer is being constructed using l-meter-long plastic scintillator paddles with photomultiplier tubes at both ends. The scintillators detect fast neutrons by proton recoil and also gamma rays by Compton scattering. The paddles are arranged in two parallel planes so that neutrons can be distinguished from muons and gamma rays by time of flight between the planes. The signal pulses are digitized with a time resolution of one gigasample per second. The location of an event along each paddle can be determined from the relative amplitudes or timing of the signals at the ends. The angle of deflection of a neutron in the first plane can be estimated from the energy deposited by the recoil proton, combined with the scattered neutron time-of-flight energy. Each scattering angle can be back-projected as a cone, and many intersecting cones define the incident neutron direction from a distant point source. Moreover, the total energy of each neutron can be obtained, allowing some regions of a fission source spectrum to be distinguished from background generated by cosmic rays. Monte Carlo calculations will be compared with measurements.

  19. Large format, small pixel pitch and hot detectors at SOFRADIR

    NASA Astrophysics Data System (ADS)

    Reibel, Y.; Rouvie, A.; Nedelcu, A.; Augey, T.; Pere-Laperne, N.; Rubaldo, L.; Billon-Lanfrey, D.; Gravrand, O.; Rothman, J.; Destefanis, G.

    2013-10-01

    Recently Sofradir joined a very small circle of IR detector manufacturers with expertise every aspect of the cooled and uncooled IR technologies, all under one roof by consolidating all IR technologies available in France. These different technologies are complementary and are used depending of the needs of the applications mainly concerning the detection range needs as well as their ability to detect in bad weather environmental conditions. SNAKE (InGaAs) and SCORPIO LW (MCT) expand Sofradir's line of small pixel pitch TV format IR detectors from the mid-wavelength to the short and long wavelengths. Our dual band MW-LW QWIP detectors (25μm, 384×288 pixels) benefit to tactical platforms giving an all-weather performance and increasing flexibility in the presence of battlefield obscurants. In parallel we have been pursuing further infrared developments on future MWIR detectors, such as the VGA format HOT detector that consumes 2W and the 10μm pitch IR detector which gives us a leading position in innovation. These detectors are designed for long-range surveillance equipment, commander or gunner sights, ground-to-ground missile launchers and other applications that require higher resolution and sensitivity to improve reconnaissance and target identification. This paper discusses the system level performance in each detector type.

  20. Probing Solar Wind Turbulence with the Jansky Very Large Array

    NASA Astrophysics Data System (ADS)

    Kobelski, A.; Bastian, T. S.; Betti, S.

    2016-04-01

    The solar wind offers an extraordinary laboratory for studying MHD turbulence, turbulent dissipation, and heating. Radio propagation phenomena can be exploited as probes of the solar wind in regions that are generally inaccessible to in situ spacecraft measurements. Here, we have undertaken a study with the Jansky Very Large Array (VLA) to observe point-like sources drawn from the JVAS catalog, and 3 VLA calibrator sources, to trans-illuminate the outer corona/inner solar wind. In doing so, we will exploit angular broadening and refractive scintillation to deduce properties of the solar wind along ≍23 lines of sight within 7 solar radii of the Sun and a wide range of position angles. By fitting the complex visibilities using well-known techniques we can deduce or constrain a number of key parameters. In particular, we fit the visibilities to a function of the known source flux, displacement of the source due to refraction, source broadening due to an elliptical structure function, spectral slope of the turbulence, and the coherence scale. Of particular interest is α, the spectral slope of the turbulence which we probe at both small (km to 10s of km) and large (thousands of km) scales. This will help us determine the presence and evolution of an inner scale, measure the degree of anisotropy, and constrain the topology of the global coronal magnetic field. The inner scale is of particular interest for constraining current theories of turbulence dissipation and heating. Initial analysis show the visibilities vary notably on timescales of individual integrations (2 seconds) and that the source is not uniformly broadened. All sources appear to preferentially broaden perpendicular to the magnetic field, consistent with theories of kinetic Alfvén waves. This type of observation will also help to interpret data from the upcoming Solar Probe Plus and Solar Orbiter missions. A full set of results and analysis is forthcoming. More details on previous results can be found

  1. Background simulations for the Large Area Detector onboard LOFT

    NASA Astrophysics Data System (ADS)

    Campana, Riccardo; Feroci, Marco; Del Monte, Ettore; Mineo, Teresa; Lund, Niels; Fraser, George W.

    2013-12-01

    The Large Observatory For X-ray Timing (LOFT), currently in an assessment phase in the framework the ESA M3 Cosmic Vision programme, is an innovative medium-class mission specifically designed to answer fundamental questions about the behaviour of matter, in the very strong gravitational and magnetic fields around compact objects and in supranuclear density conditions. Having an effective area of ˜10 m2 at 8 keV, LOFT will be able to measure with high sensitivity very fast variability in the X-ray fluxes and spectra. A good knowledge of the in-orbit background environment is essential to assess the scientific performance of the mission and optimize the design of its main instrument, the Large Area Detector (LAD). In this paper the results of an extensive Geant-4 simulation of the instrumentwillbe discussed, showing the main contributions to the background and the design solutions for its reduction and control. Our results show that the current LOFT/LAD design is expected to meet its scientific requirement of a background rate equivalent to 10 mCrab in 2‒30 keV, achieving about 5 mCrab in the most important 2-10 keV energy band. Moreover, simulations show an anticipated modulation of the background rate as small as 10 % over the orbital timescale. The intrinsic photonic origin of the largest background component also allows for an efficient modelling, supported by an in-flight active monitoring, allowing to predict systematic residuals significantly better than the requirement of 1 %, and actually meeting the 0.25 % science goal.

  2. Zero-bias microwave detectors based on array of nanorectifiers coupled with a dipole antenna

    NASA Astrophysics Data System (ADS)

    Kasjoo, Shahrir R.; Singh, Arun K.; Mat Isa, Siti S.; Ramli, Muhammad M.; Mohamad Isa, Muammar; Ahmad, Norhawati; Mohd Nor, Nurul I.; Khalid, Nazuhusna; Song, Ai Min

    2016-04-01

    We report on zero-bias microwave detection using a large array of unipolar nanodevices, known as the self-switching diodes (SSDs). The large array was realized in a single lithography step without the need of interconnection layers, hence allowing for a simple and low-cost fabrication process. The SSD array was coupled with a narrowband dipole antenna with a resonant frequency of 890 MHz, to form a simple rectenna (rectifying antenna). The extrinsic voltage responsivity and noise-equivalent-power (NEP) of the rectenna were ∼70 V/W and ∼0.18 nW/Hz1/2, respectively, measured in the far-field region at unbiased condition. Nevertheless, the estimated intrinsic voltage responsivity can achieve up to ∼5 kV/W with NEP of ∼2.6 pW/Hz1/2.

  3. Large-Array Signal Processing for Deep-Space Applications

    NASA Astrophysics Data System (ADS)

    Lee, C. H.; Vilnrotter, V.; Satorius, E.; Ye, Z.; Fort, D.; Cheung, K.-M.

    2002-04-01

    This article develops the mathematical models needed to describe the key issues in using an array of antennas for receiving spacecraft signals for DSN applications. The detrimental effects of nearby interfering sources, such as other spacecraft transmissions or natural radio sources within the array's field of view, on signal-to noise ratio (SNR) are determined, atmospheric effects relevant to the arraying problem developed, and two classes of algorithms (multiple signal classification (MUSIC) plus beam forming, and an eigen-based solution) capable of phasing up the array with maximized SNR in the presence of realistic disturbances are evaluated. It is shown that, when convolutionally encoded binary-phase shift keying (BPSK) data modulation is employed on the spacecraft signal, previously developed data pre-processing techniques that partially reconstruct the carrier can be of great benefit to array performance, particularly when strong interfering sources are present. Since this article is concerned mainly with demonstrating the required capabilities for operation under realistic conditions, no attempt has been made to reduce algorithm complexity; the design and evaluation of less complex algorithms with similar capabilities will be addressed in a future article. The performances of the candidate algorithms discussed in this article have been evaluated in terms of the number of symbols needed to achieve a given level of combining loss for different numbers of array elements, and compared on this common basis. It is shown that even the best algorithm requires approximately 25,000 symbols to achieve a combining loss of less than 0.5 dB when 128 antenna elements are employed, but generally 50,000 or more symbols are needed. This is not a serious impediment to successful arraying with high data-rate transmission, but may be of some concern with missions exploring near the edge of our solar system or beyond, where lower data rates may be required.

  4. Modelling and 3D optimisation of CdTe pixels detector array geometry - Extension to small pixels

    NASA Astrophysics Data System (ADS)

    Zumbiehl, A.; Hage-Ali, M.; Fougeres, P.; Koebel, J. M.; Regal, R.; Rit, C.; Ayoub, M.; Siffert, P.

    2001-08-01

    CdTe and CdZnTe pixel detectors offer great interest for many applications, especially for medical and industrial imaging. Up to now, the material, generally, used and investigated for pixel arrays was CZT (Hamel et al., IEEE Trans. Nucl. Sci. 43 (3) (1996) 1422; Barrett et al., Phys. Rev. Lett. 75 (1) (1995) 156; Bennett et al., Nucl. Instr. and Meth. A 392 (1997) 260; Eskin et al., J. Appl. Phys. 85 (2) (1999) 647; Brunett et al., J. Appl. Phys. 86 (7) (1999) 3926; Luke, Nucl. Instr. and Meth. A 380 (1996) 232), but cadmium telluride can also be an appropriate choice, as shown here. However, we clearly demonstrate here that the optimal pixel configuration is highly dependent on the electrical transport properties of the material. Depending on the field of primary interest, either energy resolution or counting rate efficiency in the photopeak, the geometry for each case has to be optimised. For that purpose, we have developed a calculation of the signal induced onto the pixel. Two distinct parts are used: after showing our approach for the weighting potential calculation, we present our results performed by a "pseudo-Monte Carlo" simulation. Results are supported by a few experimental comparisons. We argue about the optimum sizes with clarifying the problems caused by too small and too large pixel sizes. The study field is chosen to be vast, i.e. pixel size to detector thickness ratios ( W/ L) of 1/8-1, and detector thickness of 1.0-8.0 mm. In addition, several electrical transport properties are used. Since efficiency is often of primary interest, thick detectors could be very attractive, which are shown to be really feasible even on CdTe.

  5. Signal encoding method for a time-of-flight PET detector using a silicon photomultiplier array

    NASA Astrophysics Data System (ADS)

    Kwon, Sun Il; Lee, Jae Sung

    2014-10-01

    The silicon photomultiplier (SiPM) is a promising photosensor for magnetic resonance (MR) compatible time-of-flight (TOF) positron emission tomography (PET) scanners. The compact size of the SiPM allows direct one-to-one coupling between the scintillation crystal and the photosensor, yielding better timing and energy resolutions than the light sharing methods that have to be used in photomultiplier tube (PMT) PET systems. However, the one-to-one coupling scheme requires a huge volume of readout and processing electronics if no electric signal multiplexing or encoding scheme is properly applied. In this paper, we develop an electric signal encoding scheme for SiPM array based TOF PET detector blocks with the aim of reducing the complexity and volume of the signal readout and processing electronics. In an M×N SiPM array, the output signal of each channel in the SiPM array is divided into two signal lines. These output lines are then tied together in row and column lines. The row and column signals are used to measure the energy and timing information (or vice versa) of each incident gamma-ray event, respectively. Each SiPM channel was directly coupled to a 3×3×20 mm3 LGSO crystal. The reference detector, which was used to measure timing, consisted of an R9800 PMT and a 4×4×10 mm3 LYSO crystal and had a single time resolution of ~200 ps (FWHM). Leading edge discriminators were used to determine coincident events. Dedicated front-end electronics were developed, and the timing and energy resolutions of SiPM arrays with different array sizes (4×4, 8×8, and 12×12) were compared. Breakdown voltage of each SiPM channel was measured using energy spectra within various bias voltages. Coincidence events were measured using a 22Na point source. The average coincidence time resolution of 4×4, 8×8, and 12×12 SiPM arrays were 316 ps, 320 ps, and 335 ps (FWHM), respectively. The energy resolution of 4×4, 8×8, and 12×12 SiPM arrays were 11.8%, 12.5%, and 12.8% (FWHM

  6. A 2-D Array of Superconducting Magnesium Diboride (MgB2) Far-IR Thermal Detectors for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Lakew, Brook

    2009-01-01

    A 2-D array of superconducting Magnesium Diboride(MgB2) far IR thermal detectors has been fabricated. Such an array is intended to be at the focal plane of future generation thermal imaging far-IR instruments that will investigate the outer planets and their icy moons. Fabrication and processing of the pixels of the array as well as noise characterization of architectured MgB2 thin films will be presented. Challenges and solutions for improving the performance of the array will be discussed.

  7. Large angle solid state position sensitive x-ray detector system

    DOEpatents

    Kurtz, David S.; Ruud, Clay O.

    1998-01-01

    A method and apparatus for x-ray measurement of certain properties of a solid material. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided.

  8. Large angle solid state position sensitive x-ray detector system

    DOEpatents

    Kurtz, D.S.; Ruud, C.O.

    1998-03-03

    A method and apparatus for x-ray measurement of certain properties of a solid material are disclosed. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

  9. Large angle solid state position sensitive x-ray detector system

    DOEpatents

    Kurtz, D.S.; Ruud, C.O.

    1998-07-21

    A method and apparatus are disclosed for x-ray measurement of certain properties of a solid material. In distinction to known methods and apparatus, this invention employs a specific fiber-optic bundle configuration, termed a reorganizer, itself known for other uses, for coherently transmitting visible light originating from the scintillation of diffracted x-radiation from the solid material gathered along a substantially one dimensional linear arc, to a two-dimensional photo-sensor array. The two-dimensional photodetector array, with its many closely packed light sensitive pixels, is employed to process the information contained in the diffracted radiation and present the information in the form of a conventional x-ray diffraction spectrum. By this arrangement, the angular range of the combined detector faces may be increased without loss of angular resolution. Further, the prohibitively expensive coupling together of a large number of individual linear diode photodetectors, which would be required to process signals generated by the diffracted radiation, is avoided. 7 figs.

  10. Very Large Array and Jansky Very Large Array observations of the compact radio sources in M8

    SciTech Connect

    Masqué, Josep M.; Rodríguez, Luis F.; Dzib, Sergio

    2014-12-10

    We analyze high-resolution Very Large Array continuum observations of the M8 region carried out at several epochs that span a period of 30 yr. Our maps reveal two compact sources. One is associated with Her 36 SE, a possible companion of the O7 luminous massive star Her 36, and the other is associated with G5.97–1.17, whose proplyd nature was previously established. Using the analyzed data, we do not find significant time variability in any of these sources. The derived spectral index of ≥0.1 for Her 36 SE, the marginal offset of the radio emission with the previous infrared detection, and the associated X-ray emission previously reported suggest the presence of an unresolved interaction region between the strong winds of Her 36 and Her 36 SE. This region would contribute non-thermal contamination to the global wind emission of Her 36, flattening its spectral index. On the other hand, the emission of G5.97–1.17 can also be explained by a mixture of thermal and non-thermal emission components, with different relative contributions of both emission mechanisms along the proplyd. We argue that the shock created by the photo-evaporation flow of the proplyd with the collimated stellar wind of Her 36 accelerates charged particles in G5.97–1.17, producing considerable synchrotron emission. On the contrary, an electron density enhancement at the southwest of G5.97–1.17 makes the thermal emission dominant over this region.

  11. Small-angle scatter tomography with a photon-counting detector array

    NASA Astrophysics Data System (ADS)

    Pang, Shuo; Zhu, Zheyuan; Wang, Ge; Cong, Wenxiang

    2016-05-01

    Small-angle x-ray scatter imaging has a high intrinsic contrast in cancer research and other applications, and provides information on molecular composition and micro-structure of the tissue. In general, the implementations of small-angle coherent scatter imaging can be divided into two main categories: direct tomography and angular dispersive computerized tomography. Based on the recent development of energy-discriminative photon-counting detector array, here we propose a computerized tomography setup based on energy-dispersive measurement with a photon-counting detector array. To show merits of the energy-dispersive approach, we have performed numerical tests with a phantom containing various tissue types, in comparison with the existing imaging approaches. The results show that with an energy resolution of ~6 keV, the energy dispersive tomography system with a broadband tabletop x-ray would outperform the angular dispersive system, which makes the x-ray small-angle scatter tomography promising for high-specificity tissue imaging.

  12. Small-angle scatter tomography with a photon-counting detector array.

    PubMed

    Pang, Shuo; Zhu, Zheyuan; Wang, Ge; Cong, Wenxiang

    2016-05-21

    Small-angle x-ray scatter imaging has a high intrinsic contrast in cancer research and other applications, and provides information on molecular composition and micro-structure of the tissue. In general, the implementations of small-angle coherent scatter imaging can be divided into two main categories: direct tomography and angular dispersive computerized tomography. Based on the recent development of energy-discriminative photon-counting detector array, here we propose a computerized tomography setup based on energy-dispersive measurement with a photon-counting detector array. To show merits of the energy-dispersive approach, we have performed numerical tests with a phantom containing various tissue types, in comparison with the existing imaging approaches. The results show that with an energy resolution of ~6 keV, the energy dispersive tomography system with a broadband tabletop x-ray would outperform the angular dispersive system, which makes the x-ray small-angle scatter tomography promising for high-specificity tissue imaging. PMID:27082147

  13. Optical bandpass filters for detector arrays' modulation transfer function estimation by means of laser speckle

    NASA Astrophysics Data System (ADS)

    Astar, William

    1996-06-01

    Two apertures, a square slit (SS) and a diamond slit (DS), both zero'th-order magnitude transparencies with bandpass filters in their optical transfer functions (OTFs), are designed and optimized for the purpose of modulation transfer function (MTF) evaluation of detector arrays by means of laser speckle. The SS and DS apertures are compared to an existing design, the extended frequency aperture, and show, respectively, improvements of 464% and 58% in filter magnitude; improvements of -13.4% (a compromise) and 17% in bandwidth; and improvements of 627% and 423% in throughput, implying a greatly reduced laser power requirement. As a result, they should significantly enhance detector arrays' MTF evaluations and at a greatly reduced cost. The DS aperture possesses identical OTFs in both the horizontal and vertical directions, enabling MTF evaluation using the bandpass filters in those directions from the same speckle data frame--previously not possible. The DS aperture can be further modified to yield filter magnitude and bandwidth improvements of 111% and 40%, respectively; although becoming easier to fabricate, this modification would be a lower throughput improvement of 310% over the existing design.

  14. Dark current measurement of Type-II superlattice infrared focal plane array detector

    NASA Astrophysics Data System (ADS)

    Sakai, Michito; Katayama, Haruyoshi; Murooka, Junpei; Kimata, Masafumi; Iguchi, Yasuhiro

    2014-06-01

    We report the result of a dark current measurement of a Type-II superlattice (T2SL) infrared focal plane array (FPA), which consists of a 6 μm cutoff T2SL detector array and the readout integration circuit (ROIC) ISC0903 of FLIR Systems. In order to measure the dark current of the FPA, we obtained images with different exposure times in a fully closed cold shield of 77 K. Using the temporal change rate of the output and considering the charge conversion efficiency of the ROIC, we obtained a dark current density with an average value of 4 × 10-5 A/cm2 at a bias of -100 mV. We also compare the result of the FPA dark current measurement with that of a test element group (TEG), which was a single pixel detector, fabricated by the same process as the FPA. The dark current density of the TEG was 3 × 10-6 A/cm2 at a bias of -100 mV, lower than that of the FPA. We discuss the discrepancy between the dark current densities of the FPA and the TEG.

  15. Development of Superconducting-Tunnel-Junction Array Detectors with Three-Dimensional Structure Beyond 1000-Pixels

    NASA Astrophysics Data System (ADS)

    Fujii, Go; Ukibe, Masahiro; Shiki, Shigetomo; Ohkubo, Masataka

    2016-07-01

    Superconducting-tunnel-junction (STJ) array X-ray detectors have exhibited excellent characteristics for fluorescence-yield X-ray absorption fine structure (XAFS) in a soft X-ray range. For high-throughput XAFS analyses, we developed a new close-packed STJ arrangement with a space of 10 \\upmu m (use the correct space) between adjacent STJ pixels by using three-dimensional multilayer structure (3D-STJ) with the wiring layer underneath the STJ pixel layer. In this work, in order to solve a double-peak response originating from absorption events in the top and bottom electrodes, we have fabricated the 3D-STJ with an asymmetric layer structure. Single-peak response for the soft X-rays below 0.7 keV was obtained. The closed-packed 3D-STJ array detector with 100 pixels has an operation yield of 93 % and a mean energy resolution of 12.5 ± 0.7 eV in full-width at half-maximum for the C-Kα X-ray.

  16. Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging.

    PubMed

    Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P; Zolliker, Peter

    2016-01-01

    In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8-14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed. PMID:26861341

  17. Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging

    PubMed Central

    Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P.; Zolliker, Peter

    2016-01-01

    In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8–14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed. PMID:26861341

  18. Dosimetric performance and array assessment of plastic scintillation detectors for stereotactic radiosurgery quality assurance

    SciTech Connect

    Gagnon, Jean-Christophe; Theriault, Dany; Guillot, Mathieu; Archambault, Louis; Beddar, Sam; Gingras, Luc; Beaulieu, Luc

    2012-01-15

    Purpose: To compare the performance of plastic scintillation detectors (PSD) for quality assurance (QA) in stereotactic radiosurgery conditions to a microion-chamber (IC), Gafchromic EBT2 films, 60 008 shielded photon diode (SD) and unshielded diodes (UD), and assess a new 2D crosshair array prototype adapted to small field dosimetry. Methods: The PSD consists of a 1 mm diameter by 1 mm long scintillating fiber (BCF-60, Saint-Gobain, Inc.) coupled to a polymethyl-methacrylate optical fiber (Eska premier, Mitsubishi Rayon Co., Ltd., Tokyo, Japan). Output factors (S{sub c,p}) for apertures used in radiosurgery ranging from 4 to 40 mm in diameter have been measured. The PSD crosshair array (PSDCA) is a water equivalent device made up of 49 PSDs contained in a 1.63 cm radius area. Dose profiles measurements were taken for radiosurgery fields using the PSDCA and were compared to other dosimeters. Moreover, a typical stereotactic radiosurgery treatment using four noncoplanar arcs was delivered on a spherical phantom in which UD, IC, or PSD was placed. Using the Xknife planning system (Integra Radionics Burlington, MA), 15 Gy was prescribed at the isocenter, where each detector was positioned. Results: Output Factors measured by the PSD have a mean difference of 1.3% with Gafchromic EBT2 when normalized to a 10 x 10 cm{sup 2} field, and 1.0% when compared with UD measurements normalized to the 35 mm diameter cone. Dose profiles taken with the PSD crosshair array agreed with other single detectors dose profiles in spite of the presence of the 49 PSDs. Gamma values comparing 1D dose profiles obtained with PSD crosshair array with Gafchromic EBT2 and UD measured profiles shows 98.3% and 100.0%, respectively, of detector passing the gamma acceptance criteria of 0.3 mm and 2%. The dose measured by the PSD for a complete stereotactic radiosurgery treatment is comparable to the planned dose corrected for its SD-based S{sub c,p} within 1.4% and 0.7% for 5 and 35 mm diameter cone

  19. Non-local means-based nonuniformity correction for infrared focal-plane array detectors

    NASA Astrophysics Data System (ADS)

    Yu, Hui; Zhang, Zhi-jie; Chen, Fu-sheng; Wang, Chen-sheng

    2014-11-01

    The infrared imaging systems are normally based on the infrared focal-plane array (IRFPA) which can be considered as an array of independent detectors aligned at the focal plane of the imaging system. Unfortunately, every detector on the IRFPA may have a different response to the same input infrared signal which is known as the nonuniformity problem. Then we can observe the fixed pattern noise (FPN) from the resulting images. Standard nonuniformity correction (NUC) methods need to be recalibrated after a short period of time due the temporal drift of the FPN. Scene-based nonuniformity correction (NUC) techniques eliminate the need for calibration by correction coefficients based on the scene being viewed. However, in the scene-based NUC method the problem of ghosting artifacts widely seriously decreases the image quality, which can degrade the performance of many applications such as target detection and track. This paper proposed an improved scene-based method based on the retina-like neural network approach. The method incorporates the use of non-local means (NLM) method into the estimation of the gain and the offset of each detector. This method can not only estimates the accurate correction coefficient but also restrict the ghosting artifacts efficiently. The proposed method relies on the use of NLM method which is a very successful image denoising method. And then the NLM used here can preserve the image edges efficiently and obtain a reliable spatial estimation. We tested the proposed NUC method by applying it to an IR sequence of frames. The performance of the proposed method was compared the other well-established adaptive NUC techniques.

  20. SU-E-P-24: Simplified EDW Profile Measurements Using Two Commonly Available Detector Arrays

    SciTech Connect

    Reynolds, T; Arentsen, L; Watanabe, Y; Alaei, P

    2015-06-15

    Purpose: Enhanced dynamic wedge (EDW) profiles are needed as part of the commissioning of a treatment planning system. This work compares the acquisition of EDW profiles using a linear diode array (LDA) with two commonly used detector arrays available in the clinics, with the goal of identifying the simplest approach for these measurements. Methods: The measurements of EDW profiles were performed on a Varian TrueBeam linear accelerator for 6, 10, and 18 MV photon beams for all seven wedge angles at four depths. The measurements were done using the LDA 99 in Blue Phantom2 (IBA Dosimetry), and IC Profiler and MapCHECK2 (Sun Nuclear) in solid water phantoms. The water phantom was set up at 100 cm SSD, whereas the two other devices were set up at 75 cm due to the size limitations of the devices. The largest possible field size was used. The average and maximum percentage differences were examined within the central 90% of the field and in the penumbra. Results: Dose profiles measured with IC Profiler were in a good agreement with LDA 99 data. The average percentage difference within the field did not exceed 0.5% for all energies. MapCHECK2 measurements matched well with LDA 99 for 10 and 18 MV (within 0.3%) with discrepancies of up to 1.4% observed for the 6 MV beam. The maximum percentage differences for both devices in the penumbra exhibited larger variations than LDA 99 results due to differences in detector spacing and high dose gradient, as expected. Conclusion: Common linac QA devices such as IC Profiler or MapCHECK2 provide EDW beam profile data of reasonable accuracy as compared to measurements performed using a linear diode array in a water phantom, saving the expense and time involved in acquiring and setting up a LDA.