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

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.

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.

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.

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.

Superconducting Detector Arrays for Astrophysics

NASA Technical Reports Server (NTRS)

Chervenak, James

2008-01-01

The next generation of astrophysics instruments will feature an order of magnitude more photon sensors or sensors that have an order of magnitude greater sensitivity. Since detector noise scales with temperature, a number of candidate technologies have been developed that use the intrinsic advantages of detector systems that operate below 1 Kelvin. Many of these systems employ of the superconducting phenomena that occur in metals at these temperatures to build ultrasensitive detectors and low-noise, low-power readout architectures. I will present one such system in use today to meet the needs of the astrophysics community at millimeter and x-ray wavelengths. Our group at NASA in collaboration with Princeton, NIST, Boulder and a number of other groups is building large format arrays of superconducting transition edge sensors (TES) read out with multiplexed superconducting quantum interference devices (SQUID). I will present the high sensitivity we have achieved in multiplexed x-ray sensors with the TES technology and describe the construction of a 1000-sensor TES/SQUID array for microwave measurements. With our collaboration's deployment of a kilopixel TES array for 2 mm radiation at the Atacarna Cosmology Telescope in November 2007, we have first images of the lensed Cosmic Microwave Background at fine angular scales.

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;

The cosmology large angular scale surveyor (CLASS): 38-GHz detector array of bolometric polarimeters

NASA Astrophysics Data System (ADS)

Appel, John W.; Ali, Aamir; Amiri, Mandana; Araujo, Derek; Bennet, Charles L.; Boone, Fletcher; Chan, Manwei; Cho, Hsiao-Mei; Chuss, David T.; Colazo, Felipe; Crowe, Erik; Denis, Kevin; Dünner, Rolando; Eimer, Joseph; Essinger-Hileman, Thomas; Gothe, Dominik; Halpern, Mark; Harrington, Kathleen; Hilton, Gene; Hinshaw, Gary F.; Huang, Caroline; Irwin, Kent; Jones, Glenn; Karakula, John; Kogut, Alan J.; Larson, David; Limon, Michele; Lowry, Lindsay; Marriage, Tobias; Mehrle, Nicholas; Miller, Amber D.; Miller, Nathan; Moseley, Samuel H.; Novak, Giles; Reintsema, Carl; Rostem, Karwan; Stevenson, Thomas; Towner, Deborah; U-Yen, Kongpop; Wagner, Emily; Watts, Duncan; Wollack, Edward; Xu, Zhilei; Zeng, Lingzhen

2014-07-01

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.

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.

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.

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.

Multispectral Linear Array detector technology

NASA Astrophysics Data System (ADS)

Tower, J. R.; McCarthy, B. M.; Pellon, L. E.; Strong, R. T.; Elabd, H.

1984-01-01

The Multispectral Linear Array (MLA) program sponsored by NASA has the aim to extend space-based remote sensor capabilities. The technology development effort involves the realization of very large, all-solid-state, pushbroom focal planes. The pushbroom, staring focal planes will contain thousands of detectors with the objective to provide two orders of magnitude improvement in detector dwell time compared to present Landsat mechanically scanned systems. Attenton is given to visible and near-infrared sensor development, the shortwave infrared sensor, aspects of filter technology development, the packaging concept, and questions of system performance. First-sample, four-band interference filters have been fabricated successfully, and a hybrid packaging technology is being developed.

The hyperion particle-γ detector array

DOE PAGES

Hughes, R. O.; Burke, J. T.; Casperson, R. J.; ...

2017-03-08

Hyperion is a new high-efficiency charged-particle γ-ray detector array which consists of a segmented silicon telescope for charged-particle detection and up to fourteen high-purity germanium clover detectors for the detection of coincident γ rays. The array will be used in nuclear physics measurements and Stockpile Stewardship studies and replaces the STARLiTeR array. In conclusion, this article discusses the features of the array and presents data collected with the array in the commissioning experiment.

Signal Attenuation Curve for Different Surface Detector Arrays

NASA Astrophysics Data System (ADS)

Vicha, J.; Travnicek, P.; Nosek, D.; Ebr, J.

2014-06-01

Modern cosmic ray experiments consisting of large array of particle detectors measure the signals of electromagnetic or muon components or their combination. The correction for an amount of atmosphere passed is applied to the surface detector signal before its conversion to the shower energy. Either Monte Carlo based approach assuming certain composition of primaries or indirect estimation using real data and assuming isotropy of arrival directions can be used. Toy surface arrays of different sensitivities to electromagnetic and muon components are assumed in MC simulations to study effects imposed on attenuation curves for varying composition or possible high energy anisotropy. The possible sensitivity of the attenuation curve to the mass composition is also tested for different array types focusing on a future apparatus that can separate muon and electromagnetic component signals.

Integrated infrared detector arrays for low-background applications

NASA Technical Reports Server (NTRS)

Mccreight, C. R.; Goebel, J. H.

1982-01-01

Advanced infrared detector and detector array technology is being developed and characterized for future NASA space astronomy applications. Si:Bi charge-injection-device arrays have been obtained, and low-background sensitivities comparable to that of good discrete detectors have been measured. Intrinsic arrays are being assessed, and laboratory and telescope data have been collected on a monolithic InSb CCD array. For wavelengths longer than 30 microns, improved Ge:Ga detectors have been produced, and steps have been taken to prove the feasibility of an integrated extrinsic germanium array. Other integrated arrays and cryogenic components are also under investigation.

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.

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.

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.

Mini Compton Camera Based on an Array of Virtual Frisch-Grid CdZnTe Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Wonho; Bolotnikov, Aleksey; Lee, Taewoong

In this study, we constructed a mini Compton camera based on an array of CdZnTe detectors and assessed its spectral and imaging properties. The entire array consisted of 6×6 Frisch-grid CdZnTe detectors, each with a size of 6×6 ×15 mm 3. Since it is easier and more practical to grow small CdZnTe crystals rather than large monolithic ones, constructing a mosaic array of parallelepiped crystals can be an effective way to build a more efficient, large-volume detector. With the fully operational CdZnTe array, we measured the energy spectra for 133Ba -, 137Cs -, 60Co-radiation sources; we also located these sourcesmore » using a Compton imaging approach. Although the Compton camera was small enough to hand-carry, its intrinsic efficiency was several orders higher than those generated in previous researches using spatially separated arrays, because our camera measured the interactions inside the CZT detector array, wherein the detector elements were positioned very close to each other. Lastly, the performance of our camera was compared with that based on a pixelated detector.« less

Mini Compton Camera Based on an Array of Virtual Frisch-Grid CdZnTe Detectors

DOE PAGES

Lee, Wonho; Bolotnikov, Aleksey; Lee, Taewoong; ...

2016-02-15

In this study, we constructed a mini Compton camera based on an array of CdZnTe detectors and assessed its spectral and imaging properties. The entire array consisted of 6×6 Frisch-grid CdZnTe detectors, each with a size of 6×6 ×15 mm 3. Since it is easier and more practical to grow small CdZnTe crystals rather than large monolithic ones, constructing a mosaic array of parallelepiped crystals can be an effective way to build a more efficient, large-volume detector. With the fully operational CdZnTe array, we measured the energy spectra for 133Ba -, 137Cs -, 60Co-radiation sources; we also located these sourcesmore » using a Compton imaging approach. Although the Compton camera was small enough to hand-carry, its intrinsic efficiency was several orders higher than those generated in previous researches using spatially separated arrays, because our camera measured the interactions inside the CZT detector array, wherein the detector elements were positioned very close to each other. Lastly, the performance of our camera was compared with that based on a pixelated detector.« less

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

Arrays of Segmented, Tapered Light Guides for Use With Large, Planar Scintillation Detectors

NASA Astrophysics Data System (ADS)

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

2015-06-01

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.

PbS-PbSe IR detector arrays

NASA Technical Reports Server (NTRS)

Barrett, John R. (Inventor)

1986-01-01

A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chipping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

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).

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.

High-resolution ionization detector and array of such detectors

DOEpatents

McGregor, Douglas S [Ypsilanti, MI; Rojeski, Ronald A [Pleasanton, CA

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.

Signal detectability in diffusive media using phased arrays in conjunction with detector arrays.

PubMed

Kang, Dongyel; Kupinski, Matthew A

2011-06-20

We investigate Hotelling observer performance (i.e., signal detectability) of a phased array system for tasks of detecting small inhomogeneities and distinguishing adjacent abnormalities in uniform diffusive media. Unlike conventional phased array systems where a single detector is located on the interface between two sources, we consider a detector array, such as a CCD, on a phantom exit surface for calculating the Hotelling observer detectability. The signal detectability for adjacent small abnormalities (2 mm displacement) for the CCD-based phased array is related to the resolution of reconstructed images. Simulations show that acquiring high-dimensional data from a detector array in a phased array system dramatically improves the detectability for both tasks when compared to conventional single detector measurements, especially at low modulation frequencies. It is also observed in all studied cases that there exists the modulation frequency optimizing CCD-based phased array systems, where detectability for both tasks is consistently high. These results imply that the CCD-based phased array has the potential to achieve high resolution and signal detectability in tomographic diffusive imaging while operating at a very low modulation frequency. The effect of other configuration parameters, such as a detector pixel size, on the observer performance is also discussed.

Simulation study of PET detector configuration with thick light guide and GAPD array having large-area microcells for high effective quantum efficiency.

PubMed

Kang, Jihoon; Choi, Yong

2016-07-01

Light sharing PET detector configuration coupled with thick light guide and Geiger-mode avalanche photodiode (GAPD) with large-area microcells was proposed to overcome the energy non-linearity problem and to obtain high light collection efficiency (LCE). A Monte-Carlo simulation was conducted for the three types of LSO block, 4 × 4 array of 3 × 3 × 20 mm(3) discrete crystals, 6 × 6 array of 2 × 2 × 20 mm(3) discrete crystals, and 12 × 12 array of 1 × 1 × 20 mm(3) discrete crystals, to investigate the scintillation light distribution after conversion of the γ-rays in LSO. The incident photons were read out by three types of 4 × 4 array photosensors, which were PSPMT of 25% quantum efficiency (QE), GAPD1 with 50 × 50 µm(2) microcells of 30% photon detection efficiency (PDE) and GAPD2 with 100 × 100 µm(2) of 45% PDE. The number of counted photons in each photosensor was analytically calculated. The LCE, linearity and flood histogram were examined for each PET detector module having 99 different configurations as a function of light guide thickness ranging from 0 to 10 mm. The performance of PET detector modules based on GAPDs was considerably improved by using the thick light guide. The LCE was increased from 24 to 30% and from 14 to 41%, and the linearity was also improved from 0.97 to 0.99 and from 0.75 to 0.99, for GAPD1 and GAPD2, respectively. As expected, the performance of PSPMT based detector did not change. The flood histogram of 12 × 12 array PET detector modules using 3 mm light guide coupled with GAPDs was obtained by simulation, and all crystals of 1 × 1 × 20 mm(3) size were clearly identified. PET detector module coupled with thick light guide and GAPD array with large-area microcells was proposed to obtain high QE and high spatial resolution, and its feasibility was verified. This study demonstrated that the overall PET performance of the proposed design was

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.

Integrated detector array technology for infrared astronomy

NASA Technical Reports Server (NTRS)

Mccreight, c. R.; Goebel, J. H.; Mckelvey, M. E.; Stafford, P. S.; Lee, J. H.

1984-01-01

The status of laboratory and telescope tests of integrated infrared detector array technology for astronomical applications is described. The devices tested represent a number of extrinsic and intrinsic detector materials and various multiplexer designs. Infrared arrays have now been used in successful astronomical applications. These have shown that device sensitivities can be comparable to those of discrete detector systems and excellent astronomical imagery can be produced.

Characterization of X3 Silicon Detectors for the ELISSA Array at ELI-NP

NASA Astrophysics Data System (ADS)

Chesnevskaya, S.; Balabanski, D. L.; Choudhury, D.; Cognata, M. La; Constantin, P.; Filipescu, D. M.; Ghita, D. G.; Guardo, G. L.; Lattuada, D.; Matei, C.; Rotaru, A.; Spitaleri, C.; State, A.; Xu, Y.

2018-01-01

Position-sensitive silicon strip detectors represent one of the best solutions for the detection of charged particles as they provide good energy and position resolution over a large range of energies. A silicon array coupled with the gamma beams at the ELI-NP facility would allow measuring photodissociation reactions of interest for Big Bang Nucleosynthesis and on heavy nuclei intervening in the p-process. Forty X3 detectors for our ELISSA (ELI-NP Silicon Strip Detectors Array) project have been recently purchased and tested. We investigated several specifications, such as leakage currents, depletion voltage, and detector stability under vacuum. The energy and position resolution, and ballistic deficit were measured and analyzed. This paper presents the main results of our extensive testing. The measured energy resolution for the X3 detectors is better than results published for similar arrays (ANASEN or ORRUBA).

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

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.

Multi-anode microchannel arrays - New detectors for imaging and spectroscopy in space

NASA Technical Reports Server (NTRS)

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

1983-01-01

Consideration is given to the construction and operation of multi-anode microchannel array detector systems having formats as large as 256 x 1024 pixels. Such arrays are being developed for imaging and spectroscopy at soft X-ray, ultraviolet and visible wavelengths from balloons, sounding rockets and space probes. Both discrete-anode and coincidence-anode arrays are described. Two types of photocathode structures are evaluated: an opaque photocathode deposited directly on the curved-channel MCP and an activated cathode deposited on a proximity-focused mesh. Future work will include sensitivity optimization in the different wavelength regions and the development of detector tubes with semitransparent proximity-focused photocathodes.

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.

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.

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.

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.

Advanced Code-Division Multiplexers for Superconducting Detector Arrays

NASA Astrophysics Data System (ADS)

Irwin, K. D.; Cho, H. M.; Doriese, W. B.; Fowler, J. W.; Hilton, G. C.; Niemack, M. D.; Reintsema, C. D.; Schmidt, D. R.; Ullom, J. N.; Vale, L. R.

2012-06-01

Multiplexers based on the modulation of superconducting quantum interference devices are now regularly used in multi-kilopixel arrays of superconducting detectors for astrophysics, cosmology, and materials analysis. Over the next decade, much larger arrays will be needed. These larger arrays require new modulation techniques and compact multiplexer elements that fit within each pixel. We present a new in-focal-plane code-division multiplexer that provides multiplexing elements with the required scalability. This code-division multiplexer uses compact lithographic modulation elements that simultaneously multiplex both signal outputs and superconducting transition-edge sensor (TES) detector bias voltages. It eliminates the shunt resistor used to voltage bias TES detectors, greatly reduces power dissipation, allows different dc bias voltages for each TES, and makes all elements sufficiently compact to fit inside the detector pixel area. These in-focal plane code-division multiplexers can be combined with multi-GHz readout based on superconducting microresonators to scale to even larger arrays.

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.

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.

Performance of a scintillation detector array operated with LHAASO-KM2A electronics

NASA Astrophysics Data System (ADS)

Wang, Zhen; Guo, Yiqing; Cai, Hui; Chang, Jinfan; Chen, Tianlu; Danzengluobu; Feng, Youliang; Gao, Qi; Gou, Quanbu; Guo, Yingying; Hou, Chao; Hu, Hongbo; Labaciren; Liu, Cheng; Li, Haijin; Liu, Jia; Liu, Maoyuan; Qiao, Bingqiang; Qian, Xiangli; Sheng, Xiangdong; Tian, Zhen; Wang, Qun; Xue, Liang; Yao, Yuhua; Zhang, Shaoru; Zhang, Xueyao; Zhang, Yi

2018-04-01

A scintillation detector array composed of 115 detectors and covering an area of about 20000 m2 was installed at the end of 2016 at the Yangbajing international cosmic ray observatory and has been taking data since then. The array is equipped with electronics from Large High Altitude Air Shower Observatory Square Kilometer Complex Array (LHAASO-KM2A) and, in turn, currently serves as the largest debugging and testing platform for the LHAASO-KM2A. Furthermore, the array was used to study the performance of a wide field-of-view air Cherenkov telescope by providing accurate information on the shower core, direction and energy, etc. This work is mainly dealing with the scintillation detector array. The experimental setup and the offline calibration are described in detail. Then, a thorough comparison between the data and Monte Carlo (MC) simulations is presented and a good agreement is obtained. With the even-odd method, the resolutions of the shower direction and core are measured. Finally, successful observations of the expected Moon's and Sun's shadows of cosmic rays (CRs) verify the measured angular resolution.

Composition Studies with the Telescope Array Surface Detector

NASA Astrophysics Data System (ADS)

Kuznetsov, Mikhail; Piskunov, Maxim; Rubtsov, Grigory; Troitsky, Sergey; Zhezher, Yana

The results on ultra-high-energy cosmic-ray chemical composition based on the data from the Telescope Array surface-detector are presented. The method is based on the multivariate boosted decision tree (BDT) analysis which uses surface-detector observables. The results on average atomic mass in the energy range 1018.0-1020.0 eV are presented. A comparison with the Telescope Array hybrid results and the Pierre Auger Observatory surface detector results is shown.

Arrays of Position-Sensitive Virtual Frisch-Grid CdZnTe Detectors: Results From a $$4\\times 4$$ Array Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ocampo Giraldo, L. A.; Bolotnikov, A. E.; Camarda, G. S.

Position-sensitive virtual Frisch-grid (VFG) CdZnTe (CZT) detectors offer a unique capability for correcting the response nonuniformities caused by crystal defects. This allowed us to achieve high energy resolution, while using typical-grade commercial CZT crystals with relaxed requirements to their quality, thus reducing the overall cost of detectors. Another advantage of the VFG detectors is that they can be integrated into arrays and used in small compact hand-held instruments or large-area gamma cameras that will enhance detection capability for many practical applications, including nonproliferation, medical imaging, and gamma-ray astronomy. Here in this paper, we present the results from testing small arraymore » prototypes coupled with front-end application-specified integrated circuit. Each detector in the array is furnished with 5-mm-wide charge-sensing pads placed near the anode. The pads signals are converted into XY coordinates, which combined with the cathode signals (for Z coordinates) provide 3-D position information of all interaction points. The basic array consists of a number of detectors grouped into 2×2 subarrays, each having a common cathode made by connecting together the cathodes of the individual detectors. Lastly, these features can significantly improve the performance of detectors while using typical-grade low-cost CZT crystals to reduce the overall cost of the proposed instrument.« less

Arrays of Position-Sensitive Virtual Frisch-Grid CdZnTe Detectors: Results From a $$4\\times 4$$ Array Prototype

DOE PAGES

Ocampo Giraldo, L. A.; Bolotnikov, A. E.; Camarda, G. S.; ...

2017-08-22

Position-sensitive virtual Frisch-grid (VFG) CdZnTe (CZT) detectors offer a unique capability for correcting the response nonuniformities caused by crystal defects. This allowed us to achieve high energy resolution, while using typical-grade commercial CZT crystals with relaxed requirements to their quality, thus reducing the overall cost of detectors. Another advantage of the VFG detectors is that they can be integrated into arrays and used in small compact hand-held instruments or large-area gamma cameras that will enhance detection capability for many practical applications, including nonproliferation, medical imaging, and gamma-ray astronomy. Here in this paper, we present the results from testing small arraymore » prototypes coupled with front-end application-specified integrated circuit. Each detector in the array is furnished with 5-mm-wide charge-sensing pads placed near the anode. The pads signals are converted into XY coordinates, which combined with the cathode signals (for Z coordinates) provide 3-D position information of all interaction points. The basic array consists of a number of detectors grouped into 2×2 subarrays, each having a common cathode made by connecting together the cathodes of the individual detectors. Lastly, these features can significantly improve the performance of detectors while using typical-grade low-cost CZT crystals to reduce the overall cost of the proposed instrument.« less

High-performance ferroelectric and magnetoresistive materials for next-generation thermal detector arrays

NASA Astrophysics Data System (ADS)

Todd, Michael A.; Donohue, Paul P.; Watton, Rex; Williams, Dennis J.; Anthony, Carl J.; Blamire, Mark G.

2002-12-01

This paper discusses the potential thermal imaging performance achievable from thermal detector arrays and concludes that the current generation of thin-film ferroelectric and resistance bolometer based detector arrays are limited by the detector materials used. It is proposed that the next generation of large uncooled focal plane arrays will need to look towards higher performance detector materials - particularly if they aim to approach the fundamental performance limits and compete with cooled photon detector arrays. Two examples of bolometer thin-film materials are described that achieve high performance from operating around phase transitions. The material Lead Scandium Tantalate (PST) has a paraelectric-to-ferroelectric phase transition around room temperature and is used with an applied field in the dielectric bolometer mode for thermal imaging. PST films grown by sputtering and liquid-source CVD have shown merit figures for thermal imaging a factor of 2 to 3 times higher than PZT-based pyroelectric thin films. The material Lanthanum Calcium Manganite (LCMO) has a paramagnetic to ferromagnetic phase transition around -20oC. This paper describes recent measurements of TCR and 1/f noise in pulsed laser-deposited LCMO films on Neodymium Gallate substrates. These results show that LCMO not only has high TCR's - up to 30%/K - but also low 1/f excess noise, with bolometer merit figures at least an order of magnitude higher than Vanadium Oxide, making it ideal for the next generation of microbolometer arrays. These high performance properties come at the expense of processing complexities and novel device designs will need to be introduced to realize the potential of these materials in the next generation of thermal detectors.

Array Detector Modules for Spent Fuel Verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bolotnikov, Aleksey

Brookhaven National Laboratory (BNL) proposes to evaluate the arrays of position-sensitive virtual Frisch-grid (VFG) detectors for passive gamma-ray emission tomography (ET) to verify the spent fuel in storage casks before storing them in geo-repositories. Our primary objective is to conduct a preliminary analysis of the arrays capabilities and to perform field measurements to validate the effectiveness of the proposed array modules. The outcome of this proposal will consist of baseline designs for the future ET system which can ultimately be used together with neutrons detectors. This will demonstrate the usage of this technology in spent fuel storage casks.

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.

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.

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.

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.

AIGO: a southern hemisphere detector for the worldwide array of ground-based interferometric gravitational wave detectors

NASA Astrophysics Data System (ADS)

Barriga, P.; Blair, D. G.; Coward, D.; Davidson, J.; Dumas, J.-C.; Howell, E.; Ju, L.; Wen, L.; Zhao, C.; McClelland, D. E.; Scott, S. M.; Slagmolen, B. J. J.; Inta, R.; Munch, J.; Ottaway, D. J.; Veitch, P.; Hosken, D.; Melatos, A.; Chung, C.; Sammut, L.; Galloway, D. K.; Marx, J.; Whitcomb, S.; Shoemaker, D.; Hughes, S. A.; Reitze, D. H.; Iyer, B. R.; Dhurandhar, S. V.; Souradeep, T.; Unnikrishnan, C. S.; Rajalakshmi, G.; Man, C. N.; Heidmann, A.; Cohadon, P.-F.; Briant, T.; Grote, H.; Danzmann, K.; Lück, H.; Willke, B.; Strain, K. A.; Sathyaprakash, B. S.; Cao, J.; Cheung, Y.-K. E.; Zhang, Y.

2010-04-01

This paper describes the proposed AIGO detector for the worldwide array of interferometric gravitational wave detectors. The first part of the paper summarizes the benefits that AIGO provides to the worldwide array of detectors. The second part gives a technical description of the detector, which will follow closely the Advanced LIGO design. Possible technical variations in the design are discussed.

Active terahertz imaging with Ne indicator lamp detector arrays

NASA Astrophysics Data System (ADS)

Kopeika, N. S.; Abramovich, A.; Yadid-Pecht, O.; Yitzhaky, Y.

2009-08-01

The advantages of terahertz (THz) imaging are well known. They penetrate well most non-conducting media and there are no known biological hazards, This makes such imaging systems important for homeland security, as they can be used to image concealed objects and often into rooms or buildings from the outside. There are also biomedical applications that are arising. Unfortunately, THz imaging is quite expensive, especially for real time systems, largely because of the price of the detector. Bolometers and pyroelectric detectors can each easily cost at least hundreds of dollars if not more, thus making focal plane arrays of them quite expensive. We have found that common miniature commercial neon indicator lamps costing typically about 30 cents each exhibit high sensitivity to THz radiation [1-3], with microsecond order rise times, thus making them excellent candidates for such focal plane arrays. NEP is on the order of 10-10 W/Hz1/2. Significant improvement of detection performance is expected when heterodyne detection is used Efforts are being made to develop focal plane array imagers using such devices at 300 GHz. Indeed, preliminary images using 4x4 arrays have already been obtained. An 8x8 VLSI board has been developed and is presently being tested. Since no similar imaging systems have been developed previously, there are many new problems to be solved with such a novel and unconventional imaging system. These devices act as square law detectors, with detected signal proportional to THz power. This allows them to act as mixers in heterodyne detection, thus allowing NEP to be reduced further by almost two orders of magnitude. Plans are to expand the arrays to larger sizes, and to employ super resolution techniques to improve image quality beyond that ordinarily obtainable at THz frequencies.

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howard, Chris; Daigle, Stephen; Buckner, Matt

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.

Stressed and unstressed Ge:Ga detector arrays for airborne astronomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stacey, G.J.; Beeman, J.W.; Haller, E.E.

1992-11-01

We have constructed and used two dimensional arrays of both unstressed and stressed Ge:GA photoconductive detectors for far-infrared astronomy from the Kuiper Airborne Observatory (KAO). The 25 element (5 x 5) arrays are designed for a new cryogenically cooled spectrometer, the MPE/UCB Far-Infrared Imaging Fabry-Perot Interferometer (FIFI). All of the pixels for the stressed array performed well on the first flights with FIFI; 25% of the detectors in the array are more sensitive than our best single element detector, with background limited noise equivalent powers (NEPs) [approx lt] 3.0 [times] 10[sup [minus]15] W Hz[sup [minus]1/2] at 158 [mu]m and 40more » km s[sup [minus]1] spectral resolution. The average array element performs within [plus minus] 15% of this value. With a bias field of 0.1 V/cm, the average detector response is 20 [plus minus] 6 Amp/Watt at 158 [mu]m. The cutoff wavelength and response also compare well with our single element detectors. The unstressed array delivers significantly better performance than our single element detector due to the lower thermal background in the new spectrometer. The average background limited NEP at 88 [mu]m and 35 km s[sup [minus]1] spectral resolution is approx. 7 [times] 10[sup [minus]15] W Hz[sup [minus]1/2]. 18 refs., 10 figs., 2 tabs.« less

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.

Large format array controller (aLFA-C): tests and characterisation at ESA

NASA Astrophysics Data System (ADS)

Lemmel, Frédéric; ter Haar, Jörg; van der Biezen, John; Duvet, Ludovic; Nelms, Nick; Blommaert, Sander; Butler, Bart; van der Luijt, Cornelis; Heijnen, Jerko; Smit, Hans; Visser, Ivo

2016-08-01

For future near infrared astronomy missions, ESA is developing a complete detection and conversion chain (photon to SpaceWire chain system): Large Format Array (aLFA-N) based on MCT type detectors. aLFA-C (Astronomy Large Format Array Controller): a versatile cryogenic detector controller. An aLFA-C prototype was developed by Caeleste (Belgium) under ESA contract (400106260400). To validate independently the performances of the aLFA-C prototype and consolidate the definition of the follow-on activity, a dedicated test bench has been designed and developed in ESTEC/ESA within the Payload Technology Validation group. This paper presents the test setup and the performance validation of the first prototype of this controller at room and cryogenic temperature. Test setup and software needed to test the HAWAII-2RG and aLFA-N detectors with the aLFA-C prototype at cryogenic temperature will be also presented.

Multi-segment detector array for hybrid reflection-mode ultrasound and optoacoustic tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Merčep, Elena; Burton, Neal C.; Deán-Ben, Xosé Luís.; Razansky, Daniel

2017-02-01

The complementary contrast of the optoacoustic (OA) and pulse-echo ultrasound (US) modalities makes the combined usage of these imaging technologies highly advantageous. Due to the different physical contrast mechanisms development of a detector array optimally suited for both modalities is one of the challenges to efficient implementation of a single OA-US imaging device. We demonstrate imaging performance of the first hybrid detector array whose novel design, incorporating array segments of linear and concave geometry, optimally supports image acquisition in both reflection-mode ultrasonography and optoacoustic tomography modes. Hybrid detector array has a total number of 256 elements and three segments of different geometry and variable pitch size: a central 128-element linear segment with pitch of 0.25mm, ideally suited for pulse-echo US imaging, and two external 64-elements segments with concave geometry and 0.6mm pitch optimized for OA image acquisition. Interleaved OA and US image acquisition with up to 25 fps is facilitated through a custom-made multiplexer unit. Spatial resolution of the transducer was characterized in numerical simulations and validated in phantom experiments and comprises 230 and 300 μm in the respective OA and US imaging modes. Imaging performance of the multi-segment detector array was experimentally shown in a series of imaging sessions with healthy volunteers. Employing mixed array geometries allows at the same time achieving excellent OA contrast with a large field of view, and US contrast for complementary structural features with reduced side-lobes and improved resolution. The newly designed hybrid detector array that comprises segments of linear and concave geometries optimally fulfills requirements for efficient US and OA imaging and may expand the applicability of the developed hybrid OPUS imaging technology and accelerate its clinical translation.

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.

Method of fabricating a PbS-PbSe IR detector array

NASA Technical Reports Server (NTRS)

Barrett, John R. (Inventor)

1987-01-01

A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chiping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

High-efficiency UV/optical/NIR detectors for large aperture telescopes and UV explorer missions: development of and field observations with delta-doped arrays

NASA Astrophysics Data System (ADS)

Nikzad, Shouleh; Jewell, April D.; Hoenk, Michael E.; Jones, Todd J.; Hennessy, John; Goodsall, Tim; Carver, Alexander G.; Shapiro, Charles; Cheng, Samuel R.; Hamden, Erika T.; Kyne, Gillian; Martin, D. Christopher; Schiminovich, David; Scowen, Paul; France, Kevin; McCandliss, Stephan; Lupu, Roxana E.

2017-07-01

Exciting concepts are under development for flagship, probe class, explorer class, and suborbital class NASA missions in the ultraviolet/optical spectral range. These missions will depend on high-performance silicon detector arrays being delivered affordably and in high numbers. To that end, we have advanced delta-doping technology to high-throughput and high-yield wafer-scale processing, encompassing a multitude of state-of-the-art silicon-based detector formats and designs. We have embarked on a number of field observations, instrument integrations, and independent evaluations of delta-doped arrays. We present recent data and innovations from JPL's Advanced Detectors and Systems Program, including two-dimensional doping technology, JPL's end-to-end postfabrication processing of high-performance UV/optical/NIR arrays and advanced coatings for detectors. While this paper is primarily intended to provide an overview of past work, developments are identified and discussed throughout. Additionally, we present examples of past, in-progress, and planned observations and deployments of delta-doped arrays.

The NSLS 100 element solid state array detector

PubMed Central

Furenlid, L.R.; Kraner, H.W.; Rogers, L.C.; Cramer, S.P.; Stephani, D.; Beuttenmuller, R.H.; Beren, J.

2015-01-01

X-ray absorption studies of dilute samples require fluorescence detection techniques. Since signal-to-noise ratios are governed by the ratio of fluorescent to scattered photons counted by a detector, solid state detectors which can discriminate between fluorescence and scattered photons have become the instruments of choice for trace element measurements. Commercially available 13 element Ge array detectors permitting total count rates < 500000 counts per second are now in routine use. Since X-ray absorption beamlines at high brightness synchrotron sources can already illuminate most dilute samples with enough flux to saturate the current generation of solid state detectors, the development of next-generation instruments with significantly higher total count rates is essential. We present the design and current status of the 100 element Si array detector being developed in a collaboration between the NSLS and the Instrumentation Division at Brookhaven National Laboratory. The detecting array consists of a 10×10 matrix of 4 mm×4 mm elements laid out on a single piece of ultrahigh purity silicon mounted at the front end of a liquid nitrogen dewar assembly. A matrix of charge sensitive integrating preamplifiers feed signals to an array of shaping amplifiers, single channel analyzers, and scalers. An electronic switch, delay amplifier, linear gate, digital scope, peak sensing A/D converter, and histogramining memory module provide for complete diagnostics and channel calibration. The entire instrument is controlled by a LabView 2 application on a MacII ci; the software also provides full control over beamline hardware and performs the data collection. PMID:26722135

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.

Noncontact Characterization of PV Detector Arrays

DTIC Science & Technology

1990-06-01

11-7 3 III DIODE ARRAY AS A SAW CONVOLVER/STORAGE CORRELATOR .... III-1 III.A NONLINEAR ( VARACTOR ) ACTION OF THE DIODES .......................... I...associated with the diodes in the detector array. The varactor action of the diodes produces a voltage across the diodes which is pro- portional to the...type of interactions desired herein. An alternative approach is to em- ploy thin dielectric overlays, such as zinc oxide or silicon nitride

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;

Mechanical designs and development of TES bolometer detector arrays for the Advanced ACTPol experiment

NASA Astrophysics Data System (ADS)

Ward, Jonathan T.; Austermann, Jason; Beall, James A.; Choi, Steve K.; Crowley, Kevin T.; Devlin, Mark J.; Duff, Shannon M.; Gallardo, Patricio A.; 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; Niemack, Michael D.; Page, Lyman A.; Salatino, Maria; Schillaci, Alessandro; Schmitt, Benjamin L.; Simon, Sara M.; Staggs, Suzanne T.; Thornton, Robert; Ullom, Joel N.; Vavagiakis, Eve M.; Wollack, Edward J.

2016-07-01

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 profile 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 modified to incorporate the new AdvACT instruments. Therefore, we discuss the integration of all AdvACT arrays with pre-existing ACTPol infrastructure.

Characterization of a 2 × 2 array of large square bars of LaBr3:Ce detectors with γ-rays up to 22.5 MeV

NASA Astrophysics Data System (ADS)

Dhibar, M.; Mazumdar, I.; Chavan, P. B.; Patel, S. M.; Anil Kumar, G.

2018-03-01

LaBr3:Ce scintillators have recently become commercially available in sizes large enough for measurements of high energy gamma-rays. In this communication, we report our studies on properties and response of large volume square bars (2‧‧ ×2‧‧ ×8‧‧) of LaBr3:Ce detectors, individually, and in a compact array of four square bars, with gamma-rays up to 22.5 MeV. The properties studied are, uniformity of the crystal, internal radioactivity, energy resolution, timing resolution, linearity of the response and detection efficiencies. The response of the detectors for 22.5 MeV γ-rays produced from 11B(p , γ)12C capture reaction and for 15.1 MeV γ-rays produced from 12C(p ,p‧ γ)12C inelastic scattering reaction are studied in detail. The measured absolute efficiencies (both total detection and photo-peak) for 662 keV gamma-rays from 137Cs are compared to those obtained using realistic GEANT4 simulations. The primary aim of the array is to measure high energy gamma-rays (5-50 MeV) produced from the de-excitation of excited Giant Dipole Resonance (GDR) states, radiative capture reactions, nuclear Bremsstrahlung process and inelastic scattering process. The highly satisfactory performance of the array provides the impetus for future efforts toward building a bigger array.

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.

Sensor Modelling for the ’Cyclops’ Focal Plane Detector Array Based Technology Demonstrator

DTIC Science & Technology

1992-12-01

Detector Array IFOV Instantaneous field of view IRFPDA Infrared Focal Plane Detector Array LWIR Long-Wave Infrared 0 MCT Mercury Cadmium Telluride MTF...scale focal plane detector array (FPDA). The sensor system operates in the long-wave infrared ( LWIR ) spectral region. The detector array consists of...charge transfer inefficiencies in the readout circuitry. The performance of the HgCdTe FPDA based sensor is limited by the nonuniformity of the

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amenomori, M.; Nanjo, H.; Bi, X. J.

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 undergroundmore » water Cherenkov muon detector.« less

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

PubMed

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

2015-03-12

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.

Spectral x-ray diffraction using a 6 megapixel photon counting array detector

NASA Astrophysics Data System (ADS)

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.

2015-03-01

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.

Two-dimensional photon-counting detector arrays based on microchannel array plates

NASA Technical Reports Server (NTRS)

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

1975-01-01

The production of simple and rugged photon-counting detector arrays has been made possible by recent improvements in the performance of the microchannel array plate (MCP) and by the parallel development of compatible electronic readout systems. The construction of proximity-focused MCP arrays of novel design in which photometric information from (n x m) picture elements is read out with a total of (n + m) amplifier and discriminator circuits is described. Results obtained with a breadboard (32 x 32)-element array employing 64 charge-sensitive amplifiers are presented, and the application of systems of this type in spectrometers and cameras for use with ground-based telescopes and on orbiting spacecraft discussed.

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.

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.

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.

R-process experiments with the Advanced Implantation Detector Array

NASA Astrophysics Data System (ADS)

Estrade, Alfredo; Griffin, Chris; Davinson, Tom; Bruno, Carlo; Hall, Oscar; Liu, Zhong; Woods, Phil; Coleman-Smith, Patrick; Labiche, Marc; Lazarus, Ian; Pucknell, Victor; Simpson, John; Harkness-Brennan, Laura; Page, Robert; Kiss, Gabor; Liu, Jiajiang; Matsui, Keishi; Nishimura, Shunji; Phong, Vi; Lorusso, Giuseppe; Montes, Fernando; Nepal, Neerajan; Briken Collaboration; Ribf106 Experiment Team

2017-09-01

Decay properties of neutron rich isotopes, such as half-lives and β-delayed neutron emission probabilities, are an important input for astrophysical models of the r-process. A new generation of fragmentation beam facilities has made it possible to access large regions of the nuclear chart that are close to the path of the r-process for some astrophysical models. The Advanced Implantation Detector Array (AIDA) is a segmented active-stopper detector designed for decay experiments with fast ion beams, which was recently commissioned at the Radioactive Ion Beam Factory in RIKEN, Japan. In this presentation we describe the main characteristics of AIDA, and present preliminary results of the first experiments in the region of neutron-rich selenium isotopes and along the N=82 shell closure.

Particle Identification in the NIMROD-ISiS Detector Array

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wuenschel, S.; Hagel, K.; May, L. W.

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.

High performance large infrared and visible astronomy arrays for low background applications: instruments performance data and future developments at Raytheon

NASA Astrophysics Data System (ADS)

Beuville, Eric; Acton, David; Corrales, Elizabeth; Drab, John; Levy, Alan; Merrill, Michael; Peralta, Richard; Ritchie, William

2007-09-01

Raytheon Vision Systems (RVS) has developed a family of high performance large format infrared detector arrays for astronomy and civil space applications. RVS offers unique off-the-shelf solutions to the astronomy community. This paper describes mega-pixel arrays, based on multiple detector materials, developed for astronomy and low-background applications. New focal plane arrays under development at RVS for the astronomy community will also be presented. Large Sensor Chip Assemblies (SCAs) using various detector materials like Si:PIN, HgCdTe, InSb, and Si:As IBC, covering a detection range from visible to large wavelength infrared (LWIR) have been demonstrated with an excellent quantum efficiency and very good uniformity. These focal plane arrays have been assembled using state-of-the-art low noise, low power, readout integrated circuits (ROIC) designed at RVS. Raytheon packaging capabilities address reliability, precision alignment and flatness requirements for both ground-based and space applications. Multiple SCAs can be packaged into even larger focal planes. The VISTA telescope, for example, contains sixteen 2k × 2k infrared focal plane arrays. RVS astronomical arrays are being deployed world-wide in ground-based and space-based applications. A summary of performance data for each of these array types from instruments in operation will be presented (VIRGO Array for large format SWIR, the ORION and VISTA Arrays, NEWFIRM and other solutions for MWIR spectral ranges).

Superconducting Bolometer Array Architectures

NASA Technical Reports Server (NTRS)

Benford, Dominic; Chervenak, Jay; Irwin, Kent; Moseley, S. Harvey; Shafer, Rick; Staguhn, Johannes; Wollack, Ed; Oegerle, William (Technical Monitor)

2002-01-01

The next generation of far-infrared and submillimeter instruments require large arrays of detectors containing thousands of elements. These arrays will necessarily be multiplexed, and superconducting bolometer arrays are the most promising present prospect for these detectors. We discuss our current research into superconducting bolometer array technologies, which has recently resulted in the first multiplexed detections of submillimeter light and the first multiplexed astronomical observations. Prototype arrays containing 512 pixels are in production using the Pop-Up Detector (PUD) architecture, which can be extended easily to 1000 pixel arrays. Planar arrays of close-packed bolometers are being developed for the GBT (Green Bank Telescope) and for future space missions. For certain applications, such as a slewed far-infrared sky survey, feedhorncoupling of a large sparsely-filled array of bolometers is desirable, and is being developed using photolithographic feedhorn arrays. Individual detectors have achieved a Noise Equivalent Power (NEP) of -10(exp 17) W/square root of Hz at 300mK, but several orders of magnitude improvement are required and can be reached with existing technology. The testing of such ultralow-background detectors will prove difficult, as this requires optical loading of below IfW. Antenna-coupled bolometer designs have advantages for large format array designs at low powers due to their mode selectivity.

High Sensitivity Terahertz Detection through Large-Area Plasmonic Nano-Antenna Arrays.

PubMed

Yardimci, Nezih Tolga; Jarrahi, Mona

2017-02-16

Plasmonic photoconductive antennas have great promise for increasing responsivity and detection sensitivity of conventional photoconductive detectors in time-domain terahertz imaging and spectroscopy systems. However, operation bandwidth of previously demonstrated plasmonic photoconductive antennas has been limited by bandwidth constraints of their antennas and photoconductor parasitics. Here, we present a powerful technique for realizing broadband terahertz detectors through large-area plasmonic photoconductive nano-antenna arrays. A key novelty that makes the presented terahertz detector superior to the state-of-the art is a specific large-area device geometry that offers a strong interaction between the incident terahertz beam and optical pump at the nanoscale, while maintaining a broad operation bandwidth. The large device active area allows robust operation against optical and terahertz beam misalignments. We demonstrate broadband terahertz detection with signal-to-noise ratio levels as high as 107 dB.

High Sensitivity Terahertz Detection through Large-Area Plasmonic Nano-Antenna Arrays

PubMed Central

Yardimci, Nezih Tolga; Jarrahi, Mona

2017-01-01

Plasmonic photoconductive antennas have great promise for increasing responsivity and detection sensitivity of conventional photoconductive detectors in time-domain terahertz imaging and spectroscopy systems. However, operation bandwidth of previously demonstrated plasmonic photoconductive antennas has been limited by bandwidth constraints of their antennas and photoconductor parasitics. Here, we present a powerful technique for realizing broadband terahertz detectors through large-area plasmonic photoconductive nano-antenna arrays. A key novelty that makes the presented terahertz detector superior to the state-of-the art is a specific large-area device geometry that offers a strong interaction between the incident terahertz beam and optical pump at the nanoscale, while maintaining a broad operation bandwidth. The large device active area allows robust operation against optical and terahertz beam misalignments. We demonstrate broadband terahertz detection with signal-to-noise ratio levels as high as 107 dB. PMID:28205615

The Full-Scale Prototype for the Fluorescence Detector Array of Single-Pixel Telescopes

NASA Astrophysics Data System (ADS)

Fujii, T.; Malacari, M.; Bellido, J. A.; Farmer, J.; Galimova, A.; Horvath, P.; Hrabovsky, M.; Mandat, D.; Matalon, A.; Matthews, J. N.; Merolle, M.; Ni, X.; Nozka, L.; Palatka, M.; Pech, M.; Privitera, P.; Schovanek, P.; Thomas, S. B.; Travnicek, P.

The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design concept for the next generation of ultrahigh-energy cosmic ray (UHECR) observatories, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays. 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. Motivated by the successful detection of UHECRs using a prototype comprised of a single 200 mm photomultiplier-tube and a 1 m2 Fresnel lens system, we have developed a new "full-scale" prototype consisting of four 200 mm photomultiplier-tubes at the focus of a segmented mirror of 1.6 m in diameter. We report on the status of the full-scale prototype, including test measurements made during first light operation at the Telescope Array site in central Utah, U.S.A.

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.

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.

The "collimator monitoring fill factor" of a two-dimensional detector array, a measure of its ability to detect collimation errors.

PubMed

Stelljes, Tenzin Sonam; Looe, Hui Khee; Harder, Dietrich; Poppe, Björn

2017-03-01

Two-dimensional detector arrays are routinely used for constancy checks and treatment plan verification in photon-beam radiotherapy. In addition to the spatial resolution of the dose profiles, the "coverage" of the radiation field with respect to the detection of any beam collimation deficiency appears as the second characteristic feature of a detector array. The here proposed "collimator monitoring fill factor" (CM fill factor) has been conceived to serve as a quantitative characteristic of this "coverage". The CM fill factor is defined as the probability of a 2D array to detect any collimator position error. Therefore, it is represented by the ratio of the "sensitive area" of a single detector, in which collimator position errors are detectable, and the geometrical "cell area" associated with this detector within the array. Numerical values of the CM fill factor have been Monte Carlo simulated for 2D detector arrays equipped with air-vented ionization chambers, liquid-filled ionization chambers and diode detectors and were compared with the "FWHM fill factor" defined by Gago-Arias et al. (2012). For arrays with vented ionization chambers, the differences between the CM fill factor and the FWHM fill factor are moderate, but occasionally the latter exceeds unity. For narrower detectors such as liquid-filled ionization chambers and Si diodes and for small sampling distances, large differences between the FWHM fill factor and the CM fill factor have been observed. These differences can be explained by the shapes of the fluence response functions of these narrow detectors. A new parameter "collimator monitoring fill factor" (CM fill factor), applicable to quantitate the collimator position error detection probability of a 2D detector array, has been proposed. It is designed as a help in classifying the clinical performance of two-dimensional detector arrays in photon-beam radiotherapy. © 2017 American Association of Physicists in Medicine.

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.

X-ray tests of a microchannel plate detector and amorphous silicon pixel array readout for neutron radiography

NASA Astrophysics Data System (ADS)

Ambrosi, R. M.; Street, R.; Feller, B.; Fraser, G. W.; Watterson, J. I. W.; Lanza, R. C.; Dowson, J.; Ross, D.; Martindale, A.; Abbey, A. F.; Vernon, D.

2007-03-01

High-performance large area imaging detectors for fast neutrons in the 5-14 MeV energy range do not exist at present. The aim of this project is to combine microchannel plates or MCPs (or similar electron multiplication structures) traditionally used in image intensifiers and X-ray detectors with amorphous silicon (a-Si) pixel arrays to produce a composite converter and intensifier position sensitive imaging system. This detector will provide an order of magnitude improvement in image resolution when compared with current millimetre resolution limits obtained using phosphor or scintillator-based hydrogen rich converters. In this study we present the results of the initial experimental evaluation of the prototype system. This study was carried out using a medical X-ray source for the proof of concept tests, the next phase will involve neutron imaging tests. The hybrid detector described in this study is a unique development and paves the way for large area position sensitive detectors consisting of MCP or microsphere plate detectors and a-Si or polysilicon pixel arrays. Applications include neutron and X-ray imaging for terrestrial applications. The technology could be extended to space instrumentation for X-ray astronomy.

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

NASA Technical Reports Server (NTRS)

Timothy, J. G.

1983-01-01

The techniques and procedures for producing very-large-format pulse-counting array detector systems for use in forthcoming high-energy astrophysics facilities were defined, and the structures and performance characteristics of high-sensitivity photocathodes for use at soft X-ray wavelengths between 100 and 1 A were determined. The progress made to date in each of these areas are described and the tasks that will be undertaken when the program is continued are summarized.

MTF measurement and analysis of linear array HgCdTe infrared detectors

NASA Astrophysics Data System (ADS)

Zhang, Tong; Lin, Chun; Chen, Honglei; Sun, Changhong; Lin, Jiamu; Wang, Xi

2018-01-01

The slanted-edge technique is the main method for measurement detectors MTF, however this method is commonly used on planar array detectors. In this paper the authors present a modified slanted-edge method to measure the MTF of linear array HgCdTe detectors. Crosstalk is one of the major factors that degrade the MTF value of such an infrared detector. This paper presents an ion implantation guard-ring structure which was designed to effectively absorb photo-carriers that may laterally defuse between adjacent pixels thereby suppressing crosstalk. Measurement and analysis of the MTF of the linear array detectors with and without a guard-ring were carried out. The experimental results indicated that the ion implantation guard-ring structure effectively suppresses crosstalk and increases MTF value.

Characterization of Kilopixel TES detector arrays for PIPER

NASA Astrophysics Data System (ADS)

Datta, Rahul; Ade, Peter; Benford, Dominic; Bennett, Charles; Chuss, David; Costen, Nicholas; Coughlin, Kevin; Dotson, Jessie; Eimer, Joseph; Fixsen, Dale; Gandilo, Natalie; Halpern, Mark; Essinger-Hileman, Thomas; Hilton, Gene; Hinshaw, Gary; Irwin, Kent; Jhabvala, Christine; Kimball, Mark; Kogut, Al; Lazear, Justin; Lowe, Luke; Manos, George; McMahon, Jeff; Miller, Timothy; Mirel, Paul; Moseley, Samuel Harvey; Pawlyk, Samuel; Rodriguez, Samelys; Sharp, Elmer; Shirron, Peter; Staguhn, Johannes G.; Sullivan, Dan; Switzer, Eric; Taraschi, Peter; Tucker, Carole; Walts, Alexander; Wollack, Edward

2018-01-01

The Primordial Inflation Polarization ExploreR (PIPER) is a balloon-borne instrument optimized to measure the polarization of the Cosmic Microwave Background (CMB) at large angular scales. It will map 85% of the sky in four frequency bands centered at 200, 270, 350, and 600 GHz to characterize dust foregrounds and constrain the tensor-to-scalar ratio, r. The sky is imaged on to 32x40 pixel arrays of time-domain multiplexed Transition-Edge Sensor (TES) bolometers operating at a bath temperature of 100 mK to achieve background-limited sensitivity. Each kilopixel array is indium-bump-bonded to a 2D superconducting quantum interference device (SQUID) time-domain multiplexer (MUX) chip and read out by warm electronics. Each pixel measures total incident power over a frequency band defined by bandpass filters in front of the array, while polarization sensitivity is provided by the upstream Variable-delay Polarization Modulators (VPMs) and analyzer grids. We present measurements of the detector parameters from the laboratory characterization of the first kilopixel science array for PIPER including transition temperature, saturation power, thermal conductivity, time constant, and noise performance. We also describe the testing of the 2D MUX chips, optimization of the integrated readout parameters, and the overall pixel yield of the array. The first PIPER science flight is planned for June 2018 from Palestine, Texas.

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.

Simulated characteristics of the DEGAS γ-detector array

NASA Astrophysics Data System (ADS)

Li, G. S.; Lizarazo, C.; Gerl, J.; Kojouharov, I.; Schaffner, H.; Górska, M.; Pietralla, N.; Saha, S.; Liu, M. L.; Wang, J. G.

2018-05-01

The performance of the novel HPGe-Cluster array DEGAS to be used at FAIR has been studied through GEANT4 simulations using accurate geometries of most of the detector components. The simulation framework has been tested by comparing experimental data of various detector setups. The study showed that the DEGAS system could provide a clear improvement of the photo-peak efficiency compared to the previous RISING array. In addition, the active BGO Back-catcher could greatly enhance the background suppression capability. The add-back analysis revealed that even at a γ multiplicity of six the sensitivity is improved by adding back the energy depositions of the neighboring Ge crystals.

Image scanning microscopy using a SPAD detector array (Conference Presentation)

NASA Astrophysics Data System (ADS)

Castello, Marco; Tortarolo, Giorgio; Buttafava, Mauro; Tosi, Alberto; Sheppard, Colin J. R.; Diaspro, Alberto; Vicidomini, Giuseppe

2017-02-01

The use of an array of detectors can help overcoming the traditional limitation of confocal microscopy: the compromise between signal and theoretical resolution. Each element independently records a view of the sample and the final image can be reconstructed by pixel reassignment or by inverse filtering (e.g. deconvolution). In this work, we used a SPAD array of 25 detectors specifically designed for this goal and our scanning microscopy control system (Carma) to acquire the partial images and to perform online image processing. Further work will be devoted to optimize the image reconstruction step and to improve the fill-factor of the detector.

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 PAGES

Bolotnikov, A. E.; Ackley, K.; Camarda, G. S.; ...

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 mm 3 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 readoutmore » 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.« less

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

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

2016-03-02

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.

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.

First data with the Hybrid Array of Gamma Ray Detector (HAGRiD)

NASA Astrophysics Data System (ADS)

Smith, K.; Baugher, T.; Burcher, S.; Carter, A. B.; Cizewski, J. A.; Chipps, K. A.; Febbraro, M.; Grzywacz, R.; Jones, K. L.; Munoz, S.; Pain, S. D.; Paulauskas, S. V.; Ratkiewicz, A.; Schmitt, K. T.; Thornsberry, C.; Toomey, R.; Walter, D.; Willoughby, H.

2018-01-01

The structure of nuclei provides insight into astrophysical reaction rates that are difficult to measure directly. These studies are often performed with transfer reactions and β-decay measurements. These experiments benefit from particle-γ coincidence measurements which provide information beyond that of particle detection alone. The Hybrid Array of Gamma Ray Detectors (HAGRiD) of LaBr3(Ce) scintillators has been designed with this purpose in mind. The design of the array permits it to be coupled with particle detector systems, such as the Oak Ridge Rutgers University Barrel Array (ORRUBA) of silicon detectors and the Versatile Array of Neutron Detectors at Low Energy (VANDLE). It is also designed to operate with the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) advanced target system. HAGRiD's design avoids compromising the charged-particle angular resolution due to compact geometries which are often used to increase the γ efficiency in other systems. First experiments with HAGRiD coupled to VANDLE as well as ORRUBA and JENSA are discussed.

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.

Experimental realization of a metamaterial detector focal plane array.

PubMed

Shrekenhamer, David; Xu, Wangren; Venkatesh, Suresh; Schurig, David; Sonkusale, Sameer; Padilla, Willie J

2012-10-26

We present a metamaterial absorber detector array that enables room-temperature, narrow-band detection of gigahertz (GHz) radiation in the S band (2-4 GHz). The system is implemented in a commercial printed circuit board process and we characterize the detector sensitivity and angular dependence. A modified metamaterial absorber geometry allows for each unit cell to act as an isolated detector pixel and to collectively form a focal plane array . Each pixel can have a dedicated microwave receiver chain and functions together as a hybrid device tuned to maximize the efficiency of detected power. The demonstrated subwavelength pixel shows detected sensitivity of -77 dBm, corresponding to a radiation power density of 27 nW/m(2), with pixel to pixel coupling interference below -14 dB at 2.5 GHz.

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.

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.

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.

Large-format platinum silicide microwave kinetic inductance detectors for optical to near-IR astronomy.

PubMed

Szypryt, P; Meeker, S R; Coiffard, G; Fruitwala, N; Bumble, B; Ulbricht, G; Walter, A B; Daal, M; Bockstiegel, C; Collura, G; Zobrist, N; Lipartito, I; Mazin, B A

2017-10-16

We have fabricated and characterized 10,000 and 20,440 pixel Microwave Kinetic Inductance Detector (MKID) arrays for the Dark-speckle Near-IR Energy-resolved Superconducting Spectrophotometer (DARKNESS) and the MKID Exoplanet Camera (MEC). These instruments are designed to sit behind adaptive optics systems with the goal of directly imaging exoplanets in a 800-1400 nm band. Previous large optical and near-IR MKID arrays were fabricated using substoichiometric titanium nitride (TiN) on a silicon substrate. These arrays, however, suffered from severe non-uniformities in the TiN critical temperature, causing resonances to shift away from their designed values and lowering usable detector yield. We have begun fabricating DARKNESS and MEC arrays using platinum silicide (PtSi) on sapphire instead of TiN. Not only do these arrays have much higher uniformity than the TiN arrays, resulting in higher pixel yields, they have demonstrated better spectral resolution than TiN MKIDs of similar design. PtSi MKIDs also do not display the hot pixel effects seen when illuminating TiN on silicon MKIDs with photons with wavelengths shorter than 1 µm.

DEATH-STAR: Silicon and Photovoltaic Fission Fragment Detector Arrays for Light-Ion Induced Fission Correlation Studies

NASA Astrophysics Data System (ADS)

Koglin, J. D.; Burke, J. T.; Fisher, S. E.; Jovanovic, I.

2017-05-01

The Direct Excitation Angular Tracking pHotovoltaic-Silicon Telescope ARray (DEATH-STAR) combines a series of 12 silicon detectors in a ΔE - E configuration for charged particle identification with a large-area array of 56 photovoltaic (solar) cells for detection of fission fragments. The combination of many scattering angles and fission fragment detectors allows for an angular-resolved tool to study reaction cross sections using the surrogate method, anisotropic fission distributions, and angular momentum transfers through stripping, transfer, inelastic scattering, and other direct nuclear reactions. The unique photovoltaic detectors efficiently detect fission fragments while being insensitive to light ions and have a timing resolution of 15.63±0.37 ns. Alpha particles are detected with a resolution of 35.5 keV 1σ at 7.9 MeV. Measured fission fragment angular distributions are also presented.

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.

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. Like Transition Edge Sensors (TESs) microbolometers, MKIDs can count single X-ray photons over a wide energy range and determine their energy and arrival time. MKIDs allow very large pixel counts with a simple room temperature microwave readout. In this investigation we will develop a new type of detector based on a MKID called the Thermal Kinetic Inductance Detector, or TKID. A TKID changes the basic MKID architecture by placing the inductor of the MKID on a suspended SiN membrane. The capacitor will remain on the bulk Si to reduce noise. Much like a TES, the TKID will sense changes in temperature of the isolated SiN island caused by photon absorption. The advantages of a TKID include lack of positional/geometry dependence, a more tunable pulse decay time, a relaxation of the MKID resonator material requirements, and more. We have already fabricated a TKID with the best energy resolution seen to date in any KID. Here we propose to improve the energy resolution below 10 eV, develop mushroom absorbers compatible with our TKIDs, and integrate these detectors into small arrays.

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.

Optical Communications With A Geiger Mode APD Array

DTIC Science & Technology

2016-02-09

spurious fires from numerous sources, including crosstalk from other detectors in the same array . Additionally, after a 9 successful detection, the...be combined into arrays with large numbers of detectors , allowing for scaling of dynamic range with relatively little overhead on space and power...overall higher rate of dark counts than a single detector , this is more than compensated for by the extra detectors . A sufficiently large APD array could

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.

NOY: a neutrino observatory network project based on stand alone air shower detector arrays

NASA Astrophysics Data System (ADS)

Montanet, F.; Lebrun, D.; Chauvin, J.; Lagorio, E.; Stassi, P.

2011-09-01

We have developed a self powered stand alone particle detector array dedicated to the observation of horizontal tau air showers induced by high energy neutrinos interacting in mountain rock. Air shower particle detection reaches a 100% duty cycle and is practically free of background when compared to Cherenkov light or radio techniques. It is thus better suited for rare neutrino event search. An appropriate mountain to valley topological configuration has been identified and the first array will be deployed on an inclined slope at an elevation of 1500 m facing Southern Alps near the city of Grenoble (France). A full simulation has been performed. A neutrino energy dependent mountain tomography chart is obtained using a neutrino and tau propagation code together with a detailed cartography and elevation map of the region. The array acceptance is then evaluated between 1 PeV and 100 EeV by simulating decaying tau air showers across the valley. The effective detection surface is determined by the shower lateral extension at array location and is hence much larger than the array geometrical area. The array exposure will be 1014 cm2 sr s at 100 PeV. Several independent arrays can be deployed with the aim of constituting a large distributed observatory. Some other sites are already under study. At last, special care is dedicated to the educational and outreach aspects of such a cosmic ray detector.

Cryogen-free cryostat for large-scale arrays of superconducting tunnel junction ion detectors in time-of-flight mass spectrometry

NASA Astrophysics Data System (ADS)

Kushino, A.; Ohkubo, M.; Chen, Y. E.; Ukibe, M.; Kasai, S.; Fujioka, K.

2006-04-01

Nb-based superconducting tunnel junction (STJ) detectors have a fast time resolution of a few 100 ns and high operating temperature of 0.3 K. These advantages expand their applicable fields to time-of-flight mass spectrometry (TOF-MS). In order to enlarge effective detection area, we have built arrays based on hundreds of large STJ elements. To realize the fast readout and no-cross talk, coaxial cables made of low-thermal conductivity materials were investigated. From results of thermal conduction measurements, we chose thin coaxial cables with a diameter of 0.33 mm, consisting of CuNi center/outer conductors and Teflon insulator for the wiring between 0.3 K- 3He pot of the sorption pump and 3 K-2nd stage of GM cooler. Even after the installation of coaxial cables and a cold snout to the cryogen-free cryostat, we could keep arrays at 0.3 K for about a week, and reduction of the holding time at 0.3 K and temperature rise at 3He pot due to the installation were small, ˜0.5 day and 10 mK, respectively.

Design and evaluation of a SiPM-based large-area detector module for positron emission imaging

NASA Astrophysics Data System (ADS)

Alva-Sánchez, H.; Murrieta-Rodríguez, T.; Calva-Coraza, E.; Martínez-Dávalos, A.; Rodríguez-Villafuerte, M.

2018-03-01

The design and evaluation of a large-area detector module for positron emission imaging applications, is presented. The module features a SensL ArrayC-60035-64P-PCB solid state detector (8×8 array of tileable silicon photomultipliers by SensL, 7.2 mm pitch) covering a total area of 57.4×57.4 mm2. The detector module was formed using a pixelated array of 40×40 lutetium-yttrium oxyorthosilicate (LYSO) scintillator crystal elements with 1.43 mm pitch. A 7 mm thick coupling light guide was used to allow light sharing between adjacent SiPM. A 16-channel symmetric charge division (SCD) readout board was designed to multiplex the number of signals from 64 to 16 (8 columns and 8 rows) and a center-of-gravity algorithm to identify the position. Data acquisition and digitization was accomplished using a custom-made system based on FPGAs boards. Crystal maps were obtained using 18F-positron sources and Voronoi diagrams were used to correct for geometric distortions and to generate a non-uniformity correction matrix. All measurements were taken at a controlled room temperature of 22oC. The crystal maps showed minor distortion, 90% of the 1600 total crystal elements could be identified, a mean peak-to-valley ratio of 4.3 was obtained and a 10.8% mean energy resolution for 511 keV annihilation photons was determined. The performance of the detector using our own readout board was compared to that using two different commercially readout boards using the same detector module arrangement. We show that these large-area SiPM arrays, combined with a 16-channel SCD readout board, can offer high spatial resolution, excellent energy resolution and detector uniformity and thus, can be used for positron emission imaging applications.

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

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.

Zonal wavefront sensor with reduced number of rows in the detector array.

PubMed

Boruah, Bosanta R; Das, Abhijit

2011-07-10

In this paper, we describe a zonal wavefront sensor in which the photodetector array can have a smaller number of rows. The test wavefront is incident on a two-dimensional array of diffraction gratings followed by a single focusing lens. The periodicity and the orientation of the grating rulings of each grating can be chosen such that the +1 order beam from the gratings forms an array of focal spots in the detector plane. We show that by using a square array of zones, it is possible to generate an array of +1 order focal spots having a smaller number of rows, thus reducing the height of the required detector array. The phase profile of the test wavefront can be estimated by measuring the displacements of the +1 order focal spots for the test wavefront relative to the +1 order focal spots for a plane reference wavefront. The narrower width of the photodetector array can offer several advantages, such as a faster frame rate of the wavefront sensor, a reduced amount of cross talk between the nearby detector zones, and a decrease in the maximum thermal noise. We also present experimental results of a proof-of-concept experimental arrangement using the proposed wavefront sensing scheme. © 2011 Optical Society of America

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.

DEATH-STAR: Silicon and photovoltaic fission fragment detector arrays for light-ion induced fission correlation studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koglin, J. D.; Burke, J. T.; Fisher, S. E.

Here, the Direct Excitation Angular Tracking pHotovoltaic-Silicon Telescope ARray (DEATH-STAR) combines a series of 12 silicon detectors in a ΔE–E configuration for charged particle identification with a large-area array of 56 photovoltaic (solar) cells for detection of fission fragments. The combination of many scattering angles and fission fragment detectors allows for an angular-resolved tool to study reaction cross sections using the surrogate method, anisotropic fission distributions, and angular momentum transfers through stripping, transfer, inelastic scattering, and other direct nuclear reactions. The unique photovoltaic detectors efficiently detect fission fragments while being insensitive to light ions and have a timing resolution ofmore » 15.63±0.37 ns. Alpha particles are detected with a resolution of 35.5 keV 1σ at 7.9 MeV. Measured fission fragment angular distributions are also presented.« less

DEATH-STAR: Silicon and photovoltaic fission fragment detector arrays for light-ion induced fission correlation studies

DOE PAGES

Koglin, J. D.; Burke, J. T.; Fisher, S. E.; ...

2017-02-20

Here, the Direct Excitation Angular Tracking pHotovoltaic-Silicon Telescope ARray (DEATH-STAR) combines a series of 12 silicon detectors in a ΔE–E configuration for charged particle identification with a large-area array of 56 photovoltaic (solar) cells for detection of fission fragments. The combination of many scattering angles and fission fragment detectors allows for an angular-resolved tool to study reaction cross sections using the surrogate method, anisotropic fission distributions, and angular momentum transfers through stripping, transfer, inelastic scattering, and other direct nuclear reactions. The unique photovoltaic detectors efficiently detect fission fragments while being insensitive to light ions and have a timing resolution ofmore » 15.63±0.37 ns. Alpha particles are detected with a resolution of 35.5 keV 1σ at 7.9 MeV. Measured fission fragment angular distributions are also presented.« less

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.

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.

Far infrared through millimeter backshort-under-grid arrays

NASA Astrophysics Data System (ADS)

Allen, Christine A.; Abrahams, John; Benford, Dominic J.; Chervenak, James A.; Chuss, David T.; Staguhn, Johannes G.; Miller, Timothy M.; Moseley, S. Harvey; Wollack, Edward J.

2006-06-01

We are developing a large-format, versatile, bolometer array for a wide range of infrared through millimeter astronomical applications. The array design consists of three key components - superconducting transition edge sensor bolometer arrays, quarter-wave reflective backshort grids, and Superconducting Quantum Interference Device (SQUID) multiplexer readouts. The detector array is a filled, square grid of bolometers with superconducting sensors. The backshort arrays are fabricated separately and are positioned in the etch cavities behind the detector grid. The grids have unique three-dimensional interlocking features micromachined into the walls for positioning and mechanical stability. The ultimate goal of the program is to produce large-format arrays with background-limited sensitivity, suitable for a wide range of wavelengths and applications. Large-format (kilopixel) arrays will be directly indium bump bonded to a SQUID multiplexer circuit. We have produced and tested 8×8 arrays of 1 mm detectors to demonstrate proof of concept. 8×16 arrays of 2 mm detectors are being produced for a new Goddard Space Flight Center instrument. We have also produced models of a kilopixel detector grid and dummy multiplexer chip for bump bonding development. We present detector design overview, several unique fabrication highlights, and assembly technologies.

Development of a mercuric iodide detector array for in-vivo x-ray imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patt, B.E.; Iwanczyk, J.S.; Tornai, M.P.

A nineteen element mercuric iodide (HgI{sub 2}) detector array has been developed in order to investigate the potential of using this technology for in-vivo x-ray and gamma-ray imaging. A prototype cross-grid detector array was constructed with hexagonal pixels of 1.9 mm diameter (active area = 3.28 mm{sup 2}) and 0.2 mm thick septa. The overall detector active area is roughly 65 mm{sup 2}. A detector thickness of 1.2 mm was used to achieve about 100% efficiency at 60 keV and 67% efficiency at 140 keV The detector fabrication, geometry and structure were optimized for charge collection and to minimize crosstalkmore » between elements. A section of a standard high resolution cast-lead gamma-camera collimator was incorporated into the detector to provide collimation matching the discrete pixel geometry. Measurements of spectral and spatial performance of the array were made using 241-Am and 99m-Tc sources. These measurements were compared with similar measurements made using an optimized single HgI{sub 2} x-ray detector with active area of about 3 mm{sup 2} and thickness of 500 {mu}m.« less

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.

Integrated infrared detector arrays for low-background astronomy

NASA Technical Reports Server (NTRS)

Mccreight, C. R.

1979-01-01

Existing integrated infrared detector array technology is being evaluated under low-background conditions to determine its applicability in orbiting astronomical applications where extended integration times and photometric accuracy are of interest. Preliminary performance results of a 1 x 20 elements InSb CCD array under simulated astronomical conditions are presented. Using the findings of these tests, improved linear- and area-array technology will be developed for use in NASA programs such as the Shuttle Infrared Telescope Facility. For wavelengths less than 30 microns, extrinsic silicon and intrinsic arrays with CCD readout will be evaluated and improved as required, while multiplexed arrays of Ge:Ga for wavelengths in the range 30 to 120 microns will be developed as fundamental understanding of this material improves. Future efforts will include development of improved drive and readout circuitry, and consideration of alternate multiplexing schemes.

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

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

2016-02-06

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.

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.

Multiband selection with linear array detectors

NASA Technical Reports Server (NTRS)

Richard, H. L.; Barnes, W. L.

1985-01-01

Several techniques that can be used in an earth-imaging system to separate the linear image formed after the collecting optics into the desired spectral band are examined. The advantages and disadvantages of the Multispectral Linear Array (MLA) multiple optics, the MLA adjacent arrays, the imaging spectrometer, and the MLA beam splitter are discussed. The beam-splitter design approach utilizes, in addition to relatively broad spectral region separation, a movable Multiband Selection Device (MSD), placed between the exit ports of the beam splitter and a linear array detector, permitting many bands to be selected. The successful development and test of the MSD is described. The device demonstrated the capacity to provide a wide field of view, visible-to-near IR/short-wave IR and thermal IR capability, and a multiplicity of spectral bands and polarization measuring means, as well as a reasonable size and weight at minimal cost and risk compared to a spectrometer design approach.

Evaluation of detector array technology for the verification of advanced intensity-modulated radiotherapy

NASA Astrophysics Data System (ADS)

Hussien, Mohammad

Purpose: Quality assurance (QA) for intensity modulated radiotherapy (IMRT) has evolved substantially. In recent years, various ionization chamber or diode detector arrays have become commercially available, allowing pre-treatment absolute dose verification with near real-time results. This has led to a wide uptake of this technology to replace point dose and film dosimetry and to facilitate QA streamlining. However, arrays are limited by their spatial resolution giving rise to concerns about their response to clinically relevant deviations. The common factor in all commercial array systems is the reliance on the gamma index (γ) method to provide the quantitative evaluation of the measured dose distribution against the Treatment Planning System (TPS) calculated dose distribution. The mathematical definition of the gamma index presents computational challenges that can cause a variation in the calculation in different systems. The purpose of this thesis was to evaluate the suitability of detector array systems, combined with their implementation of the gamma index, in the verification and dosimetry audit of advanced IMRT. Method: The response of various commercial detector array systems (Delta4®, ArcCHECK®, and the PTW 2D-Array seven29™ and OCTAVIUS II™ phantom combination, Gafchromic® EBT2 and composite EPID measurements) to simulated deliberate changes in clinical IMRT and VMAT plans was evaluated. The variability of the gamma index calculation in the different systems was also evaluated by comparing against a bespoke Matlab-based gamma index analysis software. A novel methodology for using a commercial detector array in a dosimetry audit of rotational radiotherapy was then developed. Comparison was made between measurements using the detector array and those performed using ionization chambers, alanine and radiochromic film. The methodology was developed as part of the development of a national audit of rotational radiotherapy. Ten cancer centres were

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

Using confidence intervals to evaluate the focus alignment of spectrograph detector arrays.

PubMed

Sawyer, Travis W; Hawkins, Kyle S; Damento, Michael

2017-06-20

High-resolution spectrographs extract detailed spectral information of a sample and are frequently used in astronomy, laser-induced breakdown spectroscopy, and Raman spectroscopy. These instruments employ dispersive elements such as prisms and diffraction gratings to spatially separate different wavelengths of light, which are then detected by a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) detector array. Precise alignment along the optical axis (focus position) of the detector array is critical to maximize the instrumental resolution; however, traditional approaches of scanning the detector through focus lack a quantitative measure of precision, limiting the repeatability and relying on one's experience. Here we propose a method to evaluate the focus alignment of spectrograph detector arrays by establishing confidence intervals to measure the alignment precision. We show that propagation of uncertainty can be used to estimate the variance in an alignment, thus providing a quantitative and repeatable means to evaluate the precision and confidence of an alignment. We test the approach by aligning the detector array of a prototype miniature echelle spectrograph. The results indicate that the procedure effectively quantifies alignment precision, enabling one to objectively determine when an alignment has reached an acceptable level. This quantitative approach also provides a foundation for further optimization, including automated alignment. Furthermore, the procedure introduced here can be extended to other alignment techniques that rely on numerically fitting data to a model, providing a general framework for evaluating the precision of alignment methods.

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.

The detector calibration system for the CUORE cryogenic bolometer array

DOE PAGES

Cushman, Jeremy S.; Dally, Adam; Davis, Christopher J.; ...

2016-11-14

The Cryogenic Underground Observatory for Rare Events (CUORE) is a ton-scale cryogenic experiment designed to search for neutrinoless double-beta decay of 130Te and other rare events. The CUORE detector consists of 988 TeO 2 bolometers operated underground at 10 mK in a dilution refrigerator at the Laboratori Nazionali del Gran Sasso. Candidate events are identified through a precise measurement of their energy. The absolute energy response of the detectors is established by the regular calibration of each individual bolometer using gamma sources. The close-packed configuration of the CUORE bolometer array combined with the extensive shielding surrounding the detectors requires themore » placement of calibration sources within the array itself. The CUORE Detector Calibration System is designed to insert radioactive sources into and remove them from the cryostat while respecting the stringent heat load, radiopurity, and operational requirements of the experiment. In conclusion, this paper describes the design, commissioning, and performance of this novel source calibration deployment system for ultra-low-temperature environments.« less

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.

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

A sub-millimeter resolution PET detector module using a multi-pixel photon counter array

NASA Astrophysics Data System (ADS)

Song, Tae Yong; Wu, Heyu; Komarov, Sergey; Siegel, Stefan B.; Tai, Yuan-Chuan

2010-05-01

A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 × 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 × 0.8 × 3 mm3 and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 × 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and ±5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when ±10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing

A sub-millimeter resolution PET detector module using a multi-pixel photon counter array.

PubMed

Song, Tae Yong; Wu, Heyu; Komarov, Sergey; Siegel, Stefan B; Tai, Yuan-Chuan

2010-05-07

A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 x 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 x 0.8 x 3 mm(3) and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 x 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and +/-5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when +/-10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing

A sub-millimeter resolution PET detector module using a multi-pixel photon counter array

PubMed Central

Song, Tae Yong; Wu, Heyu; Komarov, Sergey; Siegel, Stefan B; Tai, Yuan-Chuan

2010-01-01

A PET block detector module using an array of sub-millimeter lutetium oxyorthosilicate (LSO) crystals read out by an array of surface-mount, semiconductor photosensors has been developed. The detector consists of a LSO array, a custom acrylic light guide, a 3 × 3 multi-pixel photon counter (MPPC) array (S10362-11-050P, Hamamatsu Photonics, Japan) and a readout board with a charge division resistor network. The LSO array consists of 100 crystals, each measuring 0.8 × 0.8 × 3 mm3 and arranged in 0.86 mm pitches. A Monte Carlo simulation was used to aid the design and fabrication of a custom light guide to control distribution of scintillation light over the surface of the MPPC array. The output signals of the nine MPPC are multiplexed by a charge division resistor network to generate four position-encoded analog outputs. Flood image, energy resolution and timing resolution measurements were performed using standard NIM electronics. The linearity of the detector response was investigated using gamma-ray sources of different energies. The 10 × 10 array of 0.8 mm LSO crystals was clearly resolved in the flood image. The average energy resolution and standard deviation were 20.0% full-width at half-maximum (FWHM) and ±5.0%, respectively, at 511 keV. The timing resolution of a single MPPC coupled to a LSO crystal was found to be 857 ps FWHM, and the value for the central region of detector module was 1182 ps FWHM when ±10% energy window was applied. The nonlinear response of a single MPPC when used to read out a single LSO was observed among the corner crystals of the proposed detector module. However, the central region of the detector module exhibits significantly less nonlinearity (6.5% for 511 keV). These results demonstrate that (1) a charge-sharing resistor network can effectively multiplex MPPC signals and reduce the number of output signals without significantly degrading the performance of a PET detector and (2) a custom light guide to permit light sharing

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.

A methodology for dosimetry audit of rotational radiotherapy using a commercial detector array.

PubMed

Hussein, Mohammad; Tsang, Yatman; Thomas, Russell A S; Gouldstone, Clare; Maughan, David; Snaith, Julia A D; Bolton, Steven C; Nisbet, Andrew; Clark, Catharine H

2013-07-01

To develop a methodology for the use of a commercial detector array in dosimetry audits of rotational radiotherapy. The methodology was developed as part of the development of a national audit of rotational radiotherapy. Ten cancer centres were asked to create a rotational radiotherapy treatment plan for a three-dimensional treatment-planning-system (3DTPS) test and audited. Phantom measurements using a commercial 2D ionisation chamber (IC) array were compared with measurements using 0.125 cm(3) IC, Gafchromic film and alanine pellets in the same plane. Relative and absolute gamma index (γ) comparisons were made for Gafchromic film and 2D-Array planes, respectively. Comparisons between individual detectors within the 2D-Array against the corresponding IC and alanine measurement showed a statistically significant concordance correlation coefficient (both ρc>0.998, p<0.001) with mean difference of -1.1 ± 1.1% and -0.8 ± 1.1%, respectively, in a high dose PTV. In the γ comparison between the 2D-Array and film it was that the 2D-Array was more likely to fail planes where there was a dose discrepancy due to the absolute analysis performed. It has been found that using a commercial detector array for a dosimetry audit of rotational radiotherapy is suitable in place of standard systems of dosimetry. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Assembly and Integration Process of the First High Density Detector Array for the Atacama Cosmology Telescope

NASA Technical Reports Server (NTRS)

Li, Yaqiong; Choi, Steve; Ho, Shuay-Pwu; Crowley, Kevin T.; Salatino, Maria; Simon, Sara M.; Staggs, Suzanne T.; Nati, Federico; Wollack, Edward J.

2016-01-01

The Advanced ACTPol (AdvACT) upgrade on the Atacama Cosmology Telescope (ACT) consists of multichroicTransition Edge Sensor (TES) detector arrays to measure the Cosmic Microwave Background (CMB) polarization anisotropies in multiple frequency bands. The first AdvACT detector array, sensitive to both 150 and 230 GHz, is fabricated on a 150 mm diameter wafer and read out with a completely different scheme compared to ACTPol. Approximately 2000 TES bolometers are packed into the wafer leading to both a much denser detector density and readout circuitry. The demonstration of the assembly and integration of the AdvACT arrays is important for the next generation CMB experiments, which will continue to increase the pixel number and density. We present the detailed assembly process of the first AdvACT detector array.

Muon–hadron detector of the carpet-2 array

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dzhappuev, D. D.; Kudzhaev, A. U., E-mail: kudjaev@mail.ru; Klimenko, N. F.

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)more » code package and performed for primary protons and iron nuclei.« less

Read-noise characterization of focal plane array detectors via mean-variance analysis.

PubMed

Sperline, R P; Knight, A K; Gresham, C A; Koppenaal, D W; Hieftje, G M; Denton, M B

2005-11-01

Mean-variance analysis is described as a method for characterization of the read-noise and gain of focal plane array (FPA) detectors, including charge-coupled devices (CCDs), charge-injection devices (CIDs), and complementary metal-oxide-semiconductor (CMOS) multiplexers (infrared arrays). Practical FPA detector characterization is outlined. The nondestructive readout capability available in some CIDs and FPA devices is discussed as a means for signal-to-noise ratio improvement. Derivations of the equations are fully presented to unify understanding of this method by the spectroscopic community.

Mercuric iodide room-temperature array detectors for gamma-ray imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patt, B.

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 themore » 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.« less

Attenuated total internal reflection infrared microspectroscopic imaging using a large-radius germanium internal reflection element and a linear array detector.

PubMed

Patterson, Brian M; Havrilla, George J

2006-11-01

The number of techniques and instruments available for Fourier transform infrared (FT-IR) microspectroscopic imaging has grown significantly over the past few years. Attenuated total internal reflectance (ATR) FT-IR microspectroscopy reduces sample preparation time and has simplified the analysis of many difficult samples. FT-IR imaging has become a powerful analytical tool using either a focal plane array or a linear array detector, especially when coupled with a chemometric analysis package. The field of view of the ATR-IR microspectroscopic imaging area can be greatly increased from 300 x 300 microm to 2500 x 2500 microm using a larger internal reflection element of 12.5 mm radius instead of the typical 1.5 mm radius. This gives an area increase of 70x before aberrant effects become too great. Parameters evaluated include the change in penetration depth as a function of beam displacement, measurements of the active area, magnification factor, and change in spatial resolution over the imaging area. Drawbacks such as large file size will also be discussed. This technique has been successfully applied to the FT-IR imaging of polydimethylsiloxane foam cross-sections, latent human fingerprints, and a model inorganic mixture, which demonstrates the usefulness of the method for pharmaceuticals.

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.

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.

A LYSO crystal array readout by silicon photomultipliers as compact detector for space applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kryemadhi, A.; Barner, L.; Grove, A.

Precise measurements of GeV range gamma rays help narrow down among var- ious gamma emission models and increase sensitivity for dark matter searches. Construction of precise as well as compact instruments requires detectors with high efficiency, high stopping power, excellent energy resolution, and excellent angular resolution. Fast and bright crystal scintillators coupled with small foot- print photo-detectors are suitable candidates. We prototyped a detector array consisting of four LYSO crystals where each crystal is read out by a 2x2 SensL ArrayJ60035 silicon photomultipliers. The LYSO crystals were chosen because of their good light yield, fast decay time, demonstrated radiation hardness,more » and small radiation length. Here, we used the silicon photomultiplier arrays as photo- detectors because of their small size, simple readout, low voltage operation, and immunity to magnetic elds. We also studied the detector performance in the energy range of interest by exposing it to 2-16 GeV particles produced at the Test Beam Facility of Fermi National Accelerator Laboratory.« less

A LYSO crystal array readout by silicon photomultipliers as compact detector for space applications

DOE PAGES

Kryemadhi, A.; Barner, L.; Grove, A.; ...

2017-10-31

Precise measurements of GeV range gamma rays help narrow down among var- ious gamma emission models and increase sensitivity for dark matter searches. Construction of precise as well as compact instruments requires detectors with high efficiency, high stopping power, excellent energy resolution, and excellent angular resolution. Fast and bright crystal scintillators coupled with small foot- print photo-detectors are suitable candidates. We prototyped a detector array consisting of four LYSO crystals where each crystal is read out by a 2x2 SensL ArrayJ60035 silicon photomultipliers. The LYSO crystals were chosen because of their good light yield, fast decay time, demonstrated radiation hardness,more » and small radiation length. Here, we used the silicon photomultiplier arrays as photo- detectors because of their small size, simple readout, low voltage operation, and immunity to magnetic elds. We also studied the detector performance in the energy range of interest by exposing it to 2-16 GeV particles produced at the Test Beam Facility of Fermi National Accelerator Laboratory.« less

MTF Determination of SENTINEL-4 Detector Arrays

NASA Astrophysics Data System (ADS)

Reulke, R.; Sebastian, I.; Williges, C.; Hohn, R.

2017-05-01

The Institute for Optical Sensor Systems was involved in many international space projects in recent years. These include, for example, the fokal plane array (FPA) of the hyperspectral sensors ENMAP or Sentinel-4, but also the FPA for the high resolution FPA for Kompsat-3. An important requirement of the customer is the measurement of the detector MTF for different wavelengths. A measuring station under clean room conditions and evaluation algorithms was developed for these measurements. The measurement setup consist of a collimator with slit target in focus for illumination at infinity, a gimbal mounted detector facing an auxiliary lens in front, a halogen lamp with monochromator or filter, as well as optical and electrical ground support equipment. Different targets and therefore also different measurement and data evaluation opportunities are possible with this setup. Examples are slit, edge, pin hole but also a Siemens star. The article describes the measurement setup, the different measuring and evaluation procedures and exemplary results for Sentinel-4 detector.

An evaluation to design high performance pinhole array detector module for four head SPECT: a simulation study

NASA Astrophysics Data System (ADS)

Rahman, Tasneem; Tahtali, Murat; Pickering, Mark R.

2014-09-01

The purpose of this study is to derive optimized parameters for a detector module employing an off-the-shelf X-ray camera and a pinhole array collimator applicable for a range of different SPECT systems. Monte Carlo simulations using the Geant4 application for tomographic emission (GATE) were performed to estimate the performance of the pinhole array collimators and were compared to that of low energy high resolution (LEHR) parallel-hole collimator in a four head SPECT system. A detector module was simulated to have 48 mm by 48 mm active area along with 1mm, 1.6mm and 2 mm pinhole aperture sizes at 0.48 mm pitch on a tungsten plate. Perpendicular lead septa were employed to verify overlapping and non-overlapping projections against a proper acceptance angle without lead septa. A uniform shape cylindrical water phantom was used to evaluate the performance of the proposed four head SPECT system of the pinhole array detector module. For each head, 100 pinhole configurations were evaluated based on sensitivity and detection efficiency for 140 keV γ-rays, and compared to LEHR parallel-hole collimator. SPECT images were reconstructed based on filtered back projection (FBP) algorithm where neither scatter nor attenuation corrections were performed. A better reconstruction algorithm development for this specific system is in progress. Nevertheless, activity distribution was well visualized using the backprojection algorithm. In this study, we have evaluated several quantitative and comparative analyses for a pinhole array imaging system providing high detection efficiency and better system sensitivity over a large FOV, comparing to the conventional four head SPECT system. The proposed detector module is expected to provide improved performance in various SPECT imaging.

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.

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 .

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

PubMed

Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

2014-02-07

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.

Performance of the Versatile Array of Neutron Detectors at Low Energy (VANDLE)

DOE PAGES

Peters, W. A.; Ilyushkin, S.; Madurga, M.; ...

2016-08-26

The Versatile Array of Neutron Detectors at Low Energy (VANDLE) is a new, highly efficient plastic-scintillator array constructed for decay and transfer reaction experimental setups that require neutron detection. The versatile and modular design allows for customizable experimental setups including beta-delayed neutron spectroscopy and (d,n) transfer reactions in normal and inverse kinematics. The neutron energy and prompt-photon discrimination is determined through the time of flight technique. Fully digital data acquisition electronics and integrated triggering logic enables some VANDLE modules to achieve an intrinsic efficiency over 70% for 300-keV neutrons, measured through two different methods. A custom Geant4 simulation models aspectsmore » of the detector array and the experimental setups to determine efficiency and detector response. Lastly, a low detection threshold, due to the trigger logic and digitizing data acquisition, allowed us to measure the light-yield response curve from elastically scattered carbon nuclei inside the scintillating plastic from incident neutrons with kinetic energies below 2 MeV.« less

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.

Detector Array Performance Estimates for Nuclear Resonance Fluorescence Applications

NASA Astrophysics Data System (ADS)

Johnson, Micah; Hall, J. M.; McNabb, D. P.

2012-10-01

There are a myriad of explorative efforts underway at several institutions to determine the feasibility of using photonuclear reactions to detect and assay materials of varying complexity and compositions. One photonuclear process that is being explored for several applications is nuclear resonance fluorescence (NRF). NRF is interesting because the resonant lines are unique to each isotope and the widths are sufficiently narrow and the level densities are sufficiently low so as to not cause interference. Therefore, NRF provides a means to isoptically map containers and materials. The choice of detector array is determined by the application and the source. We will present results from a variety of application studies of an assortment of detector arrays that may be useful. Our results stem from simulation and modeling exercises and benchmarking measurements. We will discuss the data requirements from basic scientific research that enables these application studies. We will discuss our results and the future outlook of this technology.

MCT Detectors and ROICS for Various Format MWIR and LWIR Arrays

DTIC Science & Technology

2009-10-01

ABSTRACT Silicon ROICs for MCT LWIR (4x288, 6x576) and MWIR (128x128) diode matrix arrays were designed, manufactured and tested. MCT layers...of polysilicon and two metallization levels. MCT Detectors and ROICs for Various Format MWIR and LWIR Arrays RTO-MP-SET-151 7 - 1...Format MWIR and LWIR Arrays 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f

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.

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.

Development of ultrahigh resolution alpha particle imaging detector using 1 mm channel size Si-PM array

NASA Astrophysics Data System (ADS)

Yamamoto, Seiichi; Kawaguchi, Wataru

2018-06-01

For precise distribution measurements of alpha particles, a high-resolution alpha particle imaging detector is required. Although combining a thin scintillator with a silicon photomultiplier (Si-PM) array is a promising method for achieving high resolution, the spatial resolution is limited. Reducing the size of the Si-PM array is a possible approach to improving the spatial resolution of the alpha particle imaging detector. Consequently, we employed a 1 mm channel size Si-PM array combined with a thin ZnS(Ag) sheet to form an alpha particle imaging detector and evaluated the performance. For the developed alpha particle imaging detector, an Si-PM array with 1 mm x 1 mm channel size arranged 8 x 8 was optically coupled to a ZnS(Ag) sheet with a 1-mm-thick light guide between them. The size of the alpha particle imaging detector was 9.5 mm x 9.5 mm. The spatial resolution of the developed alpha particle imaging detector was 0.14 mm FWHM, and the energy resolution was 74% FWHM for 5.5 MeV alpha particles. The uniformity of the imaging detector at the central part of the field of view (FOV) was ±4.7%. The background count rate was 0.06 counts/min. We obtained various high-resolution phantom images for alpha particles with the developed system. We conclude that the developed imaging detector is promising for high-resolution distribution measurements of alpha particles.

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.

2D Array of Far-infrared Thermal Detectors: Noise Measurements and Processing Issues

NASA Technical Reports Server (NTRS)

Lakew, B.; Aslam, S.; Stevenson, T.

2008-01-01

A magnesium diboride (MgB2) detector 2D array for use in future space-based spectrometers is being developed at GSFC. Expected pixel sensitivities and comparison to current state-of-the-art infrared (IR) detectors will be discussed.

A micro GC detector array based on chemiresistors employing various surface functionalized monolayer-protected gold nanoparticles.

PubMed

Jian, Rih-Sheng; Huang, Rui-Xuan; Lu, Chia-Jung

2012-01-15

Aspects of the design, fabrication, and characterization of a chemiresistor type of microdetector for use in conjunction with gas chromatograph are described. The detector was manufactured on silicon chips using microelectromechanical systems (MEMS) technology. Detection was based on measuring changes in resistance across a film comprised of monolayer-protected gold nanoclusters (MPCs). When chromatographic separated molecules entered the detector cell, the MPC film absorbed vapor and undergoes swelling, then the resistance changes accordingly. Thiolates were used as ligand shells to encapsulate the nano-gold core and to manipulate the selectivity of the detector array. The dimensions of the μ-detector array were 14(L)×3.9(W)×1.2(H)mm. Mixtures of eight volatile organic compounds with different functional groups and volatility were tested to characterize the selectivity of the μ-detector array. The detector responses were rapid, reversible, and linear for all of the tested compounds. The detection limits ranged from 2 to 111ng, and were related to both the compound volatility and the selectivity of the surface ligands on the gold nanoparticles. Design and operation parameters such as flow rate, detector temperature, and width of the micro-fluidic channel were investigated. Reduction of the detector temperature resulted in improved sensitivity due to increased absorption. When a wider flow channel was used, the signal-to-noise ratio was improved due to the larger sensing area. The extremely low power consumption and small size makes this μ-detector array potentially useful for the development of integrated μ-GC. Copyright © 2011 Elsevier B.V. All rights reserved.

In situ two-dimensional imaging quick-scanning XAFS with pixel array detector.

PubMed

Tanida, Hajime; Yamashige, Hisao; Orikasa, Yuki; Oishi, Masatsugu; Takanashi, Yu; Fujimoto, Takahiro; Sato, Kenji; Takamatsu, Daiko; Murayama, Haruno; Arai, Hajime; Matsubara, Eiichiro; Uchimoto, Yoshiharu; Ogumi, Zempachi

2011-11-01

Quick-scanning X-ray absorption fine structure (XAFS) measurements were performed in transmission mode using a PILATUS 100K pixel array detector (PAD). The method can display a two-dimensional image for a large area of the order of a centimetre with a spatial resolution of 0.2 mm at each energy point in the XAFS spectrum. The time resolution of the quick-scanning method ranged from 10 s to 1 min per spectrum depending on the energy range. The PAD has a wide dynamic range and low noise, so the obtained spectra have a good signal-to-noise ratio.

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.

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).

Development of depth encoding small animal PET detectors using dual-ended readout of pixelated scintillator arrays with SiPMs.

PubMed

Kuang, Zhonghua; Sang, Ziru; Wang, Xiaohui; Fu, Xin; Ren, Ning; Zhang, Xianming; Zheng, Yunfei; Yang, Qian; Hu, Zhanli; Du, Junwei; Liang, Dong; Liu, Xin; Zheng, Hairong; Yang, Yongfeng

2018-02-01

The performance of current small animal PET scanners is mainly limited by the detector performance and depth encoding detectors are required to develop PET scanner to simultaneously achieve high spatial resolution and high sensitivity. Among all depth encoding PET detector approaches, dual-ended readout detector has the advantage to achieve the highest depth of interaction (DOI) resolution and spatial resolution. Silicon photomultiplier (SiPM) is believed to be the photodetector of the future for PET detector due to its excellent properties as compared to the traditional photodetectors such as photomultiplier tube (PMT) and avalanche photodiode (APD). The purpose of this work is to develop high resolution depth encoding small animal PET detector using dual-ended readout of finely pixelated scintillator arrays with SiPMs. Four lutetium-yttrium oxyorthosilicate (LYSO) arrays with 11 × 11 crystals and 11.6 × 11.6 × 20 mm 3 outside dimension were made using ESR, Toray and BaSO 4 reflectors. The LYSO arrays were read out with Hamamatsu 4 × 4 SiPM arrays from both ends. The SiPM array has a pixel size of 3 × 3 mm 2 , 0.2 mm gap in between the pixels and a total active area of 12.6 × 12.6 mm 2 . The flood histograms, DOI resolution, energy resolution and timing resolution of the four detector modules were measured and compared. All crystals can be clearly resolved from the measured flood histograms of all four arrays. The BaSO 4 arrays provide the best and the ESR array provides the worst flood histograms. The DOI resolution obtained from the DOI profiles of the individual crystals of the four array is from 2.1 to 2.35 mm for events with E > 350 keV. The DOI ratio variation among crystals is bigger for the BaSO 4 arrays as compared to both the ESR and Toray arrays. The BaSO 4 arrays provide worse detector based DOI resolution. The photopeak amplitude of the Toray array had the maximum change with depth, it provides the worst energy resolution of

Array coding for large data memories

NASA Technical Reports Server (NTRS)

Tranter, W. H.

1982-01-01

It is pointed out that an array code is a convenient method for storing large quantities of data. In a typical application, the array consists of N data words having M symbols in each word. The probability of undetected error is considered, taking into account three symbol error probabilities which are of interest, and a formula for determining the probability of undetected error. Attention is given to the possibility of reading data into the array using a digital communication system with symbol error probability p. Two different schemes are found to be of interest. The conducted analysis of array coding shows that the probability of undetected error is very small even for relatively large arrays.

Design and Performance Testing of a Linear Array of Position-Sensitive Virtual Frisch-Grid CdZnTe Detectors for Uranium Enrichment Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ocampo, Luis

Abstract— Arrays of position-sensitive virtual Frisch-grid CdZnTe (CZT) detectors with enhanced energy resolution have been proposed for spectroscopy and imaging of gamma-ray sources in different applications. The flexibility of the array design, which can employ CZT crystals with thicknesses up to several centimeters in the direction of electron drift, allows for integration into different kinds of field-portable instruments. These can include small hand-held devices, compact gamma cameras and large field-of-view imaging systems. In this work, we present results for a small linear array of such detectors optimized for the low-energy region, 50-400 keV gamma-rays, which is principally intended for incorporationmore » into hand-held instruments. There are many potential application areas for such instruments, including uranium enrichment measurements, storage monitoring, dosimetry and other safeguards-related tasks that can benefit from compactness and isotope-identification capability. The array described here provides a relatively large area with a minimum number of readout channels, which potentially allows the developers to avoid using an ASIC-based electronic readout by substituting it with hybrid preamplifiers followed by digitizers. The array prototype consists of six (5x5.7x25 mm3) CZT detectors positioned in a line facing the source to achieve a maximum exposure area (~10 cm2). Each detector is furnished with 5 mm-wide charge-sensing pads placed near the anode. The pad signals are converted into X-Y coordinates for each interaction event, which are combined with the cathode signals (for determining the Z coordinates) to give 3D positional information for all interaction points. This information is used to correct the response non-uniformity caused by material inhomogeneity, which therefore allows the usage of standard-grade (unselected) CZT crystals, while achieving high-resolution spectroscopic performance for the instrument. In this presentation we

Large format imaging arrays for the Atacama Cosmology Telescope

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Wollack, E. J.; Marraige, T.; Staggs, S.; Niemack, M.; Doriese, B.

2006-01-01

We describe progress in the fabrication, characterization, and production of detector arrays for the Atacama Cosmology Telescope (ACT). The completed ACT instrument is specified to image simultaneously at 145, 225, and 265 GHz using three 32x32 filled arrays of superconducting transition edge sensors (TES) read out with time-division-multiplexed SQUID amplifiers. We present details of the pixel design and testing including the optimization of the electrical parameters for multiplexed readout. Using geometric noise suppression and careful tuning of operation temperature and device bias resistance, the excess noise in the TES devices is balanced with detector speed for interfacing with the ACT optics. The design also accounts for practical tolerances such as transition temperature gradients and scatter that occur in the production of multiple wafers to populate fully the kilopixel cameras. We have developed an implanted absorber layer compatible with our silicon-on-insulator process that allows for tunable optical resistance with requisite on-wafer uniformity and wafer-to-wafer reproducibility. Arrays of 32 elements have been tested in the laboratory environment including electrical, optical, and multiplexed performance. Given this pixel design, optical tests and modeling are used to predict the performance of the filled array under anticipated viewing conditions. Integration of the filled array of pixels with a tuned backshort and dielectric plate in front of the array maximize absorption and the focal plane and suppress reflections. A mechanical design for the build of the full structure is completed and we report on progress toward the construction of a prototype array for first light on the ACT.

Life test of the InGaAs focal plane arrays detector for space applications

NASA Astrophysics Data System (ADS)

Zhu, Xian-Liang; Zhang, Hai-Yan; Li, Xue; Huang, Zhang-Cheng; Gong, Hai-Mei

2017-08-01

The short-wavelength infrared (SWIR) InGaAs focal plane array (FPA) detector consists of infrared detector chip, readout integrated circuit (ROIC), and flip-chip bonding interconnection by Indium bump. In order to satisfy space application requirements for failure rates or Mean Time to Failure (MTTF), which can only be demonstrated with the large number of detectors manufactured, the single pixel in InGaAs FPAs was chosen as the research object in this paper. The constant-stress accelerated life tests were carried out at 70°C 80°C 90°C and100°C. The failed pixels increased gradually during more than 14000 hours at each elevated temperatures. From the random failure data the activation energy was estimated to be 0.46eV, and the average lifetime of a single pixel in InGaAs FPAs was estimated to be longer than 1E+7h at the practical operating temperature (5°C).

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.

Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging

PubMed Central

Iwanczyk, Jan S.; Nygård, Einar; Meirav, Oded; Arenson, Jerry; Barber, William C.; Hartsough, Neal E.; Malakhov, Nail; Wessel, Jan C.

2009-01-01

The development of an innovative detector technology for photon-counting in X-ray imaging is reported. This new generation of detectors, based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detector arrays electrically connected to application specific integrated circuits (ASICs) for readout, will produce fast and highly efficient photon-counting and energy-dispersive X-ray imaging. There are a number of applications that can greatly benefit from these novel imagers including mammography, planar radiography, and computed tomography (CT). Systems based on this new detector technology can provide compositional analysis of tissue through spectroscopic X-ray imaging, significantly improve overall image quality, and may significantly reduce X-ray dose to the patient. A very high X-ray flux is utilized in many of these applications. For example, CT scanners can produce ~100 Mphotons/mm2/s in the unattenuated beam. High flux is required in order to collect sufficient photon statistics in the measurement of the transmitted flux (attenuated beam) during the very short time frame of a CT scan. This high count rate combined with a need for high detection efficiency requires the development of detector structures that can provide a response signal much faster than the transit time of carriers over the whole detector thickness. We have developed CdTe and CZT detector array structures which are 3 mm thick with 16×16 pixels and a 1 mm pixel pitch. These structures, in the two different implementations presented here, utilize either a small pixel effect or a drift phenomenon. An energy resolution of 4.75% at 122 keV has been obtained with a 30 ns peaking time using discrete electronics and a 57Co source. An output rate of 6×106 counts per second per individual pixel has been obtained with our ASIC readout electronics and a clinical CT X-ray tube. Additionally, the first clinical CT images, taken with several of our prototype photon-counting and energy

Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging.

PubMed

Iwanczyk, Jan S; Nygård, Einar; Meirav, Oded; Arenson, Jerry; Barber, William C; Hartsough, Neal E; Malakhov, Nail; Wessel, Jan C

2009-01-01

The development of an innovative detector technology for photon-counting in X-ray imaging is reported. This new generation of detectors, based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detector arrays electrically connected to application specific integrated circuits (ASICs) for readout, will produce fast and highly efficient photon-counting and energy-dispersive X-ray imaging. There are a number of applications that can greatly benefit from these novel imagers including mammography, planar radiography, and computed tomography (CT). Systems based on this new detector technology can provide compositional analysis of tissue through spectroscopic X-ray imaging, significantly improve overall image quality, and may significantly reduce X-ray dose to the patient. A very high X-ray flux is utilized in many of these applications. For example, CT scanners can produce ~100 Mphotons/mm(2)/s in the unattenuated beam. High flux is required in order to collect sufficient photon statistics in the measurement of the transmitted flux (attenuated beam) during the very short time frame of a CT scan. This high count rate combined with a need for high detection efficiency requires the development of detector structures that can provide a response signal much faster than the transit time of carriers over the whole detector thickness. We have developed CdTe and CZT detector array structures which are 3 mm thick with 16×16 pixels and a 1 mm pixel pitch. These structures, in the two different implementations presented here, utilize either a small pixel effect or a drift phenomenon. An energy resolution of 4.75% at 122 keV has been obtained with a 30 ns peaking time using discrete electronics and a (57)Co source. An output rate of 6×10(6) counts per second per individual pixel has been obtained with our ASIC readout electronics and a clinical CT X-ray tube. Additionally, the first clinical CT images, taken with several of our prototype photon-counting and

Saturated virtual fluorescence emission difference microscopy based on detector array

NASA Astrophysics Data System (ADS)

Liu, Shaocong; Sun, Shiyi; Kuang, Cuifang; Ge, Baoliang; Wang, Wensheng; Liu, Xu

2017-07-01

Virtual fluorescence emission difference microscopy (vFED) has been proposed recently to enhance the lateral resolution of confocal microscopy with a detector array, implemented by scanning a doughnut-shaped pattern. Theoretically, the resolution can be enhanced by around 1.3-fold compared with that in confocal microscopy. For further improvement of the resolving ability of vFED, a novel method is presented utilizing fluorescence saturation for super-resolution imaging, which we called saturated virtual fluorescence emission difference microscopy (svFED). With a point detector array, matched solid and hollow point spread functions (PSF) can be obtained by photon reassignment, and the difference results between them can be used to boost the transverse resolution. Results show that the diffraction barrier can be surpassed by at least 34% compared with that in vFED and the resolution is around 2-fold higher than that in confocal microscopy.

Study of a new design of p-N semiconductor detector array for nuclear medicine imaging by monte carlo simulation codes.

PubMed

Hajizadeh-Safar, M; Ghorbani, M; Khoshkharam, S; Ashrafi, Z

2014-07-01

Gamma camera is an important apparatus in nuclear medicine imaging. Its detection part is consists of a scintillation detector with a heavy collimator. Substitution of semiconductor detectors instead of scintillator in these cameras has been effectively studied. In this study, it is aimed to introduce a new design of P-N semiconductor detector array for nuclear medicine imaging. A P-N semiconductor detector composed of N-SnO2 :F, and P-NiO:Li, has been introduced through simulating with MCNPX monte carlo codes. Its sensitivity with different factors such as thickness, dimension, and direction of emission photons were investigated. It is then used to configure a new design of an array in one-dimension and study its spatial resolution for nuclear medicine imaging. One-dimension array with 39 detectors was simulated to measure a predefined linear distribution of Tc(99_m) activity and its spatial resolution. The activity distribution was calculated from detector responses through mathematical linear optimization using LINPROG code on MATLAB software. Three different configurations of one-dimension detector array, horizontal, vertical one sided, and vertical double-sided were simulated. In all of these configurations, the energy windows of the photopeak were ± 1%. The results show that the detector response increases with an increase of dimension and thickness of the detector with the highest sensitivity for emission photons 15-30° above the surface. Horizontal configuration array of detectors is not suitable for imaging of line activity sources. The measured activity distribution with vertical configuration array, double-side detectors, has no similarity with emission sources and hence is not suitable for imaging purposes. Measured activity distribution using vertical configuration array, single side detectors has a good similarity with sources. Therefore, it could be introduced as a suitable configuration for nuclear medicine imaging. It has been shown that using

Lung counting: comparison of detector performance with a four detector array that has either metal or carbon fibre end caps, and the effect on mda calculation.

PubMed

Ahmed, Asm Sabbir; Hauck, Barry; Kramer, Gary H

2012-08-01

This study described the performance of an array of high-purity Germanium detectors, designed with two different end cap materials-steel and carbon fibre. The advantages and disadvantages of using this detector type in the estimation of the minimum detectable activity (MDA) for different energy peaks of isotope (152)Eu were illustrated. A Monte Carlo model was developed to study the detection efficiency for the detector array. A voxelised Lawrence Livermore torso phantom, equipped with lung, chest plates and overlay plates, was used to mimic a typical lung counting protocol with the array of detectors. The lung of the phantom simulated the volumetric source organ. A significantly low MDA was estimated for energy peaks at 40 keV and at a chest wall thickness of 6.64 cm.

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;

A 2D silicon detector array for quality assurance in small field dosimetry: DUO.

PubMed

Shukaili, Khalsa Al; Petasecca, Marco; Newall, Matthew; Espinoza, Anthony; Perevertaylo, Vladimir L; Corde, Stéphanie; Lerch, Michael; Rosenfeld, Anatoly B

2017-02-01

Nowadays, there are many different applications that use small fields in radiotherapy treatments. The dosimetry of small radiation fields is not trivial due to the problems associated with lateral disequilibrium and source occlusion and requires reliable quality assurance (QA). Ideally such a QA tool should provide high spatial resolution, minimal beam perturbation and real time fast measurements. Many different types of silicon diode arrays are used for QA in radiotherapy; however, their application in small filed dosimetry is limited, in part, due to a lack of spatial resolution. The Center of Medical Radiation Physics (CMRP) has developed a new generation of a monolithic silicon diode array detector that will be useful for small field dosimetry in SRS/SRT. The objective of this study is to characterize a monolithic silicon diode array designed for dosimetry QA in SRS/SRT named DUO that is arranged as two orthogonal 1D arrays with 0.2 mm pitch. DUO is two orthogonal 1D silicon detector arrays in a monolithic crystal. Each orthogonal array contains 253 small pixels with size 0.04 × 0.8 mm 2 and three central pixels are with a size of 0.18 × 0.18 mm 2 each. The detector pitch is 0.2 mm and total active area is 52 × 52 mm 2 . The response of the DUO silicon detector was characterized in terms of dose per pulse, percentage depth dose, and spatial resolution in a radiation field incorporating high gradients. Beam profile of small fields and output factors measured on a Varian 2100EX LINAC in a 6 MV radiation fields of square dimensions and sized from 0.5 × 0.5 cm 2 to 5 × 5 cm 2 . The DUO response was compared under the same conditions with EBT3 films and an ionization chamber. The DUO detector shows a dose per pulse dependence of 5% for a range of dose rates from 2.7 × 10 -4 to 1.2 × 10 -4 Gy/pulse and 23% when the rate is further reduced to 2.8 × 10 -5 Gy/pulse. The percentage depth dose measured to 25 cm depth in solid water phantom beyond the surface and

Position, Orientation and Velocity Detection of Unmanned Underwater Vehicles (UUVs) Using an Optical Detector Array

PubMed Central

Pe’eri, Shachak; Thein, May-Win; Rzhanov, Yuri; Celikkol, Barbaros; Swift, M. Robinson

2017-01-01

This paper presents a proof-of-concept optical detector array sensor system to be used in Unmanned Underwater Vehicle (UUV) navigation. The performance of the developed optical detector array was evaluated for its capability to estimate the position, orientation and forward velocity of UUVs with respect to a light source fixed in underwater. The evaluations were conducted through Monte Carlo simulations and empirical tests under a variety of motion configurations. Monte Carlo simulations also evaluated the system total propagated uncertainty (TPU) by taking into account variations in the water column turbidity, temperature and hardware noise that may degrade the system performance. Empirical tests were conducted to estimate UUV position and velocity during its navigation to a light beacon. Monte Carlo simulation and empirical results support the use of the detector array system for optics based position feedback for UUV positioning applications. PMID:28758936

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.

Advanced ACTPol Cryogenic Detector Arrays and Readout

NASA Technical Reports Server (NTRS)

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

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.

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.

Stacked Metal Silicide/Silicon Far-Infrared Detectors

NASA Technical Reports Server (NTRS)

Maserjian, Joseph

1988-01-01

Selective doping of silicon in proposed metal silicide/silicon Schottky-barrier infrared photodetector increases maximum detectable wavelength. Stacking layers to form multiple Schottky barriers increases quantum efficiency of detector. Detectors of new type enhance capabilities of far-infrared imaging arrays. Grows by molecular-beam epitaxy on silicon waferscontaining very-large-scale integrated circuits. Imaging arrays of detectors made in monolithic units with image-preprocessing circuitry.

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.

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

Large-Format HgCdTe Dual-Band Long-Wavelength Infrared Focal-Plane Arrays

NASA Astrophysics Data System (ADS)

Smith, E. P. G.; Venzor, G. M.; Gallagher, A. M.; Reddy, M.; Peterson, J. M.; Lofgreen, D. D.; Randolph, J. E.

2011-08-01

Raytheon Vision Systems (RVS) continues to further its capability to deliver state-of-the-art high-performance, large-format, HgCdTe focal-plane arrays (FPAs) for dual-band long-wavelength infrared (L/LWIR) detection. Specific improvements have recently been implemented at RVS in molecular-beam epitaxy (MBE) growth and wafer fabrication and are reported in this paper. The aim of the improvements is to establish producible processes for 512 × 512 30- μm-unit-cell L/LWIR FPAs, which has resulted in: the growth of triple-layer heterojunction (TLHJ) HgCdTe back-to-back photodiode detector designs on 6 cm × 6 cm CdZnTe substrates with 300-K Fourier-transform infrared (FTIR) cutoff wavelength uniformity of ±0.1 μm across the entire wafer; demonstration of detector dark-current performance for the longer-wavelength detector band approaching that of single-color liquid-phase epitaxy (LPE) LWIR detectors; and uniform, high-operability, 512 × 512 30- μm-unit-cell FPA performance in both LWIR bands.

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.

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.

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.

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.

Development of a High Dynamic Range Pixel Array Detector for Synchrotrons and XFELs

NASA Astrophysics Data System (ADS)

Weiss, Joel Todd

Advances in synchrotron radiation light source technology have opened new lines of inquiry in material science, biology, and everything in between. However, x-ray detector capabilities must advance in concert with light source technology to fully realize experimental possibilities. X-ray free electron lasers (XFELs) place particularly large demands on the capabilities of detectors, and developments towards diffraction-limited storage ring sources also necessitate detectors capable of measuring very high flux [1-3]. The detector described herein builds on the Mixed Mode Pixel Array Detector (MM-PAD) framework, developed previously by our group to perform high dynamic range imaging, and the Adaptive Gain Integrating Pixel Detector (AGIPD) developed for the European XFEL by a collaboration between Deustsches Elektronen-Synchrotron (DESY), the Paul-Scherrer-Institute (PSI), the University of Hamburg, and the University of Bonn, led by Heinz Graafsma [4, 5]. The feasibility of combining adaptive gain with charge removal techniques to increase dynamic range in XFEL experiments is assessed by simulating XFEL scatter with a pulsed infrared laser. The strategy is incorporated into pixel prototypes which are evaluated with direct current injection to simulate very high incident x-ray flux. A fully functional 16x16 pixel hybrid integrating x-ray detector featuring several different pixel architectures based on the prototypes was developed. This dissertation describes its operation and characterization. To extend dynamic range, charge is removed from the integration node of the front-end amplifier without interrupting integration. The number of times this process occurs is recorded by a digital counter in the pixel. The parameter limiting full well is thereby shifted from the size of an integration capacitor to the depth of a digital counter. The result is similar to that achieved by counting pixel array detectors, but the integrators presented here are designed to tolerate a

Piezo-phototronic effect enhanced photo-detector based on ZnO nano-arrays/NiO structure

NASA Astrophysics Data System (ADS)

Sun, Jingchang; Li, Peida; Gao, Ruixue; Lu, Xue; Li, Chengren; Lang, Yueyi; Zhang, Xiwen; Bian, Jiming

2018-01-01

A photo-detector with n-ZnO nano-arrays/p-NiO film structure was synthesized on flexible Ni foil substrate. In contrast to conventional detectors that detect only the photon energies greater than the band gap of working materials, the visible light with smaller photon energies (3.0 eV) than the band gap of both ZnO (3.3 eV) and NiO (3.7 eV) can be sensitively detected by this detector due to the spatially indirect type-II transition between ZnO nano-arrays and NiO film. The increase in output currents of the photo-detector with illumination density was observed at both forward and reverse bias, and it can be further enhanced by exerting external compressive strain along the c axis of ZnO nano-arrays by piezo-phototronic effect. A maximum enhancement of 1020% of the responsivity (R) was achieved under external compressive strain. The similar behaviors were demonstrated at four different excitation wavelengths (325, 365, 388 and 405 nm), providing compelling evidence that the responses performance of the photo-detector can be effectively enhanced using piezo-phototronic effect. Moreover, the piezo-phototronic effect enhanced performance can be well elucidated by the corresponding energy band diagram.

Backshort-Under-Grid arrays for infrared astronomy

NASA Astrophysics Data System (ADS)

Allen, C. A.; Benford, D. J.; Chervenak, J. A.; Chuss, D. T.; Miller, T. M.; Moseley, S. H.; Staguhn, J. G.; Wollack, E. J.

2006-04-01

We are developing a kilopixel, filled bolometer array for space infrared astronomy. The array consists of three individual components, to be merged into a single, working unit; (1) a transition edge sensor bolometer array, operating in the milliKelvin regime, (2) a quarter-wave backshort grid, and (3) superconducting quantum interference device multiplexer readout. The detector array is designed as a filled, square grid of suspended, silicon bolometers with superconducting sensors. The backshort arrays are fabricated separately and will be positioned in the cavities created behind each detector during fabrication. The grids have a unique interlocking feature machined into the walls for positioning and mechanical stability. The spacing of the backshort beneath the detector grid can be set from ˜30 300 μm, by independently adjusting two process parameters during fabrication. The ultimate goal is to develop a large-format array architecture with background-limited sensitivity, suitable for a wide range of wavelengths and applications, to be directly bump bonded to a multiplexer circuit. We have produced prototype two-dimensional arrays having 8×8 detector elements. We present detector design, fabrication overview, and assembly technologies.

Limits in point to point resolution of MOS based pixels detector arrays

NASA Astrophysics Data System (ADS)

Fourches, N.; Desforge, D.; Kebbiri, M.; Kumar, V.; Serruys, Y.; Gutierrez, G.; Leprêtre, F.; Jomard, F.

2018-01-01

In high energy physics point-to-point resolution is a key prerequisite for particle detector pixel arrays. Current and future experiments require the development of inner-detectors able to resolve the tracks of particles down to the micron range. Present-day technologies, although not fully implemented in actual detectors, can reach a 5-μm limit, this limit being based on statistical measurements, with a pixel-pitch in the 10 μm range. This paper is devoted to the evaluation of the building blocks for use in pixel arrays enabling accurate tracking of charged particles. Basing us on simulations we will make here a quantitative evaluation of the physical and technological limits in pixel size. Attempts to design small pixels based on SOI technology will be briefly recalled here. A design based on CMOS compatible technologies that allow a reduction of the pixel size below the micrometer is introduced here. Its physical principle relies on a buried carrier-localizing collecting gate. The fabrication process needed by this pixel design can be based on existing process steps used in silicon microelectronics. The pixel characteristics will be discussed as well as the design of pixel arrays. The existing bottlenecks and how to overcome them will be discussed in the light of recent ion implantation and material characterization experiments.

Downsampling Photodetector Array with Windowing

NASA Technical Reports Server (NTRS)

Patawaran, Ferze D.; Farr, William H.; Nguyen, Danh H.; Quirk, Kevin J.; Sahasrabudhe, Adit

2012-01-01

In a photon counting detector array, each pixel in the array produces an electrical pulse when an incident photon on that pixel is detected. Detection and demodulation of an optical communication signal that modulated the intensity of the optical signal requires counting the number of photon arrivals over a given interval. As the size of photon counting photodetector arrays increases, parallel processing of all the pixels exceeds the resources available in current application-specific integrated circuit (ASIC) and gate array (GA) technology; the desire for a high fill factor in avalanche photodiode (APD) detector arrays also precludes this. Through the use of downsampling and windowing portions of the detector array, the processing is distributed between the ASIC and GA. This allows demodulation of the optical communication signal incident on a large photon counting detector array, as well as providing architecture amenable to algorithmic changes. The detector array readout ASIC functions as a parallel-to-serial converter, serializing the photodetector array output for subsequent processing. Additional downsampling functionality for each pixel is added to this ASIC. Due to the large number of pixels in the array, the readout time of the entire photodetector is greater than the time between photon arrivals; therefore, a downsampling pre-processing step is done in order to increase the time allowed for the readout to occur. Each pixel drives a small counter that is incremented at every detected photon arrival or, equivalently, the charge in a storage capacitor is incremented. At the end of a user-configurable counting period (calculated independently from the ASIC), the counters are sampled and cleared. This downsampled photon count information is then sent one counter word at a time to the GA. For a large array, processing even the downsampled pixel counts exceeds the capabilities of the GA. Windowing of the array, whereby several subsets of pixels are designated

Multiple-Coil, Pulse-Induction Metal Detector

NASA Technical Reports Server (NTRS)

Lesky, Edward S.; Reid, Alan M.; Bushong, Wilton E.; Dickey, Duane P.

1988-01-01

Multiple-head, pulse-induction metal detector scans area of 72 feet squared with combination of eight detector heads, each 3 ft. square. Head includes large primary coil inducing current in smaller secondary coils. Array of eight heads enables searcher to cover large area quickly. Pulses applied to primary coil, induced in secondary coils measured to determine whether metal present within range of detector head. Detector designed for recovery of Space Shuttle debris.

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.

Past and future detector arrays for complete event reconstruction in heavy-ion reactions

NASA Astrophysics Data System (ADS)

Cardella, G.; Acosta, L.; Auditore, L.; Boiano, C.; Castoldi, A.; D'Andrea, M.; De Filippo, E.; Dell'Aquila, D.; De Luca, S.; Fichera, F.; Giudice, N.; Gnoffo, B.; Grimaldi, A.; Guazzoni, C.; Lanzalone, G.; Librizzi, F.; Lombardo, I.; Maiolino, C.; Maffesanti, S.; Martorana, N. S.; Norella, S.; Pagano, A.; Pagano, E. V.; Papa, M.; Parsani, T.; Passaro, G.; Pirrone, S.; Politi, G.; Previdi, F.; Quattrocchi, L.; Rizzo, F.; Russotto, P.; Saccà, G.; Salemi, G.; Sciliberto, D.; Trifirò, A.; Trimarchi, M.; Vigilante, M.

2017-11-01

Complex and more and more complete detector arrays have been developed in the last two decades, or are in advanced design stage, in different laboratories. Such arrays are necessary to fully characterize nuclear reactions induced by stable and exotic beams. The need for contemporary detection of charged particles, and/or γ -rays, and/or neutrons, has been stressed in many fields of nuclear structure and reaction dynamics, with particular attention to the improvement of both high angular and energy resolution. Some examples of detection systems adapted to various energy ranges is discussed. Emphasis is given to the possible update of relatively old 4π detectors with new electronics and new detection methods.

Photoelectric array detectors for use at XUV wavelengths. [for Spacelab solar-physics facilities

NASA Technical Reports Server (NTRS)

Timothy, J. G.

1981-01-01

The characteristics of photoelectric detector systems for use at visible-light, ultraviolet, and X-ray wavelengths are briefly reviewed in the context of the needs of the Spacelab solar-physics facilities. Photoelectric array detectors for use at XUV wavelengths between 90 and 1500 A are described, and their use in the ESA Grazing-Incidence Solar Telescope (GRIST) facility is discussed.

Development of an intraoperative gamma camera based on a 256-pixel mercuric iodide detector array

NASA Astrophysics Data System (ADS)

Patt, B. E.; Tornai, M. P.; Iwanczyk, J. S.; Levin, C. S.; Hoffman, E. J.

1997-06-01

A 256-element mercuric iodide (HgI/sub 2/) detector array has been developed which is intended for use as an intraoperative gamma camera (IOGC). The camera is specifically designed for use in imaging gamma-emitting radiopharmaceuticals (such as 99m-Tc labeled Sestamibi) incorporated into brain tumors in the intraoperative surgical environment. The system is intended to improve the success of tumor removal surgeries by allowing more complete removal of subclinical tumor cells without removal of excessive normal tissue. The use of HgI/sub 2/ detector arrays in this application facilitates construction of an imaging head that is very compact and has a high SNR. The detector is configured as a cross-grid array. Pixel dimensions are 1.25 mm squares separated by 0.25 mm. The overall dimension of the detector is 23.75 mm on a side. The detector thickness is 1 mm which corresponds to over 60% stopping at 140 keV. The array has good uniformity with average energy resolution of 5.2/spl plusmn/2.9% FWHM at 140 keV (best resolution was 1.9% FWHM). Response uniformity (/spl plusmn//spl sigma/) was 7.9%. A study utilizing realistic tumor phantoms (uptake ratio varied from 2:1 to 100:1) in background (1 mCi/l) was conducted. SNRs for the reasonably achievable uptake ratio of 50:1 were 5.61 /spl sigma/ with 1 cm of background depth ("normal tissue") and 2.74 /spl sigma/ with 4 cm of background for a 6.3 /spl mu/l tumor phantom (/spl sim/270 nCi at the time of the measurement).

Gross beta determination in drinking water using scintillating fiber array detector.

PubMed

Lv, Wen-Hui; Yi, Hong-Chang; Liu, Tong-Qing; Zeng, Zhi; Li, Jun-Li; Zhang, Hui; Ma, Hao

2018-04-04

A scintillating fiber array detector for measuring gross beta counting is developed to monitor the real-time radioactivity in drinking water. The detector, placed in a stainless-steel tank, consists of 1096 scintillating fibers, both sides of which are connected to a photomultiplier tube. The detector parameters, including working voltage, background counting rate and stability, are tested, and the detection efficiency is calibrated using standard potassium chloride solution. Water samples are measured with the detector and the results are compared with those by evaporation method. The results show consistency with those by evaporation method. The background counting rate of the detector is 38.131 ± 0.005 cps, and the detection efficiency for β particles is 0.37 ± 0.01 cps/(Bq/l). The MDAC of this system can be less than 1.0 Bq/l for β particles in 120 min without pre-concentration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Kilopixel Pop-Up Bolometer Arrays for the Atacama Cosmology Telescope

NASA Technical Reports Server (NTRS)

Chervenak, J. A.; Wollack, E.; Henry, R.; Moseley, S. H.; Niemack, M.; Staggs, S.; Page, L.; Doriese, R.; Hilton, G. c.; Irwin, K. D.

2007-01-01

The recently deployed Atacama Cosmology Telescope (ACT) anticipates first light on its kilopixel array of close-packed transition-edge-sensor bolometers in November of 2007. The instrument will represent a full implementation of the next-generation, large format arrays for millimeter wave astronomy that use superconducting electronics and detectors. Achieving the practical construction of such an array is a significant step toward producing advanced detector arrays for future SOFIA instruments. We review the design considerations for the detector array produced for the ACT instrument. The first light imager consists of 32 separately instrumented 32-channel pop-up bolometer arrays (to create a 32x32 filled array of mm-wave sensors). Each array is instrumented with a 32-channel bias resistor array, Nyquist filter array, and time-division SQUID multiplexer. Each component needed to be produced in relatively large quantities with suitable uniformity to meet tolerances for array operation. An optical design was chosen to maximize absorption at the focal plane while mitigating reflections and stray light. The pop-up geometry (previously implemented with semiconducting detectors and readout on the SHARC II and HAWC instruments) enabled straightforward interface of the superconducting bias and readout circuit with the 2D array of superconducting bolometers. The array construction program balanced fabrication challenges with assembly challenges to deliver the instrument in a timely fashion. We present some of the results of the array build and characterization of its performance.

Frequency-multiplexed bias and readout of a 16-pixel superconducting nanowire single-photon detector array

NASA Astrophysics Data System (ADS)

Doerner, S.; Kuzmin, A.; Wuensch, S.; Charaev, I.; Boes, F.; Zwick, T.; Siegel, M.

2017-07-01

We demonstrate a 16-pixel array of microwave-current driven superconducting nanowire single-photon detectors with an integrated and scalable frequency-division multiplexing architecture, which reduces the required number of bias and readout lines to a single microwave feed line. The electrical behavior of the photon-sensitive nanowires, embedded in a resonant circuit, as well as the optical performance and timing jitter of the single detectors is discussed. Besides the single pixel measurements, we also demonstrate the operation of a 16-pixel array with a temporal, spatial, and photon-number resolution.

Design, implementation, and performance of the Astro-H SXS calorimeter array and anticoincidence detector

NASA Astrophysics Data System (ADS)

Kilbourne, Caroline A.; Adams, Joseph S.; Brekosky, Regis P.; Chervenak, James A.; Chiao, Meng P.; Eckart, Megan E.; Figueroa-Feliciano, Enectali; Galeazzi, Masimilliano; Grein, Christoph; Jhabvala, Christine A.; Kelly, Daniel; Leutenegger, Maurice A.; McCammon, Dan; Scott Porter, F.; Szymkowiak, Andrew E.; Watanabe, Tomomi; Zhao, Jun

2018-01-01

The calorimeter array of the JAXA Astro-H (renamed Hitomi) soft x-ray spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV, enabling essential plasma diagnostics. The SXS had a square array of 36 x-ray calorimeters at the focal plane. These calorimeters consisted of ion-implanted silicon thermistors and HgTe thermalizing x-ray absorbers. These devices demonstrated a resolution of better than 4.5 eV at 6 keV when operated at a heat-sink temperature of 50 mK. We will discuss the basic physical parameters of this array, including the array layout, thermal conductance of the link to the heat sink, resistance function, absorber details, and means of attaching the absorber to the thermistor-bearing element. We will also present the thermal characterization of the whole array, including thermal conductance and crosstalk measurements and the results of pulsing the frame temperature via alpha particles, heat pulses, and the environmental background. A silicon ionization detector was located behind the calorimeter array and served to reject events due to cosmic rays. We will briefly describe this anticoincidence detector and its performance.

X-ray photon correlation spectroscopy using a fast pixel array detector with a grid mask resolution enhancer.

PubMed

Hoshino, Taiki; Kikuchi, Moriya; Murakami, Daiki; Harada, Yoshiko; Mitamura, Koji; Ito, Kiminori; Tanaka, Yoshihito; Sasaki, Sono; Takata, Masaki; Jinnai, Hiroshi; Takahara, Atsushi

2012-11-01

The performance of a fast pixel array detector with a grid mask resolution enhancer has been demonstrated for X-ray photon correlation spectroscopy (XPCS) measurements to investigate fast dynamics on a microscopic scale. A detecting system, in which each pixel of a single-photon-counting pixel array detector, PILATUS, is covered by grid mask apertures, was constructed for XPCS measurements of silica nanoparticles in polymer melts. The experimental results are confirmed to be consistent by comparison with other independent experiments. By applying this method, XPCS measurements can be carried out by customizing the hole size of the grid mask to suit the experimental conditions, such as beam size, detector size and sample-to-detector distance.

Development and Production of Array Barrier Detectors at SCD

NASA Astrophysics Data System (ADS)

Klipstein, P. C.; Avnon, E.; Benny, Y.; Berkowicz, E.; Cohen, Y.; Dobromislin, R.; Fraenkel, R.; Gershon, G.; Glozman, A.; Hojman, E.; Ilan, E.; Karni, Y.; Klin, O.; Kodriano, Y.; Krasovitsky, L.; Langof, L.; Lukomsky, I.; Nevo, I.; Nitzani, M.; Pivnik, I.; Rappaport, N.; Rosenberg, O.; Shtrichman, I.; Shkedy, L.; Snapi, N.; Talmor, R.; Tessler, R.; Weiss, E.; Tuito, A.

2017-09-01

XB n or XB p barrier detectors exhibit diffusion-limited dark currents comparable with mercury cadmium telluride Rule-07 and high quantum efficiencies. In 2011, SemiConductor Devices (SCD) introduced "HOT Pelican D", a 640 × 512/15- μm pitch InAsSb/AlSbAs XB n mid-wave infrared (MWIR) detector with a 4.2- μm cut-off and an operating temperature of ˜150 K. Its low power (˜3 W), high pixel operability (>99.5%) and long mean time to failure make HOT Pelican D a highly reliable integrated detector-cooler product with a low size, weight and power. More recently, "HOT Hercules" was launched with a 1280 × 1024/15- μm format and similar advantages. A 3-megapixel, 10- μm pitch version ("HOT Blackbird") is currently completing development. For long-wave infrared applications, SCD's 640 × 512/15- μm pitch "Pelican-D LW" XB p type II superlattice (T2SL) detector has a ˜9.3- μm cut-off wavelength. The detector contains InAs/GaSb and InAs/AlSb T2SLs, and is fabricated into focal plane array (FPA) detectors using standard production processes including hybridization to a digital silicon read-out integrated circuit (ROIC), glue underfill and substrate thinning. The ROIC has been designed so that the complete detector closely follows the interfaces of SCD's MWIR Pelican-D detector family. The Pelican-D LW FPA has a quantum efficiency of ˜50%, and operates at 77 K with a pixel operability of >99% and noise equivalent temperature difference of 13 mK at 30 Hz and F/2.7.

Visible and infrared linear detector arrays for the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

NASA Technical Reports Server (NTRS)

Bailey, Gary C.

1987-01-01

The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument uses four separate focal plane assemblies consisting of line array detectors that are multiplexed to a common J-FET preamp using a FET switch multiplexing (MUX) technique. A 32-element silicon line array covers the spectral range from 0.41 to 0.70 microns. Three additional 64-element indium antimonide (InSb) line arrays cover the spectral range from 0.68 to 2.45 microns. The spectral sampling interval per detector element is nominally 9.8 nm, giving a total of 224 spectral channels. All focal planes operate at liquid nitrogen temperature and are housed in separate dewars. Electrical performance characteristics include a read noise of less than 1000 e(-) in all channels, response and dark nonuniformity of 5 percent peak to peak, and quantum efficiency of greater than 60 percent.

Construction of a fast, inexpensive rapid-scanning diode-array detector and spectrometer.

PubMed

Carter, T P; Baek, H K; Bonninghausen, L; Morris, R J; van Wart, H E

1990-10-01

A 512-element diode-array spectroscopic detection system capable of acquiring multiple spectra at a rate of 5 ms per spectrum with an effective scan rate of 102.9 kHz has been constructed. Spectra with fewer diode elements can also be acquired at scan rates up to 128 kHz. The detector utilizes a Hamamatsu silicon photodiode-array sensor that is interfaced to Hamamatsu driver/amplifier and clock generator boards and a DRA laboratories 12-bit 160-kHz analog-to-digital converter. These are standard, commercially available devices which cost approximately $3500. The system is interfaced to and controlled by an IBM XT microcomputer. Detailed descriptions of the home-built detector housing and control/interface circuitry are presented and its application to the study of the reaction of horseradish peroxidase with hydrogen peroxide is demonstrated.

The energy spectrum of ultra-high-energy cosmic rays measured by the Telescope Array FADC fluorescence detectors in monocular mode

NASA Astrophysics Data System (ADS)

Abu-Zayyad, T.; Aida, R.; Allen, M.; Anderson, R.; Azuma, R.; Barcikowski, E.; Belz, J. W.; Bergman, D. R.; Blake, S. A.; Cady, R.; Cheon, B. G.; Chiba, J.; Chikawa, M.; Cho, E. J.; Cho, W. R.; Fujii, H.; Fujii, T.; Fukuda, T.; Fukushima, M.; Hanlon, W.; Hayashi, K.; Hayashi, Y.; Hayashida, N.; Hibino, K.; Hiyama, K.; Honda, K.; Iguchi, T.; Ikeda, D.; Ikuta, K.; Inoue, N.; Ishii, T.; Ishimori, R.; Ito, H.; Ivanov, D.; Iwamoto, S.; Jui, C. C. H.; Kadota, K.; Kakimoto, F.; Kalashev, O.; Kanbe, T.; Kasahara, K.; Kawai, H.; Kawakami, S.; Kawana, S.; Kido, E.; Kim, H. B.; Kim, H. K.; Kim, J. H.; Kim, J. H.; Kitamoto, K.; Kitamura, S.; Kitamura, Y.; Kobayashi, K.; Kobayashi, Y.; Kondo, Y.; Kuramoto, K.; Kuzmin, V.; Kwon, Y. J.; Lan, J.; Lim, S. I.; Lundquist, J. P.; Machida, S.; Martens, K.; Matsuda, T.; Matsuura, T.; Matsuyama, T.; Matthews, J. N.; Myers, I.; Minamino, M.; Miyata, K.; Murano, Y.; Nagataki, S.; Nakamura, T.; Nam, S. W.; Nonaka, T.; Ogio, S.; Ogura, J.; Ohnishi, M.; Ohoka, H.; Oki, K.; Oku, D.; Okuda, T.; Ono, M.; Oshima, A.; Ozawa, S.; Park, I. H.; Pshirkov, M. S.; Rodriguez, D. C.; Roh, S. Y.; 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, J. I.; Shirahama, T.; Smith, J. D.; Sokolsky, P.; Sonley, T. J.; Springer, R. W.; Stokes, B. T.; Stratton, S. R.; Stroman, T. A.; Suzuki, S.; Takahashi, Y.; Takeda, M.; 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.; Tsuyuguchi, Y.; Uchihori, Y.; Udo, S.; Ukai, H.; Vasiloff, G.; Wada, Y.; Wong, T.; Yamakawa, Y.; Yamane, R.; Yamaoka, H.; Yamazaki, K.; Yang, J.; Yoneda, Y.; Yoshida, S.; Yoshii, H.; Zollinger, R.; Zundel, Z.

2013-08-01

We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array's third fluorescence detector [T. Abu-Zayyad et al., The energy spectrum of Telescope Array's middle drum detector and the direct comparison to the high resolution fly's eye experiment, Astroparticle Physics 39 (2012) 109-119, http://dx.doi.org/10.1016/j.astropartphys.2012.05.012, Available from: ]. This combined spectrum corroborates the recently published Telescope Array surface detector spectrum [T. Abu-Zayyad, et al., The cosmic-ray energy spectrum observed with the surface detector of the Telescope Array experiment, ApJ 768 (2013) L1, http://dx.doi.org/10.1088/2041-8205/768/1/L1, Available from: ] with independent systematic uncertainties.

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.

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

USDA-ARS?s Scientific Manuscript database

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...

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.

Timing Results Using an FPGA-Based TDC with Large Arrays of 144 SiPMs

NASA Astrophysics Data System (ADS)

Aguilar, A.; González, A. J.; Torres, J.; García-Olcina, R.; Martos, J.; Soret, J.; Conde, P.; Hernández, L.; Sánchez, F.; Benlloch, J. M.

2015-02-01

Silicon photomultipliers (SiPMs) have become an alternative to traditional tubes due to several features. However, their implementation to form large arrays is still a challenge especially due to their relatively high intrinsic noise, depending on the chosen readout. In this contribution, two modules composed of 12 ×12 SiPMs with an area of roughly 50 mm×50 mm are used in coincidence. Coincidence resolving time (CRT) results with a field-programmable gate array, in combination with a time to digital converter, are shown as a function of both the sensor bias voltage and the digitizer threshold. The dependence of the CRT on the sensor matrix temperature, the amount of SiPM active area and the crystal type is also analyzed. Measurements carried out with a crystal array of 2 mm pixel size and 10 mm height have shown time resolutions for the entire 288 SiPM two-detector set-up as good as 800 ps full width at half maximum (FWHM).

Antenna and Electronics Cost Tradeoffs For Large Arrays

NASA Technical Reports Server (NTRS)

D'Addario, Larry R.

2007-01-01

This viewgraph presentation describes the cost tradeoffs for large antenna arrays. The contents include: 1) Cost modeling for large arrays; 2) Antenna mechanical cost over a wide range of sizes; and 3) Cost of per-antenna electronics.

Cryogenic and radiation hard ASIC design for large format NIR/SWIR detector

NASA Astrophysics Data System (ADS)

Gao, Peng; Dupont, Benoit; Dierickx, Bart; Müller, Eric; Verbruggen, Geert; Gielis, Stijn; Valvekens, Ramses

2014-10-01

An ASIC is developed to control and data quantization for large format NIR/SWIR detector arrays. Both cryogenic and space radiation environment issue are considered during the design. Therefore it can be integrated in the cryogenic chamber, which reduces significantly the vast amount of long wires going in and out the cryogenic chamber, i.e. benefits EMI and noise concerns, as well as the power consumption of cooling system and interfacing circuits. In this paper, we will describe the development of this prototype ASIC for image sensor driving and signal processing as well as the testing in both room and cryogenic temperature.

Recent results from the Telescope Array Experiment

NASA Astrophysics Data System (ADS)

Abbasi, Rasha; Telescope Array Collaboration

2016-03-01

The Telescope Array (TA) is the largest ultrahigh energy cosmic rays detector in the northern hemisphere. TA is a hybrid detector comprised of three air fluorescence stations and a large surface array consisting of 507 scintillator counters. Each of the three fluorescence stations, located at the periphery of the ground array, views 108 degrees in azimuth and up to 30 degrees in elevation. The surface detectors are arranged in a square grid of 1.2 km spacing, covering over 700 square kilometers. TA has collected more than seven years of data. In this talk, we will present some of the main results on the cosmic rays composition and energy spectrum obtained by TA and its low energy extension (TALE). Finally, we will present our results from the search for arrival direction anisotropy, including the observed large excess of events at the highest energies, seen in the region of the northern sky centered on Ursa Major. Based on the current results, the ``hot spot'' in particular, TA is pursuing the expansion of the surface array to four times its current size.

Fabrication of large dual-polarized multichroic TES bolometer arrays for CMB measurements with the SPT-3G camera

DOE Office of Scientific and Technical Information (OSTI.GOV)

Posada, C. M.; Ade, P. A. R.; Ahmed, Z.

2015-08-11

This work presents the procedures used by 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 band-passes before the millimeter-wavelength signal is fed tomore » the respective Ti/Au TES bolometers. There are six TES bolometer detectors per pixel, which allow for measurements of three band-passes (95 GHz, 150 GHz 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.« less

Development of HgCdTe large format MBE arrays and noise-free high speed MOVPE EAPD arrays for ground based NIR astronomy

NASA Astrophysics Data System (ADS)

Finger, G.; Baker, I.; Downing, M.; Alvarez, D.; Ives, D.; Mehrgan, L.; Meyer, M.; Stegmeier, J.; Weller, H. J.

2017-11-01

Large format near infrared HgCdTe 2Kx2K and 4Kx4K MBE arrays have reached a level of maturity which meets most of the specifications required for near infrared (NIR) astronomy. The only remaining problem is the persistence effect which is device specific and not yet fully under control. For ground based multi-object spectroscopy on 40 meter class telescopes larger pixels would be advantageous. For high speed near infrared fringe tracking and wavefront sensing the only way to overcome the CMOS noise barrier is the amplification of the photoelectron signal inside the infrared pixel by means of the avalanche gain. A readout chip for a 320x256 pixel HgCdTe eAPD array will be presented which has 32 parallel video outputs being arranged in such a way that the full multiplex advantage is also available for small sub-windows. In combination with the high APD gain this allows reducing the readout noise to the subelectron level by applying nondestructive readout schemes with subpixel sampling. Arrays grown by MOVPE achieve subelectron readout noise and operate with superb cosmetic quality at high APD gain. Efforts are made to reduce the dark current of those arrays to make this technology also available for large format focal planes of NIR instruments offering noise free detectors for deep exposures. The dark current of the latest MOVPE eAPD arrays is already at a level adequate for noiseless broad and narrow band imaging in scientific instruments.

High-speed femtosecond pump-probe spectroscopy with a smart pixel detector array.

PubMed

Bourquin, S; Prasankumar, R P; Kärtner, F X; Fujimoto, J G; Lasser, T; Salathé, R P

2003-09-01

A new femtosecond pump-probe spectroscopy technique is demonstrated that permits the high-speed, parallel acquisition of pump-probe measurements at multiple wavelengths. This is made possible by use of a novel, two-dimensional smart pixel detector array that performs amplitude demodulation in real time on each pixel. This detector array can not only achieve sensitivities comparable with lock-in amplification but also simultaneously performs demodulation of probe transmission signals at multiple wavelengths, thus permitting rapid time- and wavelength-resolved femtosecond pump-probe spectroscopy. Measurements on a thin sample of bulk GaAs are performed across 58 simultaneous wavelengths. Differential probe transmission changes as small as approximately 2 x 10(-4) can be measured over a 5-ps delay scan in only approximately 3 min. This technology can be applied to a wide range of pump-probe measurements in condensed matter, chemistry, and biology.

Feedhorn-Coupled Transition-Edge Superconducting Bolometer Arrays for Cosmic Microwave Background Polarimetry

NASA Technical Reports Server (NTRS)

Hubmayr, J.; Austermann, J.; Beall, J.; Becker, D.; Cho, H.-M.; Datta, R.; Duff, S. M.; Grace, E.; Halverson, N.; Henderson, S. W.;

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.

Spectrum Tunable Quantum Dot-In-A-Well Infrared Detector Arrays for Thermal Imaging

DTIC Science & Technology

2008-09-01

Spectrum tunable quantum dot-in-a- well infrared detector arrays for thermal imaging Jonathan R. Andrews1, Sergio R. Restaino1, Scott W. Teare2...Materials at the University of New Mexico has been investigating quantum dot and quantum well detectors for thermal infrared imaging applications...SEP 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Spectrum tunable quantum dot-in-a- well infrared

Large solar arrays

NASA Technical Reports Server (NTRS)

Crabtree, W. L.

1980-01-01

A spectrophotovoltaic converter, a thermophotovoltaic converter, a cassegrainian concentrator, a large silicon cell blanket, and a high flux approach are among the concepts being investigated as part of the multihundred kW solar array program for reducing the cost of photovoltaic energy in space. These concepts involve a range of technology risks, the highest risk being represented by the thermophotovoltaics and spectrophotovoltaics approaches which involve manipulation to of the incoming spectrum to enhance system efficiency. The planar array (solar blanket) has no technology risk and a moderate payback. The primary characteristics, components, and technology concerns of each of these concepts are summarized. An orbital power platform mission in the late 1980's is being used to allow a coherent technology advancement program in order to achieve a ten year life with maintenance at a capital recurring cost of $30/watt based on 1978 dollars.

A cryogenic thermal source for detector array characterization

NASA Astrophysics Data System (ADS)

Chuss, David T.; Rostem, Karwan; Wollack, Edward J.; Berman, Leah; Colazo, Felipe; DeGeorge, Martin; Helson, Kyle; Sagliocca, Marco

2017-10-01

We describe the design, fabrication, and validation of a cryogenically compatible quasioptical thermal source for characterization of detector arrays. The source is constructed using a graphite-loaded epoxy mixture that is molded into a tiled pyramidal structure. The mold is fabricated using a hardened steel template produced via a wire electron discharge machining process. The absorptive mixture is bonded to a copper backplate enabling thermalization of the entire structure and measurement of the source temperature. Measurements indicate that the reflectance of the source is <0.001 across a spectral band extending from 75 to 330 GHz.

A Cryogenic Thermal Source for Detector Array Characterization

NASA Technical Reports Server (NTRS)

Chuss, David T.; Rostem, Karwan; Wollack, Edward J.; Berman, Leah; Colazo, Felipe; DeGeorge, Martin; Helson, Kyle; Sagliocca, Marco

2017-01-01

We describe the design, fabrication, and validation of a cryogenically compatible quasioptical thermal source for characterization of detector arrays. The source is constructed using a graphite-loaded epoxy mixture that is molded into a tiled pyramidal structure. The mold is fabricated using a hardened steel template produced via a wire electron discharge machining process. The absorptive mixture is bonded to a copper backplate enabling thermalization of the entire structure and measurement of the source temperature. Measurements indicate that the reflectance of the source is less than 0.001 across a spectral band extending from 75 to 330 gigahertz.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tim Roney; Robert Seifert; Bob Pink

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 integrationmore » 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.« less

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

Properties of vapor detector arrays formed through plasticization of carbon black-organic polymer composites.

PubMed

Koscho, Michael E; Grubbs, Robert H; Lewis, Nathan S

2002-03-15

Arrays of vapor detectors have been formed through addition of varying mass fractions of the plasticizer diethylene glycol dibenzoate to carbon black-polymer composites of poly(vinyl acetate) (PVAc) or of poly(N-vinylpyrrolidone). Addition of plasticizer in 5% mass fraction increments produced 20 compositionally different detectors from each polymer composite. Differences in vapor sorption and permeability that effected changes in the dc electrical resistance response of these compositionally different detectors allowed identification and classification of various test analytes using standard chemometric methods. Glass transition temperatures, Tg, were measured using differential scanning calorimetry for plasticized polymers having a mass fraction of 0, 0.10, 0.20, 0.30, 0.40, or 0.50 of plasticizer in the composite. The plasticized PVAc composites with Tg < 25 degrees C showed rapid responses at room temperature to all of the test analyte vapors studied in this work, whereas composites with Tg > 25 degrees C showed response times that were highly dependent on the polymer/analyte combination. These composites showed a discontinuity in the temperature dependence of their resistance, and this discontinuity provided a simple method for determining the Tg of the composite and for determining the temperature or plasticizer mass fraction above which rapid resistance responses could be obtained for all members of the test set of analyte vapors. The plasticization approach provides a method for achieving rapid detector response times as well as for producing a large number of chemically different vapor detectors from a limited number of initial chemical feedstocks.

Enabling Large Focal Plane Arrays through Mosaic Hybridization

NASA Technical Reports Server (NTRS)

Miller, Timothy M.; Jhabvala, Christine A.; Costen, Nick; Benford, Dominic J.

2012-01-01

We have demonstrated the hybridization of large mosaics of far-infrared detectors, joining separately fabricated sub-units into a single unit on a single, large substrate. We produced a single detector mockup on a 100mm diameter wafer and four mockup readout quadrant chips from a separate 100mm wafer. The individually fabricated parts were hybridized using a Suss FC150 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 (CTE) 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 mockup mosaic-hybridized detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently demonstrated.

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.

A bench-top megavoltage fan-beam CT using CdWO4-photodiode detectors. I. System description and detector characterization.

PubMed

Rathee, S; Tu, D; Monajemi, T T; Rickey, D W; Fallone, B G

2006-04-01

We describe the components of a bench-top megavoltage computed tomography (MVCT) scanner that uses an 80-element detector array consisting of CdWO4 scintillators coupled to photodiodes. Each CdWO4 crystal is 2.75 x 8 x 10 mm3. The detailed design of the detector array, timing control, and multiplexer are presented. The detectors show a linear response to dose (dose rate was varied by changing the source to detector distance) with a correlation coefficient (R2) nearly unity with the standard deviation of signal at each dose being less than 0.25%. The attenuation of a 6 MV beam by solid water measured by this detector array indicates a small, yet significant spectral hardening that needs to be corrected before image reconstruction. The presampled modulation transfer function is strongly affected by the detector's large pitch and a large improvement can be obtained by reducing the detector pitch. The measured detective quantum efficiency at zero spatial frequency is 18.8% for 6 MV photons which will reduce the dose to the patient in MVCT applications. The detector shows a less than a 2% reduction in response for a dose of 24.5 Gy accumulated in 2 h; however, the lost response is recovered on the following day. A complete recovery can be assumed within the experimental uncertainty (standard deviation <0.5%); however, any smaller permanent damage could not be assessed.

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

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.

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.

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.

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.

Measurement of positron annihilation lifetimes for positron burst by multi-detector array

NASA Astrophysics Data System (ADS)

Wang, B. Y.; Kuang, P.; Liu, F. Y.; Han, Z. J.; Cao, X. Z.; Zhang, P.

2018-03-01

It is currently impossible to exploit the timing information in a gamma-ray pulse generated within nanoseconds when a high-intensity positron burst annihilation event occurs in a target using conventional single-detector methods. A state-of-the-art solution to the problem is proposed in this paper. In this approach, a multi-detector array composed of many independent detection cells mounted spherically around the target is designed to detect the time distribution of the annihilated gamma rays generated following, in particular, a positron burst emitting huge amounts of positrons in a short pulse duration, even less than a few nano- or picoseconds.

Image scanning fluorescence emission difference microscopy based on a detector array.

PubMed

Li, Y; Liu, S; Liu, D; Sun, S; Kuang, C; Ding, Z; Liu, X

2017-06-01

We propose a novel imaging method that enables the enhancement of three-dimensional resolution of confocal microscopy significantly and achieve experimentally a new fluorescence emission difference method for the first time, based on the parallel detection with a detector array. Following the principles of photon reassignment in image scanning microscopy, images captured by the detector array were arranged. And by selecting appropriate reassign patterns, the imaging result with enhanced resolution can be achieved with the method of fluorescence emission difference. Two specific methods are proposed in this paper, showing that the difference between an image scanning microscopy image and a confocal image will achieve an improvement of transverse resolution by approximately 43% compared with that in confocal microscopy, and the axial resolution can also be enhanced by at least 22% experimentally and 35% theoretically. Moreover, the methods presented in this paper can improve the lateral resolution by around 10% than fluorescence emission difference and 15% than Airyscan. The mechanism of our methods is verified by numerical simulations and experimental results, and it has significant potential in biomedical applications. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

The Design, Implementation, and Performance of the Astro-H SXS Calorimeter Array and Anti-Coincidence Detector

NASA Technical Reports Server (NTRS)

Kilbourne, Caroline A.; Adams, Joseph S.; Brekosky, Regis P.; Chiao, Meng P.; Chervenak, James A.; Eckart, Megan E.; Figueroa-Feliciano, Enectali; Galeazzi, Masimilliano; Grein, Christoph; Jhabvala, Christine A.;

Fabrication of Detector Arrays for the SPT-3G Receiver

NASA Astrophysics Data System (ADS)

Posada, C. M.; Ade, P. A. R.; Ahmed, Z.; Anderson, A. J.; Austermann, J. E.; Avva, J. S.; Thakur, R. Basu; Bender, A. N.; Benson, B. A.; Carlstrom, J. E.; Carter, F. W.; Cecil, T.; Chang, C. L.; Cliche, J. F.; Cukierman, A.; Denison, E. V.; de Haan, T.; Ding, J.; Divan, R.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Foster, A.; Gannon, R. N.; Gilbert, A.; Groh, J. C.; Halverson, N. W.; Harke-Hosemann, A. H.; Harrington, N. L.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Huang, N.; Irwin, K. D.; Jeong, O. B.; Jonas, M.; Khaire, T.; Kofman, A. M.; Korman, M.; Kubik, D.; Kuhlmann, S.; Kuo, C. L.; Lee, A. T.; Lowitz, A. E.; Meyer, S. S.; Michalik, D.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Noble, G. I.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Rahlin, A.; Ruhl, J. E.; Saunders, L. J.; Sayre, J. T.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J. A.; Stan, L.; Stark, A. A.; Story, K. T.; Suzuki, A.; Tang, Q. Y.; Thompson, K. L.; Tucker, C.; Vale, L. R.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.; Young, M. R.

2018-05-01

The South Pole Telescope third-generation (SPT-3G) receiver was installed during the austral summer of 2016-2017. It is designed to measure the cosmic microwave background across three frequency bands centered at 95, 150, and 220 GHz. The SPT-3G receiver has ten focal plane modules, each with 269 pixels. Each pixel features a broadband sinuous antenna coupled to a niobium microstrip transmission line. In-line filters define the desired band-passes before the signal is coupled to six bolometers with Ti/Au/Ti/Au transition edge sensors (three bands × two polarizations). In total, the SPT-3G receiver is composed of 16,000 detectors, which are read out using a 68× frequency-domain multiplexing scheme. In this paper, we present the process employed in fabricating the detector arrays.

Improved performance of HgCdTe infrared detector focal plane arrays by modulating light field based on photonic crystal structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang, Jian; Hu, Weida, E-mail: wdhu@mail.sitp.ac.cn; Ye, Zhenhua

2014-05-14

An HgCdTe long-wavelength infrared focal plane array photodetector is proposed by modulating light distributions based on the photonic crystal. It is shown that a promising prospect of improving performance is better light harvest and dark current limitation. To optimize the photon field distributions of the HgCdTe-based photonic crystal structure, a numerical method is built by combining the finite-element modeling and the finite-difference time-domain simulation. The optical and electrical characteristics of designed HgCdTe mid-wavelength and long-wavelength photon-trapping infrared detector focal plane arrays are obtained numerically. The results indicate that the photon crystal structure, which is entirely compatible with the large infraredmore » focal plane arrays, can significantly reduce the dark current without degrading the quantum efficiency compared to the regular mesa or planar structure.« less

Effects of 1-MeV gamma radiation on a multi-anode microchannel array detector tube

NASA Technical Reports Server (NTRS)

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

1979-01-01

A multianode microchannel array (MAMA) detector tube without a photocathode was exposed to a total dose of 1,000,000 rads of 1-MeV gamma radiation from a Co-60 source. The high-voltage characteristic of the microchannel array plate, average dark count, gain, and resolution of pulse height distribution characteristics showed no degradation after this total dose. In fact, the degassing of the microchannels induced by the high radiation flux had the effect of cleaning up the array plate and improving its characteristics.

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.

First Tests of Prototype SCUBA-2 Superconducting Bolometer Array

NASA Astrophysics Data System (ADS)

Woodcraft, Adam L.; Ade, Peter A. R.; Bintley, Dan; Hunt, Cynthia L.; Sudiwala, Rashmi V.; Hilton, Gene C.; Irwin, Kent D.; Reintsema, Carl D.; Audley, Michael D.; Holland, Wayne S.; MacIntosh, Mike

2006-09-01

We present results of the first tests on a 1280 pixel superconducting bolometer array, a prototype for SCUBA-2, a sub-mm camera being built for the James Clerk Maxwell Telescope in Hawaii. The bolometers are TES (transition edge sensor) detectors; these take advantage of the large variation of resistance with temperature through the superconducting transition. To keep the number of wires reasonable, a multiplexed read-out is used. Each pixel is read out through an individual DC SQUID; room temperature electronics switch between rows in the array by biasing the appropriate SQUIDs in turn. Arrays of 100 SQUIDs in series for each column then amplify the output. Unlike previous TES arrays, the multiplexing elements are located beneath each pixel, making large arrays possible, but construction more challenging. The detectors are constructed from Mo/Cu bi-layers; this technique enables the transition temperature to be tuned using the proximity effect by choosing the thickness of the normal and superconducting materials. To achieve the required performance, the detectors are operated at a temperature of approximately 120 mK. We describe the results of a basic characterisation of the array, demonstrating that it is fully operational, and give the results of signal to noise measurements.

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.

Gallium arsenide quantum well-based far infrared array radiometric imager

NASA Technical Reports Server (NTRS)

Forrest, Kathrine A.; Jhabvala, Murzy D.

1991-01-01

We have built an array-based camera (FIRARI) for thermal imaging (lambda = 8 to 12 microns). FIRARI uses a square format 128 by 128 element array of aluminum gallium arsenide quantum well detectors that are indium bump bonded to a high capacity silicon multiplexer. The quantum well detectors offer good responsivity along with high response and noise uniformity, resulting in excellent thermal images without compensation for variation in pixel response. A noise equivalent temperature difference of 0.02 K at a scene temperature of 290 K was achieved with the array operating at 60 K. FIRARI demonstrated that AlGaAS quantum well detector technology can provide large format arrays with performance superior to mercury cadmium telluride at far less cost.

Comparison of experimental results of a Quad-CZT array detector, a NaI(Tl), a LaBr3(Ce), and a HPGe for safeguards applications

NASA Astrophysics Data System (ADS)

Kwak, S.-W.; Choi, J.; Park, S. S.; Ahn, S. H.; Park, J. S.; Chung, H.

2017-11-01

A compound semiconductor detector, CdTe (or CdZnTe), has been used in various areas including nuclear safeguards applications. To address its critical drawback, low detection efficiency, which leads to a long measurement time, a Quad-CZT array-based gamma-ray spectrometer in our previous study has been developed by combining four individual CZT detectors. We have re-designed the developed Quad-CZT array system to make it more simple and compact for a hand-held gamma-ray detector. The objective of this paper aims to compare the improved Quad-CZT array system with the traditional gamma-ray spectrometers (NaI(Tl), LaBr3(Ce), HPGe); these detectors currently have been the most commonly used for verification of nuclear materials. Nuclear materials in different physical forms in a nuclear facility of Korea were measured by the Quad-CZT array system and the existing gamma-ray detectors. For measurements of UO2 pellets and powders, and fresh fuel rods, the Quad-CZT array system turned out to be superior to the NaI(Tl) and LaBr3(Ce). For measurements of UF6 cylinders with a thick wall, the Quad-CZT array system and HPGe gave similar accuracy under the same measurement time. From the results of the field tests conducted, we can conclude that the improved Quad-CZT array system would be used as an alternative to HPGes and scintillation detectors for the purpose of increasing effectivenss and efficiency of safeguards applications. This is the first paper employing a multi-element CZT array detector for measurement of nuclear materials—particularly uranium in a UF6 cylinder—in a real nuclear facility. The present work also suggests that the multi-CZT array system described in this study would be one promising method to address a serious weakness of CZT-based radiation detection.

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.

SU-E-T-167: Characterization of In-House Plastic Scintillator Detectors Array for Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, T; Liu, H; Dimofte, A

Purpose: To characterize basic performance of plastic scintillator detectors (PSD) array designed for dosimetry of radiation therapy. Methods: An in-house PSD array has been developed by placing single point PSD into customized 2D holder. Each point PSD is a plastic scintillating fiber-based detector designed for highly accurate measurement of small radiotherapy fields used in patient plan verification and machine commissioning and QA procedures. A parallel fiber without PSD is used for Cerenkov separation by subtracting from PSD readings. Cerenkov separation was confirmed by optical spectroscopy. Alternative Cerenkov separation approaches are also investigated. The optical signal was converted to electronic signalmore » with a photodiode and then subsequently amplified. We measured its dosimetry performance, including percentage depth dose and output factor, and compared with reference ion chamber measurements. The PSD array is then placed along the radiation beam for multiple point dose measurement, representing subsets of PDD measurements, or perpendicular to the beam for profile measurements. Results: The dosimetry results of PSD point measurements agree well with reference ion chamber measurements. For percentage depth dose, the maximal differences between PSD and ion chamber results are 3.5% and 2.7% for 6MV and 15MV beams, respectively. For the output factors, PSD measurements are within 3% from ion chamber results. PDD and profile measurement with PSD array are also performed. Conclusions: The current design of multichannel PSD array is feasible for the dosimetry measurement in radiation therapy. Dose distribution along or perpendicular to the beam path could be measured. It might as well be used as range verification in proton therapy.A PS hollow fiber detector will be investigated to eliminate the Cerenkov radiation effect so that all 32 channels can be used.« less

Performance studies of X3 silicon detectors for the future ELISSA array at ELI-NP

NASA Astrophysics Data System (ADS)

Chesnevskaya, S.; Balabanski, D. L.; Choudhury, D.; Constantin, P.; Filipescu, D. M.; Ghita, D. G.; Guardo, G. L.; Lattuada, D.; Matei, C.; Rotaru, A.; State, A.

2018-05-01

ELISSA is an array of silicon strip detectors under construction at the ELI-NP facility for measurements of photodissociation reactions using high-brilliance, quasi monoenergetic gamma beams. The detection system consists of 35 single-sided position-sensitive X3 detectors arranged in a cylindrical configuration and eight QQQ3 detectors as end-caps. A batch of forty X3 detectors have been tested at ELI-NP. The energy and position resolution, ballistic deficit, leakage currents, and depletion voltage were measured and analyzed. Measurements of the energy resolution were carried out using two read-out electronic chains, one based on multichannel preamplifiers and another based on multiplexers.

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.

Instrumentation development for an array of water Cherenkov detectors for extensive air shower experiments

NASA Astrophysics Data System (ADS)

Sheidaei, F.; Bahmanabadi, M.; Keivani, A.; Samimi, J.

2009-11-01

A new small array of Cherenkov detectors has been deployed in Tehran, 1200 m above sea level. This array contains four tanks of distilled water with a diameter of 64 cm and a height of 130 cm. The effective area of each tank is about 1382 cm2. They are used to detect air showers and to record the arrival time of the secondary particles. We have collected about 640 000 extensive air showers (EAS) in 8298 h of observation time from November 2006 to October 2007. The distribution of air showers in zenith and azimuth angles has been studied and a cosnθ distribution with n = 6.02 ± 0.01 was obtained for the zenith angle distribution. An asymmetry has been observed in the azimuthal distribution of EAS of cosmic rays due to geomagnetic field. The first and second amplitudes of the asymmetry are AI = 0.183 ± 0.001 and AII = 0.038 ± 0.001. Since the recent results are in good agreement with our previous results of scintillation detectors, and tanks of distilled water are cheaper, we prefer to use them instead of scintillators in a future larger array. By simulation, we have improved the size of the detectors to yield the highest efficiency. The best dimensions for each tank with a photomultiplier tube in the center of its lid are 40 cm in diameter and 60 cm in height.

Intensity information extraction in Geiger mode detector array based three-dimensional imaging applications

NASA Astrophysics Data System (ADS)

Wang, Fei

2013-09-01

Geiger-mode detectors have single photon sensitivity and picoseconds timing resolution, which make it a good candidate for low light level ranging applications, especially in the case of flash three dimensional imaging applications where the received laser power is extremely limited. Another advantage of Geiger-mode APD is their capability of large output current which can drive CMOS timing circuit directly, which means that larger format focal plane arrays can be easily fabricated using the mature CMOS technology. However Geiger-mode detector based FPAs can only measure the range information of a scene but not the reflectivity. Reflectivity is a major characteristic which can help target classification and identification. According to Poisson statistic nature, detection probability is tightly connected to the incident number of photon. Employing this relation, a signal intensity estimation method based on probability inversion is proposed. Instead of measuring intensity directly, several detections are conducted, then the detection probability is obtained and the intensity is estimated using this method. The relation between the estimator's accuracy, measuring range and number of detections are discussed based on statistical theory. Finally Monte-Carlo simulation is conducted to verify the correctness of this theory. Using 100 times of detection, signal intensity equal to 4.6 photons per detection can be measured using this method. With slight modification of measuring strategy, intensity information can be obtained using current Geiger-mode detector based FPAs, which can enrich the information acquired and broaden the application field of current technology.

Development activities on NIR large format MCT detectors for astrophysics and space science at CEA and SOFRADIR

NASA Astrophysics Data System (ADS)

Boulade, Olivier; Moreau, Vincent; Mulet, Patrick; Gravrand, Olivier; Cervera, Cyril; Zanatta, Jean-Paul; Castelein, Pierre; Guellec, Fabrice; Fièque, Bruno; Chorier, Philippe; Roumegoux, Julien

2016-07-01

CEA and SOFRADIR have been manufacturing and characterizing near infrared detectors in the frame of ESA's near infrared large format sensor array roadmap to develop a 2Kx2K large format low flux low noise device for space applications such as astrophysics. These detectors use HgCdTe as the absorbing material and p/n diode technology. The technological developments (photovoltaic technology, readout circuit, ...) are shared between CEA/LETI and SOFRADIR, both in Grenoble, while most of the performances are evaluated at CEA/IRFU in Saclay where a dedicated test facility has been developed, in particular to measure very low dark currents. The paper will present the current status of these developments at the end of ESA's NIRLFSA phase 2. The performances of the latest batch of devices meet or are very close to all the requirements (quantum efficiency, dark current, cross talk, readout noise, ...) even though a glow induced by the ROIC prevents the accurate measurement of the dark current. The current devices are fairly small, 640x512 15μm pixels, and the next phase of activity will target the development of a full size 2Kx2K detector. From the design and development, to the manufacturing and finally the testing, that type of detector requests a high level of mastering. An appropriate manufacturing and process chain compatible with such a size is needed at industrial level and results obtained with CEA technology coupled with Sofradir industrial experience and work on large dimension detector allow French actors to be confident to address this type of future missions.

Fast and Accurate Simulation Technique for Large Irregular Arrays

NASA Astrophysics Data System (ADS)

Bui-Van, Ha; Abraham, Jens; Arts, Michel; Gueuning, Quentin; Raucy, Christopher; Gonzalez-Ovejero, David; de Lera Acedo, Eloy; Craeye, Christophe

2018-04-01

A fast full-wave simulation technique is presented for the analysis of large irregular planar arrays of identical 3-D metallic antennas. The solution method relies on the Macro Basis Functions (MBF) approach and an interpolatory technique to compute the interactions between MBFs. The Harmonic-polynomial (HARP) model is established for the near-field interactions in a modified system of coordinates. For extremely large arrays made of complex antennas, two approaches assuming a limited radius of influence for mutual coupling are considered: one is based on a sparse-matrix LU decomposition and the other one on a tessellation of the array in the form of overlapping sub-arrays. The computation of all embedded element patterns is sped up with the help of the non-uniform FFT algorithm. Extensive validations are shown for arrays of log-periodic antennas envisaged for the low-frequency SKA (Square Kilometer Array) radio-telescope. The analysis of SKA stations with such a large number of elements has not been treated yet in the literature. Validations include comparison with results obtained with commercial software and with experiments. The proposed method is particularly well suited to array synthesis, in which several orders of magnitude can be saved in terms of computation time.

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.

Frequency multiplexed superconducting quantum interference device readout of large bolometer arrays for cosmic microwave background measurements.

PubMed

Dobbs, M A; Lueker, M; Aird, K A; Bender, A N; Benson, B A; Bleem, L E; Carlstrom, J E; Chang, C L; Cho, H-M; Clarke, J; Crawford, T M; Crites, A T; Flanigan, D I; de Haan, T; George, E M; Halverson, N W; Holzapfel, W L; Hrubes, J D; Johnson, B R; Joseph, J; Keisler, R; Kennedy, J; Kermish, Z; Lanting, T M; Lee, A T; Leitch, E M; Luong-Van, D; McMahon, J J; Mehl, J; Meyer, S S; Montroy, T E; Padin, S; Plagge, T; Pryke, C; Richards, P L; Ruhl, J E; Schaffer, K K; Schwan, D; Shirokoff, E; Spieler, H G; Staniszewski, Z; Stark, A A; Vanderlinde, K; Vieira, J D; Vu, C; Westbrook, B; Williamson, R

2012-07-01

A technological milestone for experiments employing transition edge sensor bolometers operating at sub-Kelvin temperature is the deployment of detector arrays with 100s-1000s of bolometers. One key technology for such arrays is readout multiplexing: the ability to read out many sensors simultaneously on the same set of wires. This paper describes a frequency-domain multiplexed readout system which has been developed for and deployed on the APEX-SZ and South Pole Telescope millimeter wavelength receivers. In this system, the detector array is divided into modules of seven detectors, and each bolometer within the module is biased with a unique ∼MHz sinusoidal carrier such that the individual bolometer signals are well separated in frequency space. The currents from all bolometers in a module are summed together and pre-amplified with superconducting quantum interference devices operating at 4 K. Room temperature electronics demodulate the carriers to recover the bolometer signals, which are digitized separately and stored to disk. This readout system contributes little noise relative to the detectors themselves, is remarkably insensitive to unwanted microphonic excitations, and provides a technology pathway to multiplexing larger numbers of sensors.

Detector characterization, optimization, and operation for ACTPol

NASA Astrophysics Data System (ADS)

Grace, Emily Ann

2016-01-01

Measurements of the temperature anisotropies of the Cosmic Microwave Background (CMB) have provided the foundation for much of our current knowledge of cosmology. Observations of the polarization of the CMB have already begun to build on this foundation and promise to illuminate open cosmological questions regarding the first moments of the universe and the properties of dark energy. The primary CMB polarization signal contains the signature of early universe physics including the possible imprint of inflationary gravitational waves, while a secondary signal arises due to late-time interactions of CMB photons which encode information about the formation and evolution of structure in the universe. The Atacama Cosmology Telescope Polarimeter (ACTPol), located at an elevation of 5200 meters in Chile and currently in its third season of observing, is designed to probe these signals with measurements of the CMB in both temperature and polarization from arcminute to degree scales. To measure the faint CMB polarization signal, ACTPol employs large, kilo-pixel detector arrays of transition edge sensor (TES) bolometers, which are cooled to a 100 mK operating temperature with a dilution refrigerator. Three such arrays are currently deployed, two with sensitivity to 150 GHz radiation and one dichroic array with 90 GHz and 150 GHz sensitivity. The operation of these large, monolithic detector arrays presents a number of challenges for both assembly and characterization. This thesis describes the design and assembly of the ACTPol polarimeter arrays and outlines techniques for their rapid characterization. These methods are employed to optimize the design and operating conditions of the detectors, select wafers for deployment, and evaluate the baseline array performance. The results of the application of these techniques to wafers from all three ACTPol arrays is described, including discussion of the measured thermal properties and time constants. Finally, aspects of the

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.

Development of a TES based Cryo-Anticoincidence for a large array of microcalorimeters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colasanti, L.; Macculi, C.; Piro, L.

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. Wemore » present the results of estimations, simulations and preliminary measurement.« less

A model for the distributed storage and processing of large arrays

NASA Technical Reports Server (NTRS)

Mehrota, P.; Pratt, T. W.

1983-01-01

A conceptual model for parallel computations on large arrays is developed. The model provides a set of language concepts appropriate for processing arrays which are generally too large to fit in the primary memories of a multiprocessor system. The semantic model is used to represent arrays on a concurrent architecture in such a way that the performance realities inherent in the distributed storage and processing can be adequately represented. An implementation of the large array concept as an Ada package is also described.

General MoM Solutions for Large Arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fasenfest, B; Capolino, F; Wilton, D R

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. Thismore » 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.« less

Big data challenges for large radio arrays

NASA Astrophysics Data System (ADS)

Jones, D. L.; Wagstaff, K.; Thompson, D. R.; D'Addario, L.; Navarro, R.; Mattmann, C.; Majid, W.; Lazio, J.; Preston, J.; Rebbapragada, U.

2012-03-01

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. The Jet Propulsion Laboratory is developing technologies to address big data issues, with an emphasis in three areas: 1) Lower-power digital processing architectures to make highvolume data generation operationally affordable, 2) Date-adaptive machine learning algorithms for real-time analysis (or "data triage") of large data volumes, and 3) Scalable data archive systems that allow efficient data mining and remote user code to run locally where the data are stored.

Pixel detectors for use in retina neurophysiology studies

NASA Astrophysics Data System (ADS)

Cunningham, W.; Mathieson, K.; Horn, M.; Melone, J.; McEwan, F. A.; Blue, A.; O'Shea, V.; Smith, K. M.; Litke, A.; Chichilnisky, E. J.; Rahman, M.

2003-08-01

One area of major inter-disciplinary co-operation is between the particle physics and bio-medical communities. The type of large detector arrays and fast electronics developed in laboratories like CERN are becoming used for a wide range of medical and biological experiments. In the present work fabrication technology developed for producing semiconductor radiation detectors has been applied to produce arrays which have been used in neuro-physiological experiments on retinal tissue. We have exploited UVIII, a low molecular weight resist, that has permitted large area electron beam lithography. This allows the resolution to go below that of conventional photolithography and hence the production of densely packed ˜500 electrode arrays with feature sizes down to below 2 μm. The neural signals from significant areas of the retina may thus be captured.

Basic performance evaluation of a Si-PM array-based LGSO phoswich DOI block detector for a high-resolution small animal PET system.

PubMed

Yamamoto, Seiichi

2013-07-01

The silicon photomultiplier (Si-PM) is a promising photodetector for PET. However, it remains unclear whether Si-PM can be used for a depth-of-interaction (DOI) detector based on the decay time differences of the scintillator where pulse shape analysis is used. For clarification, we tested the Hamamatsu 4 × 4 Si-PM array (S11065-025P) combined with scintillators that used different decay times to develop DOI block detectors using the pulse shape analysis. First, Ce-doped Gd(2)SiO(5) (GSO) scintillators of 0.5 mol% Ce were arranged in a 4 × 4 matrix and were optically coupled to the center of each pixel of the Si-PM array for measurement of the energy resolution as well as its gain variations according to the temperature. Then two types of Ce-doped Lu(1.9)Gd(0.1)Si0(5) (LGSO) scintillators, 0.025 mol% Ce (decay time: ~31 ns) and 0.75 mol% Ce (decay time: ~46 ns), were optically coupled in the DOI direction, arranged in a 11 × 7 matrix, and optically coupled to a Si-PM array for testing of the possibility of a high-resolution DOI detector. The energy resolution of the Si-PM array-based GSO block detector was 18 ± 4.4 % FWHM for a Cs-137 gamma source (662 keV). Less than 1 mm crystals were clearly resolved in the position map of the LGSO DOI block detector. The peak-to-valley ratio (P/V) derived from the pulse shape spectra of the LGSO DOI block detector was 2.2. These results confirmed that Si-PM array-based DOI block detectors are promising for high-resolution small animal PET systems.

Porous microwells for geometry-selective, large-scale microparticle arrays

NASA Astrophysics Data System (ADS)

Kim, Jae Jung; Bong, Ki Wan; Reátegui, Eduardo; Irimia, Daniel; Doyle, Patrick S.

2017-01-01

Large-scale microparticle arrays (LSMAs) are key for material science and bioengineering applications. However, previous approaches suffer from trade-offs between scalability, precision, specificity and versatility. Here, we present a porous microwell-based approach to create large-scale microparticle arrays with complex motifs. Microparticles are guided to and pushed into microwells by fluid flow through small open pores at the bottom of the porous well arrays. A scaling theory allows for the rational design of LSMAs to sort and array particles on the basis of their size, shape, or modulus. Sequential particle assembly allows for proximal and nested particle arrangements, as well as particle recollection and pattern transfer. We demonstrate the capabilities of the approach by means of three applications: high-throughput single-cell arrays; microenvironment fabrication for neutrophil chemotaxis; and complex, covert tags by the transfer of an upconversion nanocrystal-laden LSMA.

A superconducting focal plane array for ultraviolet, optical, and near-infrared astrophysics.

PubMed

Mazin, Benjamin A; Bumble, Bruce; Meeker, Seth R; O'Brien, Kieran; McHugh, Sean; Langman, Eric

2012-01-16

Microwave Kinetic Inductance Detectors, or MKIDs, have proven to be a powerful cryogenic detector technology due to their sensitivity and the ease with which they can be multiplexed into large arrays. A MKID is an energy sensor based on a photon-variable superconducting inductance in a lithographed microresonator, and is capable of functioning as a photon detector across the electromagnetic spectrum as well as a particle detector. Here we describe the first successful effort to create a photon-counting, energy-resolving ultraviolet, optical, and near infrared MKID focal plane array. These new Optical Lumped Element (OLE) MKID arrays have significant advantages over semiconductor detectors like charge coupled devices (CCDs). They can count individual photons with essentially no false counts and determine the energy and arrival time of every photon with good quantum efficiency. Their physical pixel size and maximum count rate is well matched with large telescopes. These capabilities enable powerful new astrophysical instruments usable from the ground and space. MKIDs could eventually supplant semiconductor detectors for most astronomical instrumentation, and will be useful for other disciplines such as quantum optics and biological imaging.

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

Code-division-multiplexed readout of large arrays of TES microcalorimeters

NASA Astrophysics Data System (ADS)

Morgan, K. M.; Alpert, B. K.; Bennett, D. A.; Denison, E. V.; Doriese, W. B.; Fowler, J. W.; Gard, J. D.; Hilton, G. C.; Irwin, K. D.; Joe, Y. I.; O'Neil, G. C.; Reintsema, C. D.; Schmidt, D. R.; Ullom, J. N.; Swetz, D. S.

2016-09-01

Code-division multiplexing (CDM) offers a path to reading out large arrays of transition edge sensor (TES) X-ray microcalorimeters with excellent energy and timing resolution. We demonstrate the readout of X-ray TESs with a 32-channel flux-summed code-division multiplexing circuit based on superconducting quantum interference device (SQUID) amplifiers. The best detector has energy resolution of 2.28 ± 0.12 eV FWHM at 5.9 keV and the array has mean energy resolution of 2.77 ± 0.02 eV over 30 working sensors. The readout channels are sampled sequentially at 160 ns/row, for an effective sampling rate of 5.12 μs/channel. The SQUID amplifiers have a measured flux noise of 0.17 μΦ0/√Hz (non-multiplexed, referred to the first stage SQUID). The multiplexed noise level and signal slew rate are sufficient to allow readout of more than 40 pixels per column, making CDM compatible with requirements outlined for future space missions. Additionally, because the modulated data from the 32 SQUID readout channels provide information on each X-ray event at the row rate, our CDM architecture allows determination of the arrival time of an X-ray event to within 275 ns FWHM with potential benefits in experiments that require detection of near-coincident events.

The use of integrated focal plane array technologies in laser microsatellite networks

NASA Astrophysics Data System (ADS)

Arnon, Shlomi

2004-10-01

Clustering micro satellites in cooperative fly formation constellations leads to high-performance space systems. The only way to achieve high-speed communication between the satellites is by a laser beam with a narrow divergence angle. In order to make the communication successful three types of focal plane detector arrays are required in the communication terminal: acquisition, tracking and communication detector arrays. The acquisition detector array is used to acquire the neighbor satellite using a wide field-of-view telescope. The tracking detector provides fast, real time and accurate direction location of the neighbor satellite. Based on the information from the acquisition and tracking detectors the receiver and transmitter maintain line of sight. The development of large, fast and very sensitive focal plane detector arrays makes it possible to implement the acquisition, tracking and communication with only one focal plane detector array. By doing so it is possible to reduce dramatically the size, weight, and cost of the optics and electronics which leads to lightweight communication terminals. As a result, the satellites are smaller and lighter, which reduces the space mission cost and increases the booster efficiency. In this paper we will present an overview of the concept of integrated focal plane arrays for laser satellite communication. We also present simulation results based on real system parameters and compare different implementation options.

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

Development of a unit cell for a Ge:Ga detector array

NASA Technical Reports Server (NTRS)

1988-01-01

Two modules of gallium-doped germanium (Ge:Ga) infrared detectors with integrated multiplexing readouts and supporting drive electronics were designed and tested. This development investigated the feasibility of producing two-dimensional Ge:Ga arrays by stacking linear modules in a housing capable of providing uniaxial stress for enhanced long-wavelength response. Each module includes 8 detectors (1x1x2 mm) mounted to a sapphire board. The element spacing is 12 microns. The back faces of the detector elements are beveled with an 18 deg angle, which was proved to significantly enhance optical absorption. Each module includes a different silicon metal-oxide semiconductor field effect transistor (MOSFET) readout. The first circuit was built from discrete MOSFET components; the second incorporated devices taken from low-temperature integrated circuit multiplexers. The latter circuit exhibited much lower stray capacitance and improved stability. Using these switched-FET circuits, it was demonstrated that burst readout, with multiplexer active only during the readout period, could successfully be implemented at approximately 3.5 K.

The Saskatchewan-Alberta large acceptance detector for photonuclear physics

NASA Astrophysics Data System (ADS)

Cairns, E. B.; Cameron, J.; Choi, W. C.; Fielding, H. W.; Green, P. W.; Greeniaus, L. G.; Hackett, E. D.; Holm, L.; Kolb, N. R.; Korkmaz, E.; Langill, P. P.; McDonald, W. J.; Mack, D.; Olsen, W. C.; Peterson, B. A.; Rodning, N. L.; Soukup, J.; Zhu, J.; Hutcheon, D.; Caplan, H. S.; Pywell, R. E.; Skopik, D. M.; Vogt, J. M.; van Heerden, I. J.

1992-09-01

The Saskatchewan-Alberta Large Acceptance Detector (SALAD) is a 4 π detector designed and built for studies of photonuclear reactions with a tagged photon beam. The design and performance of the detector are described. Its characteristics have been studied by examining p-p elastic scattering with a proton beam at TRIUMF.

Next-Generation Microshutter Arrays for Large-Format Imaging and Spectroscopy

NASA Technical Reports Server (NTRS)

Moseley, Samuel; Kutyrev, Alexander; Brown, Ari; Li, Mary

2012-01-01

A next-generation microshutter array, LArge Microshutter Array (LAMA), was developed as a multi-object field selector. LAMA consists of small-scaled microshutter arrays that can be combined to form large-scale microshutter array mosaics. Microshutter actuation is accomplished via electrostatic attraction between the shutter and a counter electrode, and 2D addressing can be accomplished by applying an electrostatic potential between a row of shutters and a column, orthogonal to the row, of counter electrodes. Microelectromechanical system (MEMS) technology is used to fabricate the microshutter arrays. The main feature of the microshutter device is to use a set of standard surface micromachining processes for device fabrication. Electrostatic actuation is used to eliminate the need for macromechanical magnet actuating components. A simplified electrostatic actuation with no macro components (e.g. moving magnets) required for actuation and latching of the shutters will make the microshutter arrays robust and less prone to mechanical failure. Smaller-size individual arrays will help to increase the yield and thus reduce the cost and improve robustness of the fabrication process. Reducing the size of the individual shutter array to about one square inch and building the large-scale mosaics by tiling these smaller-size arrays would further help to reduce the cost of the device due to the higher yield of smaller devices. The LAMA development is based on prior experience acquired while developing microshutter arrays for the James Webb Space Telescope (JWST), but it will have different features. The LAMA modular design permits large-format mosaicking to cover a field of view at least 50 times larger than JWST MSA. The LAMA electrostatic, instead of magnetic, actuation enables operation cycles at least 100 times faster and a mass significantly smaller compared to JWST MSA. Also, standard surface micromachining technology will simplify the fabrication process, increasing

Progress on uncooled PbSe detectors for low-cost applications

NASA Astrophysics Data System (ADS)

Vergara, German; Gomez, Luis J.; Villamayor, Victor; Alvarez, M.; Rodrigo, Maria T.; del Carmen Torquemada, Maria; Sanchez, Fernando J.; Verdu, Marina; Diezhandino, Jorge; Rodriguez, Purificacion; Catalan, Irene; Almazan, Rosa; Plaza, Julio; Montojo, Maria T.

2004-08-01

This work reports on progress on development of polycrystalline PbSe infrared detectors at the Centro de Investigacion y Desarrollo de la Armada (CIDA). Since mid nineties, the CIDA owns an innovative technology for processing uncooled MWIR detectors of polycrystalline PbSe. Based on this technology, some applications have been developed. However, future applications demand smarter, more complex, faster yet cheaper detectors. Aiming to open new perspectives to polycrystalline PbSe detectors, we are currently working on different directions: 1) Processing of 2D arrays: a) Designing and processing low density x-y addressed arrays with 16x16 and 32x32 elements, as an extension of our standard technology. b) Trying to make compatible standard CMOS and polycrystalline PbSe technologies in order to process monolithic large format arrays. 2) Adding new features to the detector such as monolithically integrated spectral discrimination.

A Comparative Study of Automated Infrasound Detectors - PMCC and AFD with Analyst Review.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Junghyun; Hayward, Chris; Zeiler, Cleat

Automated detections calculated by the progressive multi-channel correlation (PMCC) method (Cansi, 1995) and the adaptive F detector (AFD) (Arrowsmith et al., 2009) are compared to the signals identified by five independent analysts. Each detector was applied to a four-hour time sequence recorded by the Korean infrasound array CHNAR. This array was used because it is composed of both small (<100 m) and large (~1000 m) aperture element spacing. The four hour time sequence contained a number of easily identified signals under noise conditions that have average RMS amplitudes varied from 1.2 to 4.5 mPa (1 to 5 Hz), estimated withmore » running five-minute window. The effectiveness of the detectors was estimated for the small aperture, large aperture, small aperture combined with the large aperture, and full array. The full and combined arrays performed the best for AFD under all noise conditions while the large aperture array had the poorest performance for both detectors. PMCC produced similar results as AFD under the lower noise conditions, but did not produce as dramatic an increase in detections using the full and combined arrays. Both automated detectors and the analysts produced a decrease in detections under the higher noise conditions. Comparing the detection probabilities with Estimated Receiver Operating Characteristic (EROC) curves we found that the smaller value of consistency for PMCC and the larger p-value for AFD had the highest detection probability. These parameters produced greater changes in detection probability than estimates of the false alarm rate. The detection probability was impacted the most by noise level, with low noise (average RMS amplitude of 1.7 mPa) having an average detection probability of ~40% and high noise (average RMS amplitude of 2.9 mPa) average detection probability of ~23%.« less

SU-G-201-17: Verification of Dose Distributions From High-Dose-Rate Brachytherapy Ir-192 Source Using a Multiple-Array-Diode-Detector (MapCheck2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harpool, K; De La Fuente Herman, T; Ahmad, S

Purpose: To investigate quantitatively the accuracy of dose distributions for the Ir-192 high-dose-rate (HDR) brachytherapy source calculated by the Brachytherapy-Planning system (BPS) and measured using a multiple-array-diode-detector in a heterogeneous medium. Methods: A two-dimensional diode-array-detector system (MapCheck2) was scanned with a catheter and the CT-images were loaded into the Varian-Brachytherapy-Planning which uses TG-43-formalism for dose calculation. Treatment plans were calculated for different combinations of one dwell-position and varying irradiation times and different-dwell positions and fixed irradiation time with the source placed 12mm from the diode-array plane. The calculated dose distributions were compared to the measured doses with MapCheck2 delivered bymore » an Ir-192-source from a Nucletron-Microselectron-V2-remote-after-loader. The linearity of MapCheck2 was tested for a range of dwell-times (2–600 seconds). The angular effect was tested with 30 seconds irradiation delivered to the central-diode and then moving the source away in increments of 10mm. Results: Large differences were found between calculated and measured dose distributions. These differences are mainly due to absence of heterogeneity in the dose calculation and diode-artifacts in the measurements. The dose differences between measured and calculated due to heterogeneity ranged from 5%–12% depending on the position of the source relative to the diodes in MapCheck2 and different heterogeneities in the beam path. The linearity test of the diode-detector showed 3.98%, 2.61%, and 2.27% over-response at short irradiation times of 2, 5, and 10 seconds, respectively, and within 2% for 20 to 600 seconds (p-value=0.05) which depends strongly on MapCheck2 noise. The angular dependency was more pronounced at acute angles ranging up to 34% at 5.7 degrees. Conclusion: Large deviations between measured and calculated dose distributions for HDR-brachytherapy with Ir-192 may

Performance of a high-resolution depth-encoding PET detector module using linearly-graded SiPM arrays

NASA Astrophysics Data System (ADS)

Du, Junwei; Bai, Xiaowei; Gola, Alberto; Acerbi, Fabio; Ferri, Alessandro; Piemonte, Claudio; Yang, Yongfeng; Cherry, Simon R.

2018-02-01

The goal of this study was to exploit the excellent spatial resolution characteristics of a position-sensitive silicon photomultiplier (SiPM) and develop a high-resolution depth-of-interaction (DOI) encoding positron emission tomography (PET) detector module. The detector consists of a 30  ×  30 array of 0.445  ×  0.445  ×  20 mm3 polished LYSO crystals coupled to two 15.5  ×  15.5 mm2 linearly-graded SiPM (LG-SiPM) arrays at both ends. The flood histograms show that all the crystals in the LYSO array can be resolved. The energy resolution, the coincidence timing resolution and the DOI resolution were 21.8  ±  5.8%, 1.23  ±  0.10 ns and 3.8  ±  1.2 mm, respectively, at a temperature of -10 °C and a bias voltage of 35.0 V. The performance did not degrade significantly for event rates of up to 130 000 counts s-1. This detector represents an attractive option for small-bore PET scanner designs that simultaneously emphasize high spatial resolution and high detection efficiency, important, for example, in preclinical imaging of the rodent brain with neuroreceptor ligands.

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.

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.

Design of a Dry Dilution Refrigerator for MMC Gamma Detector Arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedrich, Stephan; Boyd, Stephen; Cantor, Robin

2017-04-03

The goal of this LCP is to develop an ultra-high resolution gamma detector based on magnetic microcalorimeters (MMCs) for accurate non-destructive analysis (NDA) of nuclear materials. For highest energy resolution, we will introduce erbium-doped silver (Ag:Er) as a novel sensor material to replace current Au:Er sensors. The detector sensitivity will be increased by developing arrays of 32 Ag:Er pixels read out by 16 SQUID preamplifiers. MMC detectors require operating temperatures of ~15 mK and thus the use of a dilution refrigerator, and the desire for user-friendly operation without cryogenic liquids requires that this refrigerator use pulse-tube pre-cooling to ~4 K.more » For long-term reliability, we intend to re-design the heat switch that is needed to apply the magnetizing current to the Ag:Er sensor and that used to fail in earlier designs after months of operation. A cryogenic Compton veto will be installed to reduce the spectral background of the MMC, especially at low energies where ultra-high energy resolution is most important. The goals for FY16 were 1) to purchase a liquid-cryogen-free dilution refrigerator and adapt it for MMC operation, and 2) to fabricate Ag:Er-based MMC γ-detectors with improved performance and optimize their response. This report discusses the design of the instruments, and progress in MMC detector fabrication. Details of the MMC fabrication have been discussed in an April 2016 report to DOE.« less

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.

Direct mapping and characterization of dry etch damage-induced PN junction for long-wavelength HgCdTe infrared detector arrays.

PubMed

Li, Yantao; Hu, Weida; Ye, Zhenhua; Chen, Yiyu; Chen, Xiaoshuang; Lu, Wei

2017-04-01

Mercury cadmium telluride is the standard material to fabricate high-performance infrared focal plane array (FPA) detectors. However, etch-induced damage is a serious obstacle for realizing highly uniform and damage-free FPA detectors. In this Letter, the high signal-to-noise ratio and high spatial resolution scanning photocurrent microscopy (SPCM) is used to characterize the dry etch-induced inversion layer of vacancy-doped p-type Hg_1-xCd_xTe (x=0.22) material under different etching temperatures. It is found that the peak-to-peak magnitude of the SPCM profile decreases with a decrease in etching temperature, showing direct proof of controlling dry etch-induced type conversion. Our work paves the way toward seeking optimal etching processes in large-scale infrared FPAs.

Detector and readout performance goals for quantum well and strained layer superlattice focal plane arrays imaging under tactical and strategic backgrounds

NASA Astrophysics Data System (ADS)

Bandara, Sumith V.

2009-11-01

Advancements in III-V semiconductor based, Quantum-well infrared photodetector (QWIP) and Type-II Strained-Layer Superlattice detector (T2SLS) technologies have yielded highly uniform, large-format long-wavelength infrared (LWIR) QWIP FPAs and high quantum efficiency (QE), small format, LWIR T2SLS FPAs. In this article, we have analyzed the QWIP and T2SLS detector level performance requirements and readout integrated circuit (ROIC) noise levels for several staring array long-wavelength infrared (LWIR) imaging applications at various background levels. As a result of lower absorption QE and less than unity photoconductive gain, QWIP FPAs are appropriate for high background tactical applications. However, if the application restricts the integration time, QWIP FPA performance may be limited by the read noise of the ROIC. Rapid progress in T2SLS detector material has already demonstrated LWIR detectors with sufficient performance for tactical applications and potential for strategic applications. However, significant research is needed to suppress surface leakage currents in order to reproduce performances at pixel levels of T2SLS FPAs.

Large-Area, Low-Cost, High-Efficiency Neutron Detector for Vehicle-Mounted Operation

NASA Astrophysics Data System (ADS)

Lacy, Jeffrey L.; Martin, Christopher S.; Athanasiades, Athanasios; Regmi, Murari; Vazquez-Flores, Gerson J.; Davenport, Stephen; King, Nicholas S.; Lyons, Tom

2017-07-01

We have developed a large-area, low-cost, high-efficiency neutron detector for vehicle-mounted operation. The detector, which has overall dimensions 12.7 cm x 91.4 cm x 102 cm (5”x36”x40”), a sensitive area equal to 0.85 m2 (1320 in2), and weight of 110 kg (242 lbs), employs an array of 90 boron-coated straw (BCS) detectors. PTI has also developed electronics to minimize cost and space while providing low-noise signal conditioning for both neutron and gamma detection channels, as well as low energy Bluetooth communication with handheld devices. Extremely low power consumption allows continuous use for 225 hours (-.10 days) using three AAA lithium-ion rechargeable batteries. We present radiological, mechanical, and environmental tests, collected from four full-scale prototypes. Outdoor neutron-counting tests with a moderated 252Cf source 2 m away from the center of the detector face showed an average detection rate of 5.5 cps/ng with a standard deviation of 0.09 cps/ng over the four individual detector measurements. Measurements showed a gamma rejection ratio of 1.0 x 10-8, and gamma absolute rejection ratio (GARRn) of 0.93. The prototypes were also operated successfully onboard a moving vehicle for high-speed tests and a long-range 1433-mile, two-day road trip from Houston, TX, USA, to Laurel, MD, USA. Using auxiliary DARPA SIGMA equipment, the GPS, timestamp, gamma and neutron data were transmitted over the cellular network with 10 Hz resolution to a server and real-time tracking website. Mechanical impact and electrostatic discharge testing produced no spurious counts in either the neutron or gamma channels. Ambient environmental temperature testing showed less than ±1% response variation over the range from -30°C to +55°C.

X-ray analog pixel array detector for single synchrotron bunch time-resolved imaging.

PubMed

Koerner, Lucas J; Gruner, Sol M

2011-03-01

Dynamic X-ray studies can reach temporal resolutions limited by only the X-ray pulse duration if the detector is fast enough to segregate synchrotron pulses. An analog integrating pixel array detector with in-pixel storage and temporal resolution of around 150 ns, sufficient to isolate pulses, is presented. Analog integration minimizes count-rate limitations and in-pixel storage captures successive pulses. Fundamental tests of noise and linearity as well as high-speed laser measurements are shown. The detector resolved individual bunch trains at the Cornell High Energy Synchrotron Source at levels of up to 3.7 × 10(3) X-rays per pixel per train. When applied to turn-by-turn X-ray beam characterization, single-shot intensity measurements were made with a repeatability of 0.4% and horizontal oscillations of the positron cloud were detected.

X-ray analog pixel array detector for single synchrotron bunch time-resolved imaging

PubMed Central

Koerner, Lucas J.; Gruner, Sol M.

2011-01-01

Dynamic X-ray studies can reach temporal resolutions limited by only the X-ray pulse duration if the detector is fast enough to segregate synchrotron pulses. An analog integrating pixel array detector with in-pixel storage and temporal resolution of around 150 ns, sufficient to isolate pulses, is presented. Analog integration minimizes count-rate limitations and in-pixel storage captures successive pulses. Fundamental tests of noise and linearity as well as high-speed laser measurements are shown. The detector resolved individual bunch trains at the Cornell High Energy Synchrotron Source at levels of up to 3.7 × 103 X-rays per pixel per train. When applied to turn-by-turn X-ray beam characterization, single-shot intensity measurements were made with a repeatability of 0.4% and horizontal oscillations of the positron cloud were detected. PMID:21335901

Optical phased array configuration for an extremely large telescope.

PubMed

Meinel, Aden Baker; Meinel, Marjorie Pettit

2004-01-20

Extremely large telescopes are currently under consideration by several groups in several countries. Extrapolation of current technology up to 30 m indicates a cost of over dollars 1 billion. Innovative concepts are being explored to find significant cost reductions. We explore the concept of an Optical Phased Array (OPA) telescope. Each element of the OPA is a separate Cassegrain telescope. Collimated beams from the array are sent via an associated set of delay lines to a central beam combiner. This array of small telescope elements offers the possibility of starting with a low-cost array of a few rings of elements, adding structure and additional Cass elements until the desired diameter telescope is attained. We address the salient features of such an extremely large telescope and cost elements relative to more conventional options.

A Deuterated Neutron Detector Array For Nuclear (Astro)Physics Studies

NASA Astrophysics Data System (ADS)

Almaraz-Calderon, Sergio; Asher, B. W.; Barber, P.; Hanselman, K.; Perello, J. F.

2016-09-01

The properties of neutron-rich nuclei are at the forefront of research in nuclear structure, nuclear reactions and nuclear astrophysics. The advent of intense rare isotope beams (RIBs) has opened a new door for studies of systems with very short half-lives and possible fascinating properties. Neutron spectroscopic techniques become increasingly relevant when these neutron rich nuclei are used in a variety of experiments. At Florida State University, we are developing a neutron detector array that will allow us to perform high-resolution neutron spectroscopic studies with stable and radioactive beams. The neutron detection system consists of 16 deuterated organic liquid scintillation detectors with fast response and pulse-shape discrimination capabilities. In addition to these properties, there is the potential to use the structure in the pulse-height spectra to extract the energy of the neutrons and thus produce directly excitation spectra. This type of detector uses deuterated benzene (C6D6) as the liquid scintillation medium. The asymmetric nature of the scattering between a neutron and a deuterium in the center of mass produces a pulse-height spectrum from the deuterated scintillator which contains useful information on the initial energy of the neutron. Work supported in part by the State of Florida and NSF Grant No. 1401574.

Layout and cabling considerations for a large communications antenna array

NASA Technical Reports Server (NTRS)

Logan, R. T., Jr.

1993-01-01

Layout considerations for a large deep space communications antenna array are discussed. A fractal geometry for the antenna layout is described that provides optimal packing of antenna elements, efficient cable routing, and logical division of the array into identical sub-arrays.

Integrated Avalanche Photodiode arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harmon, Eric S.

2017-04-18

The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

Integrated avalanche photodiode arrays

DOEpatents

Harmon, Eric S.

2015-07-07

The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

Large Area and High Efficiency Photon Counting Imaging Detectors with High Time and Spatial Resolution for Night Time Sensing and Astronomy

NASA Astrophysics Data System (ADS)

Siegmund, O.; Vallerga, J.; Tremsin, A.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

2012-09-01

The development of large area photon counting, imaging, timing detectors with high performance has significance for applications in astronomy (such as our sensor on the SAAO SALT 10m telescope), night time remote reconnaissance, airborne/space situational awareness, and high-speed adaptive optics. Sealed tube configurations for optical/IR sensing also have applications in detection of Cherenkov light (RICH), biological single-molecule fluorescence lifetime imaging microscopy and neutron imaging applications. In open faced configurations these devices are important for UV and particle detection in space astrophysics, mass spectroscopy and many time-of flight applications. Currently available devices are limited to sizes of about 5 cm and use either conventional microchannel plates, or dynode multipliers for amplification, coupled coarse pad array readouts. Extension of these schemes to devices as large as 20 cm with high spatial resolution presents significant problems and potentially considerable cost. A collaboration (Large Area Picosecond Photon Detector) of the U. Chicago, Argonne National Laboratory, U.C. Berkeley, U. Hawaii and a number of other institutions has developed novel technologies to realize 20 cm format detectors in open face or sealed tube configurations. One critical component of this development is novel microchannel plates employing borosilicate micro-capillary arrays. The microchannel plates are based on a novel concept where the substrate is constructed from a borosilicate micro-capillary array that is made to function as a microchannel plate by deposition of resistive and secondary emissive layers using atomic layer deposition. The process is relatively inexpensive compared with conventional microchannel plates and allows very large microchannel plates to be produced with pore sizes as small as 10 microns. These provide many performance characteristics typical of conventional microchannel plates, but have been made in sizes up to 20 cm, have

MMW/THz imaging using upconversion to visible, based on glow discharge detector array and CCD camera

NASA Astrophysics Data System (ADS)

Aharon, Avihai; Rozban, Daniel; Abramovich, Amir; Yitzhaky, Yitzhak; Kopeika, Natan S.

2017-10-01

An inexpensive upconverting MMW/THz imaging method is suggested here. The method is based on glow discharge detector (GDD) and silicon photodiode or simple CCD/CMOS camera. The GDD was previously found to be an excellent room-temperature MMW radiation detector by measuring its electrical current. The GDD is very inexpensive and it is advantageous due to its wide dynamic range, broad spectral range, room temperature operation, immunity to high power radiation, and more. An upconversion method is demonstrated here, which is based on measuring the visual light emitting from the GDD rather than its electrical current. The experimental setup simulates a setup that composed of a GDD array, MMW source, and a basic CCD/CMOS camera. The visual light emitting from the GDD array is directed to the CCD/CMOS camera and the change in the GDD light is measured using image processing algorithms. The combination of CMOS camera and GDD focal plane arrays can yield a faster, more sensitive, and very inexpensive MMW/THz camera, eliminating the complexity of the electronic circuits and the internal electronic noise of the GDD. Furthermore, three dimensional imaging systems based on scanning prohibited real time operation of such imaging systems. This is easily solved and is economically feasible using a GDD array. This array will enable us to acquire information on distance and magnitude from all the GDD pixels in the array simultaneously. The 3D image can be obtained using methods like frequency modulation continuous wave (FMCW) direct chirp modulation, and measuring the time of flight (TOF).

Efficiency as a function of MEQ-CWT for large area germanium detectors using LLNL phantom.

PubMed

Rajaram, S; Brindha, J Thulasi; Sreedevi, K R; Hegde, A G

2012-01-01

The lung counting system at Kalpakkam, India, used for the estimation of transuranics deposited in the lungs of occupational workers, consists of an array of three large area germanium detectors fixed in a single assembly. The efficiency calibration for low energy photons was carried out using ²⁴¹Am and ²³²Th lung sets of Lawrence Livermore National Laboratory phantom. The muscle equivalent chest wall thickness (MEQ-CWT) was derived for the three energies 59.5, 75.95 (average energy of ²³²Th) and 238.9 keV for the series of overlay plates made of different adipose mass ratios. Efficiency as a function of MEQ-CWT was calculated for individual detectors for the three energies. Variation of MEQ-CWT from 16 to 40 mm resulted in an efficiency variation of around 40 % for all the three energies. The array efficiency for different MEQ-CWT ranged from 1.4×10⁻³ to 3.2×10⁻³, 1.5×10⁻³ to 3.3×10⁻³ and 1.1×10⁻³ to 2.3×10⁻³ for 59.5, 75.95 and 238.9 keV, respectively. In the energy response, efficiency was observed to be maximum for 75.95 keV compared with 59.5 and 238.9 keV.

Readout and DAQ for Pixel Detectors

NASA Astrophysics Data System (ADS)

Platkevic, Michal

2010-01-01

Data readout and acquisition control of pixel detectors demand the transfer of significantly a large amounts of bits between the detector and the computer. For this purpose dedicated interfaces are used which are designed with focus on features like speed, small dimensions or flexibility of use such as digital signal processors, field-programmable gate arrays (FPGA) and USB communication ports. This work summarizes the readout and DAQ system built for state-of-the-art pixel detectors of the Medipix family.

Operation and performance of new NIR detectors from SELEX

NASA Astrophysics Data System (ADS)

Atkinson, D.; Bezawada, N.; Hipwood, L. G.; Shorrocks, N.; Milne, H.

2012-07-01

The European Space Agency (ESA) has funded SELEX Galileo, Southampton, UK to develop large format near infrared (NIR) detectors for its future space and ground based programmes. The UKATC has worked in collaboration with SELEX Galileo to test and characterise the new detectors produced during phase-1 of the development. In order to demonstrate the detector material performance, the HgCdTe (MCT) detector diodes (grown on GaAs substrate through MOVPE process in small 320×256, 24μm pixel format) are hybridised to the existing SELEX Galileo SWALLOW CMOS readout chip. The substrate removed and MCT thinned detector arrays were then tested and evaluated at the UKATC following screening tests at SELEX. This paper briefly describes the test setup, the operational aspects of the readout multiplexer and presents the performance parameters of the detector arrays including: conversion gain, detector dark current, read noise, linearity, quantum efficiency and persistence for various detector temperatures between 80K and 140K.

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.

High-speed X-ray imaging pixel array detector for synchrotron bunch isolation

DOE PAGES

Philipp, Hugh T.; Tate, Mark W.; Purohit, Prafull; ...

2016-01-28

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 atmore » 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. Lastly, we detail the characteristics, operation, testing and application of the detector.« less

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

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.

Improved detection limits for electrospray ionization on a magnetic sector mass spectrometer by using an array detector.

PubMed

Cody, R B; Tamura, J; Finch, J W; Musselman, B D

1994-03-01

Array detection was compared with point detection for solutions of hen egg-white lysozyme, equine myoglobin, and ubiquitin analyzed by electrospray ionization with a magnetic sector mass spectrometer. The detection limits for samples analyzed by using the array detector system were at least 10 times lower than could be achieved by using a point detector on the same mass spectrometer. The minimum detectable quantity of protein corresponded to a signal-to-background ratio of approximately 2∶1 for a 500 amol/μL solution of hen egg-white lysozyme. However, the ultimate practical sample concentrations appeared to be in the 10-100 fmol/μL range for the analysis of dilute solutions of relatively pure proteins or simple mixtures.

The Next-Generation Very Large Array: Technical Overview

NASA Astrophysics Data System (ADS)

McKinnon, Mark; Selina, Rob

2018-01-01

As part of its mandate as a national observatory, the NRAO is looking toward the long range future of radio astronomy and fostering the long term growth of the US astronomical community. NRAO has sponsored a series of science and technical community meetings to consider the science mission and design of a next-generation Very Large Array (ngVLA), building on the legacies of the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Array (VLA).The basic ngVLA design emerging from these discussions is an interferometric array with approximately ten times the sensitivity and ten times higher spatial resolution than the VLA and ALMA radio telescopes, optimized for operation in the wavelength range 0.3cm to 3cm. The ngVLA would open a new window on the Universe through ultra-sensitive imaging of thermal line and continuum emission down to milli-arcsecond resolution, as well as unprecedented broadband continuum polarimetric imaging of non-thermal processes. The specifications and concepts for major ngVLA system elements are rapidly converging.We will provide an overview of the current system design of the ngVLA. The concepts for major system elements such as the antenna, receiving electronics, and central signal processing will be presented. We will also describe the major development activities that are presently underway to advance the design.

Photoconductive terahertz near-field detector with a hybrid nanoantenna array cavity

DOE PAGES

Mitrofanov, Oleg; Brener, Igal; Luk, Ting S.; ...

2015-11-19

Nanoscale structuring of optical materials leads to modification of their properties and can be used for improving efficiencies of photonic devices and for enabling new functionalities. In ultrafast optoelectronic switches for generation and detection of terahertz (THz) radiation, incorporation of nanostructures allows us to overcome inherent limitations of photoconductive materials. We propose and demonstrate a nanostructured photoconductive THz detector for sampling highly localized THz fields, down to the level of λ/150. The nanostructure that consists of an array of optical nanoantennas and a distributed Bragg reflector forms a hybrid cavity, which traps optical gate pulses within the photoconductive layer. Themore » effect of photon trapping is observed as enhanced absorption at a designed wavelength. This optically thin photoconductive THz detector allows us to detect highly confined evanescent THz fields coupled through a deeply subwavelength aperture as small as 2 μm (λ/150 at 1 THz). As a result, by monolithically integrating the THz detector with apertures ranging from 2 to 5 μm we realize higher spatial resolution and higher sensitivity in aperture-type THz near-field microscopy and THz time-domain spectroscopy.« less

Development of a Spectral Model Based on Charge Transport for the Swift/BAT 32K CdZnTe Detector Array

NASA Technical Reports Server (NTRS)

Sato, Goro; Parsons, Ann; Hillinger, Derek; Suzuki, Masaya; Takahashi, Tadayuki; Tashiro, Makoto; Nakazawa, Kazuhiro; Okada, Yuu; Takahashi, Hiromitsu; Watanabe, Shin

2005-01-01

The properties of 32K CdZnTe (4 x 4 sq mm large, 2 mm thick) detectors have been studied in the pre-flight calibration of the Burst Alert Telescope (BAT) on-board the Swift Gamma-ray Burst Explorer (scheduled for launch in November 2004). In order to understand the energy response of the BAT CdZnTe array, we first quantify the mobility-lifetime (mu tau) products of carriers in individual CdZnTe detectors, which produce a position dependency in the charge induction efficiency and results in a low energy tail in the energy spectrum. Based on a new method utilizing (57)Co spectra obtained at different bias voltages, the mu tau for electrons ranges from 5.0 x 10(exp -4) to 1.0 x 10(exp -2) sq cm/V while the mu tau for holes ranges from 1.3 x 10(exp -5 to 1.8 x 10(exp -4) sq cm/V. We find that this wide distribution of mu tau products explains the large diversity in spectral shapes between CdZnTe detectors well. We also find that the variation of mu tau products can be attributed to the difference of crystal ingots or manufacturing harness. We utilize the 32K sets of extracted mu tau products to develop a spectral model of the detector. In combination with Monte Carlo simulations, we can construct a spectral model for any photon energy or any incident angle.

Large Scale Underground Detectors in Europe

NASA Astrophysics Data System (ADS)

Katsanevas, S. K.

2006-07-01

The physics potential and the complementarity of the large scale underground European detectors: Water Cherenkov (MEMPHYS), Liquid Argon TPC (GLACIER) and Liquid Scintillator (LENA) is presented with emphasis on the major physics opportunities, namely proton decay, supernova detection and neutrino parameter determination using accelerator beams.

A silicon strip detector array for energy verification and quality assurance in heavy ion therapy.

PubMed

Debrot, Emily; Newall, Matthew; Guatelli, Susanna; Petasecca, Marco; Matsufuji, Naruhiro; Rosenfeld, Anatoly B

2018-02-01

The measurement of depth dose profiles for range and energy verification of heavy ion beams is an important aspect of quality assurance procedures for heavy ion therapy facilities. The steep dose gradients in the Bragg peak region of these profiles require the use of detectors with high spatial resolution. The aim of this work is to characterize a one dimensional monolithic silicon detector array called the "serial Dose Magnifying Glass" (sDMG) as an independent ion beam energy and range verification system used for quality assurance conducted for ion beams used in heavy ion therapy. The sDMG detector consists of two linear arrays of 128 silicon sensitive volumes each with an effective size of 2mm × 50μm × 100μm fabricated on a p-type substrate at a pitch of 200 μm along a single axis of detection. The detector was characterized for beam energy and range verification by measuring the response of the detector when irradiated with a 290 MeV/u 12 C ion broad beam incident along the single axis of the detector embedded in a PMMA phantom. The energy of the 12 C ion beam incident on the detector and the residual energy of an ion beam incident on the phantom was determined from the measured Bragg peak position in the sDMG. Ad hoc Monte Carlo simulations of the experimental setup were also performed to give further insight into the detector response. The relative response profiles along the single axis measured with the sDMG detector were found to have good agreement between experiment and simulation with the position of the Bragg peak determined to fall within 0.2 mm or 1.1% of the range in the detector for the two cases. The energy of the beam incident on the detector was found to vary less than 1% between experiment and simulation. The beam energy incident on the phantom was determined to be (280.9 ± 0.8) MeV/u from the experimental and (280.9 ± 0.2) MeV/u from the simulated profiles. These values coincide with the expected energy of 281 MeV/u. The sDMG detector

Design optimization for a wearable, gamma-ray and neutron sensitive, detector array with directionality estimation

NASA Astrophysics Data System (ADS)

Ayaz-Maierhafer, Birsen; Britt, Carl G.; August, Andrew J.; Qi, Hairong; Seifert, Carolyn E.; Hayward, Jason P.

2017-10-01

In this study, we report on a constrained optimization and tradeoff study of a hybrid, wearable detector array having directional sensing based upon gamma-ray occlusion. One resulting design uses CLYC detectors while the second feasibility design involves the coupling of gamma-ray-sensitive CsI scintillators and a rubber LiCaAlF6 (LiCAF) neutron detector. The detector systems' responses were investigated through simulation as a function of angle in a two-dimensional plane. The expected total counts, peak-to-total ratio, directionality performance, and detection of 40 K for accurate gain stabilization were considered in the optimization. Source directionality estimation was investigated using Bayesian algorithms. Gamma-ray energies of 122 keV, 662 keV, and 1332 keV were considered. The equivalent neutron capture response compared with 3 He was also investigated for both designs.

Real-time continuous-wave terahertz line scanner based on a compact 1 × 240 InGaAs Schottky barrier diode array detector.

PubMed

Han, Sang-Pil; Ko, Hyunsung; Kim, Namje; Lee, Won-Hui; Moon, Kiwon; Lee, Il-Min; Lee, Eui Su; Lee, Dong Hun; Lee, Wangjoo; Han, Seong-Tae; Choi, Sung-Wook; Park, Kyung Hyun

2014-11-17

We demonstrate real-time continuous-wave terahertz (THz) line-scanned imaging based on a 1 × 240 InGaAs Schottky barrier diode (SBD) array detector with a scan velocity of 25 cm/s, a scan line length of 12 cm, and a pixel size of 0.5 × 0.5 mm². Foreign substances, such as a paper clip with a spatial resolution of approximately 1 mm that is hidden under a cracker, are clearly detected by this THz line-scanning system. The system consists of the SBD array detector, a 200-GHz gyrotron source, a conveyor system, and several optical components such as a high-density polyethylene cylindrical lens, metal cylindrical mirror, and THz wire-grid polarizer. Using the THz polarizer, the signal-to-noise ratio of the SBD array detector improves because the quality of the source beam is enhanced.

Digital radiology using active matrix readout: amplified pixel detector array for fluoroscopy.

PubMed

Matsuura, N; Zhao, W; Huang, Z; Rowlands, J A

1999-05-01

Active matrix array technology has made possible the concept of flat panel imaging systems for radiography. In the conventional approach a thin-film circuit built on glass contains the necessary switching components (thin-film transistors or TFTs) to readout an image formed in either a phosphor or photoconductor layer. Extension of this concept to real time imaging--fluoroscopy--has had problems due to the very low noise required. A new design strategy for fluoroscopic active matrix flat panel detectors has therefore been investigated theoretically. In this approach, the active matrix has integrated thin-film amplifiers and readout electronics at each pixel and is called the amplified pixel detector array (APDA). Each amplified pixel consists of three thin-film transistors: an amplifier, a readout, and a reset TFT. The performance of the APDA approach compared to the conventional active matrix was investigated for two semiconductors commonly used to construct active matrix arrays--hydrogenated amorphous silicon and polycrystalline silicon. The results showed that with amplification close to the pixel, the noise from the external charge preamplifiers becomes insignificant. The thermal and flicker noise of the readout and the amplifying TFTs at the pixel become the dominant sources of noise. The magnitude of these noise sources is strongly dependent on the TFT geometry and its fabrication process. Both of these could be optimized to make the APDA active matrix operate at lower noise levels than is possible with the conventional approach. However, the APDA cannot be made to operate ideally (i.e., have noise limited only by the amount of radiation used) at the lowest exposure rate required in medical fluoroscopy.

The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

DTIC Science & Technology

2010-09-01

adds an extra dimension to both IPS and other observations. The polarization of the CME synchrotron emission observed by [3] will be of great...base funding. 8. REFERENCES 1. Kassim et al., The 74 MHz System on the Very Large Array, The Astrophysical Journal Supplement Series, Vol. 172...The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar Namir E. Kassim Naval Research

Large-Area Subwavelength Aperture Arrays Fabricated Using Nanoimprint Lithography

DOE PAGES

Skinner, J. L.; Hunter, L. L.; Talin, A. A.; ...

2008-07-29

In this paper, we report on the fabrication and characterization of large-area 2-D square arrays of subwavelength holes in Ag and Al films. Fabrication is based on thermal nanoimprint lithography and metal evaporation, without the need for etching, and is compatible with low-cost, large-scale production. Reflectance spectra for these arrays display an intensity minimum whose amplitude, center wavelength, and line width depend on the geometry of the array and the reflectivity of the metal film. By placing various fluids in contact with the subwavelength aperture arrays, we observe that the center wavelength of the reflectance minimum varies linearly with themore » refractive index of the fluid with a sensitivity of over 500 nm per refractive index unit. Lastly, the surface plasmon theory is used to predict sensitivities to refractive index change with accuracies better than 0.5%.« less

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.

Large Area Flat Panel Imaging Detectors for Astronomy and Night Time Sensing

NASA Astrophysics Data System (ADS)

Siegmund, O.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

2013-09-01

Sealed tube photo-sensing detectors for optical/IR detection have applications in astronomy, nighttime remote reconnaissance, and airborne/space situational awareness. The potential development of large area photon counting, imaging, timing detectors has significance for these applications and a number of other areas (High energy particle detection (RICH), biological single-molecule fluorescence lifetime imaging microscopy, neutron imaging, time of flight mass spectroscopy, diffraction imaging). We will present details of progress towards the development of a 20 cm sealed tube optical detector with nanoengineered microchannel plates for photon counting, imaging and sub-ns event time stamping. In the operational scheme of the photodetector incoming light passes through an entrance window and interacts with a semitransparent photocathode on the inside of the window. The photoelectrons emitted are accelerated across a proximity gap and are detected by an MCP pair. The pair of novel borosilicate substrate MCPs are functionalized by atomic layer deposition (ALD), and amplify the signal and the resulting electron cloud is detected by a conductive strip line anode for determination of the event positions and the time of arrival. The physical package is ~ 25 x 25 cm but only 1.5 cm thick. Development of such a device in a square 20 cm format presents challenges: hermetic sealing to a large entrance window, a 20 cm semitransparent photocathode with good efficiency and uniformity, 20 cm MCPs with reasonable cost and performance, robust construction to preserve high vacuum and withstand an atmosphere pressure differential. We will discuss the schemes developed to address these issues and present the results for the first test devices. The novel microchannel plates employing borosilicate micro-capillary arrays provide many performance characteristics typical of conventional MCPs, but have been made in sizes up to 20 cm, have low intrinsic background (0.08 events cm2 s-1) and

Fabrication and characterization of a 0.5-mm lutetium oxyorthosilicate detector array for high-resolution PET applications.

PubMed

Stickel, Jennifer R; Qi, Jinyi; Cherry, Simon R

2007-01-01

With the increasing use of in vivo imaging in mouse models of disease, there are many interesting applications that demand imaging of organs and tissues with submillimeter resolution. Though there are other contributing factors, the spatial resolution in small-animal PET is still largely determined by the detector pixel dimensions. In this work, a pair of lutetium oxyorthosilicate (LSO) arrays with 0.5-mm pixels was coupled to multichannel photomultiplier tubes and evaluated for use as high-resolution PET detectors. Flood histograms demonstrated that most crystals were clearly identifiable. Energy resolution varied from 22% to 38%. The coincidence timing resolution was 1.42-ns full width at half maximum (FWHM). The intrinsic spatial resolution was 0.68-mm FWHM as measured with a 30-gauge needle filled with (18)F. The improvement in spatial resolution in a tomographic setting is demonstrated using images of a line source phantom reconstructed with filtered backprojection and compared with images obtained from 2 dedicated small-animal PET scanners. Finally, a projection image of the mouse foot is shown to demonstrate the application of these 0.5-mm LSO detectors to a biologic task. A pair of highly pixelated LSO detections has been constructed and characterized for use as high-spatial-resolution PET detectors. It appears that small-animal PET systems capable of a FWHM spatial resolution of 600 microm or less are feasible and should be pursued.

Design and performance of dual-polarization lumped-element kinetic inductance detectors for millimeter-wave polarimetry

NASA Astrophysics Data System (ADS)

McCarrick, H.; Jones, G.; Johnson, B. R.; Abitbol, M. H.; Ade, P. A. R.; Bryan, S.; Day, P.; Essinger-Hileman, T.; Flanigan, D.; Leduc, H. G.; Limon, M.; Mauskopf, P.; Miller, A.; Tucker, C.

2018-02-01

Aims: Lumped-element kinetic inductance detectors (LEKIDs) are an attractive technology for millimeter-wave observations that require large arrays of extremely low-noise detectors. We designed, fabricated and characterized 64-element (128 LEKID) arrays of horn-coupled, dual-polarization LEKIDs optimized for ground-based CMB polarimetry. Our devices are sensitive to two orthogonal polarizations in a single spectral band centered on 150 GHz with Δν/ν = 0.2. The 65 × 65 mm square arrays are designed to be tiled into the focal plane of an optical system. We demonstrate the viability of these dual-polarization LEKIDs with laboratory measurements. Methods: The LEKID modules are tested with an FPGA-based readout system in a sub-kelvin cryostat that uses a two-stage adiabatic demagnetization refrigerator. The devices are characterized using a blackbody and a millimeter-wave source. The polarization properties are measured with a cryogenic stepped half-wave plate. We measure the resonator parameters and the detector sensitivity, noise spectrum, dynamic range, and polarization response. Results: The resonators have internal quality factors approaching 1 × 106. The detectors have uniform response between orthogonal polarizations and a large dynamic range. The detectors are photon-noise limited above 1 pW of absorbed power. The noise-equivalent temperatures under a 3.4 K blackbody load are <100 μK √s. The polarization fractions of detectors sensitive to orthogonal polarizations are >80%. The entire array is multiplexed on a single readout line, demonstrating a multiplexing factor of 128. The array and readout meet the requirements for 4 arrays to be read out simultaneously for a multiplexing factor of 512. Conclusions: This laboratory study demonstrates the first dual-polarization LEKID array optimized specifically for CMB polarimetry and shows the readiness of the detectors for on-sky observations.

Experimental Investigation of Very Large Model Wind Turbine Arrays

NASA Astrophysics Data System (ADS)

Charmanski, Kyle; Wosnik, Martin

2013-11-01

The decrease in energy yield in large wind farms (array losses) and associated revenue losses can be significant. When arrays are sufficiently large they can reach what is known as a fully developed wind turbine array boundary layer, or fully developed wind farm condition. This occurs when the turbulence statistics and the structure of the turbulence, within and above a wind farm, as well as the performance of the turbines remain the same from one row to the next. The study of this condition and how it is affected by parameters such as turbine spacing, power extraction, tip speed ratio, etc. is important for the optimization of large wind farms. An experimental investigation of the fully developed wind farm condition was conducted using a large array of porous disks (upstream) and realistically scaled 3-bladed wind turbines with a diameter of 0.25m. The turbines and porous disks were placed inside a naturally grown turbulent boundary layer in the 6m × 2.5m × 72m test section of the UNH Flow Physics Facility which can achieve test section velocities of up to 14 m/s and Reynolds numbers δ+ = δuτ / ν ~ 20 , 000 . Power, rate of rotation and rotor thrust were measured for select turbines, and hot-wire anemometry was used for flow measurements.

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.

Sub-200 ps CRT in monolithic scintillator PET detectors using digital SiPM arrays and maximum likelihood interaction time estimation.

PubMed

van Dam, Herman T; Borghi, Giacomo; Seifert, Stefan; Schaart, Dennis R

2013-05-21

Digital silicon photomultiplier (dSiPM) arrays have favorable characteristics for application in monolithic scintillator detectors for time-of-flight positron emission tomography (PET). To fully exploit these benefits, a maximum likelihood interaction time estimation (MLITE) method was developed to derive the time of interaction from the multiple time stamps obtained per scintillation event. MLITE was compared to several deterministic methods. Timing measurements were performed with monolithic scintillator detectors based on novel dSiPM arrays and LSO:Ce,0.2%Ca crystals of 16 × 16 × 10 mm(3), 16 × 16 × 20 mm(3), 24 × 24 × 10 mm(3), and 24 × 24 × 20 mm(3). The best coincidence resolving times (CRTs) for pairs of identical detectors were obtained with MLITE and measured 157 ps, 185 ps, 161 ps, and 184 ps full-width-at-half-maximum (FWHM), respectively. For comparison, a small reference detector, consisting of a 3 × 3 × 5 mm(3) LSO:Ce,0.2%Ca crystal coupled to a single pixel of a dSiPM array, was measured to have a CRT as low as 120 ps FWHM. The results of this work indicate that the influence of the optical transport of the scintillation photons on the timing performance of monolithic scintillator detectors can at least partially be corrected for by utilizing the information contained in the spatio-temporal distribution of the collection of time stamps registered per scintillation event.

Sub-200 ps CRT in monolithic scintillator PET detectors using digital SiPM arrays and maximum likelihood interaction time estimation

NASA Astrophysics Data System (ADS)

van Dam, Herman T.; Borghi, Giacomo; Seifert, Stefan; Schaart, Dennis R.

2013-05-01

Digital silicon photomultiplier (dSiPM) arrays have favorable characteristics for application in monolithic scintillator detectors for time-of-flight positron emission tomography (PET). To fully exploit these benefits, a maximum likelihood interaction time estimation (MLITE) method was developed to derive the time of interaction from the multiple time stamps obtained per scintillation event. MLITE was compared to several deterministic methods. Timing measurements were performed with monolithic scintillator detectors based on novel dSiPM arrays and LSO:Ce,0.2%Ca crystals of 16 × 16 × 10 mm3, 16 × 16 × 20 mm3, 24 × 24 × 10 mm3, and 24 × 24 × 20 mm3. The best coincidence resolving times (CRTs) for pairs of identical detectors were obtained with MLITE and measured 157 ps, 185 ps, 161 ps, and 184 ps full-width-at-half-maximum (FWHM), respectively. For comparison, a small reference detector, consisting of a 3 × 3 × 5 mm3 LSO:Ce,0.2%Ca crystal coupled to a single pixel of a dSiPM array, was measured to have a CRT as low as 120 ps FWHM. The results of this work indicate that the influence of the optical transport of the scintillation photons on the timing performance of monolithic scintillator detectors can at least partially be corrected for by utilizing the information contained in the spatio-temporal distribution of the collection of time stamps registered per scintillation event.

SOLID2: An Antibody Array-Based Life-Detector Instrument in a Mars Drilling Simulation Experiment (MARTE)

NASA Astrophysics Data System (ADS)

Parro, Víctor; Fernández-Calvo, Patricia; Rodríguez Manfredi, José A.; Moreno-Paz, Mercedes; Rivas, Luis A.; García-Villadangos, Miriam; Bonaccorsi, Rosalba; González-Pastor, José Eduardo; Prieto-Ballesteros, Olga; Schuerger, Andrew C.; Davidson, Mark; Gómez-Elvira, Javier; Stoker, Carol R.

2008-10-01

A field prototype of an antibody array-based life-detector instrument, Signs Of LIfe Detector (SOLID2), has been tested in a Mars drilling mission simulation called MARTE (Mars Astrobiology Research and Technology Experiment). As one of the analytical instruments on the MARTE robotic drilling rig, SOLID2 performed automatic sample processing and analysis of ground core samples (0.5 g) with protein microarrays that contained 157 different antibodies. Core samples from different depths (down to 5.5 m) were analyzed, and positive reactions were obtained in antibodies raised against the Gram-negative bacterium Leptospirillum ferrooxidans, a species of the genus Acidithiobacillus (both common microorganisms in the Río Tinto area), and extracts from biofilms and other natural samples from the Río Tinto area. These positive reactions were absent when the samples were previously subjected to a high-temperature treatment, which indicates the biological origin and structural dependency of the antibody-antigen reactions. We conclude that an antibody array-based life-detector instrument like SOLID2 can detect complex biological material, and it should be considered as a potential analytical instrument for future planetary missions that search for life.

SOLID2: an antibody array-based life-detector instrument in a Mars Drilling Simulation Experiment (MARTE).

PubMed

Parro, Víctor; Fernández-Calvo, Patricia; Rodríguez Manfredi, José A; Moreno-Paz, Mercedes; Rivas, Luis A; García-Villadangos, Miriam; Bonaccorsi, Rosalba; González-Pastor, José Eduardo; Prieto-Ballesteros, Olga; Schuerger, Andrew C; Davidson, Mark; Gómez-Elvira, Javier; Stoker, Carol R

2008-10-01

A field prototype of an antibody array-based life-detector instrument, Signs Of LIfe Detector (SOLID2), has been tested in a Mars drilling mission simulation called MARTE (Mars Astrobiology Research and Technology Experiment). As one of the analytical instruments on the MARTE robotic drilling rig, SOLID2 performed automatic sample processing and analysis of ground core samples (0.5 g) with protein microarrays that contained 157 different antibodies. Core samples from different depths (down to 5.5 m) were analyzed, and positive reactions were obtained in antibodies raised against the Gram-negative bacterium Leptospirillum ferrooxidans, a species of the genus Acidithiobacillus (both common microorganisms in the Río Tinto area), and extracts from biofilms and other natural samples from the Río Tinto area. These positive reactions were absent when the samples were previously subjected to a high-temperature treatment, which indicates the biological origin and structural dependency of the antibody-antigen reactions. We conclude that an antibody array-based life-detector instrument like SOLID2 can detect complex biological material, and it should be considered as a potential analytical instrument for future planetary missions that search for life.

Predictive modeling of infrared detectors and material systems

NASA Astrophysics Data System (ADS)

Pinkie, Benjamin

Detectors sensitive to thermal and reflected infrared radiation are widely used for night-vision, communications, thermography, and object tracking among other military, industrial, and commercial applications. System requirements for the next generation of ultra-high-performance infrared detectors call for increased functionality such as large formats (> 4K HD) with wide field-of-view, multispectral sensitivity, and on-chip processing. Due to the low yield of infrared material processing, the development of these next-generation technologies has become prohibitively costly and time consuming. In this work, it will be shown that physics-based numerical models can be applied to predictively simulate infrared detector arrays of current technological interest. The models can be used to a priori estimate detector characteristics, intelligently design detector architectures, and assist in the analysis and interpretation of existing systems. This dissertation develops a multi-scale simulation model which evaluates the physics of infrared systems from the atomic (material properties and electronic structure) to systems level (modulation transfer function, dense array effects). The framework is used to determine the electronic structure of several infrared materials, optimize the design of a two-color back-to-back HgCdTe photodiode, investigate a predicted failure mechanism for next-generation arrays, and predict the systems-level measurables of a number of detector architectures.

"Phoswich Wall": A charged-particle detector array for inverse-kinematic reactions with the Gretina/GRETA γ-ray arrays

NASA Astrophysics Data System (ADS)

Sarantites, D. G.; Reviol, W.; Elson, J. M.; Kinnison, J. E.; Izzo, C. J.; Manfredi, J.; Liu, J.; Jung, H. S.; Goerres, J.

2015-08-01

A high-efficiency, forward-hemisphere detector system for light charged particles and low-Z heavy ions, as obtained in an accelerator experiment, is described. It consists of four 8×8 pixel multianode photomultiplier tubes with 2.2-mm thick CsI(Tl) and 12 -μm thick fast-plastic scintillation detectors. Its phoswich structure allows individual Z resolution for 1H, 4He, 7Li, 4He+4He, 9Be, 11B, 12C, and 14N ions, which are target-like fragments detected in strongly inverse kinematics. The device design has been optimized for use with a 4π γ-ray array, and the main applications are transfer reactions and Coulomb excitation. A high-angular resolution for the detection of the target-like fragments is achieved which permits angular distributions to be measured in the rest frame of the projectile-like fragment with a resolution of ~ 2 °.

The energy spectrum of cosmic rays above 1017.2 eV measured by the fluorescence detectors of the Telescope Array experiment in seven years

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.; 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.; 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.

2016-07-01

The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at two stations of TA are newly constructed and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 1017.2eV measured by the fluorescence detectors and a comparison with previously published results.

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

Multi-anode microchannel arrays

NASA Technical Reports Server (NTRS)

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

1977-01-01

A development program is currently being undertaken to produce photon-counting detector arrays which are suitable for use in both ground-based and space-borne instruments and which utilize the full sensitivity, dynamic range and photometric stability of the microchannel array plate (MCP). The construction of the detector arrays and the status of the development program are described.

Energy spectrum measured by the telescope array surface detector

NASA Astrophysics Data System (ADS)

Ivanov, Dmitri

2012-05-01

Two conflicting measurements of the ultra high energy cosmic ray (UHECR) flux have been reported by the Akeno Giant Air Shower Array (AGASA) and the High Resolution Fly's Eye (HiRes) experiments. HiRes observes a ˜5sigma suppression at E = 1019.75 eV, which is in agreement with the prediction of Greisen-Zatsepin-Kuz'min (GZK) theory. AGASA, in contrast, sees the flux extended well beyond E = 1020 eV with no visible break, suggesting that the flux is limited only by the rate at which the sources can produce the UHECR and not by interaction of energetic particles with the cosmic microwave background, thus challenging the relativistic invariance principle. In response to this discrepancy, a new experiment named the Telescope Array (TA) has been deployed, which combines the detection elements used separately by HiRes and AGASA. We describe the TA surface detector (SD) analysis using a technique new to the field, which consists of a detailed Monte-Carlo (MC) simulation of the SD response to the natural cosmic rays, validating the MC by comparing its distributions with the data, and calculation of the SD aperture from the MC. We will also describe our reconstruction procedure, based solely upon the data, and its application to both data and the MC. Finally, we will describe the energy spectrum resulting from this analysis, which is found to be in excellent agreement with the HiRes result, and as such, is the first confirmation of the GZK effect by a ground array of scintillation counters.

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

High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector.

PubMed

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

2014-09-01

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 × 10(8) 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 × 10(10) 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.

Spectrum measurement with the Telescope Array Low Energy Extension (TALE) fluorescence detector

NASA Astrophysics Data System (ADS)

Zundel, Zachary James

The Telescope Array (TA) experiment is the largest Ultra High Energy cosmic ray observatory in the northern hemisphere and is designed to be sensitive to cosmic ray air showers above 1018eV. Despite the substantial measurements made by TA and AUGER (the largest cosmic ray observatory in the southern hemisphere), there remains uncertainty about whether the highest energy cosmic rays are galactic or extragalactic in origin. Locating features in the cosmic ray energy spectrum below 1018eV that indicate a transition from galactic to extragalactic sources would clarify the interpretation of measurements made at the highest energies. The Telescope Array Low Energy Extension (TALE) is designed to extend the energy threshold of the TA observatory down to 1016.5eV in order to make such measurements. This dissertation details the construction, calibration, and operation of the TALE flu- orescence detector. A measurement of the flux of cosmic rays in the energy range of 1016.5 -- 1018.5eV is made using the monocular data set taken between September 2013 and January 2014. The TALE fluorescence detector observes evidence for a softening of the cosmic spectrum at 1017.25+/-0.5eV. The evidence of a change in the spectrum motivates continued study of 1016.5 -- 1018.5eV cosmic rays.

Cherenkov detectors for spatial imaging applications using discrete-energy photons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rose, Paul B.; Erickson, Anna S., E-mail: erickson@gatech.edu

Cherenkov detectors can offer a significant advantage in spatial imaging applications when excellent timing response, low noise and cross talk, large area coverage, and the ability to operate in magnetic fields are required. We show that an array of Cherenkov detectors with crude energy resolution coupled with monochromatic photons resulting from a low-energy nuclear reaction can be used to produce a sharp image of material while providing large and inexpensive detector coverage. The analysis of the detector response to relative transmission of photons with various energies allows for reconstruction of material's effective atomic number further aiding in high-Z material identification.

New Optimizations of Microcalorimeter Arrays for High-Resolution Imaging X-ray Spectroscopy

NASA Astrophysics Data System (ADS)

Kilbourne, Caroline

We propose to continue our successful research program in developing arrays of superconducting transition-edge sensors (TES) for x-ray astrophysics. Our standard 0.3 mm TES pixel achieves better than 2.5-eV resolution, and we now make 32x32 arrays of such pixels. We have also achieved better than 1-eV resolution in smaller pixels, and promising performance in a range of position-sensitive designs. We propose to continue to advance the designs of both the single-pixel and position-sensitive microcalorimeters so that we can produce arrays suitable for several x-ray spectroscopy observatories presently in formulation. We will also investigate various array and pixel optimizations such as would be needed for large arrays for surveys, large- pixel arrays for diffuse soft x-ray measurements, or sub-arrays of fast pixels optimized for neutron-star burst spectroscopy. In addition, we will develop fabrication processes for integrating sub-arrays with very different pixel designs into a monolithic focal-plane array to simplify the design of the focal-plane assembly and make feasible new detector configurations such as the one currently baselined for AXSIO. Through a series of measurements on test devices, we have improved our understanding of the weak-link physics governing the observed resistive transitions in TES detectors. We propose to build on that work and ultimately use the results to improve the immunity of the detector to environmental magnetic fields, as well as its fundamental performance, in each of the targeted optimizations we are developing.

Turbulent chimeras in large semiconductor laser arrays

PubMed Central

Shena, J.; Hizanidis, J.; Kovanis, V.; Tsironis, G. P.

2017-01-01

Semiconductor laser arrays have been investigated experimentally and theoretically from the viewpoint of temporal and spatial coherence for the past forty years. In this work, we are focusing on a rather novel complex collective behavior, namely chimera states, where synchronized clusters of emitters coexist with unsynchronized ones. For the first time, we find such states exist in large diode arrays based on quantum well gain media with nearest-neighbor interactions. The crucial parameters are the evanescent coupling strength and the relative optical frequency detuning between the emitters of the array. By employing a recently proposed figure of merit for classifying chimera states, we provide quantitative and qualitative evidence for the observed dynamics. The corresponding chimeras are identified as turbulent according to the irregular temporal behavior of the classification measure. PMID:28165053

Turbulent chimeras in large semiconductor laser arrays

NASA Astrophysics Data System (ADS)

Shena, J.; Hizanidis, J.; Kovanis, V.; Tsironis, G. P.

2017-02-01

Semiconductor laser arrays have been investigated experimentally and theoretically from the viewpoint of temporal and spatial coherence for the past forty years. In this work, we are focusing on a rather novel complex collective behavior, namely chimera states, where synchronized clusters of emitters coexist with unsynchronized ones. For the first time, we find such states exist in large diode arrays based on quantum well gain media with nearest-neighbor interactions. The crucial parameters are the evanescent coupling strength and the relative optical frequency detuning between the emitters of the array. By employing a recently proposed figure of merit for classifying chimera states, we provide quantitative and qualitative evidence for the observed dynamics. The corresponding chimeras are identified as turbulent according to the irregular temporal behavior of the classification measure.

Characterization of a novel two dimensional diode array the "magic plate" as a radiation detector for radiation therapy treatment.

PubMed

Wong, J H D; Fuduli, I; Carolan, M; Petasecca, M; Lerch, M L F; Perevertaylo, V L; Metcalfe, P; Rosenfeld, A B

2012-05-01

Intensity modulated radiation therapy (IMRT) utilizes the technology of multileaf collimators to deliver highly modulated and complex radiation treatment. Dosimetric verification of the IMRT treatment requires the verification of the delivered dose distribution. Two dimensional ion chamber or diode arrays are gaining popularity as a dosimeter of choice due to their real time feedback compared to film dosimetry. This paper describes the characterization of a novel 2D diode array, which has been named the "magic plate" (MP). It was designed to function as a 2D transmission detector as well as a planar detector for dose distribution measurements in a solid water phantom for the dosimetric verification of IMRT treatment delivery. The prototype MP is an 11 × 11 detector array based on thin (50 μm) epitaxial diode technology mounted on a 0.6 mm thick Kapton substrate using a proprietary "drop-in" technology developed by the Centre for Medical Radiation Physics, University of Wollongong. A full characterization of the detector was performed, including radiation damage study, dose per pulse effect, percent depth dose comparison with CC13 ion chamber and build up characteristics with a parallel plane ion chamber measurements, dose linearity, energy response and angular response. Postirradiated magic plate diodes showed a reproducibility of 2.1%. The MP dose per pulse response decreased at higher dose rates while at lower dose rates the MP appears to be dose rate independent. The depth dose measurement of the MP agrees with ion chamber depth dose measurements to within 0.7% while dose linearity was excellent. MP showed angular response dependency due to the anisotropy of the silicon diode with the maximum variation in angular response of 10.8% at gantry angle 180°. Angular dependence was within 3.5% for the gantry angles ± 75°. The field size dependence of the MP at isocenter agrees with ion chamber measurement to within 1.1%. In the beam perturbation study, the

New Opportunities in Decay Spectroscopy with the GRIFFIN and DESCANT Arrays

NASA Astrophysics Data System (ADS)

Bildstein, V.; Andreoiu, C.; Ball, G. C.; Ballast, T.; Bartlett, C.; Bender, P. C.; Bernier, N.; Bianco, L.; Bishop, D.; Brennan, D.; Bruhn, T.; Cheeseman, A.; Churchman, R.; Ciccone, S.; Davids, B.; Demand, G.; Dillmann, I.; Garnsworthy, A. B.; Garrett, P. E.; Georges, S.; Hackman, G.; Hadinia, B.; Kokke, R.; Krücken, R.; Linn, Y.; Lim, C.; Martin, J.-P.; Miller, D.; Mills, W. J.; Morrison, L. N.; Ohlmann, C. A.; Park, J.; Pearson, C. J.; Pore, J. L.; Rajabali, M. M.; Rand, E. T.; Rizwan, U.; Sarazin, F.; Shaw, B.; Starosta, K.; Svensson, C. E.; Sumithrarachchi, C.; Unsworth, C.; Voss, P.; Wang, Z. M.; Williams, J.; Wong, J.; Wong, S.

The GRIFFIN (Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei) project is a major upgrade of the decay spectroscopy capabilities at TRIUMF-ISAC. GRIFFIN will replace the 8π spectrometer with an array of up to 16 large-volume HPGe clover detectors and use a state-of-the-art digital data acquisition system. The existing ancillary detector systems that had been developed for 8π, such as the SCEPTAR array for β-tagging, PACES for high-resolution internal conversion electron spectroscopy, and the DANTE array of LaBr3/BaF2 scintillators for fast γ-ray timing, will be used with GRIFFIN. GRIFFIN can also accommodate the new neutron detector array DESCANT (Deuterated Scintillator Array for Neutron Tagging), enabling the study of β-delayed neutron emitters. DESCANT consists of up to 70 detectors, each filled with approximately 2 liters of deuterated benzene, a liquid scintillator that provides pulse-shape discrimination (PSD) capabilities to distinguish between neutrons and γ-rays interacting with the detector. In addition, the anisotropic nature of n-d scattering as compared to the isotropic n-p scattering allows for the determination of the neutron energy spectrum directly from the pulse-height spectrum, complementing the time-of-flight (TOF) information. The installation of GRIFFIN is under way and first experiments are planned for the fall of 2014. The array will be completed in 2015 with the full complement of 16 clovers. DESCANT will be tested coupled with GRIFFIN in spring of 2015.

Evaluation of Matrix9 silicon photomultiplier array for small-animal PET.

PubMed

Du, Junwei; Schmall, Jeffrey P; Yang, Yongfeng; Di, Kun; Roncali, Emilie; Mitchell, Gregory S; Buckley, Steve; Jackson, Carl; Cherry, Simon R

2015-02-01

The MatrixSL-9-30035-OEM (Matrix9) from SensL is a large-area silicon photomultiplier (SiPM) photodetector module consisting of a 3 × 3 array of 4 × 4 element SiPM arrays (total of 144 SiPM pixels) and incorporates SensL's front-end electronics board and coincidence board. Each SiPM pixel measures 3.16 × 3.16 mm(2) and the total size of the detector head is 47.8 × 46.3 mm(2). Using 8 × 8 polished LSO/LYSO arrays (pitch 1.5 mm) the performance of this detector system (SiPM array and readout electronics) was evaluated with a view for its eventual use in small-animal positron emission tomography (PET). Measurements of noise, signal, signal-to-noise ratio, energy resolution, flood histogram quality, timing resolution, and array trigger error were obtained at different bias voltages (28.0-32.5 V in 0.5 V intervals) and at different temperatures (5 °C-25 °C in 5 °C degree steps) to find the optimal operating conditions. The best measured signal-to-noise ratio and flood histogram quality for 511 keV gamma photons were obtained at a bias voltage of 30.0 V and a temperature of 5 °C. The energy resolution and timing resolution under these conditions were 14.2% ± 0.1% and 4.2 ± 0.1 ns, respectively. The flood histograms show that all the crystals in the 1.5 mm pitch LSO array can be clearly identified and that smaller crystal pitches can also be resolved. Flood histogram quality was also calculated using different center of gravity based positioning algorithms. Improved and more robust results were achieved using the local 9 pixels for positioning along with an energy offset calibration. To evaluate the front-end detector readout, and multiplexing efficiency, an array trigger error metric is introduced and measured at different lower energy thresholds. Using a lower energy threshold greater than 150 keV effectively eliminates any mispositioning between SiPM arrays. In summary, the Matrix9 detector system can resolve high-resolution scintillator arrays

Multi-element germanium detectors for synchrotron applications

NASA Astrophysics Data System (ADS)

Rumaiz, A. K.; Kuczewski, A. J.; Mead, J.; Vernon, E.; Pinelli, D.; Dooryhee, E.; Ghose, S.; Caswell, T.; Siddons, D. P.; Miceli, A.; Baldwin, J.; Almer, J.; Okasinski, J.; Quaranta, O.; Woods, R.; Krings, T.; Stock, S.

2018-04-01

We have developed a series of monolithic multi-element germanium detectors, based on sensor arrays produced by the Forschungzentrum Julich, and on Application-specific integrated circuits (ASICs) developed at Brookhaven. Devices have been made with element counts ranging from 64 to 384. These detectors are being used at NSLS-II and APS for a range of diffraction experiments, both monochromatic and energy-dispersive. Compact and powerful readout systems have been developed, based on the new generation of FPGA system-on-chip devices, which provide closely coupled multi-core processors embedded in large gate arrays. We will discuss the technical details of the systems, and present some of the results from them.

The MRPC-based ALICE time-of-flight detector: Status andperformance

NASA Astrophysics Data System (ADS)

Alici, A.; ALICE Collaboration

2013-04-01

The large time-of-flight (TOF) array is one of the main detectors devoted to charged hadron identification in the mid-rapidity region of the ALICE experiment at the LHC. It allows separation among pions, kaons and protons up to a few GeV/c, covering the full azimuthal angle and -0.9<η<0.9. The TOF exploits the innovative MRPC technology capable of an intrinsic time resolution better than 50 ps with an efficiency close to 100% and a large operational plateau; the full array consists of 1593 MRPCs covering a cylindrical surface of 141 m2. The TOF detector has been efficiently taking data since the first pp collisions recorded in ALICE in December 2009. In this report, the status of the TOF detector and the performance achieved for both pp and Pb-Pb collisions aredescribed.

Three-component borehole wall-locking seismic detector

DOEpatents

Owen, Thomas E.

1994-01-01

A seismic detector for boreholes is described that has an accelerometer sensor block for sensing vibrations in geologic formations of the earth. The density of the seismic detector is approximately matched to the density of the formations in which the detector is utilized. A simple compass is used to orient the seismic detector. A large surface area shoe having a radius approximately equal to the radius of the borehole in which the seismic detector is located may be pushed against the side of the borehole by actuating cylinders contained in the seismic detector. Hydraulic drive of the cylinders is provided external to the detector. By using the large surface area wall-locking shoe, force holding the seismic detector in place is distributed over a larger area of the borehole wall thereby eliminating concentrated stresses. Borehole wall-locking forces up to ten times the weight of the seismic detector can be applied thereby ensuring maximum detection frequency response up to 2,000 hertz using accelerometer sensors in a triaxial array within the seismic detector.

Weak-signal Phase Calibration Strategies for Large DSN Arrays

NASA Technical Reports Server (NTRS)

Jones, Dayton L.

2005-01-01

The NASA Deep Space Network (DSN) is studying arrays of large numbers of small, mass-produced radio antennas as a cost-effective way to increase downlink sensitivity and data rates for future missions. An important issue for the operation of large arrays is the accuracy with which signals from hundreds of small antennas can be combined. This is particularly true at Ka band (32 GHz) where atmospheric phase variations can be large and rapidly changing. A number of algorithms exist to correct the phases of signals from individual antennas in the case where a spacecraft signal provides a useful signal-to-noise ratio (SNR) on time scales shorter than the atmospheric coherence time. However, for very weak spacecraft signals it will be necessary to rely on background natural radio sources to maintain array phasing. Very weak signals could result from a spacecraft emergency or by design, such as direct-to-Earth data transmissions from distant planetary atmospheric or surface probes using only low gain antennas. This paper considers the parameter space where external real-time phase calibration will be necessary, and what this requires in terms of array configuration and signal processing. The inherent limitations of this technique are also discussed.

Optimal Chunking of Large Multidimensional Arrays for Data Warehousing

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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"whatmore » 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.« less

NEW LENSLET BASED IFS WITH HIGH DETECTOR PIXEL EFFICIENCY

NASA Astrophysics Data System (ADS)

Gong, Qian

2018-01-01

Three IFS types currently used for optical design are: lenslet array, imager slicer, and lenslet array and fiber combined. Lenslet array based Integral Field Spectroscopy (IFS) is very popular for many astrophysics applications due to its compactness, simplicity, as well as cost and mass savings. The disadvantage of lenslet based IFS is its low detector pixel efficiency. Enough spacing is needed between adjacent spectral traces in cross dispersion direction to avoid wavelength cross-talk, because the same wavelength is not aligned to the same column on detector. Such as on a recent exoplanet coronagraph instrument study to support the coming astrophysics decadal survey (LUVOIR), to cover a 45 λ/D Field of View (FOV) with a spectral resolving power of 200 at shortest wavelength, a 4k x 4k detector array is needed. This large format EMCCD pushes the detector into technology development area with a low TRL. Besides the future mission, it will help WFIRST coronagraph IFS by packing all spectra into a smaller area on detector, which will reduce the chance for electrons to be trapped in pixels, and slow the detector degradation during the mission.The innovation we propose here is to increase the detector packing efficiency by grouping a number of lenslets together to form many mini slits. In other words, a number of spots (Point Spread Function at lenslet focus) are aligned into a line to resemble a mini slit. Therefore, wavelength cross-talk is no longer a concern anymore. This combines the advantage of lenslet array and imager slicer together. The isolation rows between spectral traces in cross dispersion direction can be reduced or removed. So the packing efficiency is greatly increased. Furthermore, the today’s microlithography and etching technique is capable of making such a lenslet array, which will relax the detector demand significantly. It will finally contribute to the habitable exoplanets study to analyzing their spectra from direct images. Detailed theory

Large-scale fabrication of single crystalline tin nanowire arrays

NASA Astrophysics Data System (ADS)

Luo, Bin; Yang, Dachi; Liang, Minghui; Zhi, Linjie

2010-09-01

Large-scale single crystalline tin nanowire arrays with preferred lattice orientation along the [100] direction were fabricated in porous anodic aluminium oxide (AAO) membranes by the electrodeposition method using copper nanorod as a second electrode.Large-scale single crystalline tin nanowire arrays with preferred lattice orientation along the [100] direction were fabricated in porous anodic aluminium oxide (AAO) membranes by the electrodeposition method using copper nanorod as a second electrode. Electronic supplementary information (ESI) available: Experimental details and the information for single crystalline copper nanorods. See DOI: 10.1039/c0nr00206b

ScintSim1: A new Monte Carlo simulation code for transport of optical photons in 2D arrays of scintillation detectors.

PubMed

Mosleh-Shirazi, Mohammad Amin; Zarrini-Monfared, Zinat; Karbasi, Sareh; Zamani, Ali

2014-01-01

Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all <1%. The results validate the accuracy of the new code, which is a useful tool in scintillation detector optimization.

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.

Geometric correction methods for Timepix based large area detectors

NASA Astrophysics Data System (ADS)

Zemlicka, J.; Dudak, J.; Karch, J.; Krejci, F.

2017-01-01

X-ray micro radiography with the hybrid pixel detectors provides versatile tool for the object inspection in various fields of science. It has proven itself especially suitable for the samples with low intrinsic attenuation contrast (e.g. soft tissue in biology, plastics in material sciences, thin paint layers in cultural heritage, etc.). The limited size of single Medipix type detector (1.96 cm2) was recently overcome by the construction of large area detectors WidePIX assembled of Timepix chips equipped with edgeless silicon sensors. The largest already built device consists of 100 chips and provides fully sensitive area of 14.3 × 14.3 cm2 without any physical gaps between sensors. The pixel resolution of this device is 2560 × 2560 pixels (6.5 Mpix). The unique modular detector layout requires special processing of acquired data to avoid occurring image distortions. It is necessary to use several geometric compensations after standard corrections methods typical for this type of pixel detectors (i.e. flat-field, beam hardening correction). The proposed geometric compensations cover both concept features and particular detector assembly misalignment of individual chip rows of large area detectors based on Timepix assemblies. The former deals with larger border pixels in individual edgeless sensors and their behaviour while the latter grapple with shifts, tilts and steps between detector rows. The real position of all pixels is defined in Cartesian coordinate system and together with non-binary reliability mask it is used for the final image interpolation. The results of geometric corrections for test wire phantoms and paleo botanic material are presented in this article.

Gamma ray detector modules

NASA Technical Reports Server (NTRS)

Capote, M. Albert (Inventor); Lenos, Howard A. (Inventor)

2009-01-01

A radiation detector assembly has a semiconductor detector array substrate of CdZnTe or CdTe, having a plurality of detector cell pads on a first surface thereof, the pads having a contact metallization and a solder barrier metallization. An interposer card has planar dimensions no larger than planar dimensions of the semiconductor detector array substrate, a plurality of interconnect pads on a first surface thereof, at least one readout semiconductor chip and at least one connector on a second surface thereof, each having planar dimensions no larger than the planar dimensions of the interposer card. Solder columns extend from contacts on the interposer first surface to the plurality of pads on the semiconductor detector array substrate first surface, the solder columns having at least one solder having a melting point or liquidus less than 120 degrees C. An encapsulant is disposed between the interposer circuit card first surface and the semiconductor detector array substrate first surface, encapsulating the solder columns, the encapsulant curing at a temperature no greater than 120 degrees C.

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.

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.

Correlation Between Bulk Material Defects and Spectroscopic Response in Cadmium Zinc Telluride Detectors

NASA Technical Reports Server (NTRS)

Parker, Bradford H.; Stahle, C. M.; Barthelmy, S. D.; Parsons, A. M.; Tueller, J.; VanSant, J. T.; Munoz, B. F.; Snodgrass, S. J.; Mullinix, R. E.

1999-01-01

One of the critical challenges for large area cadmium zinc telluride (CdZnTe) detector arrays is obtaining material capable of uniform imaging and spectroscopic response. Two complementary nondestructive techniques for characterizing bulk CdZnTe have been developed to identify material with a uniform response. The first technique, infrared transmission imaging, allows for rapid visualization of bulk defects. The second technique, x-ray spectral mapping, provides a map of the material spectroscopic response when it is configured as a planar detector. The two techniques have been used to develop a correlation between bulk defect type and detector performance. The correlation allows for the use of infrared imaging to rapidly develop wafer mining maps. The mining of material free of detrimental defects has the potential to dramatically increase the yield and quality of large area CdZnTe detector arrays.

TES Detector Noise Limited Readout Using SQUID Multiplexers

NASA Technical Reports Server (NTRS)

Staguhn, J. G.; Benford, D. J.; Chervenak, J. A.; Khan, S. A.; Moseley, S. H.; Shafer, R. A.; Deiker, S.; Grossman, E. N.; Hilton, G. C.; Irwin, K. D.

2004-01-01

The availability of superconducting Transition Edge Sensors (TES) with large numbers of individual detector pixels requires multiplexers for efficient readout. The use of multiplexers reduces the number of wires needed between the cryogenic electronics and the room temperature electronics and cuts the number of required cryogenic amplifiers. We are using an 8 channel SQUID multiplexer to read out one-dimensional TES arrays which are used for submillimeter astronomical observations. We present results from test measurements which show that the low noise level of the SQUID multiplexers allows accurate measurements of the TES Johnson noise, and that in operation, the readout noise is dominated by the detector noise. Multiplexers for large number of channels require a large bandwidth for the multiplexed readout signal. We discuss the resulting implications for the noise performance of these multiplexers which will be used for the readout of two dimensional TES arrays in next generation instruments.

Graphical User Interface for a Dual-Module EMCCD X-ray Detector Array.

PubMed

Wang, Weiyuan; Ionita, Ciprian; Kuhls-Gilcrist, Andrew; Huang, Ying; Qu, Bin; Gupta, Sandesh K; Bednarek, Daniel R; Rudin, Stephen

2011-03-16

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 2000× 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 2k×1k 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.

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.

Airborne Lidar Bathymetry Beam Diagnostics Using an Underwater Optical Detector Array

NASA Astrophysics Data System (ADS)

Birkebak, Matthew

6x6 array of photodiodes. Image processing techniques were used to estimate the laser's incidence angle intercepted by the detector array. Beam patterns that resulted from intersection between the laser beam light field underwater and the detector array were modeled and used to calculate changes in position and orientation for water surface conditions containing wavelengths less than 0.1m. Finally, a total horizontal uncertainty (THU) model was estimated, which can be implemented in total propagated uncertainty (TPU) models for reporting as a measure of the quality of each measurement. The wave refraction error for various sea states and beam characteristics was successfully quantified using both experimental and analytical techniques.

β-Decay Studies of r-Process Nuclei Using the Advanced Implantation Detector Array (AIDA)

NASA Astrophysics Data System (ADS)

Griffin, C. J.; Davinson, T.; Estrade, A.; Braga, D.; Burrows, I.; Coleman-Smith, P. J.; Grahn, T.; Grant, A.; Harkness-Brennan, L. J.; Kiss, G.; Kogimtzis, M.; Lazarus, I. H.; Letts, S. C.; Liu, Z.; Lorusso, G.; Matsui, K.; Nishimura, S.; Page, R. D.; Prydderch, M.; Phong, V. H.; Pucknell, V. F. E.; Rinta-Antila, S.; Roberts, O. J.; Seddon, D. A.; Simpson, J.; Thomas, S. L.; Woods, P. J.

Thought to produce around half of all isotopes heavier than iron, the r-process is a key mechanism for nucleosynthesis. However, a complete description of the r-process is still lacking and many unknowns remain. Experimental determination of β-decay half-lives and β-delayed neutron emission probabilities along the r-process path would help to facilitate a greater understanding of this process. The Advanced Implantation Detector Array (AIDA) represents the latest generation of silicon implantation detectors for β-decay studies with fast radioactive ion beams. Preliminary results from commissioning experiments demonstrate successful operation of AIDA and analysis of the data obtained during the first official AIDA experiments is now under-way.

Gravitational-Wave Tests of General Relativity with Ground-Based Detectors and Pulsar-Timing Arrays.

PubMed

Yunes, Nicolás; Siemens, Xavier

2013-01-01

This review is focused on tests of Einstein's theory of general relativity with gravitational waves that are detectable by ground-based interferometers and pulsar-timing experiments. Einstein's theory has been greatly constrained in the quasi-linear, quasi-stationary regime, where gravity is weak and velocities are small. Gravitational waves will allow us to probe a complimentary, yet previously unexplored regime: the non-linear and dynamical strong-field regime . Such a regime is, for example, applicable to compact binaries coalescing, where characteristic velocities can reach fifty percent the speed of light and gravitational fields are large and dynamical. This review begins with the theoretical basis and the predicted gravitational-wave observables of modified gravity theories. The review continues with a brief description of the detectors, including both gravitational-wave interferometers and pulsar-timing arrays, leading to a discussion of the data analysis formalism that is applicable for such tests. The review ends with a discussion of gravitational-wave tests for compact binary systems.

An Array of Optical Receivers for Deep-Space Communications

NASA Technical Reports Server (NTRS)

Vilnrotter, Chi-Wung; Srinivasan, Meera; Andrews, Kenneth

2007-01-01

An array of small optical receivers is proposed as an alternative to a single large optical receiver for high-data-rate communications in NASA s Deep Space Network (DSN). Because the telescope for a single receiver capable of satisfying DSN requirements must be greater than 10 m in diameter, the design, building, and testing of the telescope would be very difficult and expensive. The proposed array would utilize commercially available telescopes of 1-m or smaller diameter and, therefore, could be developed and verified with considerably less difficulty and expense. The essential difference between a single-aperture optical-communications receiver and an optical-array receiver is that a single-aperture receiver focuses all of the light energy it collects onto the surface of an optical detector, whereas an array receiver focuses portions of the total collected energy onto separate detectors, optically detects each fractional energy component, then combines the electrical signal from the array of detector outputs to form the observable, or "decision statistic," used to decode the transmitted data. A conceptual block diagram identifying the key components of the optical-array receiver suitable for deep-space telemetry reception is shown in the figure. The most conspicuous feature of the receiver is the large number of small- to medium-size telescopes, with individual apertures and number of telescopes selected to make up the desired total collecting area. This array of telescopes is envisioned to be fully computer- controlled via the user interface and prediction-driven to achieve rough pointing and tracking of the desired spacecraft. Fine-pointing and tracking functions then take over to keep each telescope pointed toward the source, despite imperfect pointing predictions, telescope-drive errors, and vibration caused by wind.

Imaging detectors and electronics—a view of the future

NASA Astrophysics Data System (ADS)

Spieler, Helmuth

2004-09-01

Imaging sensors and readout electronics have made tremendous strides in the past two decades. The application of modern semiconductor fabrication techniques and the introduction of customized monolithic integrated circuits have made large-scale imaging systems routine in high-energy physics. This technology is now finding its way into other areas, such as space missions, synchrotron light sources, and medical imaging. I review current developments and discuss the promise and limits of new technologies. Several detector systems are described as examples of future trends. The discussion emphasizes semiconductor detector systems, but I also include recent developments for large-scale superconducting detector arrays.

Automated Absorber Attachment for X-ray Microcalorimeter Arrays

NASA Technical Reports Server (NTRS)

Moseley, S.; Allen, Christine; Kilbourne, Caroline; Miller, Timothy M.; Costen, Nick; Schulte, Eric; Moseley, Samuel J.

2007-01-01

Our goal is to develop a method for the automated attachment of large numbers of absorber tiles to large format detector arrays. This development includes the fabrication of high quality, closely spaced HgTe absorber tiles that are properly positioned for pick-and-place by our FC150 flip chip bonder. The FC150 also transfers the appropriate minute amount of epoxy to the detectors for permanent attachment of the absorbers. The success of this development will replace an arduous, risky and highly manual task with a reliable, high-precision automated process.