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At least 1,369 records · Page 76
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Method for the Absolute Calibration of the Location and Orientation of Large-Format Detectors Using Laser Radar

A method of mapping pixel locations of a detector array includes measuring a location on the detector array, initiating a frame readout of the detector array, measuring a location of one or more metrology targets on the detector array, analyzing the frame readout to identify a pixel at the location on the detector array, and defining a location of the identified pixel with respect to the location of the one or more metrology targets. Subsequent measurement of the metrology targets alone by another metrology system allows one to infer the six degree of freedom alignment of the detector array in space.

Coulter, Phillip↗
NASA NTRS2018

Developing a Novel Platform for Characterizing Thermoelectric Materials for Uncooled Detectors for Land Imaging Applications

Thermal land imaging (imaging at ~8-14 micron optical wavelength) is an essential tool for understanding and managing terrestrial freshwater resources. Current thermal imaging instruments employ low temperature detectors, which require cryocoolers. Consequently, cost-saving reductions in size, weight, and power can be achieved by employing uncooled detectors. One uncooled detector concept, which NASA is pursuing, is a thermopile detector with sub-micron thick doped-Si thermoelectric materials. In order to characterize the thermoelectric properties of the doped silicon, we designed and optimized a novel apparatus. This simple apparatus measures the Seebeck coefficient with thermally isolated stages and LABVIEW automation. We optimized thermal stability using PID tuning and optimized the thermal contact between the thin film samples and stages using electrically conductive springs. Utilizing our apparatus, we measured the Seebeck coefficient of 0.45 micron thick phosphorus-doped single crystal Si samples bonded to alumina substrates. Using these Seebeck coefficient measurements and four-wire electrical resistivity measurements, we determined the relationship between the thermoelectric figure of merit and dopant concentration. These characterization results for doped-Si will guide our thermopile detector design to provide an optimal and competitive detector alternative for future thermal imaging instruments.

Reid, Riley A.↗
NASA NTRS2018

Development of Transition Edge Sensor Detectors Optimized for Single-Photon Spectroscopy in the Optical and Near-Infrared

The search for biosignatures in the atmospheres of exoplanets will be a key focus of future space telescopes that operate in the ultraviolet, visible, and near-infrared bands. Detection of biosignatures requires an instrument with moderate spectral resolving power ($R \sim 100$) and a large bandwidth ($\sim 400$ nm -- $\sim 1.8$ $\mu$m). Additionally, biosignature detection is a photon-starved science; instruments designed for these measurements would ideally combine high optical efficiency with quantum-limited photon detectors (i.e., detectors that exhibit zero dark current). In this work, we report on our efforts to develop energy resolving transition edge sensor (TES)-based detectors designed for biosignature detection. TESs operated as microcalorimeters are compelling detectors for this application. Unlike semiconductor detectors, TESs eliminate the need for dispersive optics and are truly single photon detectors -- fundamental TES noise yields uncertainty in the energies of detected photons, not in the number of detected photons. We introduce TESs designed for this application and discuss the path toward realizing a TES-based dispersionless spectrometer optimized for biosignature detection.

Instrumentation and Photography↗
NASA NTRS2018

Development of Transition Edge Sensor Detectors Optimized for Single-Photon Spectroscopy in the Optical and Near-Infrared

The search for biosignatures in the atmospheres of exoplanets will be a key focus of future space telescopes that operate in the ultraviolet, visible, and near-infrared bands. Detection of biosignatures requires an instrument with moderate spectral resolving power (R ~ 100) and a large bandwidth (~ 400 nm – ~ 1.8 µm). Additionally, biosignature detection is a photon-starved science; instruments designed for these measurements would ideally combine high optical efficiency with quantum-limited photon detectors (i.e., detectors that exhibit zero dark current). In this work, we report on our efforts to develop energy resolving transition edge sensor (TES)-based detectors designed for biosignature detection. TESs operated as microcalorimeters are compelling detectors for this application. Unlike semiconductor detectors, TESs eliminate the need for dispersive optics and are truly single photon detectors – fundamental TES noise yields uncertainty in the energies of detected photons, not in the number of detected photons. We introduce TESs designed for this application and discuss the path toward realizing a TES-based dispersionless spectrometer optimized for biosignature detection.

Instrumentation and Photography↗
NASA NTRS2020

Development of High-Performance Graphene-HgCdTe Detector Technology for Mid-Wave Infrared Applications

A high-performance graphene-based HgCdTe detector technology is being developed for sensing over the mid-wave infrared (MWIR) band for NASA Earth Science, defense, and commercial applications. This technology involves the integration of graphene into HgCdTe photodetectors that combines the best of both materials and allows for higher MWIR(2-5 m) detection performance compared to photodetectors using only HgCdTe material. The interfacial barrier between the HgCdTe-based absorber and the graphene layer reduces recombination of photogenerated carriers in the detector. The graphene layer also acts as high mobility channel that whisks away carriers before they recombine, further enhancing the detector performance. Likewise, HgCdTe has shown promise for the development of MWIR detectors with improvements in carrier mobility and lifetime. The room temperature operational capability of HgCdTe-based detectors and arrays can help minimize size, weight, power and cost for MWIR sensing applications such as remote sensing and earth observation, e.g., in smaller satellite platforms. The objective of this work is to demonstrate graphene-based HgCdTe room temperature MWIR detectors and arrays through modeling, material development, and device optimization. The primary driver for this technology development is the enablement of a scalable, low cost, low power, and small footprint infrared technology component that offers high performance, while opening doors for new earth observation measurement capabilities.

Sood, Ashok K.↗
NASA NTRS2018

Intra-Pixel Response Characterization of a HgCdTe Near Infrared Detector with a Pronounced Crosshatch Pattern

The “crosshatch” pattern is a recurring “feature” of HgCdTe arrays, specifically the Teledyne HAWAII family of near infrared detectors. It is a fixed pattern of high frequency QE variations along 3 directions generally thought to be related to the crystal structure of HgCdTe. The pattern is evident in detectors used in WFC3/IR, WISE, JWST, and in candidate detectors for Euclid and WFIRST. Using undersampled point sources projected onto a HAWAII-2RG detector, we show that the pattern induces photometric variations that are not removed by a flat-field calibration, thus demonstrating that the QE variations occur on scales smaller than the 18 micron pixels. Our testbed is the Precision Projector Laboratory’s astronomical scene generator, which can rapidly characterize the full detector by scanning thousands of undersampled spots. If not properly calibrated, detectors showing strong crosshatch may induce correlated errors in photometry, astrometry, spectroscopy, and shape measurements.

Smith, Roger↗
NASA NTRSDate not supplied

Modeling and Optimizing Microwave Kinetic Inductance Detectors for the EXCLAIM Mission

Microwave Kinetic Inductance Detectors (MKIDs) are highly scalable detectors that have demonstrated background-limited sensitivity in space-like infrared environments. The detectors have a rich design space with many optimizable parameters, allowing high sensitivity measurements over a wide dynamic range. For these reasons, MKIDs are the chosen detectors for the Experiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM), a balloon-based telescope targeting nearly background-limited performance from 420- 540 GHz. We present an update on the design and measurements of the EXCLAIM MKID-spectrometer system, with a particular focus on microwave-induced pair-breaking and TLS noise. We have performed dark tests using a test detector, accurately describing the data through an MKID model mainly following existing literature with slight variations in TLS-fitting. We also review the overall architecture of the EXCLAIM detectors-spectrometer system, including an R=512 𝜇-Spec integrated spectrometer. This MKID-spectrometer system not only enables EXCLAIM with groundbreaking sensitivities to the astrophysical signal, but it also provides a critical pathfinder for future far-IR telescopes that may benefit from these technologies.

Trevor Mackintosh Oxholm↗
DOE OSTI2013

Detector Technologies for Sub-500μm High-Sensitivity PET Imaging via a Novel PET Insert Approach

The objective of this project was to develop detector technologies that would enable an ultrahigh resolution Virtual Pinhole (VP) PET insert device to provide sub-500 μm resolution high-sensitivity PET imaging of a mouse in the future. To achieve this goal, we proposed to develop and characterize finely pixelated cadmium zinc telluride (CZT) detectors and the associated readout electronics with the following specific aims: 1. Develop pixelated CZT detectors with 350μm pitches using 2-5 mm substrates; characterize their spatial, energy and timing performance through experiments; and optimize the anode design with steering grid if found necessary. 2. Develop a high-bandwidth readout system using a novel ASIC that can be directly bonded to CZT detectors with 2048 anodes of 350μm pitches; optimize its overall performance for VP-PET applications considering the tradeoffs between spatial resolution (in 3D), count rate capability, timing and energy resolutions. 3. Evaluate the performance of a VP-PET insert based on the proposed detector technology through Monte Carlo simulation and experimental validation. Overall, we have completed all three specific aims and demonstrated that pixelated CZT detectors of 350μm pitches, combined with VP-PET geometry, can provide PET image resolution of ~460 μm FWHM for small animal imaging applications.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2012

Calibration of the IMB Detector

The IMB detector (named after its founding institutions: University of California, Irvine, the University of Michigan and Brookhaven National Laboratory) collected data on a wide range of phenomena for over eight years. It was the first and the largest of the ring imaging water Cherenkov detectors. The detector consisted of 8000 metric tons of ultra-pure water instrumented with 2048 photomultiplier tubes (PMTs). The PMTs were placed on the roof, floor, and walls of the detector in a lattice of approximately 1 m spacing. It made measurements of contained events that ranged in energy from 15 MeV up to 1.5 GeV. This paper describes the calibration of the IMB detector. This procedure was accurate and stable over a wide range of physical variables. It was used with little change throughout the entire eight-year lifetime of the experiment. The IMB calibration is a model for future large-scale detectors that employ the water Cherenkov technique.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2012

Intelligent Detector Design

As the complexity and resolution of imaging detectors increases, the need for detailed simulation of the experimental setup also becomes more important. Designing the detectors requires efficient tools to simulate the detector response and reconstruct the events. We have developed efficient and flexible tools for detailed physics and detector response simulation as well as event reconstruction and analysis. The primary goal has been to develop a software toolkit and computing infrastructure to allow physicists from universities and labs to quickly and easily conduct physics analyses and contribute to detector research and development. The application harnesses the full power of the Geant4 toolkit without requiring the end user to have any experience with either Geant4 or C++, thereby allowing the user to concentrate on the physics of the detector system.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2013

Tomographic imaging using poissonian detector data

An image reconstruction method for reconstructing a tomographic image (f.sub.j) of a region of investigation within an object (1), comprises the steps of providing detector data (y.sub.i) comprising Poisson random values measured at an i-th of a plurality of different positions, e.g. i=(k,l) with pixel index k on a detector device and angular index l referring to both the angular position (.alpha..sub.l) and the rotation radius (r.sub.l) of the detector device (10) relative to the object (1), providing a predetermined system matrix A.sub.ij assigning a j-th voxel of the object (1) to the i-th detector data (y.sub.i), and reconstructing the tomographic image (f.sub.j) based on the detector data (y.sub.i), said reconstructing step including a procedure of minimizing a functional F(f) depending on the detector data (y.sub.i) and the system matrix A.sub.ij and additionally including a sparse or compressive representation of the object (1) in an orthobasis T, wherein the tomographic image (f.sub.j) represents the global minimum of the functional F(f). Furthermore, an imaging method and an imaging device using the image reconstruction method are described.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Tracking Detector Performance and Data Quality in the NOvA Experiment

NOvA is a long-baseline neutrino oscillation experiment. It uses the NuMI beam from Fermilab and two sampling calorimeter detectors located off-axis from the beam. The NOvA experiment measures the rate of electron-neutrino appearance in the almost pure muon-neutrino NuMI beam, with the data measured at the Near Detector being used to accurately determine the expected rate at the Far Detector. It is very important to have automated and accurate monitoring of the data recorded by the detectors so any hardware, DAQ or beam issues arising in the 344k (20k) channels of the Far (Near) detector which could affect the quality of the data taking are determined. This paper will cover the techniques and detector monitoring systems in various stages of data taking.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Wellbore detector with azimuthal and spectral energy resolution

A wellbore inspection device includes a radiation generation source operable to emit neutrons, and a radiation detector fixed relative to the radiation generation source and operable to detect backscattered neutron radiation from a surrounding environment. The radiation detector includes a plurality of individually addressable detector elements arranged in one or more concentric rings. Respective amounts of backscattered neutron radiation detected by the individually addressable detector elements within a ring is indicative of the azimuthal direction of the detected backscattered neutron radiation, and the respective amount of backscattered neutron radiation detected by the individually addressable detector elements of two or more concentric rings is indicative of an energy level of the backscattered neutron radiation. The inspection device determines whether a potential anomaly is present in or around the wellbore, based at least in part on the respective amounts of backscattered radiation detected by the individually addressable detector elements.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

Comparison of Simulated and Experimentally Measured Detector Impulse Responses to Pulsed X-rays

The Gamma Array Simulation Toolkit (GAST) is a multi-physics software stack comprised of Geant4, MATLAB, and experimentally measured photomultiplier tube (PMT) impulse response waveforms that is used to model and inform the end-to-end performance of radiation detector systems. In order to validate the ability of GAST to predict the impulse response of a modeled detector configuration operated in current mode, experimental measurements using the Nevada National Security Site Transformational Diagnostics and Imaging 2 MeV endpoint energy electron linear accelerator (linac) with a tungsten target were performed. Seven different detector configurations consisting of unique combinations of scintillator material, size, reflectivity conditions, presence or absence of light guide, and PMT were evaluated. The resultant impulse response of each detector configuration was recorded and compared to a GAST simulation that emulated the respective linac experiment conditions. The comparison of the experimental and simulated detector impulse responses indicated that GAST can reliably predict detector impulse responses.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2012

Detector response calibration for the NOvA quasi-elastic cross-section measurement

NOvA is a long-baseline neutrino experiment designed to observe the neutrino oscillation phenomenon of muon neutrinos oscillating into electron neutrinos. The NuMI beam line located at Fermilab produces the muon neutrinos for this observation. The Near and Far Detectors are constructed off-axis of the NuMI beam line and located at Fermilab and northern Minnesota (electron neutrino appearance maximum), respectively. In order to carry out the long-term goals of the experiment, the NOvA Near Detector Prototype (NDOS) was built and commissioned at Fermilab. Its goals are to demonstrate that, using the same materials and technologies as the larger NOvA detectors, we are able to observe neutrino data from the NuMI beam and cosmic ray muons. The cosmic ray muon data were used in the commissioning and it is currently being used in testing of detector response. These data are also being used in the development of reconstruction and calibration techniques to be used in the Near and Far Detectors. Furthermore, the neutrino data acquired are being used in the development and implementation of physics analyses, not only for NDOS data, but also for the first NOvA data. This thesis will discuss the development of the detector response calibration using cosmic ray muon data and its effects on the preliminary charged current quasi-elastic cross-section measurement using beam neutrino data in the NDOS.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Developing Low Noise, Rad-hard Detectors for Parity Violating Experiments

As parity-violating electron scattering (PVeS) experiments continue to push the frontiers of precision electro-weak asymmetry measurements, the demands on the experimental techniques and apparatus are also pushed. In particular, the need for higher resolution and radiation-hardness of the main integrating detectors has increased over the successive generations of PVeS experiments. The demand for precise measurement of GHz event rates has pushed the field toward the use of thin quartz Cerenkov light based detectors. We have been designing and testing such thin quartz detectors specifically for the upcoming experiments at Jefferson Lab, PREX-II and CREX, but this work also greatly influences the detector development for several future experiments including MOLLER at Jefferson Lab. These are all PVeS experiments that will use the new thin quartz Cerenkov detector design concept for their main asymmetry measurements (as well as for beam monitoring). The new design concept gives not only significant performance improvements compared to its predecessor from PREX-I, but also we have now thoroughly characterized its operational design and performance using a combination of test-beam data and detailed particle and optical Monte Carlo Geant4 simulations. These activities have culminated in the development and implementation of a "bench-marked" Monte Carlo package, QSIM, which constitutes a powerful design tool for present and future PVeS quartz detectors. The benchmarked simulation can replicate real photoelectron distributions (RMS and Mean) from testbeam data with ~5% precision – limited mainly by the systematic uncertainty of the PMT gain measurements.

Villarreal, Carlos Bula Villarreal↗
DOE OSTI2021

Mutli-layered neutron detector

A neutron detector including a plurality of layers of converter material and a plurality of layers of detector material. Each layer of converter material can be immediately adjacent to at least one layer of detector material and each layer of detector material can be immediately adjacent to at least one layer of converter material. The neutron detector may further include a read out integrated circuit (ROIC) that is electrically coupled to the plurality of layers of detector material. A value output by the ROIC may be indicative of a neutron interacting with a layer of converter material from amongst the plurality of layers of converter material.

Rice, William Charles↗
DOE OSTI2022

Snowmass Instrumentation Frontier IF08 Topical Group Report: Noble Element Detectors

Particle detectors making use of noble elements in gaseous, liquid, or solid phases are prevalent in neutrino and dark matter experiments and are also used to a lesser extent in collider-based particle physics experiments. These experiments take advantage of both the very large, ultra-pure target volumes achievable and the multiple observable signal pathways possible in noble-element based particle detectors. As these experiments seek to increase their sensitivity, novel and improved technologies will be needed to enhance the precision of their measurements and to broaden the reach of their physics programs. The areas of R&D in noble element instrumentation that have been identified by the HEP community in the Snowmass process are highlighted by five key messages: IF08-1) Enhance and combine existing modalities (scintillation and electron drift) to increase signal-to-noise and reconstruction fidelity; IF08-2) Develop new modalities for signal detection in noble elements, including methods based on ion drift, metastable fluids, solid-phase detectors and dissolved targets. Collaborative and blue-sky R&D should also be supported to enable advances in this area; IF08-3) Improve the understanding of detector microphysics and calibrate detector response in new signal regimes; IF08-4) Address challenges in scaling technologies, including material purification, background mitigation, large-area readout, and magnetization; and IF08-5) Train the next generation of researchers, using fast-turnaround instrumentation projects to provide the design-through-result training no longer possible in very-large-scale experiments. This topical group report identifies and documents recent developments and future needs for noble element detector technologies. In addition, we highlight the opportunity that this area of research provides for continued training of the next generation of scientists.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗