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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Self-powered perovskite photon-counting detectors

Metal-halide perovskites (MHPs) have been successfully exploited for converting photons to charges or vice versa in applications of solar cells, light-emitting diodes and solar fuels for which all these applications involve strong light. Here we show that self-powered polycrystalline perovskite photodetectors can rival the commercial silicon photomultipliers (SiPMs) for photon counting. The photon-counting capability of perovskite photon-counting detectors (PCDs) is mainly determined by shallow traps, despite that deep traps also limit charge-collection efficiency. Two shallow traps with energy depth of 5.8 ± 0.8 millielectronvolts (meV) and 57.2 ± 0.1 meV are identified in polycrystalline methylammonium lead triiodide, which mainly stay at grain boundaries and the surface, respectively. We show that these shallow traps can be reduced by grain-size enhancement and surface passivation using diphenyl sulfide, respectively. It greatly suppresses dark count rate (DCR) from >20,000 counts per second per square millimetre (cps mm –2 ) to 2 cps mm –2 at room temperature, enabling much better response to weak light than SiPMs. The perovskite PCDs can collect γ-ray spectra with better energy resolution than SiPMs and maintain performance at high temperatures up to 85 °C. The zero-bias operation of perovskite detectors enables no drift of noise and detection property. Finally, this study opens a new application of photon counting for perovskites that uses their unique defect properties.

47 OTHER INSTRUMENTATION↗
NASA NTRS2013

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

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

spectroscopy↗
NASA NTRS2021

Advances in Detector-Integrated Filter Coatings for the Far Ultraviolet

We report on the continued development of multilayer optical coatings on back-illuminated silicon imaging sensors in order to enhance the functionality of such systems at ultraviolet wavelengths. This includes the development metal-dielectric filter structures to enable solar-blind operation, and graded thickness coatings to tune the spatial response of a detector system to the dispersion of a spectrometer. Such systems can maintain the high internal quantum efficiency afforded by the delta-doping process utilized at NASA JPL, while also providing long-wavelength rejection or a spatially optimized efficiency (or both). We present the characterization of CCD and CMOS image sensors incorporating these processes, and describe the atomic layer deposition coating processes. Such detectors are currently being developed for ground-based high energy physics applications as well as NASA orbital astrophysics instruments operating at wavelengths shorter than 200 nm.

Nikzad, Shouleh↗
NASA NTRS1975

Silicon solid/state linear arrays for multispectral high resolution imaging systems

Solid-state, electronically scanned, linear detector arrays are now available which can be used in a pushbroom scan mode imaging system for high-resolution multispectral earth resource survey applications. These arrays provide high performance in the visible to near-IR region. Two performance criteria must be assessed in the choice of a detector array: signal-to-noise ratio and spectral response. Consideration of diffraction limitations shows that optics size cannot be significantly reduced by using very low-noise detectors. The required spectral response for a viable detector array should not have spectral ripples that cause a low-level, but significant, error in the detected effective reflectance of the target.

Thompson, L. L.↗
NASA NTRS1982

A monolithic lead sulfide-silicon MOS integrated-circuit structure

A technique is developed for directly integrating infrared photoconductive PbS detector material with MOS transistors. A layer of chromium, instead of aluminum, is deposited followed by a gold deposition in order to ensure device survival during the chemical deposition of the PbS. Among other devices, a structure was fabricated and evaluated in which the PbS was directly coupled to the gate of a PMOS. The external bias, load, and source resistors were connected and the circuit was operated as a source-follower amplifier. Radiometric evaluations were performed on a variety of different MOSFETs of different geometry. In addition, various detector elements were simultaneously fabricated to demonstrate small element capability, and it was shown that elements of 25 x 25 microns could easily be fabricated. Results of room temperature evaluations using a filtered 700 K black body source yielded a detectivity at peak wavelength of 10 to the 11th cm (root Hz)/W at 100 Hz chopping frequency.

Jhabvala, M. D.↗
DOE OSTI2020

Compact radiation detector

Apparatus for detecting radiation includes a sensor medium disposed within a cavity in a silicon-based substrate. An electrode arrangement is provided for collecting charge generated within the sensor medium by interactions with impinging radiation and drifted through the sensor medium. The electrode arrangement is constituted, in part, by a silicon portion of the substrate that is doped to increase its electrical conductivity and that defines part of the cavity wall.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2025

Low-energy calibration of SuperCDMS HVeV cryogenic silicon calorimeters using Compton steps

Cryogenic calorimeters for low-mass dark matter searches have achieved sub-eV energy resolutions, driving advances in both low-energy calibration techniques and our understanding of detector physics. The energy deposition spectrum of gamma rays scattering off target materials exhibits step-like features, known as Compton steps, near the binding energies of atomic electrons. Here, we demonstrate a successful use of Compton steps for sub-keV calibration of cryogenic silicon calorimeters, utilizing four SuperCDMS High-Voltage eV-resolution detectors operated with 0 V bias across the crystal. This new calibration at 0 V is compared with the established high-voltage calibration using optical photons. The comparison indicates that the detector response at 0 V is about 30% weaker than expected, highlighting challenges in detector response modeling for low-mass dark matter searches.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Novel 4x4 SiPM array readout with integrated preamplification stage, optimized for the PWO detectors of the EIC EEEMCal

Here we are reporting on a new readout circuit developed for the lead tungstate (PbWO4) scintillation detectors for the Electron Ion Collider (EIC) Electron Endcap Electromagnetic Calorimeter EEEMCal. The high magnetic field region precludes the use of photomultiplier tubes while the detector requirements specify good spectral resolution performance and fast pulse integration over a large dynamic range. We selected a silicon photomultiplier (SiPM) from Hamamatsu and produced a matrix of 4 x 4 sensors to cover the 20 mm x 20 mm scintillator coupling surface. Signal acquisition and amplification electronics boards were designed and integrated with the sensor board to produce a compact high performance readout package. A prototype detector was built and tested at Jefferson Lab with encouraging resolution and timing performance results.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Qualification study of SiPMs on a large scale for the CMVD Experiment

A Cosmic Muon Veto (CMV) detector using extruded plastic scintillators is being designed around the mini-Iron Calorimeter (mini-ICAL) detector at the transit campus of the India based Neutrino Observatory, Madurai for the feasibility study of shallow depth underground experiments. The scintillation signals that are produced in the plastic due to muon trajectories are absorbed by wavelength shifting (WLS) fibres. The WLS fibres re-emit photons of longer wavelengths and propagate those to silicon photo-multipliers (SiPMs). The SiPMs detect these photons, producing electronic signals. The CMV detector will use more than 700 scintillators to cover the mini-ICAL detector and will require around 3000 SiPMs. The design goal for the cosmic muon veto efficiency of the CMV is >99.99%. Hence, every SiPM used in the detector needs to be tested and characterised to satisfy the design goal of CMV. A mass testing system was developed for the measurement of gain and choice of the overvoltage ($V_{ov}$) of each SiPMs using an LED driver. The $V_{ov}$ is obtained by studying the noise rate, the gain of the SiPM. This paper describes the experimental setup used to test the SiPMs characteristics along with detailed studies of those characteristics as a function of temperature.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1979

Modulation improves electro-optic object detector

Device as part of integrated circuit protection line is used to detect presence or absence of silicon wafer at point along air track. System is insensitive to ambient light and electrical noise, requires no special components or adjustments, operates from single supply source, and is relatively inexpensive to build.

Currie, J. R.↗
NASA NTRS2018

Process for Fabrication of Superconducting Vias for Electrical Connection to Groundplane in Cryogenic Detectors

Disclosed are systems, methods, and non-transitory computer-readable storage media for fabrication of silicon on insulator (SOI) wafers with a superconductive via for electrical connection to a groundplane. Fabrication of the SOI wafer with a superconductive via can involve depositing a superconducting groundplane onto a substrate with the superconducting groundplane having an oxidizing layer and a non-oxidizing layer. A layer of monocrystalline silicon can be bonded to the superconducting groundplane and a photoresist layer can be applied to the layer of monocrystalline silicon and the SOI wafer can be etched with the oxygen rich etching plasma, resulting in a monocrystalline silicon top layer with a via that exposes the superconducting groundplane. Then, the fabrication can involve depositing a superconducting surface layer to cover the via.

Denis, Kevin L.↗
DOE OSTI2023

Performance of the wavelength-shifting fiber upgrade for the Mu2e cosmic-ray veto detector

The Cosmic-Ray Veto detector for the muon-to-electron conversion experiment at Fermilab consists of four plastic scintillating counter layers read out by silicon photo-multipliers through embedded wavelength-shifting fibers. In order to increase the light yield in the most critical regions of the Cosmic-Ray Veto detector for improved background rejection, a 1.8 mm diameter fiber is being used in many of the detector's critical modules instead of the previously planned 1.4 mm diameter fiber. This paper reports the testing procedure and light properties of thirty-four 1.8 mm fiber spools, with measurements performed using a custom-built scanner. We compare these new results with previously published data from the 1.4 mm diameter fiber used for regions of the cosmic-ray veto where the increased light yield is not required. In addition, measurements of fiber aging were performed.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

Low Energy Muon Beam Diagnostics - Scintillating Fiber Profile Monitor (SFPM)

The MeV Test Area (MTA) houses the 400 MeV H^− Beam at the end of the Linac and a secondary beamline of muons and pions created from hitting a Tungsten target. The MTA is in the Irradiation Test Area (ITA), where experiments involve studying the effects of radiation on materials in the MTA beam. There is a need for a retractable detector to monitor the secondary beam s intensity and coarse profile. The SFPM was chosen when considering factors like ability to measure low rates and handle high intensities. The plan was to test different scintillating fibers & Silicon Photomultiplier (SiPM) models to figure out which combination gives the best signals, and gain familiarity with the detector assembly, operation, and data acquisition software before using with final detectors in beamline. The SiPM circuit has been tested with a LED pulser successfully. The immediate steps that follow will be to set the SiPM up on the monitor with three different types of optical fibers, use the Caen software to configure the best mode of data acquisition, and proceed with an offline source test using Strontium-90. Once the most efficient measurement method is clear, they will be ready for use in the beamline.

Leith, Justin↗
DOE OSTI2024

Characterization of High-Temperature SiPM Noise

Introduction • Background: Silicon photomultipliers (SiPMs) are compact, low-power, and high-efficiency detectors that are increasingly used in radiation detection applications like medical imaging and nuclear safeguards. The have advantages of PMTs because they are smaller, operate at lower voltages, and offer high photon detection efficiency. • Challenges: SiPMs suffer from increased dark count rate (DCR) and optical crosstalk (OCT), which degrades performance. • Purpose of study: This study compares the Advansid ASD-NUV3S-P-40, Broadcom AFBR-S4K33C0147L, and Onsemi MicroFJ-30035-TSVTR under four different temperatures to compare their performance in harsh environments.

Fritchie, Jacob↗
NASA NTRS1975

Self-scanned Digicon - A digital image tube for astronomical spectroscopy

We have successfully fabricated, tested, and operated a digital image tube consisting of a magnetically focused image intensifier tube in which a self-scanned linear array of 1024 silicon photodiodes operating in the EBS mode serves as the photoelectron image detector, amplifier, and intermediate image storage device. Integral on-chip MOS shift registers driven by an external clock sequentially interrogate the photodiodes through MOS FET multiplex switch arrays. Each output frame is a sequence of 256 analog pulses on each of four video lines. Laboratory and observing tests show that the output signal is photoelectron shot noise limited over at least a range of 1-100,000 detected photoelectrons per picture element, indicating that single photon detection is achieved. High-resolution astronomical spectroscopy has been carried out in the coude spectrograph of the 2.7-m telescope at McDonald Observatory. Examples are shown.

Tull, R. G.↗
NASA NTRS1989

Nuclear fragmentation studies for microelectronic application

A formalism for target fragment transport is presented with application to energy loss spectra in thin silicon devices. Predicted results are compared to experiments with the surface barrier detectors of McNulty et al. The intranuclear cascade nuclear reaction model does not predict the McNulty experimental data for the highest energy events. A semiempirical nuclear cross section gives an adequate explanation of McNulty's experiments. Application of the formalism to specific electronic devices is discussed.

Ngo, Duc M.↗
DOE OSTI2024

Low Energy Muon Beam Diagnostics: Scintillating Fiber Profile Monitor

The MeV Test Area (MTA) houses the 400 MeV H- Beam at the end of the Linac and a secondary beamline of muons and pions created from hitting a Tungsten target. The MTA is in the Irradiation Test Area (ITA), where experiments involve studying the effects of radiation on materials in the MTA beam. There is a need for a retractable detector to monitor the secondary beam’s intensity and coarse profile. The SFPM was chosen when considering factors like ability to measure low rates and handle high intensities. The plan was to test different scintillating fibers & Silicon Photomultiplier (SiPM) models to figure out which combination gives the best signals, and gain familiarity with the detector assembly, operation, and data acquisition software before using with final detectors in beamline. The SiPM circuit has been tested with a LED pulser successfully. The immediate steps that follow will be to set the SiPM up on the monitor with three different types of optical fibers, use the Caen software to configure the best mode of data acquisition, and proceed with an offline source test using Strontium-90. Once the most efficient measurement method is clear, they will be ready for use in the beamline.

Leith, Justin↗
NASA NTRS1999

Science Observations of Deep Space One

During the Deep Space One (DS1) primary mission, the spacecraft will fly by asteroid 1992 KD and possibly comet Borrelly. There are two technologies being validated on DS1 that will provide science observations of these targets, the Miniature Integrated Camera Spectrometer (MICAS) and the Plasma Experiment for Planetary Exploration (PEPE). MICAS encompasses a camera, an ultraviolet imaging spectrometer and an infrared imaging spectrometer. PEPE combines an ion and electron analyzer designed to determine the three-dimensional distribution of plasma over its field of view. MICAS includes two visible wavelength imaging channels, an ultraviolet imaging spectrometer, and an infrared imaging spectrometer all of which share a single 10-cm diameter telescope. Two types of visible wavelength detectors, both operating between about 500 and 1000 nm are used: a CCD with 13-microrad pixels and an 18-microrad-per-pixel, metal-on-silicon active pixel sensor (APS). Unlike the CCD the APS includes the timing and control electronics on the chip along with the detector. The UV spectrometer spans 80 to 185 nm with 0.64-nm spectral resolution and 316-microrad pixels. The IR spectrometer covers the range from 1200 to 2400 nm with 6.6-nm resolution and 54-microrad pixels PEPE includes a very low-power, low-mass micro-calorimeter to help understand plasma-surface interactions and a plasma analyzer to identify de individual molecules and atoms in the immediate vicinity of the spacecraft that have been eroded off the surface of asteroid 1992 KD. It employs common apertures with separate electrostatic energy analyzers. It measures electron and ion energies spanning a range of 3 eV to 30 keV, with a resolution of five percent. and measures ion mass from one to 135 atomic mass units with 5 percent resolution. It electrostatically sweeps its field of view both in elevation and azimuth. Both MICAS and PEPE represent a new direction for the evolution of science instruments for interplanetary spacecraft. These two instruments incorporate a large fraction of the capability of five instruments that had typically flown on NASA's deep space missions The Deep Space One science team acknowledges the support of Philip Varghese, David H. Lehman, Leslie Livesay, and Marc Rayman for providing invaluable assistance in making the science observations possible.

Nelson, Robert M.↗