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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The Vacuum Cherenkov Detector (VCD) for γ-ray measurements in inertial confinement fusion experiments

Inertial confinement fusion experiments at both the National Ignition Facility (NIF) and the Laboratory for Laser Energetics OMEGA laser facility currently utilize Cherenkov detectors, with fused silica as the Cherenkov medium. At the NIF, the Quartz Cherenkov Detectors improve the precision of neutron time-of-flight measurements; and at OMEGA, the Diagnostic for Areal Density provides measurements of capsule shell areal densities. An inherent property of fused silica is the radiator’s relatively low energy threshold for Cherenkov photon production (E threshold < 1 MeV), making it advantageous over gas-based Cherenkov detectors for experiments requiring low-energy γ detection. The Vacuum Cherenkov Detector (VCD) has been specifically designed for efficient detection of low energy γ’s. Its primary use is in implosion experiments, which will study reactions relevant to stellar and big-bang nucleosynthesis, such as T( 4 He,γ) 7 Li, 4 He( 3 He,γ) 7 Be, and 12 C(p,γ) 13 N. Further, the VCD is compatible with LLE’s standard Ten-Inch Manipulator diagnostic insertion module. This work will outline the design and characterization of the VCD as well as provide results from recent experiments conducted at the OMEGA laser facility.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1990

Status of LWIR HgCdTe infrared detector technology

The performance requirements that today's advanced Long Wavelength Infrared (LWIR) focal plane arrays place on the HgCdTe photovoltaic detector array are summarized. The theoretical performance limits for intrinsic LWIR HgCdTe detectors are reviewed as functions of cutoff wavelength and operating temperature. The status of LWIR HgCdTe photovoltaic detectors is reviewed and compared to the focal plane array (FPA) requirements and to the theoretical limits. Emphasis is placed on recent data for two-layer HgCdTe PLE heterojunction photodiodes grown at Loral with cutoff wavelengths ranging between 10 and 19 microns at temperatures of 70 to 80 K. Development trends in LWIR HgCdTe detector technology are outlined, and conclusions are drawn about the ability for photovoltaic HgCdTe detector arrays to satisfy a wide variety of advanced FPA array applications.

Reine, M. B.↗
NASA NTRS2007

FIR/THz Space Interferometry: Science Opportunities, Mission Concepts, and Technical Challenges

Sensitive far-IR imaging and spectroscopic measurements of astronomical objects on sub-arcsecond angular scales are essential to our understanding of star and planet formation, the formation and evolution of galaxies, and to the detection and characterization of extrasolar planets. Cold single-aperture telescopes in space, such as the Spitzer Space Telescope and the Herschel Space Observatory, are very sensitive, but they lack the necessary angular resolution by two or more orders of magnitude. Far-IR space interferometers will address this need in the coming decades. Several mission concepts have already been studied, including in the US the Space Infrared Interferometric Telescope (SPIRIT) and the more ambitious Submillimeter Probe of the Evolution of Cosmic Structure (SPECS). This talk will describe science goals and summarize alternative concepts for future FIR/THz space interferometry missions. Small arrays of sensitive, fast, direct detectors are a key enabling technology for SPIRIT and SPECS. I will describe the technology requirements for far-IR interferometry, including the detector requirements, and their derivation from the mission science goals and instrument concepts.

Leisawitz, David↗
DOE OSTI2023

Beam-Based Target Alignment for Mu2e

The Mu2e Experiment is a precision experiment at Fermi National Accelerator Laboratory, searching for charged lepton flavor violation (CLFV) in the conversion of a muon to an electron in the presence of an atomic nucleus. In order to achieve the expected single-event sensitivity of $3\times 10^{-17}$ , Mu2e will require an intense muon beam, generated via pion decay. These pions are the product of a proton beam striking a radiatively-cooled tungsten target. In order to maximize pion production and prevent target failure, the beam will have to be aligned with the target center to within 0.5 mm. The production target monitor (PTM) will ensure this alignment. The PTM consists of a series of proportional wire chambers (PWC’s) upstream and downstream of the production target. In this dissertation, I explain the requirements of this detector system and derive the decisions about which detector model to use and how they should be arranged from these requirements. After this, I describe my e xperience building the detectors and show an early use for them in the Mu2e proton beam. I also performed a study of the sensitivity and time resolution of this model of PWC and its electronics, and give the results here. I then describe a series of simulation campaigns which shed light on the interactions between the beam and the target, and how these interactions manifest on the downstream detectors. Finally, I give the target scanning procedure to be used to align the beam and target during experiment start up.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

3D Chiplet-Based Readout for Detectors

Heterogeneous vertical integration of chiplets provides a promising way to meet the challenging requirements of pixel detectors operating in extreme environments.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS2012

Development of a TES-Based Anti-Coincidence Detector for Future X-Ray Observations

Microcalorimeters onboard future x-ray observatories require an anticoincidence detector to remove environmental backgrounds. In order to most effectively integrate this anti-coincidence detector with the main microcalorimeter array, both instruments should use similar read-out technology. The detectors used in the Cryogenic Dark Matter Search (CDMS) use a phonon measurement technique that is well suited for an anti-coincidence detector with a microcalorimeter array using SQUID readout. This technique works by using a transition-edge sensor (TES) connected to superconducting collection fins to measure the athermal phonon signal produced when an event occurs in the substrate crystal. Energy from the event propagates through the crystal to the superconducting collection fins, creating quasiparticles, which are then trapped as they enter the TES where they produce a signal. We are currently developing a prototype anti-coincidence detector for future x-ray missions and have recently fabricated test devices with Mo/Au TESs and Al collection fins. We present results from the first tests of these devices which indicate a proof of concept that quasiparticle trapping is occurring in these materials.

Bailey, Catherine N.↗
DOE OSTI2026

Interpolation of computed gamma-ray detector response functions

Gamma-ray spectra measured by traditional detectors contain features that result from a combination of the effects of detector materials/geometry, the incident gamma-ray energy, and the angle of entry. The features, such as the full-energy photopeak, Compton continuum, annihilation peak, and escape peaks, are governed by simple relationships depending on incident energy and have been known for a long time. Monte Carlo computer simulations of gamma rays interacting with a detector will show these features, and with a resolution function applied, the results should look similar to real measurements. The traditional approach to creating a detector response function requires many separate simulations of monoenergetic gamma rays striking the detector. This paper presents a new approach to developing computed detector response functions. The new approach involves a much smaller number of monoenergetic gamma-ray simulations and uses interpolation to quickly generate the responses of gamma rays that were not simulated. During the interpolation process, the underlying physics equations are used to accurately compute the response of a given energy gamma ray from the small set of simulations. Such work enables accelerated generation of synthetic radiation detector data.

Detector response↗
NASA NTRS1978

Coronal propagation and storage at energies approximately 1 MeV/nucleon

Energetic particle events relating to quasi-stationary particle populations, solar flare events, and solar composition are discussed in the context of similar observations likely to be made during solar probe encounter. Particlar emphasis is given to interrelationships with coronal magnetic structure and plasma processes. General instrumental requirements are listed, and it is concluded that energetic particle detectors meeting these requirements will successfully complement other essential experiments on the Solar Probe.

Roelof, E. C.↗
NASA NTRS1978

Evaluation of radiation interference in the Voyager Sun Sensor's cadmium sulfide detector

The simulation of radiation interference effects and the results of a radiation interference test on two Voyager Sun Sensor prototype detector assemblies are reported. The derivation of test levels and requirements are discussed and show that cobalt 60 gamma radiation is an effective and practical simulator of the ionization dose rate effects induced by high-energy electron flux incident on the spacecraft at a rate of 3.7 x 10 to the 8th e/sq cm-sec (10 rad(Si)/s) during closest approach to Jupiter. The test results provide information that is used to confirm an analytic correlation, and to predict satisfactory performance of a spacecraft sun sensing device having stringent angular resolution requirements. The measured detector response shows that at dose rates incident on the detector elements of 2 rad(Si)/sec, which is four times that expected during Jupiter encounter, the radiation-induced angle error is almost an order of magnitude less than that allowed by the acceptance criteria.

Clarke, T. C.↗
NASA NTRS2012

Three Canted Radiator Panels to Provide Adequate Cooling for Instruments on Slewing Spacecraft in LEO

Certain free-flying spacecraft in low Earth orbit (LEO) or payloads on the International Space Station (ISS) are required to slew to point the telescopes at targets. Instrument detectors and electronics require cooling. Traditionally a planar thermal radiator is used. The temperature of such a radiator varies significantly when the spacecraft slews because its view factors to space vary significantly. Also for payloads on the ISS, solar impingement on the radiator is possible. These thermal adversities could lead to inadequate cooling for the instrument. This paper presents a novel thermal design concept that utilizes three canted radiator panels to mitigate this problem. It increases the overall radiator view factor to cold space and reduces the overall solar or albedo flux absorbed per unit area of the radiator.

Choi, Michael K.↗
DOE OSTI2023

Fabrication Development for SPT-SLIM, a Superconducting Spectrometer for Line Intensity Mapping

Line Intensity Mapping (LIM) is a new observational technique that uses low-resolution observations of line emission to efficiently trace the large-scale structure of the Universe out to high redshift. Common mm/sub-mm emission lines are accessible from ground-based observatories, and the requirements on the detectors for LIM at mm-wavelengths are well matched to the capabilities of large-format arrays of superconducting sensors. We describe the development of an R = lambda/Delta lambda = 300 on-chip superconducting filter-bank spectrometer covering the 120-180 GHz band for future mm-LIM experiments, focusing on SPT-SLIM, a pathfinder LIM instrument for the South Pole Telescope. Radiation is coupled from the telescope optical system to the spectrometer chip via an array of feedhorn-coupled orthomode transducers. Superconducting microstrip transmission lines then carry the signal to an array of channelizing half-wavelength resonators, and the output of each spectral channel is sensed by a lumped element kinetic inductance detector (leKID). Key areas of development include incorporating new low-loss dielectrics to improve both the achievable spectral resolution and optical efficiency and development of a robust fabrication process to create a galvanic connection between ultra-pure superconducting thin-films to realize multi-material (hybrid) leKIDs. We provide an overview of the spectrometer design, fabrication process, and prototype devices.

microstrip resonators↗
DOE OSTI2020

Characterizing the Sensitivity of 40 GHz TES Bolometers for BICEP Array

The BICEP/Keck (BK) experiment aims to detect the imprint of primordial gravitational waves in the cosmic microwave background polarization, which would be direct evidence of the inflation theory. While the tensor-to-scalar ratio has been constrained to be $r_{0.05}<0.06$ at 95% c.l., further improvements on this upper limit are hindered by polarized galactic foreground emissions and removal of gravitational lensing polarization. The 30/40 GHz receiver of the BICEP Array (BA) will deploy at the end of 2019 and will constrain the synchrotron foreground with unprecedented accuracy within the BK sky patch. We will show the design of the 30/40 GHz detectors and test results summarizing its performance. The low optical and atmospheric loading at these frequencies requires our TES detectors to have low saturation power in order to be photon noise dominated. To realize the low thermal conductivity required from a 250 mK base temperature, we developed new bolometer leg designs. We will present the relevant measured detector parameters: $G, T_c, R_n, P_{sat}$, and spectral bands, and noise spectra. We achieved a per bolometer NEP including all noise components of 2.07×10 -17 W/$\sqrt{Hz}$, including an anticipated photon noise level 1.54×10 -17 W/$\sqrt{Hz}$.

47 OTHER INSTRUMENTATION↗
DOE OSTI2023

Study of nanodiamond photocathodes for MPGD-based detectors of single photons

The proposed new Electron–Ion Collider poses a technical and intellectual challenge for the detector design to accommodate the long-term diverse physics goals envisaged by the program. This requires a 4π detector system capable of reconstructing the energy and momentum of final state particles with high precision. The Electron-Ion Collider also requires identification of particles of different masses over a wide momentum range. A diverse spectrum of Particle IDentification detectors has been proposed. Of the four types of detectors for hadron identification, three are based on Ring Imaging Cherenkov Counter technologies, and one is realized by the Time of Flight method. The quest for a novel photocathode, sensitive in the far vacuum ultraviolet wavelength range and more robust than cesium iodide, motivated an R&D programme to explore nano-diamond (ND) based photocathodes, started by a collaboration between INFN and CNR Bari and INFN Trieste. Systematic measurements of the photoemission in different Ar:CH 4 and Ar:CO 2 gas mixtures with various types of ND powders and Hydrogenated ND (H-ND) powders are reported. A first study of the response of THGEMs coated with different photocathode materials is presented. Additionally, the progress of this R&D programme and the results obtained so far by these exploratory studies are described.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1980

Thermal IR imaging system using a self-scanned HgCdTe/CCD detector array

It is likely that future high resolution earth observation imaging systems will utilize self-scanned IR detectors. In an initial step toward this goal, an IR imaging system operating in the 10 to 12 micron spectral region has been developed. This system uses a 9-element HgCdTe/CCD linear array operating in the photoconductive mode, nine pre-amplifiers and a silicon CCD multiplexer integrated into a focal plane assembly. Opto-mechanical techniques are used to scan the scene and images are produced in real time. The imaging performance of this system is described and measurements of noise, responsivity, specific detectivity, and detector sensitivity profiles are presented. The requirements for more advanced detector arrays for use in future NASA remote sensing missions are also discussed.

Husain-Abidi, A. S.↗
NASA NTRS1989

Performance and durability of HgI2 X-ray detectors for space missions

Considerable progress has been achieved recently in HgI2 detector fabrication technology and amplification electronics. An energy resolution of 198 eV (full width at half maximum) has been obtained for the Mn k-alpha line of 5.9 keV in a practical X-ray probe without the use of cryogenic cooling. Detectors prepared with Parylene-C encapsulation have demonstrated perfect reliability in two-year tests under high vacuum and temperature and bias cycling. Other HgI2 detectors have been used to demonstrate proton-radiation-damage resistance to levels of 10 to the 12 protons/sq cm at 10.7 MeV. It is concluded that HgI2 detectors are suitable for the ordinary requirements of energy dispersive detectors in X-ray spectroscopy systems.

Iwanczyk, J. S.↗
NASA NTRS2009

Chemochromic Hydrogen Leak Detectors

At NASA, hydrogen safety is a key concern for space shuttle processing. Leaks of any level must be quickly recognized and addressed due to hydrogen s lower explosion limit. Chemo - chromic devices have been developed to detect hydrogen gas in several embodiments. Because hydrogen is odorless and colorless and poses an explosion hazard, there is an emerging need for sensors to quickly and accurately detect low levels of leaking hydrogen in fuel cells and other advanced energy- generating systems in which hydrogen is used as fuel. The device incorporates a chemo - chromic pigment into a base polymer. The article can reversibly or irreversibly change color upon exposure to hydrogen. The irreversible pigment changes color from a light beige to a dark gray. The sensitivity of the pigment can be tailored to its application by altering its exposure to gas through the incorporation of one or more additives or polymer matrix. Furthermore, through the incorporation of insulating additives, the chemochromic sensor can operate at cryogenic temperatures as low as 78 K. A chemochromic detector of this type can be manufactured into any feasible polymer part including injection molded plastic parts, fiber-spun textiles, or extruded tapes. The detectors are simple, inexpensive, portable, and do not require an external power source. The chemochromic detectors were installed and removed easily at the KSC launch pad without need for special expertise. These detectors may require an external monitor such as the human eye, camera, or electronic detector; however, they could be left in place, unmonitored, and examined later for color change to determine whether there had been exposure to hydrogen. In one type of envisioned application, chemochromic detectors would be fabricated as outer layers (e.g., casings or coatings) on high-pressure hydrogen storage tanks and other components of hydrogen-handling systems to provide visible indications of hydrogen leaks caused by fatigue failures or other failures in those systems. In another type of envisioned application, chemochromic detectors of this type could be optoelectronically instrumented for monitoring to provide measured digital indications of color changes indicative of the presence of hydrogen.

Roberson, Luke↗
DOE OSTI2023

A 4 x 4 SiPM Sensor Array with Fast Preamplified Output Engineered for the PWO Detectors of the EIC EEEMCAL

The PbWO4 scintillation detectors for the Electron-Ion Collider Electron Endcap Electromagnetic Calorimeter (EEEMCAL) cannot use vacuum photomultipler tubes due to the high magnetic field environment. We are presenting a readout solution with a 4 x 4 SiPM array directly coupled to a preamplification and summing stage. A second amplification stage with variable gain and offset adjustments is also included in the compact electronics module. The integrated power supply feeds the signal processing chain and the adjustable bias control. The parameter settings are saved locally on a EEPROM and are adjustable via the integrated communication interface through USB or RS485. The design was optimized to maximize signal collection energy resolution, for fast timing and wide dynamic range while keeping a small footprint with low power consumption and heat dissipation. The output response is fast enough to meet the 100 ? 200 ns digitization gate requirements for the detector. The electronics assembly requires no active cooling and includes a temperature sensor and a gain compensation of thermal variations which are important features for stable operation in large scale detector structures. A detector prototype was constructed with 20 mm x 20 mm x 200 mm PWO crystals affixed with individual SiPM array readouts and arranged in a 3 x 3 array. This detector was tested at the Thomas Jefferson National Accelerator Facility with 5GeV positrons. We will present the results of these detector characterization measurements.

Philip, O.↗
NASA NTRS1990

Off-plane imaging for milli-arcsecond X-ray observatories

The development of milliarcsecond imaging in X-ray astronomy is discussed in terms of a concept in which off-plane imaging is utilized to significantly increase spectroscopic and imaging resolution. Grazing incidence optics permit practical improvements of a factor of 10 in X-ray spectrographs, and a similar technique is described for a milliarcsecond X-ray observatory (MAX). MAX requires a very smooth mirror surface, operates at a plate scale that existing detectors cannot support, requires a small collecting area, and has to be designed as a highly stable structure.

Cash, Webster↗