Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “electron detectors”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,351 records · Page 75
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Development of a large-mass, low-threshold detector system with simultaneous measurements of athermal phonons and scintillation light

For this work, we have combined two low-threshold detector technologies to develop a large-mass, low-threshold detector system that simultaneously measures the athermal phonons in a sapphire detector while an adjacent silicon high-voltage detector detects the scintillation light from the sapphire detector. This detector system could provide event-by-event discrimination between electron and nuclear events due to the difference in their scintillation light yield. While such systems with simultaneous phonon and light detection have been demonstrated earlier with smaller detectors, our system is designed to provide a large detector mass with high amplification for the limited scintillation light. Future work will focus on at least an order of magnitude improvement in the light collection efficiency by having a highly reflective detector housing and custom phonon mask design to maximize light collection by the silicon high-voltage detector.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2026

Operation of a Modular 3D-Pixelated Liquid Argon Time-Projection Chamber in a Neutrino Beam

The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events.

47 OTHER INSTRUMENTATION↗
DOE OSTI2021

Search for supersymmetry in events with four or more charged leptons in 139 fb -1 of $\sqrt{s}$ = 13 TeV pp collisions with the ATLAS detector

A search for supersymmetry in events with four or more charged leptons (electrons, muons and $\tau$-leptons) is presented. The analysis uses a data sample corresponding to 139 fb -1 of proton-proton collisions delivered by the Large Hadron Collider at $\sqrt{s}$ =13 TeV and recorded by the ATLAS detector. Four-lepton signal regions with up to two hadronically decaying $\tau$-leptons are designed to target several supersymmetric models, while a general five-lepton signal region targets any new physics phenomena leading to a final state with five charged leptons. Data yields are consistent with Standard Model expectations and results are used to set upper limits on contributions from processes beyond the Standard Model. Exclusion limits are set at the 95% confidence level in simplified models of general gauge-mediated supersymmetry, excluding higgsino masses up to 540 GeV. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to charged leptons, lower limits of 1.6 TeV, 1.2 TeV, and 2.5 TeV are placed on wino, slepton and gluino masses, respectively.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS2005

CdZnTe Image Detectors for Hard-X-Ray Telescopes

Arrays of CdZnTe photodetectors and associated electronic circuitry have been built and tested in a continuing effort to develop focal-plane image sensor systems for hard-x-ray telescopes. Each array contains 24 by 44 pixels at a pitch of 498 m. The detector designs are optimized to obtain low power demand with high spectral resolution in the photon- energy range of 5 to 100 keV. More precisely, each detector array is a hybrid of a CdZnTe photodetector array and an application-specific integrated circuit (ASIC) containing an array of amplifiers in the same pixel pattern as that of the detectors. The array is fabricated on a single crystal of CdZnTe having dimensions of 23.6 by 12.9 by 2 mm. The detector-array cathode is a monolithic platinum contact. On the anode plane, the contact metal is patterned into the aforementioned pixel array, surrounded by a guard ring that is 1 mm wide on three sides and is 0.1 mm wide on the fourth side so that two such detector arrays can be placed side-by-side to form a roughly square sensor area with minimal dead area between them. Figure 1 shows two anode patterns. One pattern features larger pixel anode contacts, with a 30-m gap between them. The other pattern features smaller pixel anode contacts plus a contact for a shaping electrode in the form of a grid that separates all the pixels. In operation, the grid is held at a potential intermediate between the cathode and anode potentials to steer electric charges toward the anode in order to reduce the loss of charges in the inter-anode gaps. The CdZnTe photodetector array is mechanically and electrically connected to the ASIC (see Figure 2), either by use of indium bump bonds or by use of conductive epoxy bumps on the CdZnTe array joined to gold bumps on the ASIC. Hence, the output of each pixel detector is fed to its own amplifier chain.

Chen, C. M. Hubert↗
DOE OSTI2025

Electroweak observables in neutrino-electron scattering from a muon storage ring

We investigate the sensitivity of a companion neutrino detector situated in the plane of a high-energy, high-intensity muon storage ring to elastic ν μ and ν e scattering on electrons (EνES). Assuming a muon collider with center-of-mass energies of up to 10 TeV, we report sensitivity to the weak couplings g V and g A up to around 0.05% relative error, and sensitivity to the weak mixing angle in the momentum transfer Q ∈ [10 −2 , 2] GeV range up to around 0.03% relative error. EνES measurements with high-energy muon storage rings allow one to directly interrogate the momentum-transfer regime associated with the NuTeV anomaly. This level of precision allows unique sensitivity to the momentum-dependence of sin 2 θ W . We estimate that with the neutrinos from a E μ = 1.5 TeV (or higher) muon collider, the hypothesis that sin 2 θ W does not “run” can be safely ruled out.

electroweak precision physics↗
DOE OSTI2022

Interferometric bunch length measurements of 3 MeV picocoulomb electron beams

We report picosecond bunch length measurements using an interferometric method for a 3 MeV electron beam having bunch charge ranging from 1 to 14 pC. The method senses the single-cycle sub-terahertz (THz) pulse emitted by each electron bunch as coherent transition radiation which, in turn, is analyzed using a Michelson-type interferometer, forming an interferogram that is then processed to yield the nominal electron bunch length. This sub-THz coherent radiation intensity was measured using a quasi-optical detector (QOD) operated at room temperature. This experiment was quite challenging since the divergence angle of the sub-THz pulse emitted by the low-energy electron bunch exceeds ±10°, and its pulse energy at the entrance to the detector was as low as 100 pJ. When compared to a conventional helium-cooled silicon composite bolometer designed for frequencies above 0.5 THz, the QOD provided much better signal-to-noise ratio in the ~80 GHz frequency range, which was critical for the successful measurement of the bunch length.

36 MATERIALS SCIENCE↗
DOE OSTI2022

The straw tracking detector for the Fermilab Muon g-2 Experiment

The Muon g-2 Experiment at Fermilab uses a gaseous straw tracking detector to make detailed measurements of the stored muon beam profile, which are essential for the experiment to achieve its uncertainty goals. Positrons from muon decays spiral inward and pass through the tracking detector before striking an electromagnetic calorimeter. The tracking detector is therefore located inside the vacuum chamber in a region where the magnetic field is large and non-uniform. As such, the tracking detector must have a low leak rate to maintain a high-quality vacuum, must be non-magnetic so as not to perturb the magnetic field and, to minimize energy loss, must have a low radiation length. The performance of the tracking detector has met or surpassed the design requirements, with adequate electronic noise levels, an average straw hit resolution of (110 ± 20) μm, a detection efficiency of 97% or higher, and no performance degradation or signs of aging. The tracking detector's measurements result in an otherwise unachievable understanding of the muon's beam motion, particularly at early times in the experiment's measurement period when there are a significantly greater number of muons decaying. This is vital to the statistical power of the experiment, as well as facilitating the precise extraction of several systematic corrections and uncertainties. This paper describes the design, construction, testing, commissioning, and performance of the tracking detector.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS2005

A Search for Meteor Shower Signatures in the LDEF IDE Data

For 346 days after the deployment of the LDEF satellite on April 7, 1984, the tape recorder belonging to the Interplanetary Dust Experiment (DE) stored information on over 15,000 impacts made by submicron and larger-size particles on its metal oxide silicon (MOS) detectors. These detectors were mounted on trays facing in six orthogonal directions - LDEF ram and trailing edge, the poles of the LDEF orbit (north and south), and radially inward (towards the Earth) and outward (towards space). The 13.1 second time resolution provided by the IDE electronics, combined with the high sensitivity of the MOS detectors and large collecting area (approximately 1 sq.m) of the experiment, conclusively showed that the small particle environment at the LDEF altitude of 480 km was highly time-variable, with particle fluxes spanning over four orders of magnitude. A large number of the 15,000 impacts recorded by IDE occurred in groups, which were of two types - the spikes, single, isolated events of high intensity and the multiple orbit event sequences (MOES), which were series of events separated in time by integer multiples of the LDEF orbital period. Even though the spikes were generally more intense, the MOES could be quite long-lived, some lasting for many days. A previous paper by Cooke et al. attributed the MOES to impacts by man-made debris particles in orbits intersecting that of LDEF. The 20 day longevity of one of these events - termed the May Swarm - led to the suggestion that the debris particles must be con- stantly replenished by their source, as the orbits of micron sized particles will rapidly decay under the influence of radiation pressure and other non-gravitational forces, entering Earth's atmosphere after only a few revolutions. However, the date of onset of the May Swarm (May 22) and the long duration of this event may indicate a possible correlation with the annual Arietid meteor shower, which peaks around June 8. As this seemed to hold the promise of a less artificial explanation than a satellite or rocket body continuously dribbling debris, it was decided to take a fresh look at parts of the IDE data set in an attempt to detect meteor showers within the impact record.

Cooke, William J.↗
DOE OSTI2021

Nuclear Data to Reduce Uncertainties in Reactor Antineutrino Measurements

The large quantities of antineutrinos produced through the decay of fission fragments in nuclear reactors provide an opportunity to study the properties of these particles and investigate their use in reactor monitoring. The reactor antineutrino spectra are measured using specialized, large area detectors that detect antineutrinos through inverse beta decay, electron elastic scattering, or coherent elastic neutrino nucleus scattering; although, inverse beta decay is the only demonstrated method so far. Reactor monitoring takes advantage of the differences in the antineutrino yield and spectra resulting from uranium and plutonium fission providing an opportunity to estimate the fissile material composition in the reactor. Recent experiments reveal a deviation between the measured and calculated antineutrino flux and spectra (the reactor anomaly) indicating either the existence of yet undiscovered neutrino physics, uncertainties in the reactor source term calculation, incorrect nuclear data, or a combination of all three. To address the nuclear data that impact the antineutrino spectrum calculations and measurements, an international group of over 180 experts in antineutrino physics, reactor analysis, detector development, and nuclear data came together during the Workshop on Nuclear Data for Reactor Antineutrino Measurements (WoNDRAM) to discuss nuclear data needs and achieve concordance on a set of recommended priorities for nuclear data improvements. Three topical sessions focused on the reactor source term, the antineutrino spectrum, and the detector response, provided a forum to gain consensus amongst the participants on the most important data improvements to address two goals: 1) understand the reactor anomaly and 2) improve the ability to monitor reactors using antineutrinos. This report summarizes the outcomes of the workshop discussions and the recommendations for nuclear data efforts that reduce reactor antineutrino measurement uncertainties.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
NASA NTRS1963

Results of the telstar radiation experiments

The data from the particle experiments of the Telstar satellite have been analyzed to provide maps of the distribution of electrons and protons as measured in three of the Telstar detectors during the period from July through October, 1962. For the protons between 26 and 34 Mev and >50 Mev, the particle distributions are stable in time, but for the electron distribution there is a time decay of the electron flux over most of the region explored by the Telstar orbit. The connection of these observations to the high-altitude nuclear explosion of July 9, 1962, is discussed. The introduction of additional electrons by Russian tests at the end of October was also observed. The particle maps have been used to derive the integral particle exposure of the satellite, which is found to account quantitatively quite well for the radiation damage observed in the main solar power plant and in the radiation damage experiments on solar cells and special damage transistors carried by the satellite. In the main power plant the proton and electron contributions to damage are found to be equal. The integral particle exposure has also been used to compute the level of ionization in different depths of material in order to evaluate the degradation of semiconductor devices in the Telstar canister.

RADIATION EXPOSURE↗
NASA NTRS1975

Pioneer 10 - Observations of energetic electrons in the Jovian magnetosphere

Data obtained by Pioneer 10 on the properties of energetic electrons in the Jovian magnetosphere are analyzed. The basic detectors (seven miniature Geiger-Mueller tubes) are described together with the signal processor and sampling techniques. The model of Jupiter used in the data analysis is a centered dipole with a tilt of 9.5 deg toward 230 deg System III longitude. The energetic-electron observations within the inner magnetosphere are found to indicate that radial as well as pitch-angle diffusion of energetic electrons must take place very rapidly. Outbound observations within the magnetodisk (the region beyond 20 Jupiter radii) are found to indicate a spiraling of the apparent location of the longitude of the dipole tilt, while inbound data indicate a constant value for the apparent longitude of the dipole tilt out to 70 Jupiter radii.

Randall, B. A.↗
NASA NTRS1980

Analysis of ambient and beam particle characteristics during the ejection of an electron beam from a satellite in near-geosynchronous orbit on March 30, 1979

An electron beam system was operated over a wide range of beam currents and energies for periods both in sunlight and in eclipse. Complex pitch angle modulations of the electron spectra are separately decomposed for each beam operation. When electrons are emitted perpendicular to the magnetic field with an energy of 3 keV and a current of 0.10 mA they return as a coherent beam only to the parallel detector. Throughout the beam operations the pitch angle distributions show electrons with energy less than beam energy streaming along the field line. Analytic expressions for the satellite electric field are constructed and particle trajectories are determined.

Gussenhoven, M. S.↗
NASA NTRS1992

Electron mobility in n-type Hg(1-x)Cd(x)Te and Hg(1-x)Zn(x)Te alloys

Calculations of electron mobility in n-type mercury cadmium telluride (MCT), a candidate material for IR detectors, and n-type mercury zinc telluride (MZT) are compared. It is found that electron mobilities in MCT and MZT are nearly the same for equivalent energy gaps. The results are also found to compare will with experimental data. Directions of future research are briefly discussed.

Patterson, J. D.↗
DOE OSTI2023

Probing individual single atom electrocatalyst sites by advanced analytical scanning transmission electron microscopy

Single atom electrocatalysts (SAEs) are promising next-generation materials for promoting a variety of important reactions, such as the oxygen reduction, nitrogen reduction, and CO 2 reduction reactions. While bulk characterization techniques such as X-ray absorption spectroscopy and Mössbauer spectroscopy have significantly enhanced our understanding of these catalysts, direct probing of individual single metal atom sites at the atomic scale is necessary to understand local variations in the properties of these sites and accelerate design and synthesis of improved SAEs. Aberration-corrected scanning transmission electron microscopy (STEM) has become a powerful tool for providing this type of atomic-scale information about SAE metal sites. These sites are typically unstable under the electron beam, however, which, in combination with conventional acquisition methods and detectors, has limited the type and quantity of information obtainable by spectroscopic STEM techniques. Here, we map multiple individual SAE metal sites in a nitrogen-doped carbon containing atomically dispersed Fe and Re (FeReNC) at the atomic scale by direct electron detection electron energy-loss spectroscopy (EELS). Direct electron detection provides an improved signal-to-noise ratio over conventional scintillator-based detectors and enables detection and real space localization of weak signals. In addition, we demonstrate an automated method for identification of metal atom positions, placement of the probe on these sites, and simultaneous EELS and energy dispersive X-ray spectroscopic (EDS) signal acquisition. This simultaneous acquisition of EELS and EDS provides access to the composition and bonding of a wide range of SAE metal sites. In this study, focusing the probe directly on the metal sites also increases the relevant data acquisition rate by more than an order of magnitude over two-dimensional mapping, enabling improved statistical measurements of site properties. The versatility, sensitivity, and speed that these techniques provide enhances our ability to probe the local elemental and chemical environment of a large number of individual SAE metal site structures at the atomic scale, enabling an improved understanding of the variations in the local properties of these electrocatalysts to be gained. As a result, significantly increased information about individual metal sites will be available to future electrochemical studies through these techniques, accelerating the development of advanced SAEs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Extraction of the muon signals recorded with the surface detector of the Pierre Auger Observatory using recurrent neural networks

The Pierre Auger Observatory, at present the largest cosmic-ray observatory ever built, is instrumented with a ground array of 1600 water-Cherenkov detectors, known as the Surface Detector (SD). The SD samples the secondary particle content (mostly photons, electrons, positrons and muons) of extensive air showers initiated by cosmic rays with energies ranging from 1017eV up to more than 1020eV. Measuring the independent contribution of the muon component to the total registered signal is crucial to enhance the capability of the Observatory to estimate the mass of the cosmic rays on an event-by-event basis. However, with the current design of the SD, it is difficult to straightforwardly separate the contributions of muons to the SD time traces from those of photons, electrons and positrons. In this paper, we present a method aimed at extracting the muon component of the time traces registered with each individual detector of the SD using Recurrent Neural Networks. We derive the performances of the method by training the neural network on simulations, in which the muon and the electromagnetic components of the traces are known. We conclude this work showing the performance of this method on experimental data of the Pierre Auger Observatory. We find that our predictions agree with the parameterizations obtained by the AGASA collaboration to describe the lateral distributions of the electromagnetic and muonic components of extensive air showers.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS2006

Micro-Imagers for Spaceborne Cell-Growth Experiments

A document discusses selected aspects of a continuing effort to develop five micro-imagers for both still and video monitoring of cell cultures to be grown aboard the International Space Station. The approach taken in this effort is to modify and augment pre-existing electronic micro-cameras. Each such camera includes an image-detector integrated-circuit chip, signal-conditioning and image-compression circuitry, and connections for receiving power from, and exchanging data with, external electronic equipment. Four white and four multicolor light-emitting diodes are to be added to each camera for illuminating the specimens to be monitored. The lens used in the original version of each camera is to be replaced with a shorter-focal-length, more-compact singlet lens to make it possible to fit the camera into the limited space allocated to it. Initially, the lenses in the five cameras are to have different focal lengths: the focal lengths are to be 1, 1.5, 2, 2.5, and 3 cm. Once one of the focal lengths is determined to be the most nearly optimum, the remaining four cameras are to be fitted with lenses of that focal length.

Behar, Alberto↗
DOE OSTI2021

System and method for compact, adaptive optical sensor for obtaining areal images

The present disclosure relates to an imaging system which may make use of an electronic controller, a digital micromirror array, an aperture control system and a detector to image a desired scene. The digital micromirror array has a plurality of micromirror elements responsive to control signals generated by the electronic controller for electronically aiming the micromirror elements in a desired direction to image the desired area, and for receiving and reflecting light emanating from the desired area. The aperture control system receives light reflected from the digital micromirror array and passes a predetermined subportion of the received light therethrough. The detector is responsive to the predetermined subportion of light.

Panas, Robert Matthew↗