A5046881157- Physics of Superconductivity and Magnetism
- Superconducting and THz Device Technology
- Quantum and electron transport phenomena
- Atomic and Subatomic Physics Research
- Magnetic Field Sensors Techniques
- Particle Detector Development and Performance
- Risk Perception and Management
- Nuclear and radioactivity studies
- Radiation Detection and Scintillator Technologies
- Advanced Electrical Measurement Techniques
- Magnetic properties of thin films
- Graphite, nuclear technology, radiation studies
- Nuclear reactor physics and engineering
- Surface and Thin Film Phenomena
- Superconductivity in MgB2 and Alloys
- Neutrino Physics Research
- Thermal Radiation and Cooling Technologies
- Radio Frequency Integrated Circuit Design
- Advanced Semiconductor Detectors and Materials
- Magnetic and transport properties of perovskites and related materials
- Thermal properties of materials
- X-ray Spectroscopy and Fluorescence Analysis
- Dark Matter and Cosmic Phenomena
- Decision-Making and Behavioral Economics
- Nuclear Physics and Applications
Star Cryoelectronics (United States)
2014-2025
Institute for Basic Science
2023
California Institute of Technology
2014
Arizona State University
2014
United States Naval Research Laboratory
2014
Jet Propulsion Laboratory
2014
Columbia University
2014
Cardiff University
2014
Lawrence Livermore National Laboratory
2014
Exponent (United States)
2010-2011
This paper consists of an argument and a pilot study. First is general, perhaps philosophical, against the National Academy's viewpoint (1) that dealing with risk two‐stage process consisting (a) assessment facts, (b) evaluation facts in sociopolitical context. We argue societal intrinsically revolves around social relations as much evaluations probability. Second, we outline one particular approach to analyzing management styles. call this fairness hypothesis. Rather than focusing on...
A dc superconducting quantum interference device (SQUID) magnetometer has been integrated on a 9×9 mm2 chip with eight pick-up loops in parallel to directly form SQUID inductance of about 0.5 nH. Very simple feedback electronics have developed which do not require liquid-helium temperature impedance matching circuits or flux modulation techniques. The typical white noise 8 fT/(Hz)1/2 and 1/f corner frequency below 3.5 Hz. With an additional positive circuit at 4.2 K the level further reduced...
Despite their high relative abundance in our Universe, neutrinos are the least understood fundamental particles of nature. They also provide a unique system to study quantum coherence and wavelike nature systems due extremely weak interaction probabilities. In fact, properties emitted experimentally relevant sources virtually unknown spatial extent neutrino wavepacket is only loosely constrained by reactor oscillation data with spread 13 orders magnitude. Here, we present first direct limits...
Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal dark sector. We report new search for existence sub-MeV sterile using decay-momentum reconstruction technique in decay $^{7}\mathrm{Be}$. The experiment measures total energy $^{7}\mathrm{Li}$ daughter atom from electron capture $^{7}\mathrm{Be}$ implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first presents data single STJ operated at low...
We have fabricated several low-noise direct-current superconducting quantum interference device (SQUID) magnetometers from single layers of YBa2Cu3O7−δ on 10 mm×10 mm bicrystal substrates. The magnetometer design consists a single-turn pickup loop that is directly coupled to the SQUID inductance. At 77 K, these exhibit large voltage modulation with applied flux over 40 μV. minimum noise, measured at K using conventional flux-locked electronics bias current reversal, 3.5×10−6 Φ0/√Hz above kHz...
A directly coupled DC SQUID magnetometer with very simple feedback electronics is presented. The has been integrated on a 7.2*7.2 mm/sup 2/ chip and fabricated using four-level Nb/Si/sub x/N/sub y//Nb process. Eight pickup loops are connected in parallel to form the inductance of about 0.4 nH which leads high sensitivity B/ Phi =0.47 nT/ /sub 0/. An additional positive (APF) circuit used increase gradient V- characteristic dV/d approximately=300 mu V/ 0/ at operating point. resulting...
We report on the measurement of a very low noise equivalent power 3×10−19 W/Hz1/2 at 620 GHz in superconducting antenna-coupled hot-electron bolometer. The sensing element is micron-size titanium transition-edge sensor with NbTiN contacts fabricated sapphire substrate. high sensitivity due to small device volume, operating temperature, and weak electron-phonon coupling film. Measurements were done using cryogenic black body emitter producing well-controlled femtowatt levels. achieved optical...
We discuss the design, fabrication, and testing of prototype horn-coupled, lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic microwave background studies. The LEKIDs are made from a thin aluminum film deposited on silicon wafer patterned using standard photolithographic techniques at STAR Cryoelectronics, commercial device foundry. fabricated 20-element arrays, optimized spectral band centered 150 GHz, to test sensitivity yield devices as well multiplexing scheme....
The Beryllium Electron capture in Superconducting Tunnel junctions (BeEST) experiment searches for evidence of heavy neutrino mass eigenstates the nuclear electron decay $^7$Be by precisely measuring recoil energy $^7$Li daughter. In Phase-III, BeEST has been scaled from a single superconducting tunnel junction (STJ) sensor to 36-pixel array increase sensitivity and mitigate gamma-induced backgrounds. Phase-III also uses new continuous data acquisition system that greatly increases...
A 37-channel DC SQUID magnetometer system has been built for biomagnetic studies. The loop of each serves as the active sensing element, thereby eliminating need flux coupling circuits. magnetometers are located approximately=3 cm above outer dewar bottom. SQUIDs directly coupled to a highly simplified readout electronics using only five wires per channel; no helium temperature impedance matching circuits required. Each channel can be independently inserted into or removed from dewar. Using...
We describe a low-noise dc Superconducting QUantum Interference Device (SQUID) magnetometer that is fabricated from single layer of YBa/sub 2/Cu/sub 3/O/sub 7-x/ on 2 cm/spl times/2 cm bicrystal substrate. The design consists single-turn pickup loop directly coupled to low inductance SQUID. Using conventional flux-locked electronics with bias current reversal, the white flux noise several these magnetometers operated at 77 K observed be as 2.2 /spl mu//spl Phi//sub 0///spl radic/Hz above 10...
An optimization procedure is presented which used to design two types of ultralow-noise DC superconducting quantum interference devices (SQUIDs) with integrated flux coupling circuits, a magnetometer, and gradiometer. Essential this approach the reduction parasitic capacitance, choice layout moves input coil resonances well away from desired operating frequency SQUID, proper damping these resonances. It shown that both microwave LC can be damped in nearly noise-free manner by placing all RC...
We present a technique for increasing the internal quality factor of kinetic inductance detectors (KIDs) by nulling ambient magnetic fields with properly applied field. The KIDs used in this study are made from thin-film aluminum, they mounted inside light-tight package bulk and operated near 150 mK. Since aluminum has slightly elevated critical temperature (Tc = 1.4 K), it therefore transitions before 1.2 which also serves as shield. On cooldown, small approximately 30 µT can produce...
A complete circuit model of a dc superconducting quantum interference device (SQUID) coupled to multiturn input coil has been developed. With this model, it is shown that the rf properties SQUID can be calculated using only given parameters SQUID. There are no adjustable parameters. The resonant structures in characteristics caused by presence have quantitatively studied. Methods suppress also investigated. It present explains well experimentally observed SQUIDs. therefore useful for design...
Alpha-particle spectrometry is a powerful analytical tool for nuclear forensics and environmental monitoring. Superconducting transition-edge sensor microcalorimeters have been shown to yield unsurpassed energy resolution alpha spectrometry. With nearly an order of magnitude better (1.06 keV FWHM at 5.3 MeV) than the current state-of-the-art silicon detectors (8-10 MeV), it possible measure samples containing multiple radioisotopes that would require expensive time-consuming radiochemical...
Practical thin-film dc superconducting quantum interference devices (SQUIDs) are often built with an integrated input coil which leads to the formation of various parasitic elements. We have designed and fabricated several square washer-shaped SQUID test amounts capacitance formed by covering washer slits coverplates widths. In simplest approximation, Cp appears entirely across Josephson junctions; in a better divides total inductance into two parts, effective loop L small Lp. For both...
The U.S. National Assessment of the Potential Consequences Climate Variability and Change was a federally coordinated nationwide effort that involved thousands experts stakeholders. To draw lessons from this effort, 10 authors paper, half whom were not in Assessment, developed administered an extensive survey, prepared series working papers, conducted invitational workshop Washington, DC, on April 29, 2004. Considering all these sources, conclude largely successful implementing its basic...
We report photon-noise limited performance of horn-coupled, aluminum lumped-element kinetic inductance detectors at millimeter wavelengths. The are illuminated by a millimeter-wave source that uses an active multiplier chain to produce radiation between 140 and 160 GHz. feed the with either amplified broadband noise or continuous-wave tone from microwave signal generator. demonstrate detector response over 40 dB range power is well-described simple model considers number quasiparticles....
We have designed and fabricated a low-noise dc superconducting quantum interference device (SQUID) magnetometer that is integrated on 4×4 mm2 chip. The white flux noise of the measured in flux-locked-loop mode using simple, direct-coupled electronics with additional positive feedback (APF) 6.4×10−7 Φ0/√Hz. corresponding density 3.9 fT/√Hz. SQUID flux-to-voltage transfer function APF enhanced to 4.7 mV/Φ0 at optimal working point, thereby significantly reducing preamplifier contribution total...
A process for the fabrication of high-quality, all-refractory Josephson junctions type Nb/Six Ny /Nb is described in detail. The have been fabricated using selective niobium anodization with a tunnel barrier consisting an amorphous Si film converted to its nitride by application rf plasma nitrogen. An attractive feature these their comparably low specific capacitance C/A=3.9±0.1 μF/cm2 (for Jc =6 A/cm2 ). Junctions this having critical current densities up =2000 and Vm =16 mV fabricated....