A novel tissue-equivalent proportional counter (TEPC) based on a gas electron multiplier (GEM) for measuring H*(10) for neutrons was designed and constructed. The pulse height spectra (PHS) of two different neutron sources (a 252Cf source and a AmBe source) were measured using the new TEPC. The measurements were made with the TEPC filled with two different gases (10P gas and a propane-based tissue-equivalent gas) at various pressures. A computer simulation of the new TEPC, based on the Monte Carlo method, was performed to obtain the PHS for the two neutron sources. It is shown that the experimental results agree well with the simulation results for both 252Cf and AmBe neutron sources. Several outstanding problems are discussed and suggestions are made to make the GEM-based TEPC a practical neutron rem meter. The potential advantage of this novel neutron rem meter would be its low weight and compactness.
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http://dx.doi.org/10.1097/01.HP.0000300493.53385.5d | DOI Listing |
Sci Rep
January 2025
Los Alamos National Laboratory, Los Alamos, NM, 87544, USA.
Detecting shielded special nuclear material, such as nuclear explosives, is a difficult challenge pursued by non-proliferation, anti-terrorism, and nuclear security programs worldwide. Interrogation with intense fast-neutron pulses is a promising method to characterize concealed nuclear material rapidly but is limited by suitable source availability and proven instrumentation. In this study we have pioneered a demonstration of such an interrogation method using a high-intensity, short-pulse, laser-driven neutron source that offers potential benefits compared to conventional neutron sources.
View Article and Find Full Text PDFStructure
January 2025
Department of Computational Chemistry, Lund University, Chemical Centre, P.O. Box 124, 221 00 Lund, Sweden; European Spallation Source ESS ERIC, P.O. Box 176, 221 00 Lund, Sweden. Electronic address:
Lysozyme is a model system for crystallographers. In this issue of Structure, Ramos et al. report atomic resolution neutron structures of lysozyme, which unambiguously show the protonation states and hydrogen-bonding networks of the active site.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
Departament de Física Aplicada, Universitat d'Alacant, 03690 Alicante, Spain.
The existence of light QCD axions, whose mass depends on an additional free parameter, can lead to a new ground state of matter, where the sourced axion field reduces the nucleon effective mass. The presence of the axion field has structural consequences, in particular, it results in a thinner (or even prevents its existence) heat-blanketing envelope, significantly altering the cooling patterns of neutron stars. We exploit the anomalous cooling behavior to constrain previously uncharted regions of the axion parameter space by comparing model predictions with existing data from isolated neutron stars.
View Article and Find Full Text PDFNat Commun
January 2025
School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China.
A pressing need for enhancing lithium-ion battery (LIB) performance exists, particularly in ensuring reliable operation under extreme cold conditions. All-solid-state batteries (ASSBs) offer a promising solution to the challenges posed by conventional LIBs with liquid electrolytes in low-temperature environments. In this study, leveraging the benefits of amorphous solid-state electrolytes (SSEs) xLiN-TaCl (1 ≤ 3x ≤ 2), we develop ASSBs capable of functioning effectively under extreme cold conditions.
View Article and Find Full Text PDFNat Commun
January 2025
Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, China.
Inorganic plastic semiconductors play a crucial role in the realm of flexible electronics. In this study, we present a cost-effective plastic thermoelectric semimetal magnesium bismuthide (α-MgBi), exhibiting remarkable thermoelectric performance. Bulk single-crystalline α-MgBi exhibits considerable plastic deformation at room temperature, allowing for the fabrication of intricate shapes such as the letters "SUSTECH" and a flexible chain.
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