A precise value of the neutron lifetime is important in several areas of physics, including determinations of the quark-mixing matrix element │ │, related tests of the Standard Model, and predictions of light element abundances in Big Bang Nucleosynthesis models. We report the progress on a new measurement of the neutron lifetime utilizing the cold neutron beam technique. Several experimental improvements in both neutron and proton counting that have been developed over the last decade are presented. This new effort should yield a final uncertainty on the lifetime of 1 s with an improved understanding of the systematic effects.
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http://dx.doi.org/10.1051/epjconf/201921903002 | DOI Listing |
Nano Lett
December 2024
School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China.
Lead halide perovskites are renowned for their exceptional optoelectronic properties but face concerns over lead toxicity and stability, which drives the exploration of lead-free perovskites, with CsAgBiBr standing out as a benchmark alternative. Understanding the structural dynamics and thermal transport properties of CsAgBiBr is crucial but remains an outstanding challenge due to the complex atomic fluctuations. Here, through diffuse scattering experiments and simulations, we uncover the underlying dynamic local structure in CsAgBiBr, showing a unique two-dimensional spatial correlation.
View Article and Find Full Text PDFSmall
December 2024
Department of Materials Science and Engineering, National Cheng Kung University, Tainan, 70101, Taiwan.
Phonon dynamics in organic-inorganic hybrid perovskites (OIHPs) exhibit inherent complexity driven by the intricate interactions between rotatable organic cations and dynamically disordered inorganic octahedra, mediated by hydrogen bonding. This study aims to address this complexity by investigating the thermal transport behavior of MAPbCl as a gateway to the OIHPs family. The results reveal that the ultralow thermal conductivity of MAPbCl arises from a synergistic interplay of exceptionally low phonon velocities, short phonon lifetimes, and phonon mean free paths approaching the Regel-Ioffe limit.
View Article and Find Full Text PDFAppl Radiat Isot
February 2025
Faculty of Physics, University of Science and Technology Houari Boumediene ( USTHB), BP 32 EL ALIA, BAB EZZOUAR, Algiers, Algeria.
The present study aimed to assess organ doses and the associated cancer risks related to secondary radiation (photons and neutrons) exposure during 3D Conformational Radiotherapy (3D-CRT) for patients with prostate cancer in Algeria. To this purpose, a detailed geometric Monte Carlo (MC) modeling of the LINAC, combined with a hybrid whole-body phantom was carried out. The secondary radiation doses were calculated in patient's organs, both within and outside the field.
View Article and Find Full Text PDFNat Commun
November 2024
Chair for Electrochemical Energy Conversion and Storage Systems, Institute for Power Electronics and Electrical Drives (ISEA), RWTH Aachen University, Aachen, Germany.
While developing battery cells, the achievement of fast-charging capability is heavily dependent on avoiding metallic plating on the anode surface (i.e., lithium plating in lithium-ion cells).
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2024
Toyota Central R&D Labs., Inc., Nagakute 480-1192, Japan.
The phase transition from supercooled water to ice is closely related to the electrochemical performance and lifetime of an energy device at sub-zero temperatures. In particular, fuel cells for passenger cars face this issue because they are frequently started and stopped under sub-zero conditions during the winter season. However, there is a lack of visual information regarding the processes that occur within the fuel cell stack, and insight into how to improve the safety and performance during cold starts is lacking.
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