Subjects: Nuclear Science and Technology >> Nuclear Science and Technology submitted time 2024-04-08
Abstract: Background : The lead-free double perovskite Cs2AgBiBr6 has garnered extensive attention in the field of nuclear radiation detection as an environmentally friendly material. Experimental observations have revealed that doping Cs2AgBiBr6 with Cu+ significantly enhances the material’s stability and photoelectric conversion efficiency. Purpose :The study aims to investigate the impact of Cu+ doping on the crystal structure and electrical properties of Cs2AgBiBr6. Methods : Using first-principles calculations based on density functional theory, a simulation study was conducted to explore the effects of Cu+ doping on the structure and electrical properties of Cs2AgBiBr6. Results : The results indicate that Cu+ doping enhances the stability of Cs2AgBiBr6. The Cs2Ag1-xCuxBiBr6 compounds formed by doping, as well as the original Cs2AgBiBr6 material, exhibit an indirect bandgap semiconductor behavior. The bandgap significantly narrows with an increase in the Cu+ doping ratio. Analysis of the density of states (DOS) suggests that the bandgap narrowing is attributed to the downward shift of the conduction band minimum dominated by Bi 6p orbitals due to Cu+ doping. Conclusions : Cs2Ag1-xCuxBiBr6 exhibits higher stability and superior electrical properties compared to Cs2AgBiBr6. It emerges as a promising candidate material for semiconductor radiation detectors.
Key words First-principles calculations, Cs2Ag1-xCuxBiBr6, Electronic structure, Cu+ Doping
Subjects: Nuclear Science and Technology >> Nuclear Detection Technology and Nuclear Electronics Subjects: Physics >> Nuclear Physics submitted time 2024-02-26
Abstract: Cosmic rays are used for the calibration of the Veto detector at ETF in HIRFL-CSR of the Cooling Storage
Ring of Heavy Ion Research Facility in Lanzhou(HIRFL-CSR). The work is divided into two parts: position calibration
and time calibration. The hit positions of particles are obtained by position calibration and an uniform standard of the
measurement of particle hit time in the Veto detector is built through time calibration. The information of position and
time of particles serves as important criteria for eliminating changed particle events that hit the neutron wall detector,
providing support for the realization of the physical objectives of the neutron wall detector. A 2.53 cm position resolution
and a 1.09 ns time resolution have been achieved in this paper.
Subjects: Physics >> Nuclear Physics submitted time 2024-01-10
Abstract: The Lanzhou Heavy Ion Accelerator Cooling Storage Ring(HIRFL-CSR) is an ideal device for studying the decay of highly charged and short-lived isomers. In the lifetime measurement experiment of the short-lived highly charged ion 94mRu44+, we directly observed the decay of 94Ru from 8+ isomer to the ground state, and identified 49 decay events in the observation time window of (20 μs, 180 μs). In order to identify more decay events, a method based on spectral amplitude was studied in this paper. Based on the simulation results, this method can effectively identify decay events within (15 μs, 185 μs). By applying the new identification method to the experimental data processing, 54 decay events were identified within (15 μs, 185 μs). Based on these 54 decay events, the lifetime of 94mRu44+ in the rest frame was calculated to be 194(121) μs. The new lifetime result is within the error range of the previous result 218(148) μs, with higher precision.