Subjects: Physics >> Nuclear Physics submitted time 2024-02-29
Yang Jiao
Jie Liu
Pei-Xiong Zhao
Li-Hua Mo
Jin-Hu Yang
Yu-Zhu Liu
Ya-Nan Yin
Liang Wang
Qi-Yu Chen
Xiao-Yu Yan
Shi-Wei Zhao
Bo Li
You-Mei Sun
Abstract： The 28nm process has a high cost-performance ratio and has gradually become the standard for the field
of radiation-hardened devices. However, owing to the minimum physical gate length of only 35nm, the physical
area of a standard 6T SRAM unit is approximately 0.16 μm2, resulting in a significant enhancement of
multi-cell charge-sharing effects. Multiple-cell upsets (MCUs) have become the primary physical mechanism
behind single-event upsets (SEUs) in advanced nanometer node devices. The range of ionization track effects
increases with higher ion energies, and spacecraft in orbit primarily experience SEUs caused by high-energy
ions. However, ground accelerator experiments have mainly obtained low-energy ion irradiation data. Therefore,
the impact of ion energy on the SEU cross-section, charge collection mechanisms, and MCU patterns and
quantities in advanced nanometer devices remains unclear. In this study, based on the experimental platform
of the Heavy Ion Research Facility in Lanzhou (HIRFL), low- and high-energy heavy-ion beams were used
to study the SEUs of 28nm SRAM devices. The influence of ion energy on the charge collection processes
of small-sensitive-volume devices, MCU patterns, and upset cross-sections was obtained, and the applicable
range of the inverse-cosine law was clarified. The findings of this study are an important guide for the accurate
evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.
Subjects: Physics >> Nuclear Physics submitted time 2024-02-28
Yang yuxuan
Zhang Yue
Zhao Weijuan
Wang Hongwei
Fan Gongtao
Xu Hanghua
Liu Longxiang
Hao Zirui
Li Zhicai
Jin Sheng
Chen Kaijie
Jiao Pu
Zhou Mengdie
Wang Zhenwei
Abstract： Shanghai Laser Electron Gamma Source (SLEGS) is a quasi-monoenergetic, and energy-tunable MeV gamma-rays source generated by the inverse Laser Compton Scattering (LCS) of lasers and electrons. SLEGS is the only LCS gamma source in the world with a continuously variable collision angular range. The gamma activation analysis is one of the effective methods to study the properties of materials. This paper introduces the gamma activation platform of SLEGS, including the online activation experiment, the low background offline measurement, and the energy and efficiency calibration for the high purity germanium (HPGe) detector. The counting rate of the shielded HPGe has been controlled down to 5.2 cps/s within 60 keV-3 MeV region under the current low background environment. The activation platform of the SLEGS has provided favorable conditions for gamma activation measurements, which will play an important role in future research in the fields of nuclear physics, nuclear astrophysics, medical applications, materials science, and environmental science.
Subjects: Physics >> Nuclear Physics Subjects: Physics >> Interdisciplinary Physics and Related Areas of Science and Technology submitted time 2023-06-20
Chen, Kaijie
Liu, Longxiang
Hao, Zirui
Ma, Yugang
Wang, Hongwei
Fan, Gongtao
Cao, Xiguang
Xu, Hanghua
Niu, Yifei
Li, Xinxiang
Hu, Xinrong
Yang, Yuxuan
Jin, Sheng
Kuang, Pan
Abstract： The Shanghai laser electron gamma source (SLEGS) is a powerful tool for exploring photonuclear physics, such as giant dipole resonance (GDR) and pygmy dipole resonance, which are the main mechanisms of collective nuclear motion. The goal of the SLEGS neutron time-of-fight (TOF) spectrometer is to measure GDR and specifc nuclear structures in the energy region above the neutron threshold. The SLEGS TOF spectrometer was designed to hold 20 sets of EJ301 and LaBr3 detectors. Geant4 was used to simulate the efciency of each detector and the entire spectrometer, which provides a reference for the selection of detectors and layout of the SLEGS TOF spectrometer. Under the events of 208Pb, implementations of coincidence and time-of-fight technology for complex experiments are available; thus, y and neutron decay events can be separated. The performance of SLEGS TOF spectrometer was systematically evaluated using ofine experiments, in which the time resolution reached approximately 0.9 ns.
Subjects: Geosciences >> Geology submitted time 2017-08-08 Cooperative journals: 《古脊椎动物学报》
Abstract：New specimens from a new locality at Chutoulang in eastern Nei Mongol were identifed as Canis chihliensis, Coelodonta nihowanensis, Hipparion (Proboscidipparion) sinense,Equus sanmeniensis, Sus lydekkeri, Muntiacus cf. M. lacustris, Axis shansius, Eucladoceros boulei, Spirocerus cf. S. wongi and Bison palaeosinensis. They enriched the mammalian fauna of Chutoulang to 30 taxa together with the material from Dongliang, Dongcun Beigou and Dongcun Nangou localities. The mammalian fossils from these four localities are all from the same horizon and can be regarded as the same fauna, i.e. Chutoulang fauna. The composition of Chutoulang fauna is the closest to that of Nihewan (s.s.) by binary faunal similarity coeffcients. The age of Chutoulang fauna is between those of Nihewan (s.s.) and Juyuandong at Liucheng according to Brainerd-Robinson’s sequence, extinction rates and antiquity coeffcients. The numerical age of Chutoulang fauna is estimated between 1.4–1.6 Ma based on those of compared faunas. Carnivora are the most numerous in Chutoulang fauna with 11 taxa, but mostly the small sized ones.Perissodactyla and Artiodactyla make about half of the fauna. They are mostly large sized forms. The presence of numerous browsers or forest dwellers implies the existence of forest or woodland in Chutoulang area during that period. The presence of grazers and openland dwellers indicates the existence of larger area of grassland or steppes than that of woodland or forests. Most members of Chutoulang fauna are temperate habitat dwellers with a few cold-prone forms such as Ochotona and Coelodonta. The climate in Chutoulang area in the Early Pleistocene was thus similar to that of today. Chutoulang fauna is the most northeastern Early Pleistocene fauna in China and it can be recommended as a type site of the Early Pleistocene mammalian fauna in northeastern China.
Hits
YES
Hits
Downloads
Comment