分类: 物理学 >> 核物理学 提交时间: 2024-02-16
摘要: The Shanghai Laser Electron Gamma Source(SLEGS) has delivered a quasi-monochromatic, continuously energy-tunable gamma-ray beam. Based on the photon activation analysis(PAA) method, SLEGS has built and developed a photon activation analysis platform, including online activation and offline low-background HPGe detector measurement systems, as an alternative to direct measurement methods and a cross-tests at low throughput. Due to the short half-lives spanning from minutes to days and characteristics such as ease of fabrication, cost-effectiveness, and stability, gold (197Au) and zinc (64Zn) emerge as favorable activation targets in the gamma-ray beam flux monitor. Notably, their utility shows a multitude of advantages in monitoring the gamma-ray beam flux typically 105 photons/s with the energy of 13.16 to 19.08 MeV under the condition of the 3 mm coarse collimator. Especially in high-flux $\gamma$-ray beam experiments can be well applied.
分类: 物理学 >> 核物理学 提交时间: 2024-02-28
摘要: 上海激光电子伽马源(Shanghai Laser Electron Gamma Source,SLEGS)是通过激光与电子逆康普顿散射产生准单能、能量连续可调的兆电子伏伽马束,是目前国际上唯一一台可连续变换碰撞角度的激光康普顿散射(Laser Compton Scattering,LCS)伽马源装置。伽马活化是研究材料特性的有效手段之一,本文介绍了上海激光电子伽马源的伽马活化平台情况、包括在线活化过程,离线低本底测量,高纯锗(High Purity Germanium,HPGe)探测器的能量效率刻度等。目前的简易低本底屏蔽使得测量系统本底计数率降低到约 5.2cps/(60 keV-3 MeV 能区)。SLEGS 伽马源的活化平台为开展伽马活化测量研究提供了有利条件,未来在核物理、核天体物理、医学应用、材料科学和环境科学等领域的研究将会发挥重要的作用。
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: In this work, the NiO 8YSZ/8YSZ half-cells for planar ASCs with the large size of 30 cm 30 cm are prepared by optimizing both the sintering characteristics and the sin- tering temperature. The shrinkage rates, open porosities and flexural strength of the half- cells are investigated systematically. The large size half-cells which are prepared by the tape-casting, co-sintering and two-step sintering method show the optimal comprehensive performances with the sintering temperature being 1350 C. The NiOþ8YSZ/8YSZ/ LSMþ8YSZ anode-supported single cells are obtained at the sintering temperature of 1050 C. The maximum measurement power at output voltage of 0.8 V of the two cells and 1.6 V of the stack can reach 32.6 W, 34.7 W and 67.3 W, respectively. The two-cells stack is successively discharged under constant current of 5 A for 316 h with the degradation rate of 1.58% kh 1 and 30 A for 1161 h with no degradation at the temperature of 750 C. The large size ASCs show the good mechanical strength and an acceptable degradation.