分类: 物理学 >> 核物理学 提交时间: 2016-09-06
摘要: As a part of the effort to investigate the implications of dark matter (DM)-nucleon effective interactions on the solar DM detection, in this paper we focus on the evaporation of the solar DM for a set of the DM-nucleon spin-independent (SI) effective operators. In order to put the evaluation of the evaporation rate on a more reliable ground, we calculate the non-thermal distribution of the solar DM using the Monte Carlo methods, rather than adopting the Maxwellian approximation. We then specify relevant signal parameter spaces for the solar DM detection for various SI effective operators. Based on the analysis, we determine the minimum DM masses for which the DM-nucleon coupling strengths can be probed from the solar neutrino observations. As an interesting application, our investigation also shows that evaporation effect can not be neglectd in a recent proposal aiming to solve the solar abundance problem by invoking the momentum-dependent asymmetric DM in the Sun.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: To upgrade Hefei Light Source (HLS) Linac, eight accelerating units have been constructed to realize full-energy injection of the storage ring. Each of the units consists of two 3-m accelerators driven by one klystron. The input cavity detuning method was developed to measure and correct the phase length of the RF power distribution waveguide system. The design of the waveguide network and the principles of the detuning method are presented in this paper. After correction, the phase error between the waveguide of the two accelerators was less than �0.5�, and the maximum electron energy of Linac reached 805 MeV, which is very near the theoretical maximum value of 810 MeV. These results demonstrate that the calibration of the waveguide was successful.
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: Two series of poly(ester imide)s derived from bis(trimellitic acid anhydride) phenyl ester (TAHQ) and bis[(3,4- dicarboxylic anhydride) phenyl] terephthalate (PAHP), as well as poly(ether imide)s based on hydroquinone diphthalic anhydride (HQDPA), were synthesized with aromatic diamines via solution polycondensation. These polyimide films were transparent with an ultraviolet-visible absorption cut-off wavelength below 375 nm, and with tensile strengths of 42.0–83.8 MPa, tensile moduli of 2.5–4.7 GPa and elongations at break of 2.1–5.4%. Compared with the poly(ether imide)s, the poly(ester imide)s showed higher glass transition temperatures (Tg), lower water absorption (WA) and lower temperature of 5% weight loss (Td5%). Moreover, the poly(ester imide)s derived from PAHP with a low electron affinity of 2.04 eV by theoretical calculation achieved better transparency, lower WA and slightly lower Tg than the corresponding TAHQ- based poly(ester imide)s.