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激光具有高强度、 高极化度等优异的性能。 用激光束轰击高能电子束就可以产生高强度、 高极化度的γ射线束。 上海激光电子γ源就是上海同步辐射装置上的这样一条束线站。 预计可以获得能量范围为1—22 MeV的准单色、 高强度(109—1011 s-1)和高极化度(线极化或圆极化)的γ射线束。 介绍了这条束线站目前的进展情况。 Shanghai Laser Electron Gamma Source (SLEGS) is a high intensity,short pulse and compact γ ray source which is based on inverse Compton scattering via interaction between pulsed high power laser beams and picosecond relativistic electron bunches. One of the attractive features of the laser Compton scattering is the easy control of polarization of the produced high energy photons that duplicates polarization of the applied laser beam. The γ ray with energy up to 22 MeV and intensity of 109—1011s 1 are expected to be produced by Compton backscattering of CO2 laser photons on the 3.5 GeV electrons bunches in the Shanghai Synchrotron Radiation Facility (SSRF). In this communication, we report same simulation results and the progressing status of SLEGS. 相似文献
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符长波 陈勋 陈云华 崔祥仪 方德清 Karl Giboni Franco Giuliani 韩柯 季向东 巨永林 刘江来 马余刚 冒亚军 任祥祥 谈安迪 王宏伟 王萌 王秋宏 王思广 吴士勇 肖梦蛟 谢鹏伟 杨勇 张宏光 张涛 赵力 周宁 周小鹏 《原子核物理评论》2017,34(3):290-295
PandaX是位于四川的中国锦屏地下实验室(CJPL)内的,利用氙作为工作物质,探测暗物质等其它极稀有事件的大型地下粒子探测实验计划。PandaX探测器中的氙工作在气液两相的模式。通过检测液相和气相中闪烁光强的比例,实现对目标粒子包括WIMP和Axion等疑似信号的鉴别。PandaX已顺利完成了有效区体积约为120 kg氙的一期计划,目前正在运行实施有效区体积约为500 kg氙的二期计划。在WIMP质量为45 GeV/c2附近,探测灵敏度达2.97×10-45 cm2(90%置信度),没有发现WIMP疑似信号。本工作介绍了PandaX一期和二期的进展,以及后续升级计划,其中包括升级PandaX的时间投影室至4吨,建造用于屏蔽岩石放射性本底的水屏蔽,以及136Xe双贝塔衰变的研究计划等。PandaX is a xenon-based dark matter and other rare events searching project located at China JinPing underground Laboratory (CJPL), Sichuan province, China. Dual phases, liquid and gas phase of xenon are used in the detector. Particles, including Weak Interaction Massive Particles (WIMPs) or axions etc., may induce scintillating signals in both liquid (S1 signal) and gas (S2 signal) phases, and then are identified by analyzing the ratio of S1 and S2. The PandaX had completed its first stage, the 120 kg in fiducial volume, and now is running in its stage Ⅱ with fiducial volume of 500 kg. The running results show that the WIMP-matter cross section detecting sensitivity of about 2.97×10-45 cm2(90% C.L.) has been achieved at a WIMP mass of 44.7 GeV/c2, and no WIMP candidates are identified. The upgrading plan of the PandaX is discussed, which include to build a larger Time project chamber (TPC) of about 4 tons, a water tank for radiation shielding, and the plan of 136Xe double beta decay studies. 相似文献
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系统地研究“颈”发射过程中的中等质量碎片,能使我们更好地理解中能核反应的动力学和热力学性质.采用具有不同的同位旋靶核研究了靶同位旋与中等质量碎片的关系,以及区分反应过程中类弹、类靶产生的中等质量碎片和“颈”发射过程中产生的中等质量碎片.HJ4/9] By systematic study of the IMF produced the “neck”emission process, one can understand much better about the dynamics and thermodymanics of the intermediate energy nuclear reaction. The isospin dependence of IMF emission was studied for the reaction system with different isospin target nucleus and the different IMF production mechanisms that originate from projectile like、 target like and the “neck” were distinguished. 相似文献
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Scaling of anisotropic flows and nuclear equation of state in intermediate energy heavy ion collisions 下载免费PDF全文
Elliptic flow ($v_2$) and hexadecupole flow ($v_4$) of light
clusters have been studied in detail for 25 MeV/nucleon $^{86}$Kr
+ $^{124}$Sn at large impact parameters by using a quantum
molecular dynamics model with different potential parameters. Four
sets of parameters including soft or hard equation of state (EOS)
with or without symmetry energy term are used. Both
number-of-nucleon ($A$) scaling of the elliptic flow versus
transverse momentum ($p_{\rm t}$) and the scaling of $v_4/A^{2}$ versus
$(p_{\rm t}/A)^2$ have been demonstrated for the light clusters in all
above calculation conditions. It is also found that the ratio of
$v_4/{v_2}^2$ maintains a constant of 1/2 which is independent of
$p_{\rm t}$ for all the light fragments. Comparisons among different
combinations of the EOS and the symmetry potential term show that
the above scaling behaviours are sound and independent of the
details of potential, while the strengths of flows are sensitive
to the EOS and the symmetry potential term. 相似文献
99.
In this paper, the isotopic and isotonic distributions of projectile fragmentation products have been simulated by a modified statistical abrasion--ablation model and the isoscaling behaviour of projectile-like fragments has been discussed. The isoscaling parameters α and β have been extracted respectively, for hot fragments before evaporation and cold fragments after evaporation. It looks that the evaporation has stronger effect on α than β. For cold fragments, a monotonic increase of α and β with the increase of Z and N is observed. The relation between isoscaling parameter and the change of isospin content is discussed. 相似文献
100.
用晶格气体模型系统地研究了 129Xe热发射体的轻粒子、带电粒子和中间质量碎片的发射特性,发现了在温度5—5.5MeV区间,以上物理量的平均多重性和发射源的最大碎片余核及源的热激发能随温度变化的斜率存在着各自的峰值,同时它们的分布宽度(即涨落)也存在着最大值.进一步研究发现在5—5.5MeV区间,这些宽度随温度的变化的斜率显示了明显的不连续性.所有这些特征说明了在5—5.5MeV的拐点温度处,最大的临界涨落是自发地伴随着相变和临界现象.
关键词: 相似文献