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CSR外靶实验终端中CsI(Tl)晶体的测试；Test of CsI(Tl) Crystal at External Target Experimental Terminal of Cooling Storage Ring
No full text为测量重离子加速器冷却储存环(HIRFL-CSR)的外靶实验终端上不同能量的γ射线,一种用于探测γ射线的高能量分辨的探测装置正在中国科学院近代物理研究所建设,该探测器由中国科学院近代物理研究所自行生长的铊激活的碘化铯CsI(Tl)晶体组成。与日本Hamamatsu公司生产的S8664-1010型雪崩光二极管(APD)耦合,测试其光输出的非均匀性和能量分辨,从测试结果给出了所需CsI(Tl)晶体合格的标准。目前已完成该γ探测球计划的六分之一,所提供的晶体合格率达94%以上
8×8单元CsI(Tl)探测阵列研制；Development of 88 CsI(Tl) array detector
No full text描述了1个8×8单元CsI(Tl)探测阵列的结构和工作原理。探测阵列的每个单元是由1块前表面21 mm×21 mm、后表面23.1 mm×23.1 mm、高50 mm的CsI(Tl)棱台、1块光导和光电倍增管组成。在兰州放射性次级束流线(RIBLL)上对探测阵列进行测试,得到探测阵列对30 MeV质子的能量分辨可达2.7%,对170 MeV7Be可达1.5%,可很好地用于放射性束物理实验中带电粒子的鉴别
Unified fission model for proton emission
No full textThe unified fission model (UFM) combining with the phenomenological assault frequency has been carried out to investigate the proton-radioactivity half-lives of spherical proton emitters. The results are in good agreement with the experimental data and other theoretical values, and newly observed spherical proton emitters have been analyzed. Finally, the effect of angular momentum transfer on half-life of proton emission has been discussed in detail and a formula can be used to describe this relationship
2.6 s isomer of Nd-129
No full textNd-129 was produced by irradiation of an enriched target of Ru-96 with a Ar-36 beam and studied by using a helium-jet fast tape transport system in combination with X-gamma and gamma-gamma coincidence measurements. A 2.6s isomer of Nd-129 was observed for the first time and tentatively proposed to be the configuration of 1/2[411]
Elastic Scattering of He-6 + p at 82.3 MeV/nucleon
No full textDifferential cross sections for the elastic scattering of halo nucleus He-6 on proton target were measured at 82.3 MeV/u. The experimental results are well reproduced by optical model calculations using global potential KD02 with a reduction of the depth of real volume part by a factor of 0.7. A systematic analysis shows that this behavior might be related to the weakly bound property of unstable nuclei
Emittance estimation by an ion optical element with variable focusing strength and a viewing target
No full textThe emittance of an extracted ion beam can be estimated to first order by a series of three linear independent profile measurements. This estimation is restricted to the evaluation of an upper limit of the emittance value for a homogeneous, nonfilamented beam. The beam is assumed to be round, respectively elliptical, without any structure of the intensity distribution, no space charge has been assumed for the drifting beam, and the optics is assumed to be linear. Instead of using three different drift sections, a linear focusing element with three different focusing strengths can be used. Plotting the beam radius as function of focusing strength, three independent solutions can be used to calculate the Twiss parameters alpha, beta, and gamma and furthermore the emittance epsilon. Here we describe the measurements which have been performed with the SECRAL ion source at Institute of Modern Physics Lanzhou
NUCLEON-NUCLEON CROSS SECTIONS IN ISOSPIN ASYMMETRIC NUCLEAR MATTER
No full textThe in medium nucleon-nucleon (N N) cross sections in isospin asymmetric nuclear matter at various densities are investigated in the frame work of Brueckner-Hartree-Fock theory with the Bonn B two-body nucleon-nucleon inter action supplemented with a new version microscopic three-body force (TBF). The TBF depresses the amplitude of cross sections at high density region. At low densities, the proton-proton and neutron-neutron cross sections decrease while the proton-neutron one increases as the asymmetry increases. But the sensitivity of the N N cross sections to the isospin a symmetry are reduced with the increasing density
Stress Analysis of the Superconducting Magnet of LPT
No full textThe superconducting magnet of the LPT (Lanzhou Penning trap) consists of nine coaxial coils. The maximum magnetic field is 7 T and thus results in a large magnetic force. In order to assure the mechanical stability, it is necessary to do the stress analysis of the magnet system. The 3D Finite Element Analysis of thermal and mechanical behavior was presented in this paper. For the numerical simulation and analysis of the phenomena inside the structure, the ADINA and TOSCA code were chosen right from start. The ADINA code is commonly used for numerical simulations of the structure analysis [1] and the TOSCA code is professional software to calculate the magnetic field and Lorentz Forces. The results of the analysis were evaluated in terms of the stress and deformation
DISSOCIATIVE RECOMBINATION OF PROTONATED PROPIONITRILE, CH3CH2CNH+: IMPLICATIONS FOR TITAN'S UPPER ATMOSPHERE
No full textThe dissociative recombination of protonated propionitrile, CH3CH2CNH+, has been investigated at the heavy ion storage ring, CRYRING, at the Manne Siegbahn Laboratory, Stockholm University, Sweden. The thermal rate coefficient has been deduced to follow k(T) = (1.5 +/- 0.2) x 10(-6) (T/300)(-0.76) (+/-) (0.02) cm(3) s(-1) for electron temperatures ranging from similar to 10 to similar to 1000 K. Measurements of the branching fractions were performed at similar to 0 eV relative kinetic energy. It has been found that in 43% +/- 2% of the reactions the four heavy atoms remain in the same product fragment. An equal portion of the reactions leads to products where one of the heavy atoms is split off from the other three and 14% +/- 1% result in a breakup into two heavy fragments containing two heavy atoms each. We discuss the significance of the data to Titan's upper atmosphere
Design and Simulation Studies of CsI(Tl) Scintillator Detector Array for External Target Facility at HIRFL-CSR
No full text近几十年来， 利用高能的放射性束来研究滴线附近的奇异核性质引起了人们巨大的
兴趣。随着兰州重离子加速器冷却储存环的顺利建成，更高能量和更多种类的束流可以
被用于实验，大大拓展了兰州重离子研究装置上可开展的核物理实验研究内容。
伽玛球探测器是 CSR 主环系统外靶实验装置中关键探测器之一， 主要用于测量质心
系能量直到10 MeV的γ射线。该探测器可以提供γ总能量、γ多重性以及单γ射线能量的
测量。本论文根据 CSR 可供束流的运动学特性，完成了伽玛球探测器构型的设计。伽
玛球探测器共含有4608 个探测单元，使用 CsI(Tl)闪烁体作为探测介质，使用雪崩光二
极管作为读出器件。为优化探测器构型使其满足设计要求，建立了该探测器的蒙特卡罗
模拟平台以及单元探测器的细致模拟程序。并进一步研究了伽玛球探测器测量质心系
0.5 MeV至10 MeV的 γ射线时的性能，通过事件重构得到了探测效率（>83%）和能量
分辨（5%@5 MeV）等性能指标。
在探测单元的设计和研制中，重点研究了光子读出器件、晶体包装材料等对单元性
能的影响。对于能量为 662 keV 的 γ 射线，不同探测单元的能量分辨平均约为 6%
（FWHM） ，光收集的均匀性好于5%