Knockout reaction induced by ~6 He at 61.2 MeV/u

A knockout reaction induced by ⁶He at 61.2 MeV/u was carried out at the HIRFL-RIBLL radioactive beam line. The α core fragments at forward angles were detected in coincidence with the recoiled protons at large angles. From this coincident measurement the valence nucleon knockout mechanism and the core knockout mechanism can be separated according to the polar angle correlation between the core fragments and the recoiled protons. It is demonstrated that, when reconstructing the resonant state of a weakly bound nucleus, the contamination resulting from the core knockout mechanism should be eliminated in order to obtain the correct structure information.     

A New Measurement of ~(11)Be(p,d) Transfer Reaction

A new11 Be(p,d) transfer reaction experiment is performed in inverse kinematics with a radioactive11 Be beam at26.9 MeV. Three low-lying states, namely the 0+ground state, the 2~+ state at E_x = 3.37 MeV, and the multiplet at around 6 MeV in10 Be, are populated by this one-neutron transfer reaction. These three states in10 Be are clearly discriminated from the -value spectrum, which is rebuilt from energies and angles of the recoil deuterons in coincidence with10 Be. A spectroscopic factor for each state is extracted by comparing the experimental differential cross sections to the theoretical calculation results using the finite range adiabatic distorted wave approximation method with different global nucleon-nucleus potentials. It is found that the newly extracted spectroscopic factors for the 0+and 2+states are consistent with the previous ones, but the factor for the multiplet is smaller than the value in the reference, and the possible reason is discussed.     

Characteristics of a 4-fold segmented clover detectore

Four high-purity germanium 4-fold segmented Clover detectors have been     

A CsI(Tl) detector array used in the experiment of the proton-rich nucleus 17Ne

To investigate the configurations of the valence protons in Borromean nucleus ¹⁷Ne, a CsI(Tl) detector array, which consists of 9 CsI crystals (26×26×20mm³) coupled with photodiodes, has been successfully used in the ¹⁷Ne experiment to measure the energy of protons. In order to find the optimal working conditions and get the best energy resolutions, several technologies (including various wrapping materials, wrapping and coupling methods) have been used. The testing results showed that the best energy resolution of the CsI(Tl) is about 3.3% using the ²⁴¹Am α-source. The primary testing results with the proton beam were also provided.     

Study of a multi-wire proportional chamber with a cathode strip and delay-line readout

The design principle for a multi-wire proportional chamber with a cathode strip and delay-line readout is described. A prototype chamber of a size of 10 cm×10 cm was made together with the readout electronics circuit. A very clean signal with very low background noise was obtained by applying a transformer between the delay-line and the pre-amplifier in order to match the resistance. Along the anode wire direction a position resolution of less than 0.5 mm was achieved with a ^55Fe-5.9 keV X ray source. The simple structure, large effective area and high position resolution allow the application of a gas chamber of this kind to many purposes.     

Φ76mm×100mmBGO闪烁探测器探测效率测量

用若干低能(p,γ)共振核反应产生的单能光子测得Φ76mm×100mmBGOγ探测器在17.65、17.23、6.13MeV三个能量点下的全能峰本征探测效率分别为7%、9%和22%.     

共振核反应产额曲线的退卷积处理

在利用共振核反应测元素浓度的深度分布时,共振宽度和能量歧离等严重影响测量的精度。本文详细讨论了对共振核反应产额曲线作退卷积处理的原理和方法,介绍了自行编写的一组通用程序,并对处理结果作了举例说明。实际应用表明,我们采用的方法能有效地减小共振宽度,能量歧离等的影响,适用于多种类型的产额曲线处理。尤其当元素的分布区域比较窄时,退卷积处理可大大改善对元素深度分布状况的估计。     

用C语言编写的γ-电子级联过程的蒙特卡罗模拟程序GET

用C语言编写成γ-电子级联过程的蒙特卡罗模拟程序,可在IBM系列微机上运行。程序可实时显示粒子输运与反应的模拟物理过程,并可有选择地累积各种谱。结果以事件方式与谱方式记录,可进行数据再处理。目前适用γ能区为0.1~500MeV,可扩展至其他能区。程序可用于γ探测器研制、核辐射防护和核医学等领域。     

铅散裂靶参数的初步研究

在束流能量为150MeV的前提下计算了中子产额对铅靶尺寸的依赖性.选择某一靶尺寸后讨论了靶系统的放射性活度随时间的变化.最后则比较了不同靶尺寸下的中子能谱.