一套液闪快中子探测系统

介绍了一种在强γ辐射场中探测快中子的探测系统，利用实验室n－γ放射源，调试了系统n－γ甄别性能，确定了其最佳工艺状态。运用Monte-Carlo数值模拟，从理论上计算了模拟探测器的探测效率，并与实验测量结果进行了对比分析。     

Experimental Study of Two-Neutron Correlation in ~8He~+

A neutron detector array was used in a breakup reaction experiment at RIKEN with an 82.5 MeV/u 8He beam impinging on the CH2 and C targets. The array was calibrated using the cosmic ray, the γ ray from the 6 He+Pb reaction and the mono-energetic neutrons from the 7Li(p, n)7Be(g.s.+0.43 MeV) reaction. The position resolution, timing resolution and neutron detection efficiency were obtained accordingly. Cross-talk rejection conditions were developed based on analysis of the data taken from the 7Li(p, n) 7Be(g.s.+0.43 MeV) test experiment, and finally a preliminary two-neutron correlation function for the 8 He breakup reaction was investigated.     

The Design and Optimization of a Neutron Time-of-Flight Spectrometer with Double Scintillators for Neutron Diagnostics on EAST

Neutron energy spectrometry diagnosis plays an important role in magnetic con-finement fusion.A new neutron time-of-flight (TOF) spectrometer with double scintillators is designed and optimized for the EAST tokamak.A set of optimal parameters is obtained by Monte Carlo simulation,based on the GEANT4 and ROOT codes.The electronic setup of the measurement system is designed.The count rate capability is increased by introducing a flash ADC.The designed spectrometer with high resolution and efficiency is capable of being applied to fusion neutron diagnostics.Applications in mixed-energy and continuous energy neutron fields can also be considered.     

Recoiled Proton Tagged Knockout Reaction for ~8He

An experiment for knockout reaction induced by 8He beam at 82.5 MeV/nucleon on CH2 and C targets was carried out. The 6He and 4He core fragments at forward angles and the recoiled protons at large angles were detected coincidently. From this exclusive measurement the valence nucleon knockout mechanism and the core knockout mechanism are separated, which can be applied to the exclusive spectroscopic study on the structure of exotic nuclei.     

低能量沉积下位置灵敏硅探测器位置畸变的修正

介绍了一种低能量沉积下位置灵敏硅探测器位置畸变的修正方法,采用了与探测器中能量沉积相关的修正因子,f(Δ1,Δ2,E)调节可调参数Δ1和Δ2,对位置畸变进行了修正,得到了很好的修正效果。     

高位置分辨平行板雪崩室的研制

描述了灵敏面积为 10 0 mm× 10 0 mm和 150 mm× 150 mm两维位置灵敏雪崩室。采用分块结构 ,电极从两端分前后点引出 ,增加了延迟线的长度 ,延迟线跨边连接和在大气中直接封真空技术。在流动的 4 2 0 Pa的正庚烷气体中 ,用2 52 Cf裂变源对探测器的性能进行了测试 ,得到Δx=Δy=1mm的位置分辨。     

Study of Isotopic Distribution of the Projectile-like Fragments Produced in the 17,18N + 197Au Reactions at 33 MeV/u

The experimental data of the isotopic distribution for projectile-like fragments are presented for the 17,18N + 197Au reaction at 33MeV/u. The width of the isotopic distributions for 18N projectile is significantly broader than that for 17N projectile, and the average N/Z ratio of the former shifts to higher neutron number side. As long as the realistic nucleon density distribution is used, the isotopic distribution for fragments is reproduced by the simple abrasion-ablation model calculation, which thus provides an independent way to determine the surface distribution of the nuclear matter density for neutron-rich nuclei.     

β-Decay of Light Neutron-Rich Nuclei

The β-decays of neutron-rich carbon,nitrogen and fluorine isotopes have been sys-tematically studied using the OXBASH shell Model.In the psd,spsd and spsdpf model space,we use the W BP interaction to calculate the half-lives and neutron emission probabilities of neutron-rich carbon and nitrogen isotopes,respectively.With the USD (W) and CW interactions,we calculate the half-lives and neutron emission probabilities of neutron-rich fluorine isotope in the sd model space,respectively.The calculated half-lives and neutron emission probabilities repro-duce recent experimental data very well.It seems to show that the particles of the neutron-rich carbon and nitrogen isotopes are mainly excited in the spsd space.The β-decay of 21N to the neutron bound states in 21O is mostly the first forbidden transition which makes the neutron emission probability increase.The theoretical calculation of β-decay of 25F to 25Ne with CW interaction shows that CW interaction is better than USD interaction.     

在25 AMeV 6 He+9 Be双中子转移反应中位置灵敏望远镜探测器的应用

叙述了25 AMeV^6He ^9Be双中子转移反应微分截面测量的实验设计思想。对某些角度望远镜探测器的构造进行了改进，并与其它探测器一起用于出射粒子鉴别。实验的初步分析结果表明：基于双中子转移反应设计的探测器布局和构造达到了实验的设计要求。     

用放射性核束进行弹性散射实验的一种角分布归一化方法

介绍了放射性核束弹性散射实验中测量的角分布进行归一化的方法。由于有限的测量角区及放射性核束有较大的发散度,采用了逐个事件计算的方法,在探测器空间分布区域用事先产生的一系列点构成的数据库模拟探测器边界,对这些点进行坐标转换,再进行选择判断,得到每个事件的几何探测效率。通过每个事件的几何探测效率推算到整个空间,得到实际的角分布。