Spallation and fragmentation cross sections for 168 MeV/nucleon Xe136 ions on proton, deuteron, and carbon targets

Abstract

The spallation and fragmentation reactions of 136 Xe induced by proton, deuteron, and carbon targets at 168 MeV/nucleon were studied at RIKEN Radioactive Isotope Beam Factory via the inverse kinematics technique. A wide range of isotopic distributions of the reaction cross sections has been obtained and systematically analyzed by using the Particle and Heavy Ion Transport code System (PHITS) including dynamical and intranuclear cascade processes plus evaporation process, the semi-empirical parametrization for residue cross sections in spallation reactions (SPACS) and empirical parametrization of fragmentation cross sections (EPAX), and the deuteron-induced reaction analysis code system (DEURACS) incorporating the deuteron breakup effect. The carbon target has exhibited strong potential to produce light-mass isotopes far away from the projectile, in comparison to proton and deuteron targets. This may be attributed to the possible higher excitation energies of the prefragment induced by heavier target. It is demonstrated that the deuteron target has advantages to produce isotopic chains very close to the projectile and also the neutron-rich nuclei in other isotopic chains far away from the projectile, due basically to its structure property and the effect of the breakup neutron in the peripheral collision processes. The proton target has the advantage of being able to produce isotopes produced via charge-pickup reactions in comparison to other targets. The prediction powers of various calculation codes are examined with respective to the experimental isotopic distributions. The target and energy dependences of the produced mass distributions are also discussed.

Light fragment and neutron emission in high-energy proton induced spallation reactions *

“…In material science, neutrons produced by spallation neut-ron sources are used to probe the properties of condensed matter [14,15]. Other applications include the production of rare isotopes [16][17][18][19], cancer therapy [20][21][22], uses in biology [11], and cosmography [23]. Because of the diversity of the applications, as mentioned above, the broad range of reaction conditions, including variations in beam energy and target size, and the complicated reaction mechanisms that spallation reactions entail, great challenges have been imposed on the experimental measurements of the yields and kinematics of spallation products, on the calculation of related observables, and on the theoretical understanding of the underlying mechanisms through which the spallation products emerge.…”

质子诱发核散裂反应中产物截面的贝叶斯神经网络预测方法

“…在医疗上,利用中高能质子与物 质作用的布喇格峰特性, 可以开展肿瘤癌变治疗, 精 准杀死癌细胞,但对周围正常细胞和组织的损伤较 小 [8,9], 从而形成技术优势. 由于散裂反应在核物理、核天体和核能利用中 的重要作用, 世界各国主要的加速器和实验室开展 了大量的中高能质子诱发核散裂反应的实验测量 研究.这些实验研究的数据可以大体上分为两类,一 类是对核散裂反应中产生的余核截面的测量,主要 是为了研究核反应机制和核反应产物的性质,例如 参考文献 [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]; 另一类实验主要为了满足核天 体物理研究的需求,重点围绕在不同能量下某个核 反应中余核的激发曲线测量,用以对宇宙成因核素 的激发曲线性质进行系统的理解 [25]. 在散裂反应 理论方面, 人们试图重现发射粒子的能量、 角分 布,以及余核的质量、 电荷和同位素分布等,从而研 究散裂反应的内部机制.现已发展的理论模型有包 括量子分子动力学模型(QMD) [26]、 统计多重碎 裂模型(SMM) [27][28][29]、 级联模型(INC) [30,31] 等.…”