We extend the cascade-exciton model (CEM), and the Los Alamos version of the quark-gluon string model (LAQGSM), event generators of the Monte-Carlo N-particle transport code version 6 (MCNP6), to describe production of energetic light fragments (LF) heavier than 4He from various nuclear reactions induced by particles and nuclei at energies up to about 1 TeV/nucleon. In these models, energetic LF can be produced via Fermi break-up, preequilibrium emission, and coalescence of cascade particles. Initially, we study several variations of the Fermi break-up model and choose the best option for these models. Then, we extend the modified exciton model (MEM) used by these codes to account for a possibility of multiple emission of up to 66 types of particles and LF (up to 28Mg) at the preequilibrium stage of reactions. Then, we expand the coalescence model to allow coalescence of LF from nucleons emitted at the intranuclear cascade stage of reactions and from lighter clusters, up to fragments with mass numbers A < 8, in the case of CEM, and A < 13, in the case of LAQGSM. Next, we modify MCNP6 to allow calculating and outputting spectra of LF and heavier products with arbitrary mass and charge numbers. The improved version of CEM is implemented into MCNP6. Finally, we test the improved versions of CEM, LAQGSM, and MCNP6 on a variety of measured nuclear reactions. The modified codes give an improved description of energetic LF from particle- and nucleus-induced reactions; showing a good agreement with a variety of available experimental data. They have an improved predictive power compared to the previous versions and can be used as reliable tools in simulating applications involving such types of reactions.
CEM2k and LAQGSM as Event Generators for Space-Radiation-Shielding and Cosmic-Ray-Propagation Applications
CEM 2k和LAQGSM程序是洛斯阿拉莫斯国家实验室最近开发的用于模拟核反应的程序。我们已经基准我们的代码对大多数可用的测量数据在入射粒子能量从10兆电子伏到800 GeV，并将我们的结果与其他当前模型的预测核社区使用。在这里，我们提出了一个简短的描述我们的代码，并显示说明性的结果表明，CEM 2k和LAQGSM可以用作可靠的事件发生器的空间辐射屏蔽，宇宙射线传播，和其他天体物理应用。最后，我们使用我们的计算截面与实验数据一起从我们的LANL T-16编译产生评估文件，我们使用的银河系粒子传播的GALPROP模型，以更好地约束CR晕的大小。
Cross-sections for nuclide production in 56Fe target irradiated by 300, 500,750, 1000, 1500, and 2600 MeV protons compared with data on hydrogen target irradiation by 300, 500, 750, 1000, and 1500 MeV/nucleon 56Fe ions
Multifragmentation vs. Evaporation vs. Binary-Decay in Fragment Production
本文介绍了LANL完成改进的级联激子模型（CEM03.01）和洛斯阿拉莫斯夸克胶子弦模型（LAQGSM.03.01）的“S”和“G”版本的部分进展报告。“S”版本使用Botvina等人的统计多重碎裂模型（SMM）考虑了在2A MeV以上的激发能的反应预平衡阶段后产生的复合核的碎裂。（“S”代表SMM），而“G”版本使用Charity等人的裂变类二元衰变模型GEMINI描述反应的蒸发/裂变阶段。（“G”代表GEMINI），而不是使用Furihata的广义蒸发模型GEM 2，该模型已纳入这些规范的标准版本中。本文分析了最近的660 MeV p +129 I和3.65 GeV p +112 Sn JINR测量结果，COSY新的1.2 GeV p +（从Al到Th的13个核）数据，GSI 300 MeV和1 GeV p +56 Fe逆运动学测量数据，以及GSI新的1 GeV/核子124 He和136 He + Pb数据。为了更好地了解碎片生产的机制，我们讨论了几个计算，但尚未测量的这些反应，这是预测SMM，GEMINI，和GEM 2是完全不同的产品的运动学特征。我们发现这些运动学量是潜在的有用的区分这些反应机制，如果它们可以在未来的实验中测量。
