A new model of cosmogenic tritium (³H) production in the atmosphere is presented. The model belongs to the CRAC (Cosmic Ray Atmospheric Cascade) family and is named as CRAC:3H. It is based on a full Monte Carlo simulation of the cosmic ray induced atmospheric cascade using the Geant4 toolkit. The CRAC:3H model is able, for the first time, to compute tritium production at any location and time, for any given energy spectrum of the primary incident cosmic ray particles, explicitly treating, also for the first time, particles heavier than protons. This model provides a useful tool for the use of ³H as a tracer of atmospheric and hydrological circulation. A numerical recipe for practical use of the model is appended.

中文翻译：

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大气中产Co 3H产生的新的全3-D模型（CRAC：3H）

介绍了一种在大气中产生宇宙m（³ H）的新模型。该模型属于CRAC（宇宙射线大气级联）系列，并命名为CRAC：3H。它基于使用Geant4工具包对宇宙射线诱发的大气级联进行的完整Monte Carlo模拟。CRAC：3H模型首次能够针对主入射宇宙射线粒子的任何给定能谱，在任何位置和时间计算tri的产生，这也是首次明确处理了重于质子的粒子。该模型为将³ H用作大气和水文循环的示踪剂提供了有用的工具。附有用于该模型的实际使用的数字配方。