Nuclear physics and space radiation

Abstract

Abstract. Nuclear fragmentation reactions induced by alpha particle projectiles are an important component of the space radiation problem. Inclusive isotopic spectral distributions and double differential cross sections are used as input to the Boltzmann transport equation, which is often solved in many space radiation applications. For alpha particle projectiles, it is found that most of the available experimental data are below the pion threshold. This is a significant validation gap because the important energy range for galactic cosmic rays extends up to 10 GeV/n and above.

Space radiation accelerator experiments – The role of neutrons and light ions

“…Nuclear reactions cross sections are key inputs to such transport calculations. Unfortunately, it is precisely the neutron and light ion cross sections that represent the most significant gaps in the experimental database (Nakamura and Heilbronn, 2007;Norbury et al, 2011;. The validation of transport codes makes it important to close these gaps with a program of experimental measurements and associated nuclear reaction model development.…”

Are Further Cross Section Measurements Necessary for Space Radiation Protection or Ion Therapy Applications? Helium Projectiles

“…Previous analyses of experimental data [1][2][3][4] focused on measurement gaps for space radiation. The highest priority measurement recommendations were double differential cross sections for the following ion 2 reactions, He, C, O, Si, Fe + H, C, O, Al, Fe → 1,2,3 H, 3,4 He + X,…”

“…Space radiation protection and ion therapy applications need reliable nuclear reaction models and transport codes for energetic particles in matter. Neutrons and light ions ( 1 H, 2 H, 3 H, 3 He, and 4 He) are the most important secondary particles produced in space radiation and ion therapy nuclear reactions; these particles penetrate deeply and make large contributions to dose equivalent. Since neutrons and light ions may scatter at large angles, double differential cross sections are required by transport codes that propagate radiation fields through radiation shielding and human tissue.…”

Measurements of $^{12}$C ions fragmentation cross sections on a thin gold target with the FIRST apparatus

“…The study of the nuclear fragmentation processes occurring in the interaction of highly energetic ions in matter is of great interest both in basic research (e.g. to improve the understanding of hadronic showers development in the atmosphere) and in applied physics, in particular in cancer therapy and space radiation protection fields [1,2]. Accurate measurements of fragmentation cross sections of light ions interacting with elemental and composite targets are crucials to benchmark and improve the nuclear interaction models implemented in Monte Carlo (MC) simulation codes.…”

“…In particular, while the fluences and the total cross sections are currently well described, the production of light fragments and their angular distribution is affected by large uncertainties and different algorithms are predicting yields that can differ up to an order of magnitude. The NASA completed a survey of a large data base [2] of measured nuclear fragmentation cross sections including approximately 50000 data sets, and concluded that several experimental data are missing: accurate measurements of DDCS of light ions in the energy range 100 -1000 MeV/nucleon are, hence, urgently needed to improve nuclear interaction models and are also of great interest in the fields of ion therapy for the treatment of tumors and of space radioprotection.…”