Title: Emulation of the space radiation environment for materials testing and radiobiological experiments,
Abstract: Radiobiology studies on the effects of galactic cosmic ray radiation utilize
mono-energetic single-ion particle beams, where the projected doses for
exploration missions are given using highly-acute exposures. This methodology
does not replicate the multi-ion species and energies found in the space
radiation environment, nor does it reflect the low dose rate found in
interplanetary space. In radiation biology studies, as well as in the
assessment of health risk to astronaut crews, the differences in the biological
effectiveness of different ions is primarily attributed to differences in the
linear energy transfer of the radiation spectrum. Here we show that the linear
energy transfer spectrum of the intravehicular environment of, e.g.,
spaceflight vehicles can be accurately generated experimentally by perturbing
the intrinsic properties of hydrogen-rich crystalline materials in order to
instigate specific nuclear spallation and fragmentation processes when placed
in an accelerated mono-energetic heavy ion beam. Modifications to the internal
geometry and chemical composition of the materials allow for the shaping of the
emerging field to specific spectra that closely resemble the intravehicular
field. Our approach can also be utilized to emulate the external galactic
cosmic ray field, the planetary surface spectrum (e.g., Mars), and the local
radiation environment of orbiting satellites. This provides the first instance
of a true ground-based analog for characterizing the effects of space
radiation.