5.1 Space Radiation Physics and Biology

Exposure to space radiation will be a limiting factor in future missions beyond low Earth orbit, such as to Mars. Mission durations will range from many days to weeks and many months, all spent outside the geomagnetic field, exposed to chronic galactic cosmic rays (GCR) as well as periodic solar particle events (SPE). Experiments in space are difficult and expensive. While it is not feasible to replicate the full space radiation environment on the ground, some particle accelerators are capable of producing significant components of the GCR. From the late 1990s through the present day HIMAC has been one of the most important such facilities. In this section we review a number of experiments in which HIMAC has been used to further international research in space radiation physics and biology, including radiation shielding, detector development for crewed and robotic spacecraft, radiation effects on biological organisms and electronics.