A massive bolometer on the international space station to measure energy deposition by the space radiation environment

We describe a novel space-based low-temperature radiation detector, the “Particle Heating Detector” (PhD), which was recently selected to be part of the first mission of the Low-Temperature Microgravity Physics Facility, scheduled to fly on the International Space Station in 2008. This massive bolometer will measure total heating induced in an aluminum absorber by the space radiation environment. The use of paramagnetic alloy thermometers with SQUID readout, giving 0.3 nK/Hz resolution, combined with a large-area absorber, will enable the detector to perform high-resolution, real-time measurement of the low energy deposition levels caused by galactic cosmic rays in low-Earth orbit.