Real time measurement of LET distribution in the IML-2 Space-Lab(STS-65)

The real time monitoring of environmental radiation in the Space-Lab of STS-65 (IML-2: inclination 28.5°, altitude 300 km) has been achieved successfully through the flight by a new silicon detector telescope called ``Real time Radiation Monitoring Device'' (RRMD). It consists of two 2-dimensional position sensitive silicon detectors and six diode type silicon detectors. In this monitoring, the temporal variation of rates of particle flux, together with the dose equivalent and the LET distribution at three locations in the Space-Lab, were reasonably given in real time. The LET distribution obtained by the RRMD and CR-39 track detectors measured at the same location is in good agreement except at the highest LET region > 200 keV/μm and the lowest LET region <5 keV/μm.