Radiation measurement on the International Space Station

The results of an investigation of radiation environment on board the ISS with apogee/perigee of 420/380 km and inclination 51.6° are presented. For measurement of important characteristics of cosmic rays (particles fluxes, LET spectrum, equivalent doses and heavy ions with Z ⩾ 2 ) a nuclear photographic emulsion as a controllable threshold detector was used. The use of this detector permits a registration of the LET spectrum of charged particles within wide range of d E / d x and during last years it has already been successfully used on board the MIR station, Space Shuttles and “Kosmos” spacecrafts. An integral LET spectrum was measured in the range 0.5– 2.2 × 10 3 keV / μ m and the value of equivalent dose 360 μ Sv / day was estimated. The flux of biologically dangerous heavy particles with Z ⩾ 2 was measured ( 3.85 × 10 3 particles / cm 2 ) .