  MIDAS is a miniature detector developed with purpose to assess the radiation
field parameters near to an astronaut. Part of the device is a spectrometer for
fast neutrons. In missions outside the geomagnetic field, fast neutrons are
secondary products of the interaction of Galactic Cosmic Ray heavy ions with
the materials in the spaceship or even the astronaut body. The Relative
Biological Effectiveness of fast neutrons is high. The neutron spectrometer
first prototype has been developed, calibrated and used for measuring 252Cf
spectra.
