The GAS 2 instrument is designed to detect neutral atoms (especially H) of
the solar wind with typical energies of about 1 keV. To separate fast atoms
from intense flux of photons from the sun the coincidence technique was us
ed. The instrument was tested and calibrated and it was shown that GAS 2 co
uld really measure various kinds of light neutral atoms and ions in keV ene
rgy range in the presence of ultraviolet radiation. (C) 1999 Published by E
lsevier Science Ltd. All rights reserved.