THE RELATIONSHIP BETWEEN SOLAR-FLARE GAMMA-RAY EMISSION AND NEUTRON-PRODUCTION

We have examined six solar neutron events measured by satellite instru ments and/or neutron monitors (NM) to understand the relationship betw een the intensity-time profiles of the gamma-ray lines, the pion-relat ed gamma-rays, and the neutron production. In all six events the solar neutron production was clearly time-extended. We find that neutron em ission as detected by NMs most closely follows the emission of pion-re lated gamma-rays; whereas lower energy neutron production may follow t hat of nuclear gamma-ray line emissions. Although this distinction is not unexpected, it is safe to say that the 2.223 MeV gamma-ray line fr om neutron capture on hydrogen is a poor measure of the neutron produc tion at energies >200 MeV. During the three events on 1982, June 3, 19 90, May 24 and 1991, June 4 solar neutrons with energies greater than 200 MeV were recorded by NMs. The NM increases on 1982, June 3 and 199 0, May 24 can be modeled using the time profile of the pion-related ga mma-rays. For the 1991, June 4 event the NM signal was small but laste d for similar to 60 min and the high-energy gamma-ray data available t o us are insufficient to conclude unambiguously that the high-energy n eutron production followed the pion-related gamma-rays, In the other t hree events on 1991, June 9, 11, and 15 solar neutrons with energies 1 0-100 MeV were observed by the COMPTEL gamma-ray instrument on the Com pton Gamma Ray Observatory. The duration of the low-energy neutron pro duction on 1991, June 9 corresponded clearly to the high-energy and no t to the low-energy gamma-ray emission.