Modelling the effects of a solar flare on INTEGRAL.

The delayed effects of a large solar flare proton flux on the instruments on-board INTEGRAL have been modelled. We simulated exposing INTEGRAL to a flux of 1.5×10[sup 8] protons/cm[sup 2] over a period of five days. The induced count rates due to this proton flux over an energy range of 30 MeV–2 GeV one minute after the end of the flare are 4170±30 c/s for IBIS (the imager) and 190±2 c/s for SPI (the spectrometer). We show that lowering the minimum incident proton energy range in the simulations below 30 MeV has no effect on the delayed count rate. Energy spectra indicate that there is little evolution of the spectral shape of the induced background up to 24 hours after the flare. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]