Peculiarities of the energy release in the solar flare observed at 00:18 UT on April 22, 1994

The development of energy-release processes in the solar flare that began at soft X-ray energies at 00:18 UT on April 22, 1994, is here discussed. The soft X-ray emission was detected by the IRIS X-ray spectrometer, which was included in the scientific payload for an international research project to investigate solar activity and solar-terrestrial phenomenon on board the automated orbiting station CORONAS-I. Analysis of the energy spectra and time profiles of the soft X-ray radiation suggests that the usual expansion of the flare volume during the late stages of the flare did not occur in this event. On the contrary, it appears that the flare plasma may have been thermally insulated.