The polarization of X-ray emission of some solar flares in July 1974

Preliminary results of polarization measurements at three solar flares of July 5 and 6, 1974, are given. The measurements were performed at hγ approximately 15 keV with Thomson-scattering polarimeter on the 'Intercosmos 11' satellite. At the decay phase of the flare on July 5 the authors obtained P=3.4-5.0%, which did not exclude some contribution from non-thermal processes. At the flares of July 6 the authors found P=1.0-1.9% and P=0.1-2.0%, respectively: neither value exceeds the level of statistical fluctuations. (Auth.)