OPTICAL DETECTION OF MAGNETIC RESONANCES OF LOOSE AGGREGATES OF F CENTERS IN KCl CRYSTAL P. A. SCHNEGG, M. ECABERT, C. JACCARD et M. A AEGERTER J. Phys. Colloques, 34 C9 (1973) C9-93-C9-96 DOI: 10.1051/jphyscol:1973915