“…Tritium in hydrogen was measured by Mosichev, L'vov, and Khartsizov (421) with high-frequency discharge excitation. Mosichev and L'vov (420) and L'vov, Mosichev, and Plyushch (358) described the determination of l99Hg in 198Hg by excitation in an electrodeless discharge, obtaining the required resolution with a Fabry-Perot interferometer.…”