SINGLE PARTICLES FROM HIGH-YIELD AIR BURSTS TT TTT TTT ttt Tg = | TT 105 oO ' Nn _ o ' ow BETA ACTIVITY (RELATIVE SCALE) 107! 1074 103 ft ‘ tL 10 te tT ttt DECAY TIME, DAYS 100 1000 Fig. 5—Beta-activity decay of unfractionated ?®U and Pu fissionproduct mixtures.