112 BENSON, GLEIT, AND LEVENTHAL | > w Oo < oO — Littl | I a 2 ° + por, [ Letty BACKGROUND L Ty + 145 DAYS ° tpi Ty + 42 DAYS =p —— 140, Tt ToT — ARBITRARY UNITS — _ 107 Litittl r 106 0.2 0.4 0.6 0.8 1.0 ENERGY, MEV Fig. 2—Particle gamma spectrum. 1.2 1.4