Lifetimes of States in 62,64Cu and 67,70Ga

Abstract

The Doppler shift attenuation method of lifetime determination has been employed following the 62.6 4 Ni(p, ny)62.6 4 Cu and 67. 70Zn(p, ny)67. 70Ga reactions. The lifetime of the 62CU state at 637 keY was found to be 220 :':1~g fs; lower limits of 230 and 250 fs were set for the levels at 426 and 548 keYrespectively. For 64 CU, a lower limit of 175 fs was set for both the 609 and 663 keY states. Lifetimes in 67Ga were determined for the indicated levels as: 828 keY, 280 +igg fs; 911 keY, 370 :,:~~g fs; 1412 keY, 900 :,:~~go fs; 1519 keY, 750 :,:!ggo fs; 1555 keY, 190 :,:~g fs; 1639 keY, 150 :,:!g fs; 2041 keY, 150 :,:~g fs; and 2174 keY, 80 :':jg fs. Lower limits of 600 and 110 fs were set on the lifetime values for the 1202 and 1978 keY levels respectively. Similarly, lower limits on the lifetimes of the 70Ga levels at 1203 and 1245 keY were set at 320 and 720 fs, while values for the 1312 and 1446 keY levels of 70Ga were found to be 245 :':~~ and 390 :':~~~ fs.