Coulomb Excitation of As⁷⁵

Abstract

Coulomb excitation of As 75 was studied using protons and α-particles at the energy range from 2.1 Mev to 2.8 Mev and 3.0 Mev to 3.8 Mev respectively. Four levels of 199 keV, 280 keV, 574 keV and 810 keV were excited and gamma transition from these levels to the ground state were observed. The excitation functions and absolute cross sections of excitation were measured. The reduced transition probabilities were obtained to be 0.012±0.0025, 0.023±0.005, 0.078±0.015 and 0.044±0.013 ( e 2 ×10 -48 cm 4 ) respectively. The angular distribution of 280 keV gammarays was studied and obtained to be 1-0.182 P 2 (cos θ)+0.0035 P 4 (cos θ). The anisotropies of 199 keV, 574 keV and 810 keV gammarays were also measured as 0.04±0.04, 0.19±0.02 and 0.00±0.05 respectively. From these results the spins and parities of four levels are found to be 1/2 - , 5/2 - , 5/2 - and 3/2 - or 1/2 - . E 2– M 1 mixing parameters of 280 keV and 574 keV transitions are also obtained to be δ=0.42±0.05. and 2.4±1.0 or 0.75±0.15. No coincidence of gamma rays was found.