Lifetime measurements of the yrast 8 + and 9 + states in As 70

The lifetimes of the yrast 8(+) and 9(+) states of As-70 have been measured via the gamma-ray lineshape method following population by the Be-9 (Rb-78, As-70) reaction at 101.6 MeV/nucleon. The strength of the E1 8(+) -> 7(-) transition is found to be B(E1) = 1.3(5) x 10(-5) e(2) fm(2) or 1.2(4) x 10(-5) Weisskopf units (W.u.) while the 9(+) -> 8(+) M1 transition is found to have a strength of B(M1) = 1.5(8) mu(2)(N) or 0.85(42) W.u. The implications for the structure of these states is discussed and found to be consistent with an assignment to a pi g(9/2)nu g(9/2) configuration.