Lifetime measurements of excited states in 38K

Excitation energies and mean lives of levels in ³⁸K up to 3.85 MeV, excited in the ⁴⁰Ca(d,αγ)³⁸K reaction at $E_d=4.421$ MeV, have been measured using the Doppler-shift attenuation method. The γ rays were detected at 31.7 and 121.7° in coincidence with α particles detected in an annular detector with an average angle of 169°. The following mean lifetimes were found (excitation energy in keV, lifetimes in fsec): 459, > 4000; 1698, 65 ± 17; 2401, 90 ± 25; 2613, 9000₋₂₀₀₀⁺⁷⁰⁰⁰; 2646, > 12000; 2829, 280 ± 70; 2870, 4500 ± 1200; 2993, 220 ± 50; 3315, 2450 ± 420; 3342, 55; 3668, 150; 3725, 120; 3849, 55. Several spin-parity restrictions made in earlier work have been made stricter on the basis of these results.[NUCLEAR REACTION ⁴⁰Ca(d,αγ)³⁸K, $E_d=4.42$ MeV; measured αγ coin., $E_{\gamma }$, Doppler-shift attenuation. ³⁸K deduced levels E, T_1/2, B(Λ).]