MEAN LIVES, BRANCHING RATIOS, AND EXCITATION ENERGIES OF LEVELS IN F-20 BELOW 4 MEV

The F19(d,p)F20 reaction has been used to study the mean lives, branching ratios, and excitation energies of several of the levels of F20. The Doppler-shift attenuation method was used to obtain the following information concerning the mean lives of the low-lying levels in F20: (0.66MeV)=(3. 6±0.7)×10-13 sec, (0.82MeV)4.4×10-12 sec,(0.98MeV)=(1.3-0. 4+0.6)×10-12 sec,(1.06MeV)9.2×10-14 sec, and (1.31MeV)=(1.1-0.3+0.4) ×10-12 sec. In addition, upper limits were found for levels at 2.04, 2.19, 2.96, 3.49, and 3.53 MeV. A previously unreported branching ratio of the 2.96-MeV level was found to be (2.960.0 MeV) 0.24±0.03, (2.960.66 MeV) 0.14±0.02, and (2.960.82 MeV) 0.62±0.06. A value of 3+ is suggested for the spin and parity of the 0.66-MeV level. © 1969 The American Physical Society.