Nuclear Structure ofNa22.I. Gamma-Ray Correlations and Lifetime Measurements for Levels ofEex<3.1MeV

摘要: Levels of ${\mathrm{Na}}^{22}$ below an excitation energy 3.1 MeV have been investigated through the ${\mathrm{F}}^{19}(\ensuremath{\alpha}, n\ensuremath{\gamma}){\mathrm{Na}}^{22}$ and ${\mathrm{Ne}}^{20}({\mathrm{He}}^{3}, p\ensuremath{\gamma}){\mathrm{Na}}^{22}$ reactions. Gamma-ray spectra from first reaction were recorded with 8-cc Ge(Li) detector at 90\ifmmode^\circ\else\textdegree\fi{}, 0\ifmmode^\circ\else\textdegree\fi{}, 166\ifmmode^\circ\else\textdegree\fi{} to $\ensuremath{\alpha}$ beam using Ca${\mathrm{F}}_{2}$ targets energies between 4.0 7.0 MeV. Spectra similarly 90\ifmmode^\circ\else\textdegree\fi{} for ${E}_{{\mathrm{He}}^{3}}=5.65$ in second reaction. These studies supplemented by $\ensuremath{\gamma}\ensuremath{-}\ensuremath{\gamma}$ coincidence measurements both NaI(Tl)-NaI(Tl) NaI(Tl)-Ge(Li) $\ensuremath{\gamma}$-ray combinations. angular distributions measured ${E}_{\ensuremath{\alpha}}=5.48$ n){\mathrm{Na}}^{22}$ $p\ensuremath{-}\ensuremath{\gamma}$ correlations p){\mathrm{Na}}^{22}$ From these decay modes determined levels 3.1-MeV excitation, information on spin-parity isotopic-spin assignments was obtained, values or limits mean lifetimes extracted observations Doppler shifts. An assignment $T=1$ made 1.952-MeV level; all other range $0.7l{E}_{x}(\mathrm{MeV})l3.1$ assigned $T=0$. Upon combining our results previously available information, we deduce following lifetime ${{E}_{\mathrm{ex}}(\mathrm{MeV})[{J}^{\ensuremath{\pi}}; {\ensuremath{\tau}}_{m}(\mathrm{psec})]}$ third eleventh ${\mathrm{Na}}^{22}$: 0.891 (${4}^{+}$; g8), 1.528 (${3}^{+}$, ${5}^{+}$; 3.8\ifmmode\pm\else\textpm\fi{}0.9), 1.937 (${1}^{+}$; 0.06), 1.952 (1, 2; 0.09), 1.984 (${2}^{+}$, ${3}^{+}$; 1.6\ifmmode\pm\else\textpm\fi{}0.34), 2.211 (1; g11), 2.572 (\ensuremath{\le}3; g10), 2.969 0.14), 3.059 0.09). The combined influence effects initial states shapes full-energy-loss peaks \ensuremath{\rightarrow} 0 0.583 transitions is quite marked. analysis obtain given above described detail. Some incidental concerning ${\mathrm{F}}^{19}$ ${\mathrm{Ne}}^{22}$ Appendix.