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Hydrodynamic simulations of classical novae on ONe white dwarfs predict substantial production of 22 Na. Observation of 22 Na decay should be correlated with the corresponding nova because the half life of 22 Na is only 2.6 years. The 1275-keV gamma ray from the β decay of 22 Na is, therefore, an excellent diagnostic for the nova phenomenon and a long-sought target of gamma-ray telescopes. Nova simulations determine the maximum 22 Na-detection distance to be < 1 kpc for the INTEGRAL spectrometer SPI, consistent with its non-observation to date. However, model estimates are strongly dependent on the thermonuclear rate of the 22 Na(p, γ) 23 Mg reaction, which destroys 22 Na in novae. The 22 Na(p, γ) 23 Mg rate is expected to

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We have measured the angular asymmetry in the (γ, n) reaction on natural lead, cadmium, and calcium in the energy region of the isovector quadrupole resonance (20–40 MeV). The asymmetry increases from low values, about 0.2, to high values, 0.6–0.8, where this resonance is expected. This increasing asymmetry is interpreted as resulting from the interference between the E1 and E2 isovector amplitudes. We have fitted direct−semidirect calculations for lead and cadmium and have obtained resonance energies of 23.5 ± 1.5 and 26.5 ± 1.5 MeV for these elements, respectively. For calcium, preliminary results indicate a resonance energy of 34 ± 2 MeV. The widths are found to be considerably larger than those of the E1 resonance.