Summary
The mean lives of some levels in27Si have been measured with the Doppler-shift attenuation method, by means of the28Si(3He, α)27Si reaction. The γ-rays were detected in coincidence with alphas at the angle ϑ=60°. The results for the mean lives are the following:τ m =(1.8±0.6) ps, (65 +40−35 ) fs, > 5 ps and < 63 fs for the 0.957, 2.162, 0.781 and 2.647 MeV levels, respectively.
Riassunto
Si sono misurate le vite medie di alcuni livelli eccitati del27Si col metodo dello spostamento Doppler attenuato. La reazione usata per ottenere il27Si eccitato era28Si(3He, α)27Si all’energiaE τ =6.6 MeV. I raggi γ venivano rivelati in coincidenza con le particelle α emesse a (60 ± 5)° rispetto alla direzione del fascio incidente. I risultati per le vite medie sono i seguenti:τ m =(1.8±0.6) ps,τ m =(65 +40−35 ) fs,τ m > 5 ps eτ m < 63 fs, rispettivamente, per i livelli a 0.957, 2.162, 0.781 e 2.647 MeV.
Реэюме
Испольэуя реакцию28Si(3He, α)27Si, были иэмерены средние времена жиэни некоторых уровней в27Si с помошью метода, основанного на уменьщении допплеровского сдвига. γ-лучи детектировались по совпадению с альфа-частицами при угле ϑ=60°. Реэультаты для средних времен жиэни следуюшие: τ m =(1.8±0.6) рs, (65 +40−35 ) fs, > 5 рs и > 63 fs соответственно для уровней 0.957, 2.162, 0.781 и 2.647 МзВ.
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Bini, M., Bizzeti, P.G. & Bizzeti-Sona, A.M. Lifetimes of lower excited states in27Si. Nuov Cim A 6, 543–552 (1971). https://doi.org/10.1007/BF02723385
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DOI: https://doi.org/10.1007/BF02723385