Alpha decay 225Ac→221Fr{}^{225}Ac \to {}^{221}Fr

In-depth investigation of (alpha-gamma)-coincidences at the sup 2 sup 2 sup 5 Ac decay is carried out. Twenty-one new weak gamma-rays are found; 18 gamma-rays earlier ascribed to the sup 2 sup 2 sup 5 Ac decay are not confirmed. The quantitative analysis of the (alpha-gamma)-coincidences makes it possible to find the intensity of population of sup 2 sup 2 sup 1 Fr levels by the alpha decay and multipolarities of five weak gamma-transitions. The conversion electron spectrum is investigated in the range of 5-24 keV with a high (some 20 eV) energy resolution. A new M1 type 10.6-keV gamma-transition is found. The proposed sup 2 sup 2 sup 5 Ac decay scheme includes 31 excited sup 2 sup 2 sup 1 Fr states. Parities are established for 16 of them. Possible spin values are proposed for sup 2 sup 2 sup 1 Fr levels. Properties of excited sup 2 sup 2 sup 1 Fr states are satisfactorily described by the quasiparticle-phonon nuclear model without the assumption of static octupole deformatio

Alpha decay sup 2 sup 2 sup 5 Ac-> sup 2 sup 2 sup 1 Fr

In-depth investigation of (alpha-gamma)-coincidences at the sup 2 sup 2 sup 5 Ac decay is carried out. Twenty-one new weak gamma-rays are found; 18 gamma-rays earlier ascribed to the sup 2 sup 2 sup 5 Ac decay are not confirmed. The quantitative analysis of the (alpha-gamma)-coincidences makes it possible to find the intensity of population of sup 2 sup 2 sup 1 Fr levels by the alpha decay and multipolarities of five weak gamma-transitions. The conversion electron spectrum is investigated in the range of 5-24 keV with a high (some 20 eV) energy resolution. A new M1 type 10.6-keV gamma-transition is found. The proposed sup 2 sup 2 sup 5 Ac decay scheme includes 31 excited sup 2 sup 2 sup 1 Fr states. Parities are established for 16 of them. Possible spin values are proposed for sup 2 sup 2 sup 1 Fr levels. Properties of excited sup 2 sup 2 sup 1 Fr states are satisfactorily described by the quasiparticle-phonon nuclear model without the assumption of static octupole deformatio