Study of the Spins and Parities of Excited Levels of Nuclei by Methods of Low-Temperature Orientation, Angular Correlations, and Direction-Polarization Correlations (thesis); ETUDE DES SPINS ET PARITES DE NIVEAUX EXCITES DE NOYAUX PAR DES METHODES D'ORIENTATION AUX BASSES TEMPERATURES, DE CORRELATIONS ANGULAIRES ET DE CORRELATIONS DIRECTION-POLARISATION (theses)
The methods of Bleaney and Gorter-Rose were used to orient at low temperatures several radioactive nuclei. The orientation was detected by measurement of the anisotropy and the polarization of the gamma rays emitted. The character of the first excited state of /sup 54/Cr was established as 2+, and the gamma radiation emitted by this state was electric nuadrupole. It was shown that the K capture by which this state decays to the ground state of /sup 54/Mn corresponds to an allowed Fermi transition. The alignment of /sup 57/Co furnished an effect of zero anisotropy, but a polarization effect different from 0. This established that the 123-kev radiation corresponds to an M/sub 1/E/sub 2/ mixture with a mixing coefficient of 0.19 plus or minus 0.02. In the decay of / sup 147/Nd, the 7/2+ character of the 92-kev level was verified. It was shown that the 530-kev level was also a 7/2+ level. The two rays correspond to M/sub 1/ and E/sub 2/ mixtures. The mixing coefficients and the magnetic moment of /sup 147/Nd were also determined. The 145-kev ray emitted in the decay of /sup 141/Ce also corresponds to an M/sub 1/E/sub 2/ mixture. It was not possible to choose between the possibilities j = 0 and j = 1 for the angular moment for the corresponding BETA transition. The hyperfine structure constant A and the magnetic moment mu of /sup 141/Ce were determined for both cases. Radioactive nuclei were also studied by angular correlation and direction-polarization correlation methods. The 2+ and 3--character of the first and second excited states of /sup 88/Sr was verified. It was shown that the 910-kev gamma transition corresponded to an E/sub 1/M/sub 2/ mixture. The decay scheme of /sup 140/La was studied by the same methods. The intensity of the principal gamma radiations was measured. The first three excited states of /sup 140/Ce were determined as 2+, 4+, and 3+. The 815-kev radiation corresponded to an M/sub 1/E/ sub 2/ mixture. An upper limit of 6 x 10/sup -10/ sec was established, using delayed coincidence methods, for the mean lifetime of the 530kev excited state of /sup 147/Pm. (tr-auth)
- Research Organization:
- Paris. Universite, Orsay
- NSA Number:
- NSA-18-021208
- OSTI ID:
- 4004910
- Report Number(s):
- NP-13841
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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Study of the Disintegration Process and of the Angular Moments of the Excited Levels of Pm-147 Using Spectrographic and Angular Correlation Measurements (thesis); ETUDE DU SCHEMA DE DESINTEGRATION ET DES MOMENTS ANGULAIRES DES NIVEAUX EXCITES DU Pm 147 PAR DES MESURES DE SPECTROGRAPHIE ET DE CORRELATIONS ANGULAIRES (these)
Related Subjects
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
ANISOTROPY
BETA DECAY
CAPTURE
CERIUM 140
CERIUM 141
CHROMIUM 54
COBALT 57
COINCIDENCE METHODS
ELECTRIC MOMENTS
ENERGY LEVELS
GAMMA RADIATION
HYPERFINE STRUCTURE
LANTHANUM 140
LIFETIME
MAGNETIC MOMENTS
MANGANESE 54
MEASURED VALUES
MIXING
MOMENTUM
NEODYMIUM 147
NUCLEAR MODELS
PARITY
POLARIZATION
PROMETHIUM 147
RADIATION DETECTORS
RADIOACTIVITY
SPIN
STRONTIUM 88
TRANSIENTS