Yrast level structure of the N = 82 and 83 nuclei /sup 149/Ho and /sup 150/Ho; negative parity states in /sup 188/Os from the /sup 186/W (. cap alpha. ,2n) reaction

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 1981

OSTI ID:5737833

Wilson, J A

The yrast level structure of the N = 82 and 83 nuclei /sup 149/Ho and /sup 150/Ho have been investigated by in-beam ..gamma..-ray spectroscopy following reactions of 150-180 MeV /sup 32/S beams with /sup 121/Sb and /sup 122/Te targets. In the three valence proton nucleus /sup 149//sub 67/Ho/sub 82/, (a(..pi..h/sub (11/2)/)/sup 3/ sequence of yrast levels have been identified and both the level spacings and the measured B(E2) value for the 27/2/sup -/ ..-->.. 23/2/sup -/ (..pi..h/sub (11/2)/)/sup 3/ recoupling transition has been found to be in excellent agreement with shell model calculations in which the residual proton-proton interactions and the ..pi..h/sub (11/2)/ effective E2 charge were taken from the experimental (..pi..h/sub (11/2)/)/sup 2/ spectrum of 148Dy. The expected 15/2/sup +/, 19/2/sup +/ and 23/2/sup +/ yrast states arising from the coupling of the additional h/sub (11/2)/ proton to the 3/sup -/, 5/sup -/ and 7/sup -/ /sup 148/Dy states have also been identified. In /sup 150//sub 67/Ho/sub 83/, the main yrast level sequence is found to agree closely with shell model predictions of level energies, isomeric half-life and deexcitation pathway for the (..pi..h/sub(11/2)/)/sup 3/ nuf/sub (7/2)/ configuration. High lying isomers of both /sup 149/H/sub 0/ and /sup 150/H/sub 0/ have been identified but not fully characterized. The yrast negative parity level structure of /sup 188/Os has been investigated following the /sup 186/W (..cap alpha..,2n) reaction. Energies, spins and parities were established for many levels and I/sup ..pi../ = 7/sup -/ and 9/sup -/ isomers with t/sub (1/2)/ = 16 +/- 2 ns and 10 +/- 1 ns were established. The properties of the negative parity states in /sup 188/Os are compared to those of 1) the semidecoupled bands built on 5/sup -/ states in the oblate or triaxial even-even Hg and Pt nuclei, and 2) negative parity two quasiparticle Nilsson states observed in prolate even-even W nuclei.

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• OSTI ID: 5737833
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
HOLMIUM 149
YRAST STATES
HOLMIUM 150
OSMIUM 188
ANTIMONY 121
GAMMA SPECTROSCOPY
NUCLEAR REACTIONS
SULFUR 32
TELLURIUM 122
TUNGSTEN 186
ANTIMONY ISOTOPES
DAYS LIVING RADIOISOTOPES
ENERGY LEVELS
EVEN-EVEN NUCLEI
HEAVY NUCLEI
HOLMIUM ISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
OSMIUM ISOTOPES
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
SPECTROSCOPY
STABLE ISOTOPES
SULFUR ISOTOPES
TELLURIUM ISOTOPES
TUNGSTEN ISOTOPES
400702* - Radiochemistry & Nuclear Chemistry- Properties of Radioactive Materials
400201 - Chemical & Physicochemical Properties