High angular momentum structure in A@140 nuclei: sup 140 Nd, sup 141 Pm

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5091650

Guelmez, E

Recently a new region of deformation has been predicted for Z {le} 64, N {le} 82 nuclei. To further establish the high angular momentum structure in this region and to probe the onset of this deformation we have studied the gamma-ray deexcitation of states in {sup 140}Nd and {sup 141}Pm. The states in {sup 140}Nd were populated via the {sup 126,128}Te({sup 18,16}O,4n) reactions. Excitation functions for both reactions were measured over a beam energy range of 64-76 MeV and 72-76 MeV, respectively, with 2 MeV increments. Gamma-ray angular distribution and gamma-gamma coincidence data were taken with a 76 MeV {sup 16}O beam and a 72 MeV {sup 18}O beam, respectively. From these data a level spectrum up to E{sub x} {approximately} 6.4 MeV and I = 17 has been obtained. Above the 7{sup {minus}} and 10{sup +} isomers several new bands were found. Shell model calculations using a modified surface delta residual interaction were performed for {sup 140}Nd. The gamma-ray deexcitation of states in {sup 141}Pm was studied via the {sup 126}Te({sup 19}F,4n gamma) reaction. Excitation function measurements were carried out over a beam energy range of 74-84 MeV. Gamma-ray angular distribution and gamma-gamma coincidence data were taken with 80 meV and 78 MeV {sup 19}F beams, respectively. A level spectrum up to E{sub x} {approximately} 4.8 meV has been developed. The low-lying levels of {sup 141}Pm can be interpreted as a valence proton coupled to the core within a simple particle-core coupling model or the excitations of three valence particles, for example, a proton and two neutron holes.

• Research Organization: Yale Univ., New Haven, CT (USA)
• OSTI ID: 5091650
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
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A=90-149
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
DATA
ELEMENTS
ENERGY RANGE
EXPERIMENTAL DATA
GAMMA SPECTROSCOPY
INFORMATION
MEASURING INSTRUMENTS
MEASURING METHODS
METALS
MEV RANGE
MEV RANGE 10-100
NEODYMIUM
NUMERICAL DATA
PROMETHIUM
RARE EARTHS
SPECTROSCOPY