Muonic x-ray measurement of the monopole and quadrupole charge parameters of /sup 154-158,160/Gd

Journal Article · Fri Apr 01 04:00:00 EST 1983 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.27.1772· OSTI ID:6081232

Laubacher, D B; Tanaka, Y; Steffen, R M; Shera, E B; Hoehn, M V

Monopole and quadrupole charge distributions of /sup 154/Gd, /sup 155/Gd, /sup 156/Gd, /sup 157/Gd, /sup 158/Gd, and /sup 160/Gd were investigated by muonic-atom K and L x-ray measurements. The model-independent Barrett charge radii R/sub k/ and the isotope shifts ..delta..R/sub k/ were measured, and values of and ..delta.. were deduced. A pronounced even-odd staggering effect of the nuclear charge radii was observed for the series /sup 156 -158/Gd. The quadrupole moments of the first excited states of the even-A Gd nuclei were determined to be Q/sup 154/(2/sup +/) = -1.82(4) e b, Q/sup 156/(2/sup +/) = -1.93(4) e b, Q/sup 158/(2/sup +/) = -2.01(4) e b, and Q/sup 160/(2/sup +/) = -2.08(4) e b, and the quadrupole moments of the (3/2)/sup -/ ground states of the odd-A /sup 155,157/Gd nuclei were determined to be Q/sup 155/((3/2)/sup -/) = 1.27(3) e b and Q/sup 157/((3/2)/sup -/) = 1.35(3) b. Comparison with a separate measurement of the odd-A ground-state quadrupole moments based on the static hyperfine splitting of the muonic M x rays showed that the model error in the extracted quadrupole moments of these nuclei is less than 2 percent. The quadrupole moments and the B(E2) values obtained in the present experiment for the low-lying Gd states are in satisfactory agreement with the axially symmetric rotational model. However, the /sup 154/Gd nucleus exhibits a considerable softness as indicated by the isomer shift of the 2/sup +/ excited state and by the experimental value of the ratio Q(2/sup +/)/B(E2:0/sup +/..-->..2/sup +/).

• Research Organization: Department of Physics, Purdue University, West Lafayette, Indiana 47907
• OSTI ID: 6081232
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 27:4; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR MOMENTUM
ATOMS
CHARGE DISTRIBUTION
ELEMENTS
ENERGY LEVELS
GADOLINIUM
GADOLINIUM ISOTOPES
ISOMER SHIFT
ISOTOPES
METALS
MONOPOLES
MUONIC ATOMS
NUCLEAR STRUCTURE
PARITY
PARTICLE PROPERTIES
QUADRUPOLE MOMENTS
RARE EARTH ISOTOPES
RARE EARTHS
SPECTRA
SPECTRAL SHIFT
SPIN
X-RAY SPECTRA