DOUBLE COULOMB EXCITATION WITH OXYGEN IONS

Thesis/Dissertation · Mon Jan 01 04:00:00 EST 1962

OSTI ID:4720991

Graetzer, R U

Total cross sections for Coulomb excitation of the first and second excited states of the ground-state rotational bands of nine even-even nuclei were measured. Oxygen ions accelerated to energies in the range 14 to 50 Mev in a Tandem Van de Graaff accelerator produced the nuclear excitations. Thin targets were prepared by evaporation of isotopically enriched rare-earth oxide powders onto thick metal target supports. The incident oxygen beam was monitored by an n- p junction detector, which counted the particles elastically scattered at 155 deg with respect to the incident beam. In each isotope the nuclear de-excitations from the second excited state to the first, and from the first excited state to the ground state were detected by analyzing the emitted internal conversion electrons in a wedge-shaped magnetic beta spectrometer. Cross sections for excitation of the 2/sup +/ levels yield B(E2) values in good agreement with those obtained from lifetime measurements and from inelastic scattering of protons and deuterons. Cross sections for excitation of the 4/sup +/ levels are compared with the multiple Coulomb excitation theory of Alder and Winther. The data are in qualitative agreement with the theory. However the observed cross-sections are systematically smaller than predicted at the lower bombarding energies. This deviation is attributed to an approximation ( xi = 0) in the theoretical calculation. A systematic difference between Dy/sup 162/ and Sm/sup 154/ data was not explained. The energies of the 4/sup +/ levels were determined to plus or minus 2 kev. (Dissertation Abst., Vol. 23, No. 7)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-017291
• OSTI ID: 4720991
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALDER-WINTER THEORY
ANGULAR DISTRIBUTION
BETA SPECTROMETERS
COULOMB EXCITATION
COUNTERS
CROSS SECTIONS
DECAY
DEUTERONS
DYSPROSIUM 162
ELECTRONS
ENERGY
ENERGY LEVELS
ENERGY RANGE
ENRICHMENT
EVAPORATION
EXCITATION
INTERNAL CONVERSION
ION BEAMS
ISOTOPES
LIFETIME
MAGNETIC FIELDS
MEASURED VALUES
METALS
NUCLEI
OXIDES
OXYGEN
PARITY
PHYSICS
PREPARATION
PROTONS
RARE EARTHS
ROTATION
SAMARIUM 154
SCATTERING
SEMICONDUCTORS
SPIN
TARGETS
VAN DE GRAAFF ACCELERATORS