Neutron knockout reactions from /sup 40/Ca and /sup 48/Ca

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6738261

Ahmad, M

The reactions /sup 40/Ca(p,pn)/sup 39/Ca and /sup 48/Ca(p,pn)/sup 47/Ca at 149.5 MeV were studied at the Indiana University Cylcotron Facility in coplanar geometries with (theta/sub p/, theta/sub n/) = (44.3/sup 0/, 36.1/sup 0/) and (47.3/sup 0/, 36.1/sup 0/), respectively. An overall separation-energy resolution of about 1 MeV was achieved. The analysis of the (p-n) coincidence data was performed within the framework of the distorted-wave impulse approximation (DWIA). Spectroscopic factors (C/sup 2/S) were extracted for neutron-hole states: C/sup 2/S = 1.90 +/- 0.20 for /sup 40/Ca (2s/sub 1/2/; C/sup 2/S = 8 for /sup 48/Ca (1f/sub 7/2/; C/sup 2/S = 1.3 for /sup 48/Ca (2s/sub 1/2/). Energy-sharing spectra for the knockout of valence neutrons from the /sup 40/Ca (2s/sub 1/2/) state and /sup 48/Ca (1f/sub 7/2/) and (2s/sub 1/2/) states are consistent with tthe DWIA interpretation; however, measurements for the /sup 40/Ca (1d/sub 3/2/) state are in poor agreement with DWIA calculations, possibly because of /sup 16/O(p,pn)/sup 15/O ground-state strength from /sup 16/O in the target. A limited amount of data obtained at several asymmetry quasifree angle pairs was used to extract energy-sharing cross sections for the 2s/sub 1/2/ neutron knockout from /sup 40/Ca for comparison with free p-n scattering cross sections. These measurements are consistent with a factorization approximation used in the distorted-wave impulse approximation. The DWIA calculations for valence neutrons are found to be extremely sensitive in magnitude to the neutron single-particle wave functions used. Within the framework of the DWIA, the following limits on rms radii for single-particle states were extracted: 1) for 1f/sub 7/2/ neutrons in /sup 48/Ca: C/sup 2/S = 7 +/- 2 ..-->.. /sup 1/2/ = 4.2 +/- 0.2 fm; 2) for 2s/sub 1/2/ neutrons in /sup 40/Ca: C/sup 2/S = 1.6 +/- 0.5 ..-->.. /sup 1/2 = 3.55 +/- 0.20 fm.

• Research Organization: Kent State Univ., OH (USA)
• OSTI ID: 6738261
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALINE EARTH ISOTOPES
BARYON REACTIONS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CALCIUM 39
CALCIUM 40
CALCIUM 40 TARGET
CALCIUM 47
CALCIUM 48
CALCIUM 48 TARGET
CALCIUM ISOTOPES
CHARGED-PARTICLE REACTIONS
COINCIDENCE METHODS
COUNTING TECHNIQUES
DATA
DAYS LIVING RADIOISOTOPES
DIRECT REACTIONS
DISTORTED WAVE THEORY
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FERMIONS
HADRON REACTIONS
HADRONS
IMPULSE APPROXIMATION
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOTOPES
KNOCK-OUT REACTIONS
LIGHT NUCLEI
MEV RANGE
MEV RANGE 100-1000
NEUTRONS
NUCLEAR PROPERTIES
NUCLEAR RADII
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
NUMERICAL DATA
PROTON REACTIONS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
STABLE ISOTOPES
TARGETS