The energy dependence of the T sup > Gamow-Teller strength in p-shell nuclei observed in the (n,p) reaction

Technical Report · Wed May 01 04:00:00 EDT 1991

OSTI ID:5727490

Sorenson, D S

Cross sections have been measured for the transitions to the ground state of the residual nucleus using the (n,p) reaction on the targets{sup 6}Li, {sup 12}C, and {sup 13}C. A white'' continuum neutron source was utilized to measure cross sections for neutron energies from 60 to 260 MeV simultaneously. Charged particles were detected using a facility developed over the last few years which makes use of the five target'' wire chambers, four x and y multiwire drift chambers, a 5 kilo gauss magnetic field which deflects the charged particles out of the neutron beam, a wall of 15 CsI calorimeters, and a large-area plastic delta E detector. This arrangement allows four targets to be run simultaneously, and with magnet-on, scattering angles between 0 and 15 degrees can be measured concurrently as well. Angular distributions for the Gamow-Teller transitions are made and are extrapolated to q=0. At q=0 a simple expression relates the cross section to the volume integral for the effective nucleon-nucleon (N-N) interaction (J{sub {sigma}{tau}}), the inverse {Beta}-decay matrix element and the distortion factor. For all transitions considered here B{sub GT} can be obtained from measured half-lifes and so the cross section measurements can be use to extract J{sub {sigma}{tau}} from 60 to 260 MeV. J{sub {sigma}{tau}} should be a smooth function of A. However, (p,n) experiments have been carried out, where cross sections were measured for the isobaric analog states of the transitions that are considered in this thesis, and the J{sub {sigma}{tau}} extracted were found to vary by as much as 40 percent for odd A nuclei as in the case of {sup 12}C(p,n) and {sup 13}C(p,n). This discrepancy will not be seen to exist in the (n,p) direction.

• Research Organization: Los Alamos National Lab., NM (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5727490
• Report Number(s): LA-12061-T; ON: DE91014115
• Country of Publication: United States
• Language: English

Related Subjects

651320* -- Nuclear Properties & Reactions
A=6-19
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALI METAL ISOTOPES
ANGULAR DISTRIBUTION
BARYON REACTIONS
BARYON-BARYON INTERACTIONS
BETA DECAY
BORN APPROXIMATION
CARBON 12
CARBON 13
CARBON ISOTOPES
CHARGE-EXCHANGE REACTIONS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DECAY
DISTRIBUTION
DRIFT CHAMBERS
DWBA
ENERGY DEPENDENCE
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
GAMOW-TELLER RULES
HADRON REACTIONS
HADRON-HADRON INTERACTIONS
INFORMATION
INTERACTIONS
ISOTOPES
LIGHT NUCLEI
LITHIUM 6
LITHIUM ISOTOPES
MATRIX ELEMENTS
MEASURING INSTRUMENTS
MULTIWIRE PROPORTIONAL CHAMBERS
NEUTRON REACTIONS
NUCLEAR DECAY
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
NUCLEI
NUCLEON REACTIONS
NUCLEON-NUCLEON INTERACTIONS
NUMERICAL DATA
ODD-ODD NUCLEI
PARTICLE INTERACTIONS
PROPORTIONAL COUNTERS
PROTON REACTIONS
RADIATION DETECTORS
STABLE ISOTOPES