The Inelastic scattering of electrons from carbon - 12
Abstract
In this thesis we present measured values of the nuclear matrix
element for the 19.4 MeV level in 12C and describe the experimental
equipment which was used for this investigation of nuclear structure
by the technique of electron scattering.
Previous electron scattering measurements on this level have been
made at momentum transfers less than 120 MeV/c and greater than 270
MeV/c. We have measured the matrix element for this level in the
previously uninvestigated region of momentum transfers between 120
MeV/c and 220 MeV/c. All present measurements were made at the
largest attainable scattering angle to enhance the transverse terms in
the cross section.
The experimental matrix elements have been compared with
theoretical results both fora 1- and for a 2- level predicted to lie
in this energy region. These theoretical particle-hole calculations
show that in the region of intermediate momentum transfers which we
have investigated, the magnitude of the matrix element is most
sensative to the spin-parity assignment. The 1- matrix element has a
minimum in this region whereas the 2- matrix element has a
maximum.
The measured matrix elements are in satisfactory agreement with
the particle-hole calculations for a 2- level in 12c and the present
values favourably compare with other measurements in the region of
overlap.