Abstract
The magnetic form factors of the -shell nuclei , , , , , , have been measured by high-energy electron scattering at an angle of 180°. Incident electron energies up to 230 MeV ( ) were used. The incident- and scattered-electron paths were separated by use of a uniform magnetic field. Back-ground due to charge scattering was subtracted by varying the scattering angle around 180°. At the higher momentum transfers the scattering from those nuclei having spin , was dominated by the octupole moment distributions. Results are interpreted in terms of harmonic-oscillator and finite-square-well shell models. Parameters dependent only on the coupling of the angular momenta in the shell may be obtained from the data. They show a general trend from coupling to coupling as the mass number increases, in agreement with calculations of magnetic dipole moments and energy-level schemes. The outstanding exception is , whose form factor is accurately described by the extreme independent-particle model. ( coupling is quite incompatible with the data.) The results may also be interpreted in terms of an "alpha plus deuteron" model. Numerical results for the harmonic-well strengths are obtained and compare favorably with electron-charge-scattering values. It is also possible to estimate magnetic octupole moments, where applicable, with fair accuracy, although these estimations are to a certain extent model-dependent.
- Received 1 December 1965
DOI:https://doi.org/10.1103/PhysRev.144.859
©1966 American Physical Society