TABLE OF CONTENTS The scattering of alpha particles from deformed nuclei, although not directly related to microscopic theories of reactions, is important for several reasons. Historically it provided the first convincing evidence for higher-order components in the deformation of nuclei, and it also provided evidence that a few collective states by themselves contribute important components to the optical potential. The calculation of contributions to the optical potential arising from specific transitions has recently become an area of active research, so it is worth understanding the empirical basis that provided the initial motivation. Finally, the collective description of the inelastic transitions provides a very important basis for the understanding of transfer reactions between deformed nuclei (which is treated in Chapter 15).
Strongly deformed nuclei are those that have an energy spectrum corresponding to a rigid rotor
| (13.1) |  |
This relation is obeyed with considerable accuracy by the first few states of many nuclei. In addition, the electromagnetic transition rates are enhanced over single-particle rates, and the relationship of the quadrupole transitions connecting consecutive members of a band are consistent with this interpretation. Of course, the nucleons are not frozen in place. Therefore, the rotor spectrum implies that the nucleon motion within the deformed nuclear potential is frequent enough, compared with the rotational frequency, so that the intrinsic structure is not disturbed by the rotation. It is able to readjust adiabatically to the rotation. This implies that there is a rotational band based on each of the various intrinsic...
