ANGULAR-MOMENTUM TRANSFER IN THE DEEP INELASTIC REACTIONS OF 237-MEV AR-40 WITH Y-89

The mechanisms of strongly damped collisions of 237 MeV Ar40 with Y89 have been studied by measurements of the energy distributions and angular distributions of the identified products. Average gamma-ray multiplicities Mγ and average gamma-ray energies Eγ have been measured for these reactions. Empirical relationships between Mγ and the average angular momenta were employed to determine the angular momenta of the primary fragments produced in the reactions. The angular momentum transfer in the strongly damped collisions increases with increasing angle of emission of the projectile-like fragment. Evidence is presented that for the lowest partial waves contributing to strongly damped collisions the condition of rigid rotation is achieved. The use of such reactions to select nuclei of particular J is discussed. NUCLEAR REACTIONS Y89, (Ar40,X), E=237 MeV, deep inelastic collisions; Measured angular distributions, energy spectra and average gamma-ray multiplicities, deduced primary fragment angular momenta. © 1979 The American Physical Society.