Mean square radii of light radioactive projectiles, including exotic isotopes close to the neutron drip line ("Li, 14Be, and 17B), have been deduced from total reaction cross-section measurements, using a simple microscopic model. The isospin dependence of nuclear radii is discussed and compared to other experimental results.

Total nuclear reaction cross-sections are determined by means of a 4 re-7 method. The results cover a wide span of targets for various stable beams. The validity of the method is shown in a combined systematics including also the results of transmission-type experiments. The data are very well described by the formula developed by Kox et al. The same method is applied to secondary fragment beams produced from a 44 MeV/u 22Ne beam on a 332 mg/cm 2 181Ta target. Using the LISE spectrometer the fragments 4'6He, [6][7][8][9][7][8][9][10][11][12] are analyzed and transported to interact with a 199.4 mg/cm 2 Cu target surrounded by a 4rc-7 counter. The measured total reaction cross-sections oR are discussed in terms of the reduced strong absorption radius ro and compared with other experimental results.

The nucleusGe has been studied via the +Zn{n, 2ny) Ge reaction at E~= 30 MeV using different in-beam y spectroscopic techniques. Levels up to 5.5 MeV have been identified and spins up to 8+ have been established.NUCLEAR REACTIONS +Zn{n, 2ny) E~= 30 MeV, yy coincidences, angular distributions, level scheme deduced.

New levels strongly excited by 112-MeV "C ions on even Ni and Zn isotopes are J" assigned on kinematical and geometrical arguments, crude shell-model calculations, and distorted-wave Born approximation angular-distribution analysis. These tentative assignments are supported by the Bansal-French model. Because of the contribution of additional collective effects, the two-proton transfer reaction spectra are less selectively fed than those obtained with the analogous two-neutron transfer reactions induced on the same targets in a similar energy range. 42 1297 1990 The American Physical Society 1298

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Particle-particle coincidence measurements have been made for the reactions 312and 680-MeV Ar+"'"Ag. The large-angle correlation data indicate essentially complete energy thermalization even for 680-MeV "Ar+"'"Ag. They also allow for an assignment of =646 for the rms spin and =4.3 MeV for the average initial temperature of the composite. nuclei formed by incomplete fusion. The small-angle correlation data for 'H-'H and 'H-H are consistent with phase-space, statistical-model predictions of the evaporation lifetimes. This result implies that energy mixing and evaporative particle-emission steps occur with intervals of =10 s, a time period comparable to the traversal time for a projectile velocity of 17 MeV/nucleon.Currently there is great interest in the properties of very highly excited nuclei. ' At modest temperatures of~3 MeV the notion is well established of a hot liquid drop