Studies of 12Be and other off-stability nuclei

In collaboration with the Tandem Van de Graaff staff at the University of Pennsylvania the reaction 10Be(t,p)12Be at E/sub t/ = 12 MeV has been used to study the properties of 12Be. The first excited state of 12Be has been found to lie at 2.110 +- 0.015 MeV and to have J = 2 from p,γ angular correlation measurements. Using a chopped beam the search for delayed neutrons from the decay of 12Be was negative. However, the decay curve for β rays can be fitted only if a half-life component of about 25 msec for 12Be is included along with the activities 12B, 9Li, and 8Li known to be present. A review of the search for new T/sub z/ = +5/2 isotopes in the s-d shell at the Brookhaven Tandem Van de Graaff is presented and recent results on the T/sub z/ = +3 nucleus 34Si, formed in the 18O(18O,2p)34Si reaction, are outlined. Utilizing new ion-source techniques to form a beam of 9Be ions the reaction 48Ca(9Be,pn)55V has been used to find and study the new isotope 55V of 6 sec half-life. The extension of these techniques to higher Z may be possible although recent studies of heavy-ion reactions indicate that the cross sections may be very small