New neutron-rich nuclei Zr103,104 and the A100 region of deformation

Partial decay schemes in the neutron-rich nuclei Zr103 and Zr104 have been measured for the first time and rotational bands in Zr100 102 have been extended to spins of up to 10Latin small letter h with stroke by observing prompt rays from the spontaneous fisson of Cm248. These nuclei are among the most deformed known at low spin and excitation energy. The level structures in the odd-A nuclei show that the h11/2 intruder orbital plays an important role in stabilizing the deformation in this region

Trends in the study of light proton rich nuclei

Recent work in light proton-rich nuclei is reviewed. Evidence for the first T/sub z/ = -5/2 nuclide, /sup 35/Ca, is presented. The mechanisms of two-proton emission following beta-decay is investigated. Future directions in this field are discussed. 23 refs., 5 figs. (WRF

Delayed proton activities produced in /sup 24/Mg + Ca and /sup 28/Si + Ca reactions

A search for new delayed proton emitters in /sup 24/Mg and /sup 28/Si bombardments of Ca targets has been conducted to extend knowledge about the proton drip line in the A = 60 to 65 mass region. Definitive evidence for the A = 4n + 1, T/sub z/ = -3/2 nuclide /sup 61/Ge is presented, but a search for the next member in this series, /sup 65/Se, proved fruitless. 6 refs., 3 figs

Improvements to the helium-jet coupled on-line mass separator RAMA

Some general improvements to the on-line mass separator RAMA have yielded a factor of five increase in yield for most elements. By placing the ion source region at the full accelerating potential of 20 kV, the effective skimmer-plasma distance has been reduced from 12 cm to <2 cm. Changes in the helium-jet chamber and large volume pumping arrangement necessitated by placing the ion source region at high voltage are also given. Finally, details for a new highly shielded detector station are presented

Recent developments at the ANTARES AMS centre.

A. M. Smith, D. Fink, M. A. C. Hotchkis, G. E. Jacobsen, E. M. Lawson, C. Tuniz, E. Sacchi, D. Louvat, G. M. Zuppi and R. Bonett

Accumulation of plutonium in mammalian wildlife tissues following dispersal by accidental-release tests

We examined the distribution of plutonium (Pu) in the tissues of mammalian wildlife inhabiting the relatively undisturbed, semi-arid former Taranaki weapons test site, Maralinga, Australia. The accumulation of absorbed Pu was highest in the skeleton (83% ± 6%), followed by muscle (10% ± 9%), liver (6% ± 6%), kidneys (0.6% ± 0.4%), and blood (0.2%). Pu activity concentrations in lung tissues were elevated relative to the body average. Foetal transfer was higher in the wildlife data than in previous laboratory studies. The amount of Pu in the gastrointestinal tract was highly elevated relative to that absorbed within the body, potentially increasing transfer of Pu to wildlife and human consumers that may ingest gastrointestinal tract organs. The Pu distribution in the Maralinga mammalian wildlife generally aligns with previous studies related to environmental exposure (e.g. Pu in humans from worldwide fallout), but contrasts with the partitioning models that have traditionally been used for human worker-protection purposes (approximately equal deposition in bone and liver) which appear to under-predict the skeletal accumulation in environmental exposure conditions

14^{14}C in uranium and thorium minerals: a signature of cluster radioactivity?

Various uranium and thorium minerals have been analysed with accelerator mass spectrometry to determine their $^{14}$C content. It is found that, whenever the contribution from secondary reactions such as the $^{11}$B($\alpha$,p)$^{14}$C is sufficiently low, the $^{14}$C concentration is consistent with that expected from $^{14}$C (spontaneous) cluster radioactivity from radium isotopes of the uranium and thorium natural series