No abstract available

No abstract available

[en] Complete text of publication follows. The shape isomers of light nuclei attract much attention from different structure studies, and provide a close connection to nuclear reactions as well. Superdeformed (SD) bands in ³⁶Ar and ⁴⁰Ca have been well-established through gamma-ray spectroscopy. In addition, candidate hyperdeformed states have been suggested from reaction studies. There has been considerable theoretical effort, recently, in considering superdeformed and other highly deformed configurations in ²⁸Si. From the experimental side, there are a set of states in ²⁸Si identified in the ¹²C(²⁰Ne,α)²⁸Si reaction which have been attributed to the superdeformed band by Kubono et al.. This sequence does not, however, have the smooth characteristics expected for such a band, and the moment of inertia is not in line with the result of a recent AMD calculation. Jenkins et al. have reviewed the available experimental data, and extended them with new γ-transitions. As a result they propose a new candidate for the SD band. Inspired by this exciting situation with open questions on the SD state, we have carried out an independent theoretical analysis of highly-deformed structures in ²⁸Si. In particular we performed a Nilsson-calculation, combined with quasi-dynamical U(3) considerations, and determined the allowed binary clusterization of the shape isomers. We have found eight shape isomers ranging from the ground state up to a linear alphachain configuration (see Fig. 1). In searching for the allowed clusterizations the clusters were considered to have deformations, like the ground states of the corresponding nuclei, and no constraint was applied for their relative orientation. The alpha-like clusterizations proved to be energetically favoured. The hyperdeformed state allows only a single binary clusterization (of intrinsic ground state clusters): ²⁰Ne+⁸Be, the ground state can have core+alpha, as well as core+⁸Be. The prolate and the superdeformed state allow several clusterizations. For the SD state, which is the focus of the present work, we find that the ⁴He+²⁴Mg, and the ¹²C+¹⁶O cluster configurations are the most probable, taking account of both the selection rules and energetic preference. Our result on the SD state supports the new candidate state proposed by Jenkins et al.

[en] With the emergence of new, biological vehicles of great organ specificity (e.g. steroid hormones, antibodies) the concept of systemic tumor therapy with the aid of radiotherapeutica has gained new momentum. In order to assess the options open for optimal adaptation of the radiation properties to the pharmacocinetics of a vehicle, a search was done to identify potentially useful therapeutic radionuclides. Main criteria for selection were half life, low gamma-yield and stable daughter nuclide. The resulting possibilities fall into 4 categories: 1) alpha-emitters (At-211); 2) beta/sup -/-emitters that can be prepared in a carrierfree fashion (P-32, S-35, As-77, Y-90, Ag-111, Pm-149, Tb-161, Lu-177), 3) beta/sup -/-emitters with carrier added (Pd-109, Pr-142, Gd-159, Er-169, Tm-172, Yb-175, Re-188, Ir-194, Pt-197) and 4) electron capture nuclides, emitting Auger-cascades (Cr-51, Ga-67, Ge-71, Br-77, Ru-97, Sb-119, I-123, Cs-129, Nd-140, Er-165, Ta-177, Hg-197, Tl-201). Among the 4th group some well known, diagnostically used nuclides are found. Their therapeutic use necessitates the precise localisation in or very near the genetic material of the cell to be killed; only there the destructive power of the very short range Auger-electrons can be used. For each of the selected nuclides a summary of decay data, possibilities of preparation and chemical reactivity for labelling of vehicles is given. (author)

[en] We propose a simple expression for nuclear densities, which brings out the following important nuclear properties: (i) shell effects in proton and neutron central densities, (ii) approximate global constancy of neutron central densities, (iii) approximate constancy of RNsup(-1/3) and Rsub(p)Zsup(-1/3) where R is the nuclear half-density radius and Rsub(p) is the rms radius of the proton density, (iv) larger surface thickness and rms radius for neutron density as compared to those for proton density. (orig.)

[en] Electronic stopping powers of various light elements in Ti, Fe, Ni, Cu, Ag, and Au have been reported recently. Earlier, measurements were made for the stopping of ¹6O in Ni, Ag, and Au. With the aid of the Northcliffe-Schilling stopping-power tables these values were extrapolated to values of E/A equal to 0.0125 and 12.0 MeV/amu. Ranges calculated from these stopping-power values and the stopping powers themselves are presented

No abstract available

[en] An evaluation has been made of the decay data of 91 activation products and related nuclides. The resultant recommended data have been produced in ENDF/B-IV format for use in reactor calculation codes. The data include half-life, branching ratios, alpha, beta and gamma radiation energies and intensities, total decay energy, mean alpha, beta and gamma energies, internal conversion coefficients and associated uncertainties. Conversion electron, Auger electron, X-ray and internal bremsstrahlung data are also included. The alpha, beta and gamma radiation intensities are given as fractions, and all such data are the best estimate of the decay mode intensity per disintegration. In this report the data are presented in a clear form by means of an intermediary listing program. (author)

[en] Beams of 96- and 115-MeV α particles were used to study the giant resonance region in 27 nuclei ranging from ¹⁴N to ²⁰⁸Pb. A prominent broad (GAMMA=3--7 MeV) peak is present in the spectra at an excitation energy of approx.63/A¹/³ MeV for all nuclei studied with A> or =36. No such prominent peak is apparent for A<32. The angular distributions of the peak are characterized by an oscillatory behavior which is quite different from the monotonic behavior of the background. Distorted wave calculations with L=2 reproduce the experimental angular distributions quite well for most of the nuclei. Energy-weighted sum rule fractions range from 30--50% for the lighter targets to near 100% for the heavier targets. Distorted wave calculations with a breathing mode (L=0) form factor fail to reproduce the observed resonance strength by about a factor of 3 for all targets. The width of the peak is smallest for the closed shell nuclei ⁴⁰Ca, ⁹⁰Zr, ¹⁴⁴Sm, and ²⁰⁸Pb. A small but significant broadening is observed in the rare-earth region of deformed nuclei. The giant dipole resonance is not appreciably excited for any of the targets

[en] The recognized need for high purity radionuclides and the need for organ specific radiopharmaceuticals will stimulate the demand for large quantities of stable isotopes. Stable isotopes currently under investigation for use as targets for radionuclide production include: ^9598100Mo, ²⁰³²⁰⁵Tl, ²⁰¹Hg, ⁶⁶⁶⁷Zn, ¹²²¹²³Te, ¹¹²Sn, ¹¹¹¹¹²Cd, ⁵⁰Cr, ⁵⁰V, ⁸²Kr, ¹⁹⁷Au, ⁷²⁷⁴Ge, ⁵⁴⁵⁸Fe, ⁶³Cu, ⁶⁴Ni, ⁶⁹Ga, ⁴³⁴⁶Ca, ⁴¹K, ³⁵Cl, ²³Na, ⁸¹Br, ⁸⁴Sr, ⁸⁵Rb, ⁷⁵As, ⁷⁶Se, ⁸¹Br, ³¹P, ²⁹Si, ¹⁵⁶Dy, ¹⁵²Sm, ¹⁷⁰Er, ¹⁷⁵Lu, ¹⁷⁸Lu, ¹⁶⁸Yb, ¹¹B, ¹⁴N, ¹⁶O, ²⁰Ne, and ¹²⁴Xe. As isotope production and radiopharmaceutical preparation costs are lowered and FDA approvals are secured, increased demand could develop for most of the stable isotopes listed. Requirements appear to be increasing for isotopes of those elements which are considered biologically essential (currently 25 elements) or for those which have an effect on the life processes. Demand is currently developing for the isotopes of the elements; K, Ca, Mg, Fe, Cu, Zn, Ni, Cd, and Cr. High isotope costs, however, and the scarcity of some metal isotopes have severely limited biomedical research programs