Yrast excitations in129Te

Gamma-ray studies of130Te+275 MeV64Ni reaction products have identified yrast states of129Te up to a 33 ns isomer at 2138 keV. Thebeta \u2013-decay of 17.7 min129Sb to levels in129Te is elucidated

Yrast excitations in A = 126\u2013131 Te nuclei from deep inelastic 130Te+64Ni reactions

Thick target \u3b3\u3b3 coincidence measurements for the system 130Te + 275 MeV 64Ni have been performed using the GASP Ge detector array at Legnaro. For the isotopic assignments of previously unknown \u3b3-ray cascades, prompt \u3b3\u3b3 coincidences observed between Te and Ni partner products were of vital importance. The results yield much new information about excited states of moderate spins in A = 126\u2013131 tellurium nuclei, especially about yrast excitations of the little studied odd-A isotopes 127Te, 129Te, and 131Te. Level systematics of tellurium nuclei are presented, and both single-particle and collective aspects of the level spectra are discussed

Toward 100Sn : studies of excitation functions for the reaction between 58Ni and 54Fe ions

Production of nuclei above 100Sn in fusion-evaporation reactions between 58Ni and 54Fe ions was studied at Oak Ridge National Laboratory by means of the recoil mass spectrometer and charged particle detection. The beam energy was varied to optimize the yields for the two-, three- and four-particle evaporation channels. Experimental results verified the predictions of the statistical model code HIVAP. The optimum energy for the 54Fe(58Ni,4n)108Xe reaction channel that allows one to study the 108Xe-104Te-100Sn decay chain is deduced as 240 MeV

\u3b3-ray studies of neutron-rich N=18,19 nuclei produced in deep-inelastic collisions

Neutron-rich sdf shell nuclei have been produced in deep-inelastic processes during collision of 230 MeV 37Cl ions on a thick 208Pb target. The in-beam as well as off-beam \u3b3-\u3b3 coincidence data yielded new spectroscopic information on some hard-to-access N=18,19 isotones. A new 27 ns isomer at 5583 keV in 32Si has been located. A candidate for the negative parity state 4- has been identified above the 200 ns isomer in 32Al

High-spin states in 208Pb

High-spin states in 208Pb have been studied by \u3b3-ray-spectroscopy methods in deep inelastic reactions induced by beams of 208Pb, 136Xe and 76Ge beams on a thick 208Pb target. The 11+ 2 state and new \u3b3-transitions between the one-particle one-hole states of highest spin have been found and electromagnetic matrix elements verified. High-spin states of two-particle two-hole structure have been detected for the first time. The results are compared to shell model calculations with realistic interactions in the complete Kuo-Herling space

On the alpha decay of 109I and its implications for the proton decay of 105Sb and the astrophysical rapid proton-capture process

In an experiment at the Recoil Mass Spectrometer at the Holifield Radioactive Ion Beam Facility, the very small -decay branch of 109I, b = (1.4\ub10.4)\ub710 124, has been measured. The Q-value for this transition allowed for the determination of Qp(105Sb) = 356\ub122 keV, about 130 keV lower than previously claimed. This difference increases the partial half-life for proton decay by several orders of magnitude, making the probability of observing direct proton decay of 105Sb very small, much below any previous experimental limit. The results and consequences for the astrophysical rp-process are discusse

\u3b1 decay of 109I and its implications for the proton decay of 105Sb and the astro-physical rapid proton-capture process

An \u3b1-decay branch of (1.4\ub10.4) 710-4 has been discovered in the decay of 109I, which predominantly decays via proton emission. The measured Q\u3b1 value of 3918\ub121 keV allows the indirect determination of the Q value for proton emission from 105Sb of 356\ub122 keV, which is approximately of 130 keV more bound than previously reported. This result is relevant for the astrophysical rapid proton-capture process, which would terminate in the 105Sn(p,\u3b3)106Sb(p,\u3b3)107Te(\u3b1 decay)103Sn cycle at the densities expected in explosive hydrogen burning scenarios, unless unusually strong pairing effects result in a 103Sn(p,\u3b3)104Sb(p,\u3b3)105Te(\u3b1 decay)101Sn) cycle

N=40 Neutron Subshell Closure in the Ni68 Nucleus

The 68Ni nucleus has been identified among the products of deep-inelastic reactions of 64Ni projectiles bombarding 130Te and 208Pb targets. Three new states, including the high-lying 2+ (2033 keV) and the 0.86 ms 5- isomer, indicate a substantial subshell closure at neutron number N=40. The level structure and the observed very slow E3 transition speed are discussed within the shell model

Shell structure beyond the proton drip line studied via proton emission from deformed 141Ho

Fine structure in proton emission from the 7/2 12[523] ground state and from the 1/2+[411] isomer in deformed nucleus 141Ho was studied by means of fusion-evaporation reactions and digital signal processing. Proton transitions to the first excited 2+ state in 140Dy, with the branching ratio of Igs p (2+) = 0.9 \ub1 0.2% and Imp (2+) = 1.7 \ub1 0.5%, were observed. The data are analyzed within the non-adiabatic weak coupling model assuming a large quadrupole deformation of the daughter nucleus 140Dy as predicted by the self-consistent theory. Implications of this result on coexistence effects around N = 74 are discussed. Significant modifications of the proton shell structure when going from the valley of beta stability to the proton drip line are discussed in terms of self-consistent theory involving the two-body tensor interaction