[en] The reaction ³¹S(p,γ)³²Cl is critical for the understandin gof the nucleosynthesis in the Si-S mass region in Hot and Explosive Hydrogen Burning. Shell model calculations and the level structure of the mirror nucleus ³²P suggest that only a few low lying resonances above the proton threshold in ³²Cl will contribute significally to the reaction rate

[en] Thin sources of ²⁸P and ³²Cl were prepared by depositing recoil atoms from the reactions ²⁸Si(p, n)²⁸P and ³²S(p, n)³²Cl with a helium jet onto a fast transport tape. Delayed particle spectra were measured with high resolution using Si(Au) surface barrier detectors. Six proton groups and ten α-particle groups in the energy ranges 0.4 MeV < Esub(p) < 1.3 MeV and 1.3 MeV < Esub(α) < 2.7 MeV were assigned to the decay of ²⁸P. Six proton and eleven α-particle groups in the energy ranges 0.7 MeV < Esub(α) < 1.9 MeV and 1.5 MeV < Esub(α) < 3.6 MeV were identified in the decay of ³²Cl. (Auth.)

[en] We have built a new set of isospin-nonconserving (INC) shell-model Hamiltonians and we have applied it. First, to study the isobaric-mass multiplet equation (IMME) beyond a quadratic form in the A = 35, 3/2"+ quartet. Secondly, to compute the isospin mixing corrections to superallowed Fermi branch of 1"+ → 1"+ β decay of "3"2Cl, and thirdly, to obtain the isospin-forbidden branching ratios of β-delayed proton emission from "2"5Si. (authors)

[en] For the A=32, T=2 quintet we provide a unified theoretical description for three related aspects of isospin mixing: the necessity of more than three terms in the isobaric mass multiplet equation, isospin-forbidden proton decay in ³²Cl, and a correction to the allowed Fermi β⁺ decay of ³²Ar. We demonstrate that all three effects observed in experiment can be traced to a common origin related to isospin mixing of the T=2 states with T=1 states.

No abstract available

[en] β-delayed protons have been observed from ³²Ar (t/sub 1/2/ approx. 75 msec), the most neutron-deficient nucleus whose radioactive decay has ever been recorded. From the proton spectrum, the T = 2 state in ³²Cl has been identified to have a mass excess of -8295.6 +- 5.2 keV. As the fourth accurately known member of an isobaric quintet, it provides an accurate test for a cubic term in the isobaric-multiplet mass equation as applied to narrow T = 2 states: The coefficient of such a possible term is determined to be 0.5 +- 2.5 keV

[en] Simultaneous progress in astronomical observations and nuclear physics experiments with radioactive beams offers new opportunities in nuclear astrophysics, in particular concerning the r-process and the rp-process. I review some of the open questions and recent developments, and present two recent experimental results from the new Coupled Cyclotron Facility at MSU. These are the measurement of the half-life of ⁷⁸Ni relevant for the r-process and the measurement of excited states in ³³Ar that reduce the uncertainties in the ³²Cl(p, γ)³³Ar reaction rate in the rp-process by several orders of magnitude

[en] Higher order effects in the electromagnetic excitation with fast nuclei are investigated in a systematic way. Since first order (one photon exchange) processes are dominant, a perturbation approach seems appropriate. After a general framework, which is elaborated especially for second order effects, the excitation of ¹⁴O and ³²Cl is discussed as typical examples for an astrophysical application. We find that the method of Coulomb dissociation is in general not affected by higher order effects. The influence of the electromagnetic excitation mechanism on the apparent line shape of the one- and two-phonon giant dipole resonance is studied

[en] A New Line of Radioactive ions at very low energy (below 30 KeV) is under development. The construction of this new line, including experimental area and monitoring room, will be completed in the course of the year 2003. Later on, PIRAL phase-II or ion production in cave 2 will further enlarge the possibilities of LIRAT with minor modifications or none. In particular, and this is certainly not the least interest, it will enable to realize two different experiments in parallel, one using LIRAT, the other using CIME. (author)

No abstract available