J. Gehring

Observation of the one- to six-neutron transfer reactions at sub-barrier energies

Abstract Cross sections for the one- to six-neutron transfer reactions have been measured at sub-barrier energies in the system 58 Ni+ 100 Mo. The cross sections for multi-neutron transfer processesshow an exponential falloff in agreement with recent theoretical calculations. Upper limits for the absolute yields to the ground states have been extracted and are compared to theoretical predictions.

Measurements of heavy-ion induced fusion cross sections with the gas-filled-magnet technique

Abstract A gas-filled magnet has been used to measure excitation functions of heavy-ion induced fusion reactions. Equipped with a large x − y -position sensitive parallel-grid avalanche detector in the focal plane the setup allows for a very efficient measurement of fusion cross sections at energies above and below the Coulomb barrier.

The Use of a Gas-Filled-Magnet in Experiments with Radioactive Ion Beams

Abstract A detection system has been developed for experiments with radioactive beams which have considerable contamination from a stable isobar. The system uses the gas-filled magnet technique and identifies reaction products according to nuclear charge and mass with good resolution even at energies below 1 MeV/u. In a first experiment the device has been used to measure cross sections for the 18F(p, α)15O reaction in the energy range between 650 and 840 keV/u.

Sub-barrier fusion cross sections in 58,64Ni+92,100Mo studied with the gas-filled magnet technique

Abstract Cross sections for evaporation residue formation in the systems 58,64 Ni+ 92,100 Mo have been measured over a large range of energies using the gas-filled magnet technique for the separation of projectiles and evaporation residues. Contrary to the results of previous studies, good arrangement between the experimental data and coupled-channel calculations is observed for both, excitation functions and spin distributions for 64 Ni+ 100 Mo.

Nuclear Reactions Studies with Radioactive 18F Beams at ATLAS

Abstract The contribution of the 18 F(p,γ) reaction to the production of 19 Ne which is the crucial isotope for the breakout from the hot CNO cycle into the rp process, has been investigated in experiments with 18 F beams. Measurements of the cross sections for the 18 F(p,α) 15 O and the 18 F(p,γ) 19 Ne reactions indicate that the contribution from the (p,γ) route to the formation of 19 Ne is small.

The influence of 18F induced reactions in the hot CNO cycle

Abstract The contribution of the 18 F(p,γ) reaction to the production of 19 Ne, which is an important isotope in connection with the breakout from the hot CNO cycle, has been investigated in experiments with 18 F beams. Measurements of the cross sections for the 18 F(p,α) 15 O and 18 F(p,γ) 19 Ne reactions indicate that the contribution of the 18 F(p,γ) route to the formation of 19 Ne is small.

Proton-induced fission of sup 238 U at extreme sub-barrier energies

Cross sections for proton-induced fission of {sup 238}U have been measured at seven proton energies ranging from 3.0 to 4.45 MeV using a kinematic coincidence technique, and an upper limit established at an energy of 2.5 MeV. Contrary to recent findings of Ajitanand {ital et} {ital al}. Phys. Rev. Lett. 58, 1520 (1987), the present work indicates that the fission cross section decreases as expected at extreme sub-barrier energies down to a level of {congruent}20 pb at 3 MeV.