Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF)

The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.     

The TRASGO Project. Present Status and Results

Physics of Atomic Nuclei - The TRASGO project develops high resolution tracking detectors, sensitive to single electrons and muons as well as to bundles of both kinds of particles. Two detectors...     

Production cross-sections of neutron-rich Pb and Bi isotopes in the fragmentation of 238U

Neutron-rich lead and bismuth isotopes have been produced by cold-fragmentation reactions induced by ²³⁸U projectiles at 1A GeV impinging on a beryllium target. The high-resolving power FRagment Separator (FRS) at GSI allowed us to identify and determine the production cross-sections of 43 nuclei, nine of them for the first time ( ^{216, 217, 218, 219}Pb and ^{219, 220, 221, 222, 223}Bi . These data are compared to other previously measured cross-sections in similar reactions and model calculations.     

Dielectron production in 12C+12C collisions at 2A GeV with the HADES spectrometer

The invariant-mass spectrum of e+e- pairs produced in 12C+12C collisions at an incident energy of 2 GeV per nucleon has been measured for the first time. The measured pair production probabilities span over 5 orders of magnitude from the pi(0)-Dalitz to the rho/omega invariant-mass region. Dalitz decays of pi(0) and eta account for all the yield up to 0.15 GeV/c(2), but for only about 50% above this mass. A comparison with model calculations shows that the excess pair yield is likely due to baryon-resonance and vector-meson decays. Transport calculations based on vacuum spectral functions fail, however, to describe the entire mass region.