A Model for the 3He(\vec d, p)4He Reaction at Intermediate Energies

Polarization correlation coefficients have been measured atRIKEN for the \vec 3He(\vec d,p)4He reaction at intermediate energies. We propose a model for the (\vec d, p) reaction mechanism using the pd elastic scattering amplitude which is rigorously determined by a Faddeev calculation and using modern NN forces. Our theoretical predictions for deuteron polarization observables A_y, A_{yy}, A_{xx} and A_{xz} at E_d=140, 200 and 270 MeV agree qualitatively in shape with the experimental data for the reaction 3He(\vec d,p)4He.Comment: 6 pages, 11 figures, 1 table, reference: http://www.phys.ntu.edu.tw/english/fb16/contribution/topic4/Uesaka_Tomohiro1. ps in Contribution for the XVIth IUPAP International Conference on Few-Body Problems in Physics, (Taipei, Taiwan 6-11, March 2000

Nuclear astrophysics with radioactive ions at FAIR

The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes

Geochemical Detection of the pp-Neutrino flux with 205Tl LOREX collaboration

An indispensable goal of this proposal still remains the determination of the neutrino capture probability by 205Tl. The ratio 205Pb/205Tl in lorandite provides only the product of solar neutrino flux and neutrino capture probability into the different nuclear states of 205Pb

Probing the density tail of radioactive nuclei with antiprotons

We propose an experiment to determine the proton and neutron content of the radial density tail in short-lived nuclei. The objectives are to (i) to evidence new proton and neutron halos, (ii) to understand the development of neutron skins in medium-mass nuclei, (iii) to provide a new observable that characterises the density tail of short-lived nuclei

Geochemical Determination of the pp-Neutrino Flux with 205Tl-LOREX: A Progress Report

Intensive research from the 1970's to 1990's towards geochemical detection of solar neutrinos using 205 Tl, 98 Mo and 81 Br has left 205 Tl the only viable candidate. LOREX (LORandite EXperiment ) is based on determining the solar (pp) neutrino flux for the period of 4.3 Ma from the reaction 205 Tl+v e → 205 Pb+e - , the lowest threshold (52 keV) for neutrino capture. The ratio of 205 Pb/ 205 Tl in lorandite (TlAsS 2 ) depends also on contributions from fast muon cosmic radiation. The latter is a function of paleo - depth, including the eroded layer over 4.3 Ma, determined using cosmogenic nuclides ( 26 Al, 36 Cl, 3 He and 21 Ne) in the ore body Crven Dol (Tl - As - Sb - S) in Allchar (Macedonia). The results give a l ower limit of paleo - depth of 490mwe and an upper limit of 2300mwe. From this the ratios 205 Pb ve / 205 Pb tot are estimated as 2:8 and 6:4, respectively. Identification of the 205 Pb nuclei in the lead sample extracted from the lorandite mineral requires 10 - 10 to 10 - 11 overall detection sensitivity for 205 Pb/Pb and comparable suppression of the 205 Tl isobar. This is proposed by full stripping of 205 Pb at high energy (345MeV/u) at the RIKEN - RIBF ion - beam facility. 205 Tl isobar separation is already largely achiev ed by chemical Pb - Tl separation by the overall sample preparation. Samples with a higher concentration ( 205 Tl/natPb=1%) are necessary for a guide - beam and initial accelerator tuning. A sample with a considerably lower level of about 10 - 8 is needed for cont rol of the beam analysis system with 205 Tl ions, in the presence ultimately of a lighter guide beam, to limit the in - beam production of 205 Pb by the (p,n) reaction on 205 Tl in the energy - loss and ion - stripping steps in the accelerator and the subsequent Bi gRIPS/Mass - Ring experimental apparatus. The relative cross sections between full stripping of 205 Pb and (p,n) on 205 Tl is estimated as 10 5 . Test experiments to verify the various aspects of the proposed approach at the RIBF are under preparation