Photodissociation of neutron deficient nuclei

Abstract

Abstract. The knowledge of the cross sections for photodissociation reactions like e.g. (γ, n) of neutron deficient nuclei is of crucial interest for network calculations predicting the abundances of the so-called p nuclei. However, only single cross sections have been measured up to now, i.e., one has to rely nearly fully on theoretical predictions. While the cross sections of stable isotopes are accessible by experiments using real photons, the bulk of the involved reactions starts from unstable nuclei. Coulomb dissociation (CD) experiments in inverse kinematics might be a key to expand the experimental database for p-process network calculations. The approach to test the accuracy of the CD method is explained.PACS. 25.20.-x Photonuclear reactions -26.30.+k Nucleosynthesis in novae, supernovae and other explosive environments

Activation Experiments forp-Process Nucleosynthesis

“…Such a measurement can be carried out at setups like R 3 B at the future FAIR facility if Coulomb dissociation in inverse kinematics is used. First approaches on the determination of (γ,n) rates of different molybdenum isotopes were performed to test the method and yielded promising results [39,40]. However, to measure (γ,n), (γ,p), and (γ,α) reaction cross sections simultaneously at the future R 3 B setup amendments concerning the detection of the emitted α particles have to be developed and integrated to the setup.…”

Photo-induced nucleosynthesis: Current problems and experimental approaches

“…Here the strong virtual photon field of a heavy target nucleus is used for the electromagnetic breakup of the projectile. The main advantage of this method is the much larger cross section (compared to the direct photon-induced reaction) which allows to study the properties of unstable nuclei using radioactive ion beams [72]. However, one must be aware of such complications in the interpretation of data as contributions of nuclear breakup, a mixture of virtual photons with different multipolarity, and the final-state interaction known as post-Coulomb acceleration.…”

Experiments on photon-induced reactions for p-process nucleosynthesis

“…Experiments using Coulomb Dissociation (CD) in inverse kinematics as feasible at the SIS/FRS/LAND setup at GSI, Darmstadt, [37] can extend the investigations in that direction. A first test was carried out on the (γ,n) cross sections of the isotopes 92,93,94,100 Mo [38]. To compare the reliability of the CD method, the cross sections of 92 Mo(γ,n)+(γ,p) [39] and 100 Mo(γ,n) were observed at the ELBE accelerator at Forschungszentrum Dresden and at the S-DALINAC, Darmstadt, respectively, using continuous-energy bremsstrahlung.…”