S. Galanopoulos

Chemical state speciation by resonant Raman scattering

In the resonant Raman scattering (RRS) process the emitted photon exhibits a continuous energy distribution with a high energy cutoff limit. This cutoff energy depends on the chemical state of the element under examination. In the present work, the possibility of identifying the chemical state of V atoms by employing RRS spectroscopy with a semiconductor Si(Li) detector is investigated. A proton induced Cr Kα x-ray beam was used as the incident radiation, having a fixed energy lower than the V K-absorption edge. The net RRS distributions extracted from the energy dispersive spectra of metallic V and its compound targets were simulated by an appropriate theoretical model. The results showed the possibility of employing RRS spectroscopy with a semiconductor detector for chemical speciation studies.

Proton and alpha-particle capture reactions at sub-Coulomb energies relevant to the p process

Several cross-section measurements of proton as well as α-particle capture reactions in the Se–Sb region have been carried out at sub-Coulomb energies with the aim to obtain global input parameters for Hauser–Feshbach (HF) calculations. Some of the results are compared with HF calculations using various optical model potentials and nuclear level densities.

A systematic study of proton capture reactions in the SeSb region at energies relevant to the p process

Abstract A systematic investigation of (p,γ) cross sections of nuclei from Se to Sb is presented. In-beam cross section measurements were carried out at E p = 1.4–5 MeV by using an array of 4 HPGe detectors of 100% relative efficiency shielded with BGO crystals. The S factors obtained are compared with the predictions of the statistical model code MOST.

Isomeric Cross‐Section Study of Neutron‐Induced Reactions on Ge

The 72Ge(n,α)69mZn, 74Ge(n,α)71mZn, 76Ge(n,2n)75g+mGe reaction cross sections have been measured from 9.6 to 11.4 MeV and studied, along with data from literature, within the frame of the statistical model using the code EMPIRE‐II.

Neutron induced reactions at the Athens Tandem Accelerator of NCSR “Demokritos”

In the 5.5 MV tandem T11/25 Accelerator Laboratory of NCSR “Demokritos” monoenergetic neutron beams have been used in the energy range 7–11.5 MeV, produced via the 2H(d,n) reaction. The flux variation of the neutron beam is monitored by using a BF3 detector, while an investigation of the energy dependence of the neutron fluence is carried out via the multiple foil activation technique. The 232Th(n,2n)231Th and 241Am(n,2n)240Am as well as (n,2n), (n,p) and (n,α) reactions on natural Ge and Hf isotopes, have been investigated from threshold up to 11.5 MeV, by using the activation method. The cross section values have been determined relative to the 197Au(n,2n)196Au, 27Al(n,α)24Na and 93Nb(n,2n) reference reaction cross sections.

Neutron activation measurements on natural Ge and Hf

Cross section measurements of neutron induced reactions on isotopes of natural Ge and Hf have been carried out at the 5.5 MV Tandem accelerator of the NCSR “Demokritos” in Athens, Greece, using the activation technique. The measurements have been performed at neutron incident energies 8.8, 9.6, 10.6, 11.1, 11.4 MeV for the case of Ge and at 8.8, 9.6, 11.1, 11.4 MeV for the Hf one. In all cases the target material was Ge and HfO2 powder of high purity.