High Spin Structure of 122Xe

Abstract

High spin states in the isotope 122Xe were populated using the reaction 96Zn(30Si,2n)122Xe at a beam energy of 135 MeV. The subsequent γ-ray deexcitation was studied using γ-ray spectroscopic methods. The analysis of γ-γ coincidences has revealed two new structures of competing dipole and quadrupole transitions. The highest states of a positive parity band provide characteristics consistent with an approach to band termination.

High-energy neutron facility at the Athens Tandem Accelerator NCSR “Demokritos”

“…At the 5.5 MV Tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" quasi-monoenergetic neutron beams can be produced with a maximum flux of the order of 10 6 n/s•cm 2 , in the energy range ∼4-11.2 MeV by using the 2 H(d,n) reaction, at the corresponding deuteron beam energies 0.8-8.2 MeV [2]. These neutron beams have been used for neutron-induced cross section measurements mainly with the activation method [3][4][5][6][7][8][9]. This neutron facility has been characterized by means of MCNP5 Monte Carlo simulations, multiple foil activation unfolding technique and deconvolution of recoil energy spectra taken with the BC501A liquid scintillator detector at various neutron energies [10].…”

“…In view of the above remarks, a new Ti-tritiated target of 373 GBq activity has been installed at the 5.5 MV Tandem T11/25 Accelerator of NCSR "Demokritos", to produce neutrons in the energy range ∼16-19 MeV by means of the 3 H(d,n) 4 He reaction. In absence of time-of-flight capabilities, the energy spectrum of the neutron beam has been investigated by means of the Multiple Foil Activation Analysis technique, using reactions with different energy thresholds.…”

“…. The new high-energy neutron facility In the 5.5 MV tandem T11/25 Accelerator Laboratory of NCSR "Demokritos" a new neutron facility has been installed, producing beams at energies ∼16-19 MeV by means of the 3 H(d,n)4 He reaction. The…”

Investigation of (n,2n) reactions using the high energy neutron facility at NCSR “Demokritos”

“…The nuclei investigated in the present work, are of particular interest for various applications. Hf is used for reactor control rods in nuclear submarines, since apart from the fact that it is extremely corrosion resistant, it has good absorption cross section for thermal neutrons [1]. Furthermore, in assessing radioactive waste production, neutron induced reactions on W and Ta in reactor materials can lead to long-lived isomeric states of Hf isotopes with rather harmful γ radiation ( 178m2 Hf, T 1/2 = 31y) [2].…”

“…The 197 Au(n,2n) and 191 Ir(n,2n) reactions present interesting cases since the residual nuclei 196 Au and 190 Ir can be produced either in their ground state or in one of their high spin isomeric states, thus offering great sensitivity for such studies. These reactions have been investigated in the past by many groups, including our group [1,7,8], from ~8 to ~24 MeV, with many discrepancies among the data, differing by as much as 50% in some cases. In the present work, the 174 Hf(n,2n), 197 Au(n,2n) and 191 Ir(n,2n) reactions have been measured at 15.3 and 17.1 MeV.…”