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Title: Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 191}Ir

Abstract

The {sup 191}Ir(n,2n){sup 190}Ir cross section was measured by means of the activation technique at four neutron energies in the range 10.0-11.3 MeV. The quasimonoenergetic neutron beam was produced via the {sup 2}H(d,n){sup 3}He reaction at the 5.5 MV Tandem Van de Graaff accelerator of NCSR 'Demokritos'. The cross section for the population of the second high spin (11{sup -}) isomeric state was measured along with the sum of the reaction cross section populating both the ground (4{sup -}) and the first isomeric state (1{sup -}). Statistical model calculations taking into account pre-equilibrium emission were performed and compared with all the available experimental data. The experimentally deduced excitation function for populating both the ground and first isomeric state was well reproduced by the theoretical calculations. The statistical model calculations of populating the second metastable state revealed its strong dependence on the details of the introduced level scheme, as well as on the ratio between the effective moment of inertia and the rigid body moment of inertia of the residual nucleus. The experimental cross-section data corresponding to the second isomeric state and to the isomeric ratio were reproduced in a quite consistent way by the calculations.

Authors:
; ; ; ; ; ; ;  [1];  [2]
  1. Department of Physics, National Technical University of Athens, Athens (Greece)
  2. (Greece)
Publication Date:
OSTI Identifier:
20995139
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.75.034607; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; DEUTERIUM; EXCITATION FUNCTIONS; HELIUM 3; IRIDIUM 190; IRIDIUM 191; ISOMER RATIO; METASTABLE STATES; MEV RANGE 10-100; MOMENT OF INERTIA; NCSR; NEUTRON BEAMS; NEUTRONS; SPIN; STATISTICAL MODELS; VAN DE GRAAFF ACCELERATORS

Citation Formats

Patronis, N., Papadopoulos, C. T., Galanopoulos, S., Kokkoris, M., Perdikakis, G., Vlastou, R., Lagoyannis, A., Harissopulos, S., and Institute of Nuclear Physics, NCSR 'Demokritos', Athens. Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 191}Ir. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.034607.
Patronis, N., Papadopoulos, C. T., Galanopoulos, S., Kokkoris, M., Perdikakis, G., Vlastou, R., Lagoyannis, A., Harissopulos, S., & Institute of Nuclear Physics, NCSR 'Demokritos', Athens. Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 191}Ir. United States. doi:10.1103/PHYSREVC.75.034607.
Patronis, N., Papadopoulos, C. T., Galanopoulos, S., Kokkoris, M., Perdikakis, G., Vlastou, R., Lagoyannis, A., Harissopulos, S., and Institute of Nuclear Physics, NCSR 'Demokritos', Athens. Thu . "Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 191}Ir". United States. doi:10.1103/PHYSREVC.75.034607.
@article{osti_20995139,
title = {Activation cross section and isomeric cross-section ratio for the (n,2n) reaction on {sup 191}Ir},
author = {Patronis, N. and Papadopoulos, C. T. and Galanopoulos, S. and Kokkoris, M. and Perdikakis, G. and Vlastou, R. and Lagoyannis, A. and Harissopulos, S. and Institute of Nuclear Physics, NCSR 'Demokritos', Athens},
abstractNote = {The {sup 191}Ir(n,2n){sup 190}Ir cross section was measured by means of the activation technique at four neutron energies in the range 10.0-11.3 MeV. The quasimonoenergetic neutron beam was produced via the {sup 2}H(d,n){sup 3}He reaction at the 5.5 MV Tandem Van de Graaff accelerator of NCSR 'Demokritos'. The cross section for the population of the second high spin (11{sup -}) isomeric state was measured along with the sum of the reaction cross section populating both the ground (4{sup -}) and the first isomeric state (1{sup -}). Statistical model calculations taking into account pre-equilibrium emission were performed and compared with all the available experimental data. The experimentally deduced excitation function for populating both the ground and first isomeric state was well reproduced by the theoretical calculations. The statistical model calculations of populating the second metastable state revealed its strong dependence on the details of the introduced level scheme, as well as on the ratio between the effective moment of inertia and the rigid body moment of inertia of the residual nucleus. The experimental cross-section data corresponding to the second isomeric state and to the isomeric ratio were reproduced in a quite consistent way by the calculations.},
doi = {10.1103/PHYSREVC.75.034607},
journal = {Physical Review. C, Nuclear Physics},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}