Helium and hydrogen measurements for F-82H alloys enriched up to 96% in 54Fe demonstrate accelerated gas production due to differences in the isotopic cross sections. The samples were irradiated in the JP-17 and JP-22 experiments in HFIR. Results are compared to calculations using isotopic helium production cross sections from ENDF/B-VI or the computer code, GNASH, for the radioactive isotope 55Fe. Helium measurements demonstrated an accelerated helium (appm)/dpa ratio of 2.3 after a 1.25-year irradiation, an increase of a factor of 4.3 over natural iron, due to higher helium production cross sections for 54Fe and 55Fe. Alloys doped with 55Fe could achieve helium/dpa ratios up to about 20, well above the fusion reactor ratio of 10. Calculations predict that hydrogen production is accelerated by about a factor of 13 over natural iron. However, measurements show that most of this hydrogen is not retained in the samples.
Revised: July 27, 2010 |
Published: September 1, 2000
Citation
Greenwood L.R., B.M. Oliver, S. Ohnuki, K. Shiba, Y. Kohno, A. Kohyama, and J.P. Robertson, et al. 2000.Accelerated Helium and Hydrogen Production in Fe-54 Doped Alloys - Measurements and Calculations for the FIST Experiment. In Fusion Materials: Semi-Annual Progress Report Ending December 31, 1999, edited by Rowcliffe, A.F. 236. Washington Dc:Department of Energy, Office of Fusion Energy Sciences.PNNL-SA-31873.