AVS 46th International Symposium
    Applied Surface Science Division Wednesday Sessions
       Session AS-WeM

Paper AS-WeM10
Technique for Production of Calibrated Metal Hydride Films

Wednesday, October 27, 1999, 11:20 am, Room 6A

Session: Gaede-Langmuir Award Address and Quantitative Surface Analysis
Presenter: R.A. Langley, Sandia National Laboratories
Authors: R.A. Langley, Sandia National Laboratories
J.F. Browning, Sandia National Laboratories
S.D. Balsley, Sandia National Laboratories
J.C. Banks, Sandia National Laboratories
B.L. Doyle, Sandia National Laboratories
W.R. Wampler, Sandia National Laboratories
Correspondent: Click to Email
A technique has been developed for producing calibrated metal hydride films for use in the measurement of high-energy (5-15 MeV) particle reaction cross sections for hydrogen and helium isotopes on hydrogen isotopes. Absolute concentrations of various hydrogen isotopes in the film is expected to be determined to better than ± 2% leading to the capacity of accurately measuring various reaction cross sections. Hydrogen isotope concentrations from near 100% to 5% can be made accurately and reproducibly. This is accomplished with the use of high accuracy pressure measurements coupled with high accuracy mass spectrometric measurements of each constituent partial pressure of the gas mixture during loading of the metal occluder films. Various techniques are used to verify the amount of metal present as well as the amount of hydrogen isotopes: high energy ion scattering analysis, PV measurements before, during and after loading, and thermal desorption/mass spectrometry measurements. The most appropriate metal to use for the occluder film appears to be titanium but other occluder metals are also being considered. Calibrated gas ratio samples, previously prepared, are used for the loading gas. Deviations from this calibrated gas ratio are measured using mass spectrometry during and after the loading process. These techniques will be discussed and results presented.