View More View Less
  • 1 MS-J576 Los Alamos National Laboratory Energy and Process Engineering 87545 Los Alamos NM USA
  • | 2 MS-E510 Los Alamos National Laboratory Nuclear Materials Technology 87545 Los Alamos NM USA
Restricted access

Cross Mark

Abstract  

Trace239Pu and241Am contamination on a surface whose alpha count is dominated by235U and234U decay has been successfully quantified by counting swipes in external alpha-spectroscopy chambers. The swipe process, however, is labor intensive and subject to uncertainties in the swiping process as well as degraded spectral resolution due to the presence of the swipe material. A multichannel instrument for automated in situ measurements of interior and exterior contamination has been developed which incorporates a rotary table, 13 fixed ion-implanted silicon detectors, and spectroscopy electronics. Custom software was written to allow alpha-spectrometer to function as a virtual instrument in the LabView environment. This system gives improved speed and resolution as well as a complete log of the location of areas of high surface contamination, a feature not practical to obtain by other methods, and one which opens the possibility of long term studies such as Pu outgrowth evaluation employing the instrument. We present performance data as well as system integration, calibration, control, and dynamic geometric efficiency calculations related to the design of this and next generation systems.