Further improvement in the precision of 233U measurements by accelerator mass spectrometry at the Lawrence Livermore National Laboratory.

Tumey, S J ; Brown, T A ; Hamilton, T F ; Buchholz, B A

关键词: ACCELERATORS;    ACCURACY;    FARADAY CUPS;    IONIZATION CHAMBERS;    LAWRENCE LIVERMORE NATIONAL LABORATORY;    MASS SPECTROSCOPY;    MODIFICATIONS;   

DOI  :  10.2172/926045
RP-ID  :  LLNL-TR-401375
PID  :  OSTI ID: 926045
Others  :  TRN: US0802525

美国|英语

来源: SciTech Connect

【 摘 要 】

In response to sponsor interest in October 2005 we proposed two methods for enhancing the precision of {sup 233}U accelerator mass spectrometry (AMS) capabilities at the Lawrence Livermore National Laboratory (LLNL). In a previous report we evaluated the first method and demonstrated that by increasing sample loading by a factor of four coupled with performing four replicates of each sample, we could achieve measurement precision of {approx}1%. Recent modifications to our system have enabled us to test the second proposed method. By changing our setup to normalize {sup 233}U ions counted in a gas ionization chamber to {sup 238}U measured as a current in an off-axis Faraday cup we were able to attain 1% precision without the need for replicate analysis. This method could be further refined to achieve 0.5% precision in samples of interest.