Abstract
Prompt gamma-ray neutron activation analysis (PGNAA) and neutron inelastic scattering (NIS) techniques have been widely used for measuring elemental composition in bulk samples. The neutrons and gamma-rays used in this technique are highly penetrating, which allows the analysis of large sample volumes. In the oil well logging industry, there are limitations on the size of detectors used - particularly the detector diameter. This limitation can lead to a low detection probability for the high energy gamma-rays. A new NaI detector arrangement (patent pending) has been designed to deal with this problem. The arrangement consists of two NaI detectors, one of which is a well type. The first detector is 1″x5″ and the second is a well type 5″ long with a wall thickness of 0.35″ and a hole diameter of one inch. The first detector is placed inside of the well detector for use. Feasibility studies were performed with this arrangement using a 24Na radioactive source and a sulfur sample or prompt gamma-rays. An enhancement in the signal-to-noise ratio (SNR) was observed in both cases based on the peak height to continuum height in the resulting prompt gamma-ray spectra.
| Original language | English |
|---|---|
| Pages (from-to) | 133-137 |
| Number of pages | 5 |
| Journal | Journal of Radioanalytical and Nuclear Chemistry |
| Volume | 264 |
| Issue number | 1 |
| DOIs | |
| State | Published - Apr 2005 |
| Externally published | Yes |
Funding
The authors gratefully acknowledge the financial support of the Associates Program for Nuclear Techniques in Oil Well Logging with members Baker-Atlas and Advantage Engineering, Shell, and Exxon Mobil.