Search Results
You are looking at 1 - 3 of 3 items for
- Author or Editor: J. Wacker x
- Refine by Access: All Content x
Abstract
Traditional methods of quantitation of radioactive isotopes includeradioactivity counting and thermal ion mass spectrometry (TIMS). These techniquesrequire extensive matrix separation and sample purification methods beforeunequivocal identification of specific isotopes and their relative abundanceis possible. Counting techniques become very time consuming when the half-lifeof the target analyte is very long or the concentration of the analyte low.Atom counting using ICP-MS meets the nuclear industry requirements for manyactinides and their daughter products. Recent improvements in quadrupole ICP-MSsignal-to-background have resulted in attogram mass detection capability andimproved analysis of shorter half-life isotopes.
Abstract
The fast transfer system in the DR 2 reactor for irradiation at a thermal neutron flux density of 1013 n·cm−2·sec−1 was used for the determination of lithium by the7Li(n, γ)8Li reaction. β-counting with a large perspex Cerenkov detector begun at 0.3 s after the end of irradiation, and multi-scaler data was accumulated in 300 channels at 0.1 s per channel. With a suitable choice of discrimination level only16N and background interfere, and the 0.84 s half-life of8Li was resolved by the method of weighted least squares. Results are presented for 36 international geochemical reference materials, and for a few biological samples, including BOWEN's kale and the NBS Standard Reference Material 1571 Orchard Leaves.
Abstract
The Comprehensive Test Ban Treaty calls for the monitoring of aerosol radionuclides throughout the globe. Pacific Northwest National Laboratory has developed the Radionuclide Aerosol Sampler/Analyzer (RASA) for the Department of Energy to automatically collect and measure radioactive aerosols from the atmosphere. The RASA passes high volumes of air through a 3MTM Substrate Blown Microfiber Media (SBMF) specifically designated as SBMF-40VF. It then automatically moves the filter media in front of a high-purity germanium detector and collects a gamma spectrum. If further analysis on the filter is desired, the filter is sent to a laboratory and radiochemical analysis is performed. This paper discusses the method of dissolution of the SBMF-40VF filter media and the separation of the radioisotopes of interest.
