Analysis of /sup 81/Kr in groundwater using laser resonance ionization spectroscopy

Conference · Tue Oct 01 04:00:00 EDT 1985

OSTI ID:6242288

Kramer, S D; Hurst, G S; Chen, C H; Payne, M G; Allman, S L; Phillips, R C; Lehmann, B E; Oeschger, H; Loosli, H H; Willis, R D

A new analytical technique based on resonant ionization of krypton with a vacuum ultraviolet (VUV) laser source was used to determine low-level /sup 81/Kr concentrations in groundwater. The long half-life (210,000 years) and low concentration (1.3 x 10/sup 3/ /sup 81/Kr atoms per liter of modern water at 10/sup 0/C) make the detection of /sup 81/Kr by radioactive counting techniques extremely difficult. In this method, krypton gas was removed from water taken from an underground Swiss aquifer using standard cryogenic and chromatographic techniques. Stable krypton isotopes were then reduced by a factor of 10/sup 7/ by a two-stage isotopic enrichment cycle using a commercially available mass spectrometer. The enriched gas containing about 10/sup 8/ stable krypton atoms and about 10/sup 3/ atoms of /sup 81/Kr was implanted into a silicon disc. This disc was then placed in the high vacuum final counting chamber and the krypton was released by laser annealing. This chamber contained a quadrupole mass spectrometer which used a pulsed VUV laser source as the ionizer. The measured signal indicated that the sample contained 1200 (+-300) atoms of /sup 81/Kr.

• Research Organization: Oak Ridge National Lab., TN (USA); Bern Univ. (Switzerland); Atom Sciences, Inc., Oak Ridge, TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6242288
• Report Number(s): CONF-8510205-1; ON: DE86002214
• Country of Publication: United States
• Language: English

Related Subjects

520301* -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- Water-- (1987)
54 ENVIRONMENTAL SCIENCES
BETA DECAY RADIOISOTOPES
ECOLOGICAL CONCENTRATION
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
GROUND WATER
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON 81
KRYPTON ISOTOPES
MASS SPECTROSCOPY
NUCLEI
OXYGEN COMPOUNDS
RADIOACTIVITY
RADIOECOLOGICAL CONCENTRATION
RADIOISOTOPES
RESONANCE IONIZATION MASS SPECTROSCOPY
SECONDS LIVING RADIOISOTOPES
SPECTROSCOPY
WATER
YEARS LIVING RADIOISOTOPES