Compton-suppression gamma counting in the neutron activation analysis measurement of noble metals

Conference · Fri Jan 01 04:00:00 EST 1988 · Transactions of the American Nuclear Society; (USA)

OSTI ID:5554815

Millard, Jr, H T

Recent interest in studying elemental abundance anomalies associated with the Cretaceous and Tertiary (K-T) boundary in geologic strata has increased the importance of analytical methods for the determination of low levels of iridium and other noble metals. The determination of iridium anomalies that are in the range from 1 to 100 {mu}g/kg (ppb) requires radiochemical separation procedures following neutron activation. Faster and less laborious instrumental neutron activation analysis (NAA) techniques using elaborate Compton-suppression gamma counters are under development. Compton-suppression gamma counting (CSGC) uses anticoincidence shielded Ge(Li) detectors that enhance the signal-to-background ratios for gamma photopeaks situated on high Compton backgrounds. In this method, an anti- or noncoincidence spectrum and a coincidence spectrum are collected simultaneously. Most Compton-suppression counting has been done at low count rates, but neutron-activated samples ordinarily produce much higher count rates. In the work reported in this paper, K-T boundary and adjacent samples were neutron irradiated, the noble metals separated as a group, and the noble metal group separately counted using CSGC. Iridium, gold, platinum, and silver were determined. The counting data from these analyses were available for a thorough evaluation of the value of CSGC to the determination of this particular suite of noble metals in geologic samples.

• OSTI ID: 5554815
• Report Number(s): CONF-880601--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101* -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
ACTIVATION ANALYSIS
BASIC INTERACTIONS
CHEMICAL ANALYSIS
CHEMISTRY
COMPTON EFFECT
DETECTION
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
ELEMENTS
GAMMA DETECTION
GEOLOGY
INTERACTIONS
IRIDIUM
METALS
MITIGATION
PLATINUM METALS
RADIATION DETECTION
RADIOCHEMISTRY
SCATTERING
TRANSITION ELEMENTS