A borehole probe for in situ neutron activation analysis.
Baicker-JA; Lister-DB; Marr-RE; Goldman-LH
Denver, CO: U.S. Department of the Interior, Bureau of Mines, Contract H0262045, 1984 Jun; :1-119
A prototype borehole probe for ore grade determinations by means of in situ neutron activation analysis was designed, built, and tested in a two-phase program. Phase I dealt with the design and fabrication of a borehole logging system for operation in 7.6 Cm (3 in) diameter or larger boreholes. It consisted of a 5.06 Cm (2 in) diameter borehole probe containing an intrinsic germanium detector, a canister-type solid cryogen cooling system, cooled field-effect transistor preamplifier, linear amplifier, high voltage supply, analog-to-digital converter, microprocessor-based multichannel analyzer, buffer memory, bidirectional cable link, power supplies, and a californium-252 neutron source. A surface support vehicle was designed and outfitted. A minicomputer system was constructed, and software was developed and tested. In Phase II, the system was field tested at several minesites. Tests were performed at sites pertinent to uranium, iron, coal, copper, silver, and gold. Technical feasibility was demonstrated for all these applications except gold; the gold results were inconclusive. In situ neutron activation analysis using high resolution gamma ray spectrometry was found to be a potentially viable logging method for ore grade analysis under certain conditions.
Boreholes; Probes; Design; Fabrication; Neutron activation analysis; Field tests
CP; Final Contract Report
NTIS Accession No.
OFR 132-85; Contract-H0262045
Denver, CO: U.S. Department of the Interior, Bureau of Mines, Contract H0262045
Princeton Gamma Tech, Inc.