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Title: LOW BACKGROUND THIN-WALL FLOW COUNTERS FOR MEASURING BETA ACTIVITY OF SOLIDS

Abstract

The construction and performance of disk-shaped thinwalled flow counters suitable for measuring very small beta activities of solids is described. The circular faces, which serve as the cathode, consist of conducting films. Either a single pear-shaped loop of wire whose plane is parallel to that of the faces, or a group of straight wires stretched across the midplane serves as the anode. The counters are operated in the Geiger region. Samples can be counted against both faces of the counter. Performance data are given for counters having active volumes of 0.2 to 7 cc, and having active areas of 1.8 to 23 cm/sup 2/. Counting efficiencies for natural potassium (mounted on Lucite) vary from 30% to 47%, depending on the relationship of sample area to counter dimensions. Inside a 20- cm steel shield and an anticoincidence ring the background counting rates varied approximately as 1 count/hr/cm/sup 2/ of counting area. Backgrounds as low as 1 count/hr were obtained. The disk geometry permits the use of a smaller metal and anticoincidence shield than is possible with cylindrical geometry. Counters shielded successively with 1.9-cm mercury, 5-cm steel, and 5-cm lead, and operated with a flat multiple-anode anticoincidence counter (15 cm/sup 2/), actuallymore » gave lower background than with the 20-cm steel and anticoincidence ring assembly. An integral counter assembly, consisting of ~2-cm diam disk-shaped counter and a diskshaped guard counter (~7-cm diam), was constructed and gave satisfactory results. (auth)« less

Authors:
;
Publication Date:
Research Org.:
Scripps Institution of Oceanography, La Jolla, Calif.
Sponsoring Org.:
USDOE
OSTI Identifier:
4172022
NSA Number:
NSA-14-013907
Resource Type:
Journal Article
Journal Name:
Rev. Sci. Instr.
Additional Journal Information:
Journal Volume: Vol: 31; Other Information: Orig. Receipt Date: 31-DEC-60
Country of Publication:
Country unknown/Code not available
Language:
English
Subject:
ENGINEERING AND EQUIPMENT; ANODES; BACKGROUND; BETA PARTICLES; CATHODES; COINCIDENCE METHODS; CONFIGURATION; COUNTERS; CYLINDERS; DIAGRAMS; ELECTRIC CONDUCTIVITY; FOILS; IONIZATION CHAMBERS; LEAD; LUCITE; MEASURED VALUES; MERCURY; OPERATION; PERFORMANCE; POLYMERS; POTASSIUM; RADIOACTIVITY; SAMPLING; SHIELDING; SOLIDS; STEELS; VOLUME; WIRES

Citation Formats

Lal, D, and Schink, D R. LOW BACKGROUND THIN-WALL FLOW COUNTERS FOR MEASURING BETA ACTIVITY OF SOLIDS. Country unknown/Code not available: N. p., 1960. Web. doi:10.1063/1.1716988.
Lal, D, & Schink, D R. LOW BACKGROUND THIN-WALL FLOW COUNTERS FOR MEASURING BETA ACTIVITY OF SOLIDS. Country unknown/Code not available. https://doi.org/10.1063/1.1716988
Lal, D, and Schink, D R. 1960. "LOW BACKGROUND THIN-WALL FLOW COUNTERS FOR MEASURING BETA ACTIVITY OF SOLIDS". Country unknown/Code not available. https://doi.org/10.1063/1.1716988.
@article{osti_4172022,
title = {LOW BACKGROUND THIN-WALL FLOW COUNTERS FOR MEASURING BETA ACTIVITY OF SOLIDS},
author = {Lal, D and Schink, D R},
abstractNote = {The construction and performance of disk-shaped thinwalled flow counters suitable for measuring very small beta activities of solids is described. The circular faces, which serve as the cathode, consist of conducting films. Either a single pear-shaped loop of wire whose plane is parallel to that of the faces, or a group of straight wires stretched across the midplane serves as the anode. The counters are operated in the Geiger region. Samples can be counted against both faces of the counter. Performance data are given for counters having active volumes of 0.2 to 7 cc, and having active areas of 1.8 to 23 cm/sup 2/. Counting efficiencies for natural potassium (mounted on Lucite) vary from 30% to 47%, depending on the relationship of sample area to counter dimensions. Inside a 20- cm steel shield and an anticoincidence ring the background counting rates varied approximately as 1 count/hr/cm/sup 2/ of counting area. Backgrounds as low as 1 count/hr were obtained. The disk geometry permits the use of a smaller metal and anticoincidence shield than is possible with cylindrical geometry. Counters shielded successively with 1.9-cm mercury, 5-cm steel, and 5-cm lead, and operated with a flat multiple-anode anticoincidence counter (15 cm/sup 2/), actually gave lower background than with the 20-cm steel and anticoincidence ring assembly. An integral counter assembly, consisting of ~2-cm diam disk-shaped counter and a diskshaped guard counter (~7-cm diam), was constructed and gave satisfactory results. (auth)},
doi = {10.1063/1.1716988},
url = {https://www.osti.gov/biblio/4172022}, journal = {Rev. Sci. Instr.},
number = ,
volume = Vol: 31,
place = {Country unknown/Code not available},
year = {1960},
month = {4}
}