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Title: Method of and apparatus for measuring the mean concentration of thoron and/or radon in a gas mixture

Abstract

A method of and an apparatus for detecting and accurately measuring the mean concentrations of .sup.222 Rn and .sup.220 Tn in a gas mixture, such as the ambient atmosphere in a mine, is provided. The apparatus includes an alpha target member which defines at least one operative target surface and which is preferably fabricated from a single piece of an alpha particle sensitive material. At least one portion of the operative target surface is covered with an alpha particle filter. The uncovered and filter covered operative surface is exposed to the gas mixture containing the .sup.222 Rn and .sup.220 Tn. In the radioactive decay series of these isotopes the maximum kinetic energy emitted by the alpha decay of .sup.222 Rn is about 1.1 MeV less than the maximum kinetic energy emitted by the alpha decay of a .sup.220 Tn. The alpha particle filter has a predetermined mass per unit area of the covered portion of the operative target surface that prevents penetration of alpha particles which originate from .sup.222 Rn decay, but which allows passage therethrough of the maximum kinetic energy alpha particles from .sup.220 Tn decay. Thus, a count of the alpha particle tracks in the uncovered portion ofmore » the target member is proportional to the mean concentration of sum of .sup.222 Rn and .sup.220 Tn in the gas mixture, while the count of alpha tracks in the target member under the filter is proportional to the concentration of only the .sup.220 Tn in the gas mixture.« less

Inventors:
 [1]
  1. P.O. Box 1454, Sedona, AZ 86336
Issue Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
OSTI Identifier:
867626
Patent Number(s):
4975574
Assignee:
Lucas, Henry (P.O. Box 1454, Sedona, AZ 86336)
Patent Classifications (CPCs):
Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y10 - TECHNICAL SUBJECTS COVERED BY FORMER USPC Y10S - TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
G - PHYSICS G01 - MEASURING G01T - MEASUREMENT OF NUCLEAR OR X-RADIATION
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; measuring; mean; concentration; thoron; radon; gas; mixture; detecting; accurately; concentrations; 222; 220; tn; ambient; atmosphere; mine; provided; alpha; target; defines; operative; surface; preferably; fabricated; single; piece; particle; sensitive; material; portion; covered; filter; uncovered; exposed; containing; radioactive; decay; series; isotopes; maximum; kinetic; energy; emitted; mev; predetermined; mass; unit; prevents; penetration; particles; originate; allows; passage; therethrough; count; tracks; proportional; passage therethrough; particle tracks; single piece; ambient atmosphere; mixture containing; gas mixture; target surface; alpha particle; alpha particles; kinetic energy; radioactive decay; accurately measuring; sensitive material; uncovered portion; alpha tracks; particle filter; energy emitted; particle track; mean concentration; /250/

Citation Formats

Lucas, Henry. Method of and apparatus for measuring the mean concentration of thoron and/or radon in a gas mixture. United States: N. p., 1990. Web.
Lucas, Henry. Method of and apparatus for measuring the mean concentration of thoron and/or radon in a gas mixture. United States.
Lucas, Henry. Mon . "Method of and apparatus for measuring the mean concentration of thoron and/or radon in a gas mixture". United States. https://www.osti.gov/servlets/purl/867626.
@article{osti_867626,
title = {Method of and apparatus for measuring the mean concentration of thoron and/or radon in a gas mixture},
author = {Lucas, Henry},
abstractNote = {A method of and an apparatus for detecting and accurately measuring the mean concentrations of .sup.222 Rn and .sup.220 Tn in a gas mixture, such as the ambient atmosphere in a mine, is provided. The apparatus includes an alpha target member which defines at least one operative target surface and which is preferably fabricated from a single piece of an alpha particle sensitive material. At least one portion of the operative target surface is covered with an alpha particle filter. The uncovered and filter covered operative surface is exposed to the gas mixture containing the .sup.222 Rn and .sup.220 Tn. In the radioactive decay series of these isotopes the maximum kinetic energy emitted by the alpha decay of .sup.222 Rn is about 1.1 MeV less than the maximum kinetic energy emitted by the alpha decay of a .sup.220 Tn. The alpha particle filter has a predetermined mass per unit area of the covered portion of the operative target surface that prevents penetration of alpha particles which originate from .sup.222 Rn decay, but which allows passage therethrough of the maximum kinetic energy alpha particles from .sup.220 Tn decay. Thus, a count of the alpha particle tracks in the uncovered portion of the target member is proportional to the mean concentration of sum of .sup.222 Rn and .sup.220 Tn in the gas mixture, while the count of alpha tracks in the target member under the filter is proportional to the concentration of only the .sup.220 Tn in the gas mixture.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1990},
month = {1}
}