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Title: Method and apparatus for noble gas atom detection with isotopic selectivity

Abstract

Apparatus and methods of operation are described for determining, with isotopic selectivity, the number of noble gas atoms in a sample. The analysis is conducted within an evacuated chamber which can be isolated by a valve from a vacuum pumping system capable of producing a pressure of 10.sup.-8 Torr. Provision is made to pass pulses of laser beams through the chamber, these pulses having wavelengths appropriate for the resonance ionization of atoms of the noble gas under analysis. A mass filter within the chamber selects ions of a specific isotope of the noble gas, and means are provided to accelerate these selected ions sufficiently for implantation into a target. Specific types of targets are discussed. An electron measuring device produces a signal relatable to the number of ions implanted into the target and thus to the number of atoms of the selected isotope of the noble gas removed from the gas sample. The measurement can be continued until a substantial fraction, or all, of the atoms in the sample have been counted. Furthermore, additional embodiments of the apparatus are described for bunching the atoms of a noble gas for more rapid analysis, and for changing the target for repetitive cyclingmore » of the gas in the chamber. The number of repetitions of the cyclic steps depend upon the concentration of the isotope of interest, the separative efficiency of the mass filter, etc. The cycles are continued until a desired selectivity is achieved. Also described are components and a method of operation for a pre-enrichment operation for use when an introduction of a total sample would elevate the pressure within the chamber to levels in excess of those for operation of the mass filter, specifically a quadrupole mass filter. Specific examples of three noble gas isotope analyses are described.« less

Inventors:
 [1];  [2];  [3];  [1]
  1. (Oak Ridge, TN)
  2. (Harriman, TN)
  3. (Knoxville, TN)
Issue Date:
Research Org.:
Sandia National Laboratories (SNL), Albuquerque, NM, and Livermore, CA
OSTI Identifier:
864843
Patent Number(s):
4426576
Assignee:
Atom Sciences, Inc. (Oak Ridge, TN) SNL
DOE Contract Number:  
AC04-76
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; noble; gas; atom; detection; isotopic; selectivity; methods; operation; described; determining; atoms; sample; analysis; conducted; evacuated; chamber; isolated; valve; vacuum; pumping; capable; producing; pressure; 10; -8; torr; provision; pass; pulses; laser; beams; wavelengths; appropriate; resonance; ionization; mass; filter; selects; specific; isotope; means; provided; accelerate; selected; sufficiently; implantation; target; types; targets; discussed; electron; measuring; device; produces; signal; relatable; implanted; removed; measurement; continued; substantial; fraction; counted; furthermore; additional; embodiments; bunching; rapid; changing; repetitive; cycling; repetitions; cyclic; steps; depend; concentration; separative; efficiency; etc; cycles; desired; achieved; components; pre-enrichment; introduction; total; elevate; levels; excess; specifically; quadrupole; examples; analyses; quadrupole mass; specific isotope; vacuum pumping; resonance ionization; mass filter; specific examples; substantial fraction; gas sample; laser beams; laser beam; measuring device; noble gas; evacuated chamber; vacuum pump; gas atoms; specific example; selected isotope; specific type; device produces; isotopic selectivity; /250/

Citation Formats

Hurst, G. Samuel, Payne, Marvin G., Chen, Chung-Hsuan, and Parks, James E. Method and apparatus for noble gas atom detection with isotopic selectivity. United States: N. p., 1984. Web.
Hurst, G. Samuel, Payne, Marvin G., Chen, Chung-Hsuan, & Parks, James E. Method and apparatus for noble gas atom detection with isotopic selectivity. United States.
Hurst, G. Samuel, Payne, Marvin G., Chen, Chung-Hsuan, and Parks, James E. Sun . "Method and apparatus for noble gas atom detection with isotopic selectivity". United States. https://www.osti.gov/servlets/purl/864843.
@article{osti_864843,
title = {Method and apparatus for noble gas atom detection with isotopic selectivity},
author = {Hurst, G. Samuel and Payne, Marvin G. and Chen, Chung-Hsuan and Parks, James E.},
abstractNote = {Apparatus and methods of operation are described for determining, with isotopic selectivity, the number of noble gas atoms in a sample. The analysis is conducted within an evacuated chamber which can be isolated by a valve from a vacuum pumping system capable of producing a pressure of 10.sup.-8 Torr. Provision is made to pass pulses of laser beams through the chamber, these pulses having wavelengths appropriate for the resonance ionization of atoms of the noble gas under analysis. A mass filter within the chamber selects ions of a specific isotope of the noble gas, and means are provided to accelerate these selected ions sufficiently for implantation into a target. Specific types of targets are discussed. An electron measuring device produces a signal relatable to the number of ions implanted into the target and thus to the number of atoms of the selected isotope of the noble gas removed from the gas sample. The measurement can be continued until a substantial fraction, or all, of the atoms in the sample have been counted. Furthermore, additional embodiments of the apparatus are described for bunching the atoms of a noble gas for more rapid analysis, and for changing the target for repetitive cycling of the gas in the chamber. The number of repetitions of the cyclic steps depend upon the concentration of the isotope of interest, the separative efficiency of the mass filter, etc. The cycles are continued until a desired selectivity is achieved. Also described are components and a method of operation for a pre-enrichment operation for use when an introduction of a total sample would elevate the pressure within the chamber to levels in excess of those for operation of the mass filter, specifically a quadrupole mass filter. Specific examples of three noble gas isotope analyses are described.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1984},
month = {1}
}

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