CO2-CS2 Geiger Counter

Journal Article · Tue Aug 01 04:00:00 EDT 1961 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1717573· OSTI ID:4840618

Crane, H. R.

Experiments on the mechanism and characteristics of a C0₂-CS₂ Geiger counter are reported, and circuits and methods of operation which satisfy the special requirements are described. Counter: The active part is 27/8 in. in diameter and 16 in. long, filled to 1 atm, 95% C0₂ and 5% CS₂. The cathode is copper and the anode is 0.005-in.dia. Chromel A. Characteristics: The electrons released by an ionizing particle beome attached, probably to CS₂. The self-quenching action of the counter is excellent, no spurious counts are observed in the absence of electronic quenching. However, a dead time of several milliseconds must be imposed electronically because of the long interval during which the negative ions arrive at the anode. Method: An electronic quench is used which is triggered both by the C0₂-CS₂ counter and the anticoincidence ring. This serves to impose the required dead time and also to prevent the firing of the C0₂-CS₂ counter by mesons. Measurements: The plateau was measured to 1900 v above threshold and was found to be level to within 1% from 400 to 1600 v above threshold. The maximum drift time of the negative ions was found to be about 9 msec with a sharp cutoff. Tests with various combinations of gas indicated, but did not prove, that the charge carrier was CS2. The effects of common contaminants were determined. At voltages over 400 above threshold, 1% 0₂ gave no detectable effect; 0.3% SO₂ gave a 2 to 3% reduction in counting rate. Extensive tests of the efficiency were made. Comparisons of the CO₂-CS₂ fllling with an argon-ethane filling gave identical results within the experimental error. No basis was found for supposing that there was any failure of the C0₂-CS₂ counter to register counts. Reliability: The counter described has been used for C/sup 14/ dating purposes over a long period of time. There has been no indication that there are variations in counting rate outside those expected on the basis of statistics. The counting rate for "dead" C0₂ in an iron shield 9 in. thick and after anticoincidence is 8 per min. (auth)

• Research Organization: Univ. of Michigan, Ann Arbor
• Sponsoring Organization: USDOE
• NSA Number: NSA-15-029494
• OSTI ID: 4840618
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 8 Vol. 32; ISSN 0034-6748; ISSN RSINAK
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANODES
ARGON
CARBON 14
CARBON OXIDES
CARBON SULFIDES
CATHODES
CHROMEL
CHROMIUM ALLOYS
CIRCUITS
COINCIDENCE METHODS
COPPER
COUNTERS
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRONS
ENGINEERING AND EQUIPMENT
ETHANE
FAILURES
GEIGER-MUELLER COUNTERS
IONS
IRON
LIFETIME
MEASURED VALUES
MESONS
NICKEL ALLOYS
OXYGEN
SHIELDING
STANDARDS
STATISTICS
SULFUR OXIDES