Bakeable ionization chamber for low-level tritium counting

Journal Article · Tue Jan 01 04:00:00 EST 1974 · Nucl. Instrum. Methods, v. 114, no. 2, pp. 269-275

DOI:https://doi.org/10.1016/0029-554X(74)90544-8· OSTI ID:4345748

Colmenares, C A

In order to minimize background and facilitate decontamination, a cylindrical ionization chamber using ultrahigh-vacuum metallic seals was constructed. Sapphire and pure alumina insulators isolated the collector electrode from the chamber. The chamber and inlet lines are bakeable to 450 deg C and withstand pressures up to 3 atm. The unshielded background of a new chamber was 2fA. The operating voltage plateau of the chamber was determined at 20 and 764 torr. Output current vs total tritium content was calibrated using tritiated methane and a tritium-argon mixture, both by increasing the pressure of a constant-concentration standard and by diluting the standard gas mixture at constant pressure. Theoretical calculations of efflciency of beta-energy absorption in spherical vessels fllled with several gases are presented, as well as experiment ally determined chamber efflciencies for methane and argon. (auth)

• Research Organization: Univ. of California, Livermore
• NSA Number: NSA-29-015691
• OSTI ID: 4345748
• Journal Information: Nucl. Instrum. Methods, v. 114, no. 2, pp. 269-275, Journal Name: Nucl. Instrum. Methods, v. 114, no. 2, pp. 269-275; ISSN NUIMA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*IONIZATION CHAMBERS-- PERFORMANCE
*TRITIUM-- RADIOMETRIC ANALYSIS
CALIBRATION
EFFICIENCY
LOW LEVEL COUNTERS
N40130 --Chemistry--Analytical & Separations Chemistry--Radiometric & Radiochemical Procedures
N46110* --Instrumentation--Radiation Detection Instruments-- General Detectors & Monitors
OPERATION