MODEL IV-GRAPHITE, CARBON DIOXIDE 4-CC IONIZATION CHAMBER

Technical Report · Tue Mar 01 04:00:00 EST 1960

OSTI ID:4166345

Hall, C C; Johnson, S D

The Model IV 4-cc ionization chamber, a graphite-CO/sub 2/ chamber filled with 99.99% pure CO/sub 2/ to a pressure of 30 in. Hg, was designed to withstand mechanical vibration as well as high gamma dose rates. The materials used were selected for long life in high radiation fields and for low neutron activation. To determine saturation characteristics, the ionization chamber was exposed to a gamma dose rate of 7.4 x 10/sup 7/ ergs/g-hr and the chamber voltage was varied from 10 to 1500 volts. The chamber was saturated at 400 volts and the ion current output remained constant from 400 to 1500 volts. The chamber was also placed in gamma fields ranging from 10/sup 3/ to 10/sup 8/ ergs/g-hr. For each gamma dose rate, the voltage required to give 90% saturation was determined. The 4-cc ion chamber was calibrated by comparing readings on it with those of a calorimeter and a Victoreen R-meter and chamber calibrated by the National Bureau of Standards. Angular response of the chamber was detemnined using 250-kvp x rays and radiation from the Radiation Effects Reactor. Temperature sensitivity was determined by placing the ion chamber in a water bath and controlling water temperature. (M.C.G.)

• Research Organization: Lockheed Nuclear Products, Marietta, Ga.
• NSA Number: NSA-14-019144
• OSTI ID: 4166345
• Report Number(s): NP-8856; NR-70
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ANGULAR DISTRIBUTION
CARBON DIOXIDE
CONTROL
ELECTRIC POTENTIAL
ENGINEERING AND EQUIPMENT
GAMMA RADIATION
GRAPHITE
IONIZATION CHAMBERS
PLANNING
PRESSURE
RADIATION DOSES
RADIATIONS
SENSITIVITY
TEMPERATURE
VARIATIONS
VIBRATIONS
VOLUME
WATER
X RADIATION