The Activity of Gamma Emitters as Measured by Ionization Chambers. The Determination of the Specific Gamma Emission Coefficient for Some Radioelements (thesis); MESURE DE L'ACTIVITE DES EMETTEURS GAMMA PAR CHAMBRES D'IONISATION. DETERMINATION DU COEFFICIENT SPECIFIQUE D'EMISSION GAMMA DE QUELQUES RADIOELEMENTS (thesis)

Technical Report · Mon Jan 01 04:00:00 EST 1962

OSTI ID:4751217

Englemann, J

The object of this work is to study techniques of measurement using the gamma ionization chamber, making it possible either to measure the activities of radioactive sources, or to determine the specific emission coefficient gamma (or the coefficient K) of a given radio-element. The ionization chambers studied belong to two categories: graphite cavity-chambers, and 4 pi gamma chambers. For the cavity-chamber measurements, the different correction factors of which account must be taken have been calculated, in particular the geometric and hygrometric corrections. The absorption and autoabsorption corrections have led to the introduction of the notion of the effective energy, gamma , of a radio- element. In the case of 4 pi gamma chambers, it has been shown that appropriately shaped electrodes make it possible to improve their performanccs. One of the chambers described permits the measurement of BETA emitters using the associated bremsstrahlung. The K coefficients of some radio-elements were measured, using a graphite-coated 4 pi gamma chamber, a radium standard was used for comparison. The validity of the method was checked with radio-elements for whom the K coefficient values are well-known (Na/sup 24/, Co/sup 60/, I/sup 131/, Au/sup 198/). For other radaoelements, the following values were obtained (expressed in r cm/sup 2/ mc/sup -1/ h/sup -1/) Cr/sup 51/:0.18 Sb/sup 124/:9.9 Ce/sup 141/:0.46 Mn/sup 56/:8.8 Cs/sup 134/:9.3 Tm/sup 170/:0.023 Zn/sup 65/:3.05 Cs/sup 137/:3.35 Ir/sup 192/:4.9 These values have been corrected for the contribution to the dose of the fluorescent radiation which may be emitted by the source, except in the case of Tm/sup 170/. The performances of the differert electrometric devices used were compared. (auth)

• Research Organization: France. Commissariat a l'Energie Atomique. Centre d'Etudes Nucleaires, Saclay
• NSA Number: NSA-17-006431
• OSTI ID: 4751217
• Report Number(s): CEA-2036
• Country of Publication: France
• Language: English

Related Subjects

ABSORPTION
ANTIMONY 124
BETA PARTICLES
CERIUM 141
CESIUM 134
CESIUM 137
CHROMIUM 51
COATING
COBALT 60
ELECTRODES
ELECTRONIC EQUIPMENT
EMISSION
GAMMA RADIATION
GAMMA SOURCES
GOLD 198
GRAPHITE
INSTRUMENTS AND INSTRUMENTATION
IODINE 131
IONIZATION CHAMBERS
IRIDIUM 192
MANGANESE 56
MEASURED VALUES
MERCURY ISOTOPES
PERFORMANCE
QUANTITATIVE ANALYSIS
RADIOACTIVITY
RADIOISOTOPES
RADIUM
SODIUM 24
STANDARDS
THULIUM 170
ZINC 65