title: Calculated calibrations for ion chambers fabricated from plastics simulating air and muscle; determination of W and tauRa.
abstract: An experiment is described utilizing two 16-liter ionization chambers, fabricated from electrically conducting plastics which closely simulate air and human muscle, designed to minimize most of the errors inherent in the use of cavity chambers. A careful calibration was done, using a 226Ra source in 0.5 mm platinum, in an almost scatter-free environment which permitted the derivation of accurate corrections for scatter and air attenuation. Calibrations calculated from the physical measurements of the ion chambers are compared with the experimental calibrations. Values of Wbeta for air, and muscle gas and of tauRa are derived.
authors: Radiological Physics Division, Argonne National Laboratory, Argonne, Illinois, USA.
authors: J E
authors: JE
authors: Rose
authors: F R
authors: FR
authors: Shonka
mesh_terms: D000388:Air; D000465:Algorithms; D040761:Biomimetic Materials / Q000737:chemistry*; D002138:Calibration; D007477:Ions; D018482:Muscle, Skeletal / Q000502:physiology*; D010969:Plastics / Q000737:chemistry*; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods / Q000592:standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007477:Ions; D010969:Plastics