Steve R. Domen

  • Citations Per Year
Learn More
Advantage was taken of the low thermal diffusivity of water and the imperviousness of polyethylene film to water to construct a calorimeter for directly measuring absorbed dose in that medium. An ultrasmall bead thermistor was sandwiched between two thin films stretched on polystyrene rings and immersed in an unregulated water bath. Ten cobalt-60(More)
To explain a difference of 0.5 % between the absorbed-dose standards of the National Institute of Standards and Technology (NIST) and the National Research Council of Canada (NRCC), Seuntjens et al. suggest the fault lies with the NIST water calorimeter being operated at 22 °C and the method with which the measurements were made. Their calculations show(More)
An X-ray calorimeter has been used to determine the to ta l energy t ransported by bremsstrahlung beams with maximum photon energies between 18.2 and 170 Mev. The measurements from two experiments have been used to calibrate an aluminum ionization chamber for routine determinations of to ta l beam energy. The calibrations are compared with calibrations of(More)
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001 The NIST sealed water calorimeter is intended for direct measurement of absorbed dose to water. This calorimeter was used for a series of approximately 3700 measurements to investigate the so-called heat defect, that is, anomalous endothermic or exothermic effects caused by(More)
The paper describes a new type of calorimeter that can be quickly put into operation for determining absorbed dose at a point in polystyrene. It also describes a unique method of decreasing drifts in electrical signals caused by temperature gradients. Two calibrated thermistors were placed close together between sandwiched polystyrene discs that were(More)
Extensive experimental comparisons of calorimetric and ionometric measurements have been made that cover a broader range of electron energies and depths in graphite than previously reported. Electron beams of 15, 20, 25, 30, 40, and 50 MeV were used. Calorimetric absorbed-dose measurements and ionometric specific-charge measurements in air were compared in(More)
National Bureau of Standards Gaithersburg, MD 20899 Electrica1 powers from 5 to 1 SO J.t-W were dissip.a.ted in a thermistor. causing it to rise to equilibrium tem:peratllres above the Magnant surrouoding water. Natura:. c·:n ..... ectioD was. t:h.en s,jtnu1!rted by f.o::ced I:onvection of water flowing up or down at known rates from 1.3 to 17 mm/mio. The(More)
In the present investigation a liquid ionization chamber has been used as a transfer instrument for the quantity absorbed dose in water in a cobalt-60 gamma-ray beam. The characteristics of the liquid ionization chamber are described. The transferred dosimetric information has been compared with absorbed-dose determination using air-ionization-chamber(More)
Some thermal properties of A-150 tissue-equivalent plastic have been determined. The results are: thermal diffusivity, 2.72 x 10(-3) cm2s-1 +/- 0.4%; specific heat, 1.72 J g-1 K-1 +/- 1.3%; and thermal conductivity, 5.3 x 10(-3) WK-1 cm-1 +/- 1.4%. The significance of the measurements for the design of a calorimeter core calibration heater is briefly(More)
  • 1