Journal ArticleDOI
An Experimental Method for Determining the Heat Defect of Water Using Total Absorption of High-energy Electrons
M Roos,B Grosswendt,K Hohlfeld +2 more
TLDR
The experimental procedure described in detail enables the heat defect of water caused by electron radiation in the energy range from 1 MeV to 5 MeV with an overall uncertainty of less than 0.5% for the correction factor as mentioned in this paper.Abstract:
The experimental procedure described here in detail enables the heat defect of water caused by electron radiation in the energy range from 1 MeV to 5 MeV to be determined with an overall uncertainty of less than 0,5% for the correction factor. The principle of measurement is based on a comparison of the temperature increase caused by the radiation energy of electrons totally absorbed in water with that caused by an ohmic heating of the water. In measuring the radiant energy of the electrons, corrections are needed for backscatter of the electrons entering the water and for bremsstrahlung energy loss during electron slowing down. Precise knowledge of the heat defect is a prerequisite for the establishment of the water absorbed-dose calorimeter as a primary standard of absorbed dose to water.read more
Citations
More filters
Journal ArticleDOI
Water calorimetry for radiation dosimetry
Carl K. Ross,Norman V. Klassen +1 more
TL;DR: Absorbed dose standards based on water calorimetry and with a relative standard uncertainty of 0.5-1% now seem achievable.
Journal ArticleDOI
A sealed water calorimeter for measuring absorbed dose
TL;DR: The NIST sealed water 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 dissolved gases.
Journal ArticleDOI
Correction factors and performance of a C sealed water calorimeter
Jan Seuntjens,Hugo Palmans +1 more
TL;DR: In this paper, the constructional details of a C sealed water calorimeter currently in operation at the University of Gent are summarized and the relevant correction factors for heat transport and for field perturbation are described.
Journal ArticleDOI
Correction factors for a cylindrical ionization chamber used in medium-energy X-ray beams
TL;DR: New correction factors are derived for a cylindrical NE2571 ionization chamber, for absorbed dose determinations in medium-energy X-rays, and three components in the overall correction factor are investigated: the effect of the displaced volume, the combined angular-energy dependence of the chamber response within the water phantom and the stem correction.
Journal ArticleDOI
A comparison of absorbed dose standards for high-energy X-rays
TL;DR: An indirect comparison of the absorbed dose to water standards of the PTB and the NRC was carried out for 18/20 MV X-rays using five ionization chambers as transfer instruments, finding the difference found between the standards of 0.4% is within the expected uncertainties.
References
More filters
Journal ArticleDOI
Atomic form factors, incoherent scattering functions, and photon scattering cross sections
TL;DR: In this paper, the atomic form factor and the incoherent scattering function were derived from available state-of-the-art theoretical data, including the Pirenne formulas for Z=1, configuration-into-action results by Brown using Brown‐Fontana and Weiss correlated wavefunctions for Z =2 to 6 non-relativistic Hartree‐Fock results by Cromer for Z ≥ 0.005 A−1 to 109 A− 1, for all elements A=1 to 100.
Journal ArticleDOI
Bremsstrahlung Cross-Section Formulas and Related Data
H. W. Koch,J. W. Motz +1 more
Journal ArticleDOI
Theorie der Streuung schneller geladener Teilchen II. Mehrfach- und Vielfachstreuung
TL;DR: Theorie der inkohärenten Mehrfach-und Vielfach-streuung zu (absolut) kleinen Winkeln wird neu entwickelt as discussed by the authors.
Journal ArticleDOI
Photon mass attenuation and mass energy-absorption coefficients for H, C, N, O, Ar, and seven mixtures from 0. 1 keV to 20 MeV
TL;DR: From this cross-section data base, mass energy-absorption coefficients pen/p, taking into account bremsstrahlung losses and positron annihilation in flight, Compton-scattered and fluorescence photons, and mass-attenuation coefficients p/p are tabulated for the above elements and for the mixtures.