Original scientific paper
Photographic dosimetry of X and gama rays
Mirka Fugaš
; Institut za medicinska istraživanja i medicinu rada u Zagrebu
L. Jenček
; Fizikalni institut Medicinskog fakulteta, Sveučilišta u Ljubljani
Abstract
Preliminary investigations of »Adox« and »Ferrania« dosimetric and dental X-ray films respectively, have been carried out by exposing the films to the »normal radiation« (Wachsmann) of 50 to·200 kV on a Siemens »Stabilipan«. During exposure the films were put into bakelite film badges containing 3 copper filters of different thickness (0.05, 0.5 and 1.2 mm), one lead filter (0.5 mm), and an open window. Doses were measured by a Victoren Condenser -r- meter. The Films were developed in an »EFKA« developer for X-ray films, while the optical density was measured by an »EEL« densitometer. Calibration curves were established giving relationship between the optical density and the radiation dose for 50, 60, 70, 100 and 200 kV of normal radiation. A curve showing the relation of the film response to the radiation energy and curves concerning the »hardness factor« and dose ratios (Dressel) were plotted. The possibility of reducing the dependence of the film response on radiation energy has been examined by the estimation of the dose (1) from the sum of the densities of a less sensitive film without filter and a more sensitive film with filter (Stekelenburg) and (2) from the film blackening beneath the Pb filter only (Behourrek and others). Both methods decrease the dependance of film response on the radiation energy enabling the estimation of the dose for any of the energies from a single calibration curve. The method for the estimation of the dose by identifying the radiation energy by means of dose ratios and the hardness factor seems to be the most accurate, but too complicated for routine work. Van Stekelenburg's method is likely to be the most promising for practical work.
Keywords
Hrčak ID:
182947
URI
Publication date:
17.12.1959.
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