[Setting of the soft X-ray field for the calibration of the dosimeters used in mammographic field].
In order to produce a cheap and stable X-ray generator system for calibration of dosimeters used in mammographic field, a dummy source of mammographic X-ray was developed using a tungsten (W) target X-ray tube and a molybdenum (Mo) filter. The photon fluence spectra of mammographic equipment were calculated using Birch's formula and aluminum (Al) attenuation curves were derived. The Al attenuation curves of X-rays from W target with Mo filter of various thicknesses were similarly obtained. Comparing the similarities of attenuation curves, the best fit Mo filter thickness was chosen. Consequently, a 0.04 mm thick Mo plus a 4 mm thick poly-methylmethacrylate filter were chosen to be added to W target industrial X-ray tube. The similarity of Al attenuation curves were verified by ionization chamber measurements.
Department of Radiology, The University of Tokyo Hospital, Japan.
Michiharu
M
Sekimoto
Tsuguhisa
T
Katoh
Masanori
M
Satoh
Keiichi
K
Yano
D000535:Aluminum; D002138:Calibration; D005374:Filtration / Q000295:instrumentation* / Q000379:methods; D008327:Mammography / Q000295:instrumentation*; D008982:Molybdenum; D019904:Polymethyl Methacrylate; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D014414:Tungsten
D008982:Molybdenum; D019904:Polymethyl Methacrylate; D000535:Aluminum; D014414:Tungsten