Microdosimetry of diagnostic X-rays: applications of the variance-covariance method.

Microdosimetric measurements in beams of diagnostic X rays (between
30 and 125 kV) have been performed. In these pulsed radiation
fields, microdosimetric measurements are possible only by
application of the variance-covariance technique. The dose mean
lineal energy, yD, is determined for various simulated diameters,
at different depths in the absorber, and at different points within
the pulse intervals. From the measured temporal dependences one can
also obtain values of yD for different X-ray pulse generators. The
results demonstrate the potential of the variance-covariance method
for a diversity of microdosimetric measurements in radiation
protection and in the quality control of radiation beams.