[Measurement on a 42-meV betatron with regard to the radiological protection of patients (author's transl)].

In order to examine the side radiation field of X-rays from the 42-meV Siemens betatron, transverse and depth dose distributions were measured in the phantom with LiF dosemeters. The influence on the dose distribution exerted by the kind of radiation and its energy, the rotation angle of the patient's table, and the field dimensions was determined. The quality of the side radiation and the effect of additional lead shieldings were examined. The dose distributions can be calculated approximately by means of an exponent which can be used in order to estimate the surface dose for all desired irradiation conditions and to determine any distances from the field edges.