抄録
The principle and the actual procedure for imaging the beam focus on the film are described in this paper.
A radiation source, the rotation table A on which a patient is placed and the rotation table B on which an X-ray film is placed, are arranged in this order so that the radiation source and the axis of the tables A and B are contained in a vertical plane. When two rotation tables are rotated synchronously during irradiation, the axial transverse cross section of the beam focus is imaged on the film on the table B.
In practice the patient is placed stationarily on the therapy table with the radiation source rotating around the patient.
The construction of the attachment of the beam focus radiograph is also described in detail.
