[The recombination factor in an ionizing chamber used for dosimetry of a linear accelerator]

The authors starting from the discussion of Boag address experimentally the ion recombination in an ionizing camera. They outline the fact that several basic dosimetry protocols do not highlight the importance of the used radiation sources, beam width, ionizing camera dimensions, even though they mention to take into account the recombination factor. The authors determine experimentally the recombination factor with two kinds of ionizing camera, one cylindrical and the other flat, on a linac pulsed and scanned radiation beams. As a result it ensued that it is advisable to use a Markus type ionizing camera rather than a cylindrical one, especially when scanning beams are used, to reduce the recombination phenomena.