Addendum to the determination of recombination and polarity correction factors, k S and k P , for small cylindrical ionization chambers in pulsed filtered and unfiltered beams: PTW 31023.

This addendum provides correction factors for the recombination and the polarity effect for the new ionization chamber PTW PinPoint (type 31023). The measurements were made in filtered (WFF) and unfiltered (FFF) high-energy photon beams. It could be confirmed that both the initial and the general recombination effect of the chamber mainly depends on dose per pulse at the point of measurement and is independent of the filtration of the photon beam.