Ion recombination correction for a parallel-plate ionization chamber in a carbon ion beams

Due to the development and increased use of hadrontherapy, reference dosimetry of charged particle beam, and in particular the absorbed dose to water measurement using ionization chambers, has to be improved to decrease the uncertainty of the treatment and improve its consistency. Ion recombination is one of the corrections that need to be applied to an ionization chamber measurement that is potentially much larger in a carbon ion beam as compared to conventional photon or electron beams. This work aims at measuring the ion recombination correction (ks) for parallel-plate ionization chambers in a carbon ion beam from a slow cycle synchrotron.