A ring-shaped recombination chamber for hadron therapy dosimetry

An innovative recombination chamber has been designed for estimation of stray radiation doses and quality factors in hadron therapy. The chamber allows for determination of absorbed dose and recombination index of radiation quality in phantoms at small distances from simulated organs. The chamber body and electrodes are ring shaped, so the beam may be directed through the empty centre of the ring. The ionisation of the filling gas is caused by secondary or scattered radiation and can be related to the dose absorbed in the tissues close to the irradiated target volume.