Energy dependence of Farmer‐type ionization chambers used in kilovoltage x‐ray beam reference dosimetry

Cylindrical ionization chambers frequently used for reference dosimetry of kV x-ray beams exhibit different energy dependence based on model type. Some models frequently employed and recommended for use in absorbed dose determination do not satisfy international protocol recommendations regarding energy dependence. International recommendations and protocols for absorbed dose determination for kilovoltage x-rays based solely on kVp should be reviewed and further developed to explicitly account for the effect of filtration (HVL) on chamber response. The results of this work support the adoption or refinement of the recommended chamber types within reference dosimetry protocols.