Energy verification in Ion Beam Therapy

The adoption of synchrotrons for medical applications necessitates a comprehensive on-line verification of all beam parameters, autonomous of common beam monitors. In particular for energy verification, the required precision of down to 0.1MeV in absolute terms, poses a special challenge regarding the betatron-core driven 3rd order extraction mechanism which is intended to be used at MedAustron [1]. Two different energy verification options have been studied and their limiting factors were investigated: 1) A time-of-flight measurement in the synchrotron, limited by the orbit circumference information and measurement duration as well as extraction uncertainties. 2) A calorimeter-style system in the extraction line, limited by radiation hardness and statistical fluctuations. The paper discusses in detail the benefits and specific aspects of each method.