Experimental validation of the energy verification system for radio frequency knockout extractions at MedAustron

Abstract

One of the most important prerequisites for the medical operation of a particle accelerator is the precise control of the particle energy, since due to the direct proportionality to the penetration depth, even a slight deviation can lead to damage to a patient’s healthy tissue. At MedAustron, this control is performed by the ’Energy Verification System (EVS)’. In the event of an energy deviation that leads to a change in the penetration depth of more than 0.3 mm, this system immediately deflects the particle beam into the beam dump.With the introduction of a new extraction method, the Radio Frequency Knockout (RFKO), a modification of the EVS is necessary. The approach for the new system is a verification via the magnetic field of the dipole magnets and the revolution frequency of the particles, which will be the content of this thesis. For this purpose, measurements of the frequency at the accelerating radio frequency cavity (RFC), the magnetic field at the dipole magnets and range measurements based on the bragg peak position using the PTW Peakfinder system in the irradiation room will be performed simultaneously in RFKO operation. A deviation of the particle energy from the nominal value, measured by the Peakfinder, should be visible in both the RFC and the magnetic field measurements. An analysis of these data should show that the chosen approach is suitable for the new EVS.