Determination of the external beam energy of a variable energy. Multiparticle cyclotron

Optimization of commercial production of GBq batches of radioisotopes by threshold nuclear reactions needs an accurate knowledge of the particle beam energy. We present three independent techniques allowing energy determination with 2% accuracy for external beams of a multiparticle cyclotron with a positionable deflector used in isotope production. Stopping power analysis, activation analysis followed by comparison with monitor reaction cross-sections and direct time-of-flight (ToF) study of the particle velocity using a double beam pick-up set up allows us to conclude that only at the high energy end a discrepancy exists between real and calculated energy (maximal 4.5% for alpha-particles).