Polyvinyltoluene scintillators for relative ion dosimetry: An investigation with Helium, Carbon and Neon beams

We present a dosimeter prototype, devoted to ion beam dosimetry, tested with Helium, Carbon and Neon ions having an equivalent range in water of 150 mm. A polyvinyltoluene based plastic scintillator is used to convert the deposited energy into scintillation, a measurement probe and a long optical fibre guide the light to a photon counting unit. Using 10-40 μm thick scintillators we show that the dosimeter gain is enough to provide useful measurements, the ion-induced scintillation can be interpreted using a model taking into account the energy deposited by secondary electrons. For a practical purpose it is shown that a linear relationship can be established between the scintillation signal and the relative dose.