On-line monitoring of fluence distributions and imaging of scanning ion beams

In this paper we describe the design of an ion-beam monitor developed to control irradiations of biological samples with ions at the Grand Accélérateur National d’Ions Lourds (GANIL). This device can be used as an on-line monitor to provide transverse fluence distributions for active scanning ion irradiations. It can also be used as an interceptive beam imager to provide beam profiles or fluence depth distributions. A prototype of the monitor has been tested at GANIL with five different ion beams, having intensities from 104 to 109 ions/s. Real-time transverse fluence distributions have been obtained with a 1 mm spatial resolution.