Construction and tests of an in-beam PET demonstrator (LAPD) for hadrontherapy beam ballistic control

We present the first results obtained with a detector, called Large Area PixelizedDetector (LAPD), dedicated to the study of the ballistic control of the beam deliveredto the patient by in-beam and real time detection of secondary particles, emittedduring its irradiation in the context of hadrontherapy. These particles are 511 keVgammas from the annihilation of a positron issued from the beta+ emitters induced inthe patient tissues along the beam path.