A fast position sensitive microchannel plate detector for ray-tracing of charged particles

Studies of nuclear reactions by the use of secondary beams involve the need of ray-tracing of either the incident beam or the reaction products. For high resolution experiments, the material interposed to the trajectory of particles must be very thin, in order to produce a minimum of perturbation of their characteristics. Secondary electrons emitted from thin foils are well suited for fast position determination. A microchannel plate detector has been developed in order to accomplish the tracing of these electrons. A parallel E- and B-field configuration, applied as a focusing device for the emitted electrons, produces an image of a reaction vertex. Thus an image of the trajectory of particles can be obtained by placing the electron producing foil into the beamline and record the position of the accelerated and focused electrons hitting a grid of sensewires.