Development of neutron image sensor technology for AD-BANG project

A demonstrator of the portable position sensitive neutron detecting device for neutron imaging in a mixed radiation field is presented. A detector of the device is based on multilayer perpendicularly crossed strip sensors interlaced with neutron converter. A 6LiF converter producing energetic alpha particles and tritons is used. The converter permits precise determination of a position of the neutron interaction even in a radiation fields with a high gamma background. The neutron detection efficiency is increased with a 3D structured surface of the multilayer silicon strip sensor. The demonstrator is comprised of the neutron sensitive multilayer silicon strip detector, a 128 channel general purpose charge sensitive amplifier ASICs IDEAS VATAGP8 with nominal dynamic range of +/− 250 fC, a 13 bit analogue to digital conversion and an FPGA control. Basic characteristics of the amplifier like amplifier linearity probed with an external charge generator is shown. Moreover, results of experimental tests of the demonstrator with alpha, beta, gamma sources and neutrons is demonstrated. The device may be used for neutron imaging via position sensitive detection of particular neutrons on the basis of coincidence detection of neutron conversion products or on the basis of response comparison of individual strips. An effect of charge sharing between individual strips on position resolution will be elaborately discussed.