Improved fast neutron detector based on timepix and plastic scintillating converter

The detection of fast neutrons by recoiled protons from a plastic scintillator situated very close to the pixel detector Timepix was introduced. The directional sensitivity of the detection was proven when signal generated by the scintillating light collected by silicon photomultipliers (SiPM) was used for triggering and synchronization of the system. In the proposed contribution the technique refines measuring the analog value of the scintillation light from all segments of an array 4×4 of silicon photomultipliers. Position and energy sensitivity of the silicon pixel detector Timepix is supplemented by position and energy sensitivity of the plastic scintillator. Each of 16 SiPM segments is connected to the independent channel of the spectroscopic ASIC VATA64HDR16. The ASIC provides trigger signal for the system including the pixel detector readout interface FITPix. Variable threshold allows changing the sensitive level and omitting SiPM dark noise or low-energetic particles. Sampled and hold analog value can be readout channel-by-channel through an analog multiplex and converted by an ADC for further digital processing. The whole activity is controlled by a FPGA. The results of measurements with a laboratory radioactive source (Am Be) will be presented.