FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT

A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy (BNCT) is being developed based on the two-dimensional Micromegas detector. To address the issue of long processing times in traditional offline position reconstruction methods, this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber principle. This method encapsulates key technical aspects: a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length, fast sorting, a coordinate-matching technique based on the mapping between signal timestamps and random access memory (RAM) addresses, and a precise start point-merging technique utilizing a circular combined RAM. The performance test of the self-adaptive serial link shows that the bit error rate of the link is better than 10−12 at a confidence level of 99