Programmable Front-End Data Acquisition Module for Radio-Xenon Monitors

摘要

Detecting radioactive xenon isotopes in air is one of the methods employed in nuclear explosion monitoring. Using scintillator detectors, the xenon signal is distinguished from background via coincidence spectroscopy. The resulting detectors are complex instruments, with up to 12 scintillators, requiring specialized data acquisition (DAQ) electronics. Bridgeport Instruments, in collaboration with Pacific Northwest National Laboratory is developing a compact, lowcost DAQ solution. The DAQ module produces raw data, such as energies, arrival times, triggers, etc in real time using digital signal processing embedded in FPGAs. These raw data are available immediately and can be combined in real time by an event builder to form complex events and to check for trigger patterns. It is a unique characteristic of the DAQ module, that the event builder can be implemented by the customer in an open-source FPGA. In a similar manner, multiple DAQ modules can be connected to a backplane that contains programmable units, such as a trigger FPGA and a communication and control FPGA. All programmable logic on the backplane will be completely open-source. With this approach we are creating a very versatile platform that uses proprietary code only to generate raw data from the scintillator detector pulses (energies, triggers, etc.). All other aspects, especially those that create a unique instrument from the combination of scintillator detectors are completely under customer control. In this paper we present the architecture of this new nuclear instrumentation platform.