Digital Data Acquisition For the Low Energy Neutron Detector Array (LENDA)

TL;DR

This paper presents a digital data acquisition system for LENDA, improving neutron detection capabilities and efficiency, enabling lower thresholds and better timing resolution for low-energy neutron measurements in nuclear physics experiments.

Contribution

Introduction of a digital DAQ system for LENDA that enhances detection sensitivity, efficiency, and scalability over previous analog systems.

Findings

Achieved 400 ps timing resolution for a LENDA bar.

Lowered neutron detection threshold below 100 keV.

Successfully used in a charge-exchange experiment at NSCL.

Abstract

A digital data acquisition system (DDAS) has been implemented for the Low Energy Neutron Detector Array (LENDA). LENDA is an array of 24 BC-408 plastic-scintillator bars designed to measure low-energy neutrons with kinetic energies in the range of 100 keV to 10 MeV from (p,n)-type charge-exchange reactions. Compared to the previous data acquisition (DAQ) system for LENDA, DDAS offers the possibility to lower the neutron detection threshold, increase the overall neutron-detection efficiency, decrease the dead time of the system, and allow for easy expansion of the array. The system utilized in this work was XIA's Digital Gamma Finder Pixie-16 250 MHz digitizers. A detector-limited timing resolution of 400 ps was achieved for a single LENDA bar. Using DDAS, the neutron detection threshold of the system was reduced compared to the previous analog system, now reaching below 100 keV. The new DAQ system was successfully used in a recent charge-exchange experiment using the $^{16}$C(p,n) reaction at the National Superconducting Cyclotron Laboratory (NSCL).