A team of researchers designed, built, and tested the Phase II time projection chamber (TPC) for the Proton Detector and Gaseous Detector with Germanium Tagging (GADGET) system, a gaseous detector that identifies weak, low-energy, beta-delayed protons and alpha particles. Christopher Wrede, professor of physics at FRIB, led the team, which published its testing results in Physical Review C (“Time projection chamber for GADGET II”).

Using a machine-learning grant received from the U.S. Department of Energy Office of Science (DOE-SC), Wrede, a professor of physics at FRIB, and his team equipped GADGET with a new high-granularity MICROMEGAS board and a high-density data acquisition system to record and process gas avalanche signals. The upgrades are meant to automatically detect, identify, and create 3D images of low-energy beta-delayed single- and multi-particle emissions for astrophysical studies. 

According to the team, the GADGET II TPC device is the first of its kind to use a resistive anode in low-energy nuclear physics. Additionally, it will be the first TPC surrounded by a high-efficiency array of high-purity gamma-ray detectors. The GADGET II TPC can detect and identify alpha particles and measure their track direction, range, and energy. It can also track minimum-ionizing particles. As a result of the testing, the team has determined that the GADGET II TPC is ready for use at FRIB. 

This work has been supported by the U.S. Department of Energy Office of Science and the U.S. National Science Foundation.

Michigan State University (MSU) operates the Facility for Rare Isotope Beams (FRIB) as a user facility for the U.S. Department of Energy Office of Science (DOE-SC), with financial support from and furthering the mission of the DOE-SC Office of Nuclear Physics.