Gas Catcher Development for the St. Benedict Project

The Superallowed Transition Beta-Neutrino Decay Ion Coincidence Trap (St. Benedict) project, currently under development at the University of Notre Dame Nuclear Science Laboratory (NSL), seeks to probe the limits of the Standard Model by measuring superallowed mixed decays to test the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Any deviation from unitarity, even by a small amount, could provide evidence for physics beyond the Standard Model. Several complex devices are required for this endeavor, including a large volume gas catcher. This device is used to thermalize the fast radioactive ion beam from the NSL TwinSOL facility and extract the beam at a low energy so that it can be bunched and transported to an ion trap where the measurement of the nuclear beta decays will take place. The gas catcher includes both DC and RF circuitry that provide voltages to electrode rings surrounding the interior of the gas cell in order to contain and transport ions through the chamber. These features, as well as the vacuum capabilities of the chamber, were tested and improvements were made to increase the efficiency of the RF and DC systems. The future work needed before commissioning the gas catcher for use in St. Benedict is discussed.