Off-line Commissioning of the St. Benedict Radio Frequency Quadrupole Ion Guide

TL;DR

This paper reports on the off-line commissioning of the RFQ ion guide for the St. Benedict experiment, achieving high transport efficiency and providing calibration capabilities for the upcoming measurements of beta-neutrino correlations.

Contribution

It introduces the off-line commissioning process of the RFQ ion guide and demonstrates its high efficiency, aiding in calibration for the St. Benedict experiment.

Findings

Transport efficiency >95% from RF carpet chamber

60% efficiency from off-line 90° source

Successful calibration setup for future measurements

Abstract

The Superallowed Transition Beta-Neutrino Decay Ion Coincidence Trap (St. Benedict) is currently under construction at the Nuclear Science Laboratory (NSL) of the University of Notre Dame. It aims to measure the beta-neutrino angular correlation parameter for superallowed mixed mirror beta decay transitions. Measurements of this kind offer unique insight into the electroweak part of the Standard Model through tests of unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. St. Benedict is comprised of several beam-manipulating components including a radio frequency quadrupole (RFQ) ion guide. This ion guide features an off-line source at $90^\circ$ to the beam path for testing and calibration of downstream components once St. Benedict is online. Off-line commissioning of the ion guide demonstrated a transport efficiency greater than 95% for ions coming from the upstream RF carpet chamber. When taking ions from the $90^\circ$ off-line source a lower efficiency of 60% was obtained.