Low-Background In-Trap Decay Spectroscopy with TITAN at TRIUMF

Abstract

An in-trap decay spectroscopy setup has been developed and constructed for use with the TITAN facility at TRIUMF. The goal of this device is to observe weak electron-capture (EC) branching ratios for the odd-odd intermediate nuclei in the $\beta\beta$ decay process. This apparatus consists of an up-to 6 Tesla, open-access spectroscopy ion-trap, surrounded radially by up to 7 planar Si(Li) detectors which are separated from the trap by thin Be windows. This configuration provides a significant increase in sensitivity for the detection of low-energy photons by providing backing-free ion storage and eliminating charged-particle-induced backgrounds. An intense electron beam is also employed to increase the charge-states of the trapped ions, thus providing storage times on the order of minutes, allowing for decay-spectroscopy measurements. The technique of multiple ion-bunch stacking was also recently demonstrated, which further extends the measurement possibilities of this apparatus. The current status of the facility and initial results from a $^{116}$In measurement are presented.