Improvements to TITAN's Mass Measurement and Decay Spectroscopy Capabilities

TL;DR

This paper reports recent technical advancements at the TITAN facility, enhancing mass measurement precision and decay spectroscopy capabilities for short-lived nuclei, including improved charge breeding and new cooling techniques.

Contribution

It introduces innovations in charge breeding, in-trap decay spectroscopy, and ion cooling that extend TITAN's capabilities for studying very short-lived nuclei.

Findings

Successful charge breeding enhancement demonstrated with $^{30}$Al.

Commissioning of decay spectroscopy setup with $^{124}$Cs.

Development of CPET for cooling highly charged ions.

Abstract

The study of nuclei farther from the valley of $\beta$-stability goes hand-in-hand with shorter-lived nuclei produced in smaller abundances than their more stable counterparts. The measurement, to high precision, of nuclear masses therefore requires innovations in technique in order to keep up. TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) facility deploys three ion traps, with a fourth in the commissioning phase, to perform and support Penning trap mass spectrometry and in-trap decay spectroscopy on some of the shortest-lived nuclei ever studied. We report on recent advances and updates to the TITAN facility since the 2012 EMIS Conference. TITAN's charge breeding capabilities have been improved and in-trap decay spectroscopy can be performed in TITAN's electron beam ion trap (EBIT). Higher charge states can improve the precision of mass measurements, reduce the beam-time requirements for a given measurement, improve beam purity and opens the door to access, via in-trap decay and recapture, isotopes not available from the ISOL method. This was recently demonstrated during TITAN's mass measurement of $^{30}$Al. The EBIT's decay spectroscopy setup was commissioned with a successful branching ratio and half-life measurement of $^{124}$Cs. Charge breeding in the EBIT increases the energy spread of the ion bunch sent to the Penning trap for mass measurement so a new Cooler Penning Trap (CPET), which aims to cool highly charge ions with an electron plasma, is undergoing online commissioning. Already, CPET has demonstrated the trapping and self-cooling of a room-temperature electron plasma which was stored for several minutes. A new detector has been installed inside the CPET magnetic field which will allow for in-magnet charged particle detection.