The TITAN in-trap decay spectroscopy facility at TRIUMF

Abstract

This paper presents an upgraded in-trap decay spectroscopy apparatus which has been developed and constructed for use with TRIUMF׳s Ion Trap for Atomic and Nuclear science (TITAN). This device consists of an open-access electron-beam ion-trap (EBIT), which is surrounded radially by seven low-energy planar Si(Li) detectors. The environment of the EBIT allows for the detection of low-energy photons by providing backing-free storage of the radioactive ions, while guiding charged decay particles away from the trap centre via the strong (up to 6 T) magnetic field. In addition to excellent ion confinement and storage, the EBIT also provides a venue for performing decay spectroscopy on highly charged radioactive ions. Recent technical advancements have been able to provide a significant increase in sensitivity for low-energy photon detection, towards the goal of measuring weak electron-capture branching ratios of the intermediate nuclei in the two-neutrino double beta (2νββ2νββ) decay process. The design, development, and commissioning of this apparatus are presented together with the main physics objectives. The future of the device and experimental technique are discussed

High-precision QEC -value measurement of the superallowed β+ emitter Mg22 and an ab

“…The TITAN facility consists of four primary components: (i) A Radio-Frequency Quadrupole (RFQ) linear Paul trap [27,28], (ii) a Multi-Reflection Time-of-Flight (MR-ToF) isobar separator [29], iii) an Electron-Beam Ion Trap (EBIT) for generating Highly Charged Ions (HCIs) [30,31] and performing decay spectroscopy [32,33], and (iv) a 3.7 T, high-precision mass Measurement PEnning Trap (MPET) [34]. Following the delivery of the continuous A = 22 ISAC beam to TITAN, ions were injected into the RFQ where they were cooled using a He buffer gas.…”

Studies at the border between nuclear and atomic physics: Weak decays of highly charged ions

“…Therefore, in order to study weak decays of HCIs, it is necessary to create radioactive nuclei in a nuclear reaction, remove a number of bound electrons producing the required atomic charge state, and then preserve this charge state for an extended period of time sufficient for the ions to decay. Apart from the recent studies in the Electron Beam Ion Trap (EBIT) at TRIUMF [17,18], all other investigations of weak decays of HCIs were performed in the experimental storage ring ESR at GSI Helmholtz Center [19].…”

Electroweak Decay Studies of Highly Charged Radioactive Ions with TITAN at TRIUMF

“…One clearly identified limitation of the current system, however, is the low geometric coverage of the photon detectors due to the limited optical access to the trap center (∼2% of the total 4π solid angle [10]). This limits the number of angles that can be used for angular correlations, and thus limits the statistics that can be used for extracting the physically relevant quantities from Equation (2).…”

“…(1) A radio-frequency quadrupole (RFQ) linear Paul trap [7] for buffer-gas cooling and bunching the low-energy ion beam, (2) A 3.7 T, high-precision mass-measurement Penning trap (MPET) [8], and (3) An electron-beam ion trap (EBIT) that is used to create HCIs [9], and for performing decay spectroscopy on trapped radioactive nuclei [10].…”