Vanessa V. Simon

The on-line charge breeding program at TRIUMF's Ion Trap For Atomic and Nuclear Science for precision mass measurements

TRIUMFs Ion Trap for Atomic and Nuclear science (TITAN) constitutes the only high precision mass measurement setup coupled to a rare isotope facility capable of increasing the charge state of short-lived nuclides prior to the actual mass determination in a Penning trap. Recent developments around TITANs charge breeder, the electron beam ion trap, form the basis for several successful experiments on radioactive isotopes with half-lives as low as 65 ms and in charge states as high as 22+.

First Use of High Charge States for Mass Measurements of Short-lived Nuclides in a Penning Trap

Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly charged ions, using the TITAN facility at TRIUMF. Compared to singly charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb isotopes have been charge bred in an electron beam ion trap to q=8-12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly charged ions at a radioactive beam facility opens the door to unrivaled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed β emitter 74Rb (T(1/2)=65  ms). The determination of its atomic mass and an improved Q(EC) value are presented.

TITAN's digital RFQ ion beam cooler and buncher, operation and performance

We present a description of the Radio Frequency Quadrupole (RFQ) ion trap built as part of the TITAN facility. It consists of a gas-filled, segmented, linear Paul trap and is the first stage of the TITAN setup with the purpose of cooling and bunching radioactive ion beams delivered from ISAC-TRIUMF. This is the first such device to be driven digitally, i.e., using a high voltage (Vpp=400V), wide bandwidth (0.2<f<1.2MHz) square-wave as compared to the typical sinusoidal wave form. Results from the commissioning of the device as well as systematic studies with stable and radioactive ions are presented including efficiency measurements with stable 133Cs and radioactive 124,126Cs. A novel and unique mode of operation of this device is also demonstrated where the cooled ion bunches are extracted in reverse mode, i.e., in the same direction as previously injected.

Verifying the accuracy of the TITAN Penning-trap mass spectrometer

Abstract TITAN (TRIUMFs Ion Traps for Atomic and Nuclear science) is an online facility designed to carry out high-precision mass measurements on singly and highly charged radioactive ions. The TITAN Penning trap has been built and optimized in order to perform such measurements with an accuracy in the sub ppb-range. A detailed characterization of the TITAN Penning trap is presented and a new compensation method is derived and demonstrated, verifying the performance in the range of sub-ppb.

Penning-trap mass spectrometry of highly charged, neutron-rich Rb and Sr isotopes in the vicinity of A≈100

The neutron-rich mass region around A � 100 presents challenges for modeling the astrophysical r-process because of rapid shape transitions. We report on mass measurements using the TITAN Penning trap at TRIUMF-ISAC to attain more reliable theoretical predictions of r-process nucleosynthesis paths in this region. A new approach using highly charged (q = 15+) ions has been applied which considerably saves measurement time and preserves accuracy. New mass measurements of neutron-rich 94,97,98 Rb and 94,97 99 Sr have uncertainties of less than 4 keV and show deviations of up to 11� to previous measurements. An analysis using a parameterized r-process model is performed and shows that mass uncertainties for the A = 90 abundance region are eliminated.

Highly charged ions in Penning traps: A new tool for resolving low-lying isomeric states

The use of highly charged ions increases the precision and resolving power, in particular for short-lived species produced at on-line radio-isotope beam facilities, achievable with Penning trap mass spectrometers. This increase in resolving power provides a new and unique access to resolving low-lying long-lived (

Trapped-ion decay spectroscopy towards the determination of ground-state components of double-beta decay matrix elements

T_{1/2} > 50

New determination of double-β-decay properties in 48Ca: High-precision Qββ-value measurement and improved nuclear matrix element calculations

ms) nuclear isomers. Recently, the

Charge breeding rare isotopes for high precision mass measurements: challenges and opportunities

111.19(22)

Cooling of highly-charged, short-lived ions for precision mass spectrometry at TRIUMF's Ion Trap for Atomic and Nuclear Science

keV (determined from