First on-line application of the high-resolution spectroscopy laser ion source PI-LIST at ISOLDE

In‐Source High‐Resolution Spectroscopy Using an Integrated Tunable Raman Laser

“…For our particular experimental scenario, the laser beam was intersecting the ion beam at z = 6 mm with a Gaussian beam diameter of around 1 mm (1/e 2 ), yielding an estimated resolution of Δf r ≈ 0.4 GHz. We note that this value is slightly higher than the experimental one reported in previous works [13] for a comparable Doppler broadening environment, which was of the order of 200 -300 MHz.…”

“…[53] The PI-LIST version employed in this work is identical to the units recently adapted for ISOLDE operation, featuring the perpendicular laser access by internal metal mirror surfaces. [13] The atomizer in operation at the ISOLDE Offline-2 mass separator laboratory [54] is a standard ISOLDE target/ion source unit, where atoms are generated by evaporating a sample within the Ohmic-heated target container or an additional sample reservoir capillary and effuse through a transfer line, after which they enter an independently heated hot-cavity capillary (atomizer) of 34 mm length and 3 mm inner diameter. In the case of the measurements presented here, the target container and transfer line were omitted and the sample from the reservoir fed directly from the back of the atomizer.…”

“…The experiments were carried out in a Doppler-reduced geometry utilizing crossed laser beams interacting with samarium atoms effusing from a hot-cavity capillary under high-vacuum (10 −6 mbar) conditions. [13] We target a narrow linewidth transition of 152 Sm -with no hyperfine splittingsin order to unequivocally measure the cumulative resolution and sensitivity of our spectroscopic setup. The results are accompanied by end-to-end Monte Carlo particle tracing simulations of the thermal and effusion effects at the ion source, which greatly influence the overall achievable spectral resolution, as well as a Raman laser model for predicting the spectral purity achievable using a monolithic Raman laser platform.…”