All-optical ion generation for ion trap loading

TL;DR

This paper explores all-optical ion generation via photo-ionisation of atoms produced by pulsed laser ablation, comparing it with traditional oven sources, and demonstrating its efficiency and lower thermal load for ion trap loading.

Contribution

It introduces a method using pulsed laser ablation for ion generation, showing advantages over oven sources in thermal load and atomic flux control.

Findings

Pulsed laser ablation produces large calcium flux comparable to high-temperature ovens.

The method results in significantly lower thermal load than oven sources.

Atomic beam composition depends on laser pulse fluence, with ion and excited atom production above certain thresholds.

Abstract

We have investigated the all-optical generation of ions by photo-ionisation of atoms generated by pulsed laser ablation. A direct comparison between a resistively heated oven source and pulsed laser ablation is reported. Pulsed laser ablation with 10 ns Nd:YAG laser pulses is shown to produce large calcium flux, corresponding to atomic beams produced with oven temperatures greater than 650 K. For an equivalent atomic flux, pulsed laser ablation is shown to produce a thermal load more than one order of magnitude smaller than the oven source. The atomic beam distributions obey Maxwell-Boltzmann statistics with most probable speeds corresponding to temperatures greater than 2200 K. Below a threshold pulse fluence between 280 mJ/cm^2 and 330 mJ/cm^2, the atomic beam is composed exclusively of ground state atoms. For higher fluences ions and excited atoms are generated.