Laser ablation loading of a radiofrequency ion trap

TL;DR

This study explores laser ablation as a method for loading ions into RF traps, demonstrating efficient production and trapping of ions like Th+ with potential applications in quantum technologies.

Contribution

It introduces laser ablation as a viable ion source for RF traps and investigates the ion production, charge state distribution, and trapping efficiency.

Findings

Singly charged ions produced at ~10^5 ions per pulse

Achieved trapping efficiencies of 10^-7 to 10^-6

No observed RF phase dependence on capture probability

Abstract

The production of ions via laser ablation for the loading of radiofrequency (RF) ion traps is investigated using a nitrogen laser with a maximum pulse energy of 0.17 mJ and a peak intensity of about 250 MW/cm^2. A time-of-flight mass spectrometer is used to measure the ion yield and the distribution of the charge states. Singly charged ions of elements that are presently considered for the use in optical clocks or quantum logic applications could be produced from metallic samples at a rate of the order of magnitude 10^5 ions per pulse. A linear Paul trap was loaded with Th+ ions produced by laser ablation. An overall ion production and trapping efficiency of 10^-7 to 10^-6 was attained. For ions injected individually, a dependence of the capture probability on the phase of the RF field has been predicted. In the experiment this was not observed, presumably because of collective effects within the ablation plume.