# Cold, dense atomic ion clouds produced by cryogenic buffer gas cooling

## TL;DR

This paper demonstrates a method to produce cold, dense atomic ion clouds using laser ablation and cryogenic buffer gas cooling, enabling new research avenues in cold plasma physics and spectroscopy.

## Contribution

It introduces a novel technique for creating cold, dense ion clouds of metals like Ca$^+$ and Dy$^+$ at cryogenic temperatures, expanding experimental capabilities.

## Key findings

- Achieved ion densities at temperatures as low as 6 K
- Produced cold ion clouds of Ca$^+$ and Dy$^+$
- Enabled new spectroscopic studies of non-laser-coolable ions

## Abstract

We produce cold and dense clouds of atomic ions (Ca$^+$, Dy$^+$) by laser ablation of metal targets and cryogenic buffer gas cooling of the resulting plasma. We measure the temperature and density of the ion clouds using laser absorption spectroscopy. We find that large ion densities can be obtained at temperatures as low as 6 K. Our method opens up new ways to study cold neutral plasmas, and to perform survey spectroscopy of ions that cannot be laser-cooled easily.