Production of long-lived atomic vapor inside high-density buffer gas

TL;DR

This study demonstrates the production and characterization of long-lived atomic vapors of gold, silver, lithium, and rubidium inside various buffer gases at different temperatures and densities, achieving significant vapor densities and decay times.

Contribution

It introduces a method to generate and analyze long-lived atomic vapors of multiple elements inside high-density buffer gases using laser ablation, with detailed insights into their decay mechanisms.

Findings

Achieved vapor densities of up to 10^{11} cm^{-3}.

Observed decay times up to 110 ms for silver at 20 K.

Identified impurities, dimer formation, and sputtered clusters as potential loss mechanisms.

Abstract

Atomic vapor of four different paramagnetic species: gold, silver, lithium, and rubidium, is produced and studied inside several buffer gases: helium, nitrogen, neon, and argon. The paramagnetic atoms are injected into the buffer gas using laser ablation. Wires with diameters 25 $\mu$m, 50 $\mu$m, and 100 $\mu$m are used as ablation targets for gold and silver, bulk targets are used for lithium and rubidium. The buffer gas cools and confines the ablated atoms, slowing down their transport to the cell walls. Buffer gas temperatures between 20 K and 295 K, and densities between $10^{16}$ cm$^{-3}$ and $2\times10^{19}$ cm$^{-3}$ are explored. Peak paramagnetic atom densities of $10^{11}$ cm$^{-3}$ are routinely achieved. The longest observed paramagnetic vapor density decay times are 110 ms for silver at 20 K and 4 ms for lithium at 32 K. The candidates for the principal paramagnetic-atom loss mechanism are impurities in the buffer gas, dimer formation and atom loss on sputtered clusters.