Two-dimensional magneto-optical trap as a source for cold strontium atoms

TL;DR

This paper presents a compact two-dimensional magneto-optical trap for cold strontium atoms, achieving high atomic flux and tunable beam velocity, offering advantages over traditional sources like Zeeman slowers.

Contribution

The development and characterization of a transversely loaded 2D magneto-optical trap as a cold strontium atom source with high flux and adjustable velocity.

Findings

Atomic flux exceeds 10^9 atoms/s at 500°C

Beam velocity tunable over tens of m/s

Loading rate up to 10^9 atoms/s without saturation

Abstract

We report on the realization of a transversely loaded two-dimensional magneto-optical trap serving as a source for cold strontium atoms. We analyze the dependence of the source's properties on various parameters, in particular the intensity of a pushing beam accelerating the atoms out of the source. An atomic flux exceeding $10^9\,\mathrm{atoms/s}$ at a rather moderate oven temperature of $500\,^\circ\mathrm{C}$ is achieved. The longitudinal velocity of the atomic beam can be tuned over several tens of m/s by adjusting the power of the pushing laser beam. The beam divergence is around $60$ mrad, determined by the transverse velocity distribution of the cold atoms. The slow atom source is used to load a three-dimensional magneto-optical trap realizing loading rates up to $10^9\,\mathrm{atoms/s}$ without indication of saturation of the loading rate for increasing oven temperature. The compact setup avoids undesired effects found in alternative sources like, e.g., Zeeman slowers, such as vacuum contamination and black-body radiation due to the hot strontium oven.