Hollow Beam Optical Ponderomotive Trap for Ultracold Neutral Plasma

TL;DR

This paper introduces a novel hollow-beam optical trap for ultracold neutral plasma using high-power CO2 lasers, effectively confining plasma with minimal collisional absorption, which could improve antimatter storage.

Contribution

The paper proposes and analyzes a flat-bottomed hollow-beam ponderomotive trap for ultracold plasma, demonstrating its advantages over RF traps through molecular dynamics simulations.

Findings

Effective trapping of plasma within a dark region by light walls.

Reduced ponderomotive energy per electron compared to RF traps.

Negligible collisional absorption due to low collision frequency.

Abstract

Rapidly oscillating, inhomogeneous electromagnetic field from laser exert a force that repels charged particles from regions of high light intensity. We propose and analyze a flat-bottomed hollow-beam ponderomotive optical trap for an ultracold neutral plasma (UNP), driven by a high-power CO$_2$ laser. Molecular dynamics simulations show that the plasma and Rydberg atoms are effectively trapped within a nearly uniform dark region bounded by repulsive light walls. In contrast to RF traps, flat-bottomed traps yield a small density-weighted mean ponderomotive energy per electron, while the UNP collision frequency is far below the laser frequency, thereby making collisional absorption negligible and does not limit the lifetime of the trap. This approach could enhance antimatter production and storage.