The very slow expansion of an ultracold plasma formed in a seeded supersonic molecular beam of NO

Abstract

The double-resonant laser excitation of nitric oxide, cooled to 1 K in a seeded supersonic molecular beam, yields a gas of $\approx 10^{12}$ molecules cm${}^{-3}$ in a single selected Ryberg state. This population evolves to produce prompt free electrons and a durable cold plasma of electrons and intact NO${}^{+}$ ions. This plasma travels with the molecular beam through a field free region to encounter a grid. The atomic weight of the expansion gas controls the beam velocity and hence the flight time from the interaction region to the grid. Monitoring electron production as the plasma traverses this grid measures its longitudinal width as a function of flight time. Comparing these widths to the width of the laser beam that defines the initial size of the illuminated volume allows us to gauge the rate of expansion of the plasma. We find that the plasma created from the evolution of a Rydberg gas of NO expands at a small but measurable rate, and that this rate of expansion accords with the Vlasov equations for an initial electron temperature of $T_e\approx 8K$.

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References in corpus (9)

• Using Absorption Imaging to Study Ion Dynamics in an Ultracold Neutral Plasma
• Mechanical effect of van der Waals interactions observed in real time in an ultracold Rydberg gas
• Ultracold Neutral Plasmas
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• Electron Temperature of Ultracold Plasmas
• Using Three-Body Recombination to Extract Electron Temperatures of Ultracold Plasmas
• Experimental Realization of an Exact Solution to the Vlasov Equations for an Expanding Plasma
• Electron Temperature Evolution in Expanding Ultracold Neutral Plasmas
• Ultracold neutral plasma expansion in two dimensions

Cited by in corpus (11)

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• Excitation and characterization of long-lived hydrogenic Rydberg states of nitric oxide
• Dissipative dynamics of atomic and molecular Rydberg gases: Avalanche to ultracold plasma states of strong coupling
• Influence of Electron Evaporative Cooling on Ultracold Plasma Expansion
• Heating and cooling of electrons in an ultracold neutral plasma using Rydberg atoms
• Creating Non-Maxwellian Velocity Distributions in Ultracold Plasmas
• The role of collisions and strong coupling in ultracold plasmas
• What is the temperature of an ultra-cold Rydberg plasma?
• Expansion of an ultracold Rydberg plasma