A Rubidium Vapor Source for a Plasma Source for AWAKE

TL;DR

This paper describes a rubidium vapor source designed as a plasma source for the AWAKE experiment, meeting strict density and uniformity requirements through analytical and simulation validation.

Contribution

It introduces a novel rubidium vapor source scheme that satisfies the precise plasma parameters needed for wakefield acceleration in AWAKE.

Findings

Rubidium vapor density meets the required plasma parameters.

Simulation confirms the uniformity and gradient control of the vapor source.

Laser ionization effectively transfers vapor properties to plasma.

Abstract

We present the scheme for a rubidium vapor source that is used as a plasma source in the AWAKE plasma wakefield acceleration experiment. The plasma wakefield acceleration process requires a number of stringent parameters for the plasma: electron density adjustable in the (1-10)$\times$10$^{14}$cm$^{-3}$ range, 0.25% relative density uniformity, sharp ($<$10cm) density ramps at each end, density gradient adjustable from -3 to +10% over 10m, and %-level density step near the beginning the plasma column. We show with analytical and direct Simulation Monte Carlo results that the rubidium density in the proposed source should meet these requirements. Laser ionization then transfers the above neutral vapor parameters to the plasma.