Beam emittance preservation using Gaussian density ramps in a beam-driven plasma wakefield accelerator

Area of Science:

• Plasma Physics
• Particle Accelerators
• Beam Optics

Background:

• Transverse beam emittance preservation is a key challenge in plasma wakefield accelerators (PWFA).
• Beam matching, balancing beam divergence with plasma focusing forces, is essential for emittance preservation.
• Plasma density ramps offer a method for gradual focusing and beam matching.

Purpose of the Study:

• To investigate beam dynamics within a Gaussian plasma density ramp.
• To develop an empirical formula for achieving near-perfect beam matching using a plasma density ramp.
• To assess the robustness and experimental feasibility of the developed method.

Main Methods:

• Analysis of particle beam dynamics in a Gaussian plasma density ramp.
• Derivation of an empirical formula based on the beam vacuum waist beta function.
• Numerical simulations to validate the formula across various demagnification factors.

Main Results:

• An empirical formula was identified for calculating optimal plasma ramp length and beam waist location.
• The method achieves near-perfect beam matching.
• The formula demonstrates robustness for a wide range of beta function demagnification factors with favorable experimental tolerances.

Conclusions:

• The Gaussian plasma density ramp method provides an effective solution for beam matching in PWFA.
• The derived empirical formula simplifies the process of achieving precise beam matching.
• This technique holds promise for enhancing the performance and reliability of future PWFA facilities.