Effectiveness of rf phase modulation for increasing bunch length in electron storage rings

Area of Science:

• * Accelerator physics
• * Particle beam dynamics

Background:

• * Electron storage rings require long beam lifetimes for experiments.
• * Beam lifetime is limited by factors including bunch length.
• * Radio frequency (RF) phase modulation is a potential technique to increase bunch length.

Purpose of the Study:

• * To investigate the effectiveness of RF phase modulation near parametric resonance for increasing bunch length.
• * To analyze the impact of RF parameters on longitudinal emittance.
• * To compare theoretical predictions with simulation results.

Main Methods:

• * Experimental investigation of RF phase modulation in electron storage rings.
• * Simulation studies varying RF parameters.
• * Comparison of theoretical predictions, simulations, and experimental data.

Main Results:

• * RF phase modulation was studied for its effect on longitudinal emittance under various RF parameters.
• * Synchrotron radiation was observed to negatively impact the parametric resonance.
• * A criterion for the survival of resonance islands was determined.

Conclusions:

• * RF phase modulation shows potential for increasing bunch length but is sensitive to ring parameters.
• * Synchrotron radiation poses a challenge to the efficacy of this technique.
• * Understanding the criterion for island survival is crucial for optimizing beam lifetime.