Considerations on wakefield effects in a VUV FELO driven by a superconducting tesla-type linac

TL;DR

This paper examines how wakefields in TESLA-type cavities affect beam stability and FEL oscillator performance at 120 nm, highlighting potential emittance degradation and power stability issues.

Contribution

It provides a detailed analysis of wakefield effects on beam dynamics in a VUV FEL driven by a superconducting TESLA-type linac, including simulation results.

Findings

Wakefields cause measurable centroid shifts affecting FEL output.

Wakefields induce head-tail kicks leading to emittance degradation.

Simulations show impact on FEL power stability.

Abstract

The effects on beam dynamics from long-range and short-range wakefields from TESLA-type cavities are considered in regard to a proposed FEL oscillator (FE-LO) operating at 120 nm. This would be driven by the Fermilab Accelerator Science and Technology (FAST) linac at 300 MeV with a 3-MHz micropulse repetition rate. Our wakefield studies showed measurable effects on submacropulse centroid stability and on submicropulse head-tail kicks that can lead to emittance degradation. In the case of the former, we use MINERVA/OPC to simulate the ~100-$\mu$m centroid slew effects on the saturated output power levels of the FELO.