LINAC2026 - 33rd Linear Accelerator Conference

Development of an Automated Lorentz Force Detuning Compensation System for the ITN Cryomodule at KEK

TUPO076

18 Aug 2026, 16:00

2h

1F Exhibition Hall (Daejeon Convention Center)

Poster Presentation MC4.A04: Low level RF TUPO - Poster Session

Speakers

Mathieu Omet (High Energy Accelerator Research Organization)Dr Rishabh Bajpai (High Energy Accelerator Research Organization)

Description

At KEK, an International Linear Collider prototype cryomodule with eight TESLA-type cavities is under development. The cryomodule will operate in pulsed mode at 5 Hz. During RF operation, electromagnetic forces mechanically deform the cavity structure, shifting the resonance frequency through Lorentz Force Detuning (LFD).
A common method for LFD compensation is feedforward control using a piezo actuator driven by a half-sine waveform to restore resonance during the flat-top. Effective compensation requires optimization of waveform amplitude, frequency, DC offset, and phase relative to the RF pulse. Manual tuning is feasible for a small number of cavities but is time-consuming and difficult to scale.
To address this, an automated LFD compensation algorithm is being developed on a Red Pitaya FPGA platform using Vivado. The system automatically optimizes the piezo drive parameters for cavity tuning. This contribution presents the current progress of the automated compensation algorithm and the cavity simulator developed for testing
and evaluation.