LLRF Topical Workshop on Advanced Feedback Control (TWoAFC)

Minimizing the RF Beam Component During Bunch Splitting in the EIC

Oct 13, 2026, 9:45 AM

30m

Nova Gorica, Slovenia

Oral Control Architecture and Strategies Control Loop Modeling, Tuning and Optimization

Speaker

Arshdeep Singh (Brookhaven National Laboratory)

Description

The Hadron Storage Ring (HSR) of the Electron-Ion Collider (EIC) will perform a 1 to 4 bunch split to reach its luminosity goals. After the bunch splitting, the beam is compressed by 197 MHz and 591 MHz RF systems. It is important that, during the splitting process, the voltage on the compression cavities stays close to 0 V to prevent any detrimental effects on the beam emittance and bunch-by-bunch charge variation. During this bunch splitting process, the beam current at 197 MHz reaches a peak of 1 A while the 197 MHz cavity voltage is still at 0 volts. Feedback is used to keep the cavity voltage near 0 V, however, there is not enough installed power to cancel the RF component of the beam. To fight this beam component, a “defocusing cavity” at 197 MHz is introduced to provide bunch shaping such that the beam component at 197 MHz is minimized. Simulations are performed to determine the voltage and phase program on the defocusing cavity throughout the splitting process. Regulation in the presence of transient-beam loading is also studied.