Researcher tests beam-position monitor for ALS Upgrade.

Today’s large and complex accelerator-based projects often require expertise from across a single laboratory or even among multiple institutions. We play crucial roles in advancing low-level LLRF controls and beam diagnostic instrumentation for these cutting-edge applications. We designed a normal conducting 1.5 GHz higher-order-mode-damped third harmonic cavity, engineered to elongate electron bunches without inducing beam instabilities. This is vital for achieving target beam lifetimes at the ALS-U Storage Ring, where electron bunches must be stretched by a factor of four or more.

Our expertise extends to precise beam orbit measurement and feedback control in storage rings, mainly  focusing on low-emittance electron rings. Our efforts have achieved remarkable transverse beam stability, maintaining micron-level precision over extended timeframes (multiple days). Additionally, we spearheaded the electromagnetic design and validation of ALS-U’s beam position monitors (BPMs). These BPMs pose unique challenges due to tight spaces and varying chamber geometries, but through collaborative efforts with ALS-U mechanical engineers, we overcame these hurdles using high-fidelity simulations, precise bench measurements, and rigorous beamline tests at the ALS.

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In addition to BPMs, our contributions encompass the development of key instruments such as injection-extraction kickers, beam current monitors, and longitudinal feedback kickers, among others. We have comprehensively evaluated beam impedance for various vacuum components at ALS-U, devising innovative designs to manage impedances within predefined constraints. Leveraging these impedance assessments, we have investigated various beam instabilities to ensure stable beam operation.