Researcher tests beam-position monitor for ALS Upgrade.

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.

Student and mentor use modeling software.

Mentoring of undergraduate and graduate students is an important part of BACI’s mission.

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.