Engineering topics
Publications and source records attributed to Eldred, J. [Fermilab] (ORCID:000000034432072X).
For many synchrotrons which cross $γ_t$ transition, a high intensity threshold has been identified beyond which significant beam losses are observed. These losses are due to a high-intensity mode coupling instability, which can be suppressed by adjusting the chromaticity curve to cross zero slightly after $γ_t$ transition.
A $\gamma_{T}$ scheme may be required for the PIP-II era performance or ACE-MIRT era performance of the Booster. PIP-II era operations of the Fermilab proton complex will require the Fermilab Booster to increase beam intensity from 4.5e12 to 6.7e12 protons, while also increasing its ramp from 15 Hz to 20 Hz. These changes pose particular challenges for transition-crossing in the Booster, where longitudinal beam quality must be controlled in order to facilitate slip-stacking in the Recycler Ring later in the Main Injector cycle. Two novel $\gamma_{T}$-jump schemes are proposed, termed Double $\gamma_{T}$ jump and Partial $\gamma_{T}$-jump , which optimize the magnitude of the $\gamma_{T}$-jump within optics and power supply constraints.
The longitudinal compression of high-intensity, space-charge-dominated proton bunches is a critical requirement for future proton-driven muon colliders. We propose a proton bunch compression experiment at the Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab to investigate optimal radio-frequency (RF) cavity parameters and lattice configurations. IOTA is a compact, fixed-energy storage ring dedicated to beam physics Research and Development and capable of circulating a 2.5 MeV proton beam under extreme space-charge conditions. Using the ImpactX code with its 3D space-charge solver, simulations indicate that the bunch length can be rapidly reduced by at least a factor of two without appreciable degradation of transverse beam quality--even in the strong space-charge regime. However, longitudinal defocusing due to the space-charge remains a significant challenge in short-pulsed intense proton bunches, and the optimization of compression under these conditions is discussed.