CERN PSB

CERN PSB
Name	Proton Synchrotron Booster
Established	1972
Location	Meyrin, Geneva
Type	Particle accelerator
Owner	CERN
Operator	CERN

CERN PSB

The Proton Synchrotron Booster is a four-ring synchrotron injector situated at CERN near Geneva. It serves as an intermediate accelerator between the Linac4/Proton Synchrotron and downstream facilities such as the Super Proton Synchrotron, Large Hadron Collider, and experimental areas like ISOLDE, AD, and Neutrino platform. The PSB supports beams for physics programs at ATLAS, CMS, LHCb, ALICE, and fixed-target experiments such as NA61/SHINE and NA62.

Overview

The PSB comprises four vertically stacked rings housed in a tunnel adjacent to the Proton Synchrotron. It accepts injections from Linac4 and previously from Linac2, then delivers protons to the Proton Synchrotron at energies used by SPS and LHC. The machine integrates RF systems, beam transfer lines, and vacuum systems to match emittance and intensity requirements of downstream accelerators like LEIR, ISOLDE and the Antiproton Decelerator. The facility coordinates with CERN departments including Accelerator Complex, Engineering Department, Beams Department, and collaborations with institutes such as INFN, DESY, and STFC.

History and Development

Conceived during expansions in the late 1960s, the PSB was constructed to augment the capacity of the Proton Synchrotron and enable higher intensities for emerging experiments. Construction paralleled projects such as Super Proton Synchrotron and the LEP conceptual studies, influenced by accelerator research at Princeton Plasma Physics Laboratory and Brookhaven National Laboratory. Commissioning occurred in the early 1970s, contemporaneous with installations at Fermilab and upgrades at Brookhaven National Laboratory. Over decades the PSB evolved alongside programs at ISR, CERN Neutrino to Gran Sasso (CNGS), and the advent of the Large Hadron Collider.

Design and Technical Specifications

The PSB uses four independent synchrotron rings with a combined footprint designed to minimize space while maximizing flexibility for beam dynamics. Each ring incorporates magnets patterned after designs tested at CERN Meyrin, with bending magnets, quadrupoles, sextupoles, and correction coils derived from developments at SLAC and KEK. Radiofrequency cavities operate at harmonics compatible with Longitudinal dynamics requirements similar to those used at PS and SPS. The injection chain integrates H- charge exchange from sources akin to those at TRIUMF and CERN Linac4, with stripping foils and charge exchange injection hardware reflecting practices from BNL and DESY. Vacuum technology uses NEG coatings influenced by implementations at SOLEIL and ESRF. Control systems are integrated with the CERN Controls Middleware and align with EPICS-style architectures used at ITER and Diamond Light Source.

Operation and Beam Types

The PSB accelerates primarily protons but also handles ions for programs feeding LEIR and ISOLDE. Beam modes include low-intensity probe pulses for commissioning, high-intensity cycles for LHC injection, and dedicated spills for experiments like AD and n_TOF. Pulse structures are tailored for experiments such as CAST and ISOLDE isotope production, and timing coordination is maintained with SPS extraction and LHC injection sequences. Diagnostics derive from instrumentation standards developed at CERN Accelerator Beam Instrumentation Group, with beam position monitors, profile systems, and intensity monitors comparable to those at FAIR and GSI. Operational coordination involves scheduling between user groups at NA61/SHINE, COMPASS, and accelerator operation teams including CERN EN Department.

Upgrades and Modernization

Major upgrade phases included adaptations for LHC luminosity enhancement programs and the LIU (LHC Injectors Upgrade) project, coordinated with facilities such as Linac4 and LEIR. Upgrades covered RF systems, magnet power supplies, vacuum improvements, and the introduction of modern control electronics influenced by initiatives at CERN BE-BI and partners like CERN-PS Division collaborators in Germany and Italy. Planned modernization addressed reliability, beam intensity, and space-charge mitigation using techniques developed at IHEP, RAL, and CEA Saclay. Improvements to cooling, shielding, and residual activation handling drew on experience from CERN Radiation Protection and accelerator decommissioning at J-PARC.

Scientific Contributions and Experiments

The PSB has been instrumental in enabling a wide spectrum of experiments across particle, nuclear, and applied physics. Its beams have supported discoveries at downstream detectors including ATLAS, CMS, ALICE, and LHCb by providing the necessary intensity and timing. The machine has supplied isotopes for ISOLDE nuclear physics research, antiprotons for the Antiproton Decelerator experiments such as ALPHA and ATRAP, and neutrino-targeting beams for programs connected to CERN Neutrino Platform. The PSB’s role in injector chains contributed to milestones celebrated by organizations like European Physical Society and projects linked to awards such as the EPS HEPP recognitions. Developments in beam handling and space-charge compensation influenced research at GSI Helmholtz Centre and the ESS project.

Category:Particle accelerators at CERN