IPAC'26 - the 17th International Particle Accelerator Conference

MAX 4U, an upgrade of the MAX IV 3 GeV ring.

THI2M01

21 May 2026, 09:00

30m

Auditorium Michel d’Ornano (C.I.D )

Invited Oral Presentation MC2.A05: Synchrotron Radiation Facilities MC2 : Photon Sources and Electron Accelerators

Speakers

Aashoo Sharma (MAX IV Laboratory) Ake Andersson (MAX IV Laboratory) Eshraq Al-Dmour (MAX IV Laboratory) Francis Cullinan (MAX IV Laboratory) Hamed Tarawneh (MAX IV Laboratory) Henrique de Oliveira Caiafa Duarte (MAX IV Laboratory)Mr Karl Åhnberg (MAX IV Laboratory) Magnus Sjöström (MAX IV Laboratory) Marco Apollonio (MAX IV Laboratory) Marek Grabski (MAX IV Laboratory) Murilo Barbosa Alves (MAX IV Laboratory) Pedro Tavares (MAX IV Laboratory) Robert Lindvall (MAX IV Laboratory) Sara Thorin (MAX IV Laboratory)Dr Stephen Molloy (MAX IV Laboratory)

Description

The MAX IV 3 GeV storage ring in Lund, Sweden, was the first implementation of a multibend achromat (MBA) lattice fourth-generation light source. Since it started delivery of light in 2016, four succeeding MBA-based rings and variants have come on-line: ESRF-EBS, Sirius, APS-U and SLS 2.0. Several others are being planned, designed, built or commissioned. All of these capitalize on the MBA concept and expand it to push the brightness and coherence performance even further. In order to continue to offer the Swedish and international scientific communities’ competitive tools beyond the end of this decade, MAX IV Laboratory launched in 2024 the conceptual design of MAX 4U, an upgrade of its 3 GeV storage ring aiming at an emittance below 100 pm.rad. This performance boost is to be achieved through a minimum-interference upgrade in which localized interventions in selected subsystems and components are carefully chosen to provide the maximum performance increase with minimum cost and, equally important, minimum dark time for the MAX IV user community. In 2025, the conceptual design report (CDR) is published, and the focus in 2026 is to elaborate on the solutions identified for this upgrade through the Technical Design Report (TDR), to be published in 2027. This contribution describes the latest developments in accelerator physics and engineering aspects of the MAX 4U design.

Funding Agency

We acknowledge funding from The Crafoord Foundation (Crafoordska stiftelsen) (Grant 20250007).