- Coordinator: Maja Olvegård (Uppsala University, Sweden)
- Co-Coordinator: Natalia Milas (European Spallation Source, Lund, Sweden)
- Team membership
The overall objective of WP4 is to produce a conceptual design of a low energy nuSTORM facility (LEnuSTORM). An intense proton pulse will be transferred from the ESSnuSB accumulator ring to a dedicated target station for nuSTORM. There, pions, one charge at a time, will be collected and transferred to a racetrack storage ring. Very soon after injection, which takes place at the start of one of the long straight sections in the ring, these pions will decay and emit a muon which will be stored in the ring for a number of turns. Any pion that has not decayed at the end of the first straight section will be extracted to a beam dump. As the stored muons circulate in the ring they decay, emitting two neutrinos. Some of these neutrinos will be emitted in the direction of a near detector close to the storage ring, and a far detector at the ESS site, the latter coinciding with the far detector in the ESSnuSB long-baseline experiment.
The overall goal of work package 4 is to produce an as intense neutrino flux as possible from the stored muons. This means that the stored muon intensity must be maximized, but also that the ring design is done to maximize the muon flow in the specific direction of the neutrino detectors.
The work package includes designing a new transfer line from the accumulator to the target station; to transfer and inject pions into the storage ring; to design the racetrack storage ring; and to estimate the resulting neutrino flux. In addition, the current design of the accelerator complex for ESSnuSB will be consolidated in order to improve the performance of the ESSnuSB and the nuSTORM experiments.
The design work is associated with a number of challenges, such as creating a compact racetrack ring while ensuring a large acceptance in momentum and transverse phase space. This can mean relying on strong, combined-function magnets, and possible exotic lattices.