Abstract
The -LEM beamline at Paul Scherrer Institute (PSI, Switzerland) is a special muon beamline combining the hybrid-type surface muon beamline with the low-energy muon (LEM) facility and delivers with tunable energy up to 30 keV for low-energy muon spin rotation (LE-) experiments. We investigate a possible upgrade scenario for the surface muon beamline by replacing the last set of quadrupole triplets with a special solenoid to obtain 1.4 times the original beam intensity on the LEM muon moderator target. In order to avoid the muon beam intensity loss at the LEM spectrometer due to the stray magnetic field of the solenoid, three kinds of solenoid models have been explored and the stray field of the solenoid at the LEM facility is finally reduced to the magnitude of the geomagnetic field. A more radical design, “Super-,” has also been investigated for further increasing the brightness of the low-energy muon beam, where we make use of the current channel and all sets of quadrupole triplets are replaced by large aperture solenoids. Together with the new slanted muon target E, at least 2.9 times the original muon beam intensity can be expected in the Super- beamline. Our work demonstrates the feasibility of upgrading surface muon beamlines by replacing quadrupole magnets with normal-conducting solenoids, resulting in higher muon rates and smaller beam spot sizes.
18 More- Received 15 August 2021
- Accepted 21 March 2022
DOI:https://doi.org/10.1103/PhysRevAccelBeams.25.051601
Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
Published by the American Physical Society