Quadrupole offset measurement by beam-based alignment (updated on 19.Feb 2025)
Immediately after the two-day workshop, we are planning the joint experiment at the Karlsruhe Research Accelerator (KARA), a 2.5 GeV electron storage ring.
The topic of the planned joint experiment is Beam Based Alignment (BBA): BBA has been used to search for the magnetic field centre of quadrupole magnets by observing the beam position with BPMs placed close to the quadrupole magnets. In other words, the BBA results give us information about the spatial offset of the quadrupole magnets.
This time we plan a series of BBA measurements by changing the operating beam energy of the KARA storage ring: due to the operational flexibility of KARA, we can flexibly switch the operating beam energy in the range from 0.5 to 2.5 GeV. For the experiment, we have chosen some typical beam energies, 2.2 and/or 2.3 GeV, which have been used for user operation in the past, in order to reduce the power consumption of the machine. In the lower energy operation, we deactivated one of the two klystrons to reduce the power consumption: it is still possible to provide synchrotron light to the users with sufficient beam current. However, it was not clear whether the axis of the synchrotron radiation was maintained at the normal 2.5 GeV condition due to the change in thermal load on each magnet in the storage ring. The BBA results in lower energy conditions will give us information about the stability of the light source operation in different operating modes and about the effect of the change in thermal load on the beam stability.
The parallel BBA method will be used in the experiment: the parallel BBA can drastically reduce the measurement time. In the experiment we will repeat the parallel BBA measurement with different beam energies (2.2, 2.3 and 2.5 GeV). Changing other operating conditions, such as the beam current, is also a possible extension.
In order to orientate the motivations for the experiment, we will organise online meetings before the workshop to discuss the experimental plans in detail. During the workshop, we will have an introductory talk about BBA and a discussion session immediately after the introductory talk: we will have a face-to-face discussion session just before the joint experiment.
The joint experiment on stability of ring-based synchrotron light sources (20-21 March 2025 at KIT) will be co-funded by the European Union within the EURO-LABS project. This project has received funding from the European Union’s Horizon Europe Research and Innovation programme under Grant Agreement No 101057511 (EURO-LABS).
