We would like to standardize our software for operating transverse deflecting structures across facilities and devices:
- XFEL injector
- XFEL BC2
- FLASH LOLA
- FLASHforward Polarix (commissioning not earlier than September 2019)
- other future installations
Olaf Hensler is going to provide finite state machine servers for switching the RF on/off and associated services for moving the pulse on/off beam. Josef Wilgen is going to provide image analysis servers; an option to rotate the TDS image freely is desirable for the Polarix structures. Bolko Beutner will agree with Pau Gonzalez Caminal on how to continue development of the Matlab tool for longitudinal phase space measurements.
Switch-over for RF stations
On Matthias' suggestion, we discuss how to make the switch-over from a tripped RF station to a spare one easier and less error-prone. Trajectory changes account for a big part of the problems in these scenarios – we'll attempt to reconfigure the L3 orbit feedback so that it covers the entire cold linac. An SVD orbit correction server is also an option. Optics errors from bad energy settings on the magnets are another source of errors.
Energy profile server
We decide that the energy profile server should no longer scale its profile to the beam-based energy measurements. We'll rely on the LLRF-based profile with manually adjusted fudge factors instead. This will at least eliminate jumps in the energy profile when beam is switched on or off. (Note: done right after the meeting)
LLRF energy gain server
We still suffer frequently from LLRF electronics failures that cause energy gain data to be missing. The resulting "holes" in the energy profile make several applications unreliable, among them the magnet energizer and the high level status server. Olaf is going to implement a workaround.
Matthias notes that a server version of the magnet energizer would be desirable. It would receive commands like "scale magnets from component_a to component_b in beamline X to beam energy for subtrain S". Such a server could be used directly from the BBA tool, for example.
FEL status save&restore tool
We need a tool to make switching between wavelengths at the various FELs easier and faster; the Sequencer client is too generic for this task. Matthias (and maybe Frank?) is going to develop a tool that reads stored settings directly from the Sequencer server.
Shan and Josef have made a lot of progress on their collimator bump scan tool; they are going to develop it into something that can be used by operators to reliably steer the beam through the center of the collimators.
- Collimator steering tool: Implement Josef Wilgen @Shan Liu
- Image analysis server: Implement free rotation Josef Wilgen
- Bunch length measurement tool: Extend for FLASHforward or fork Bolko Beutner
- Orbit feedback: Test extended L3 setup covering the entire linac Raimund Kammering
- LLRF energy gain server: Implement workaround for "holes" in energy profile Olaf Hensler
- Magnet energizer server: Formulate design ideas Lars Froehlich
- FEL save&restore tool: Implement Matthias Scholz