SASE3 Summary of Maintenance Period and Ramp up activities

Maintenance

- Soft Mono motions (grating horizontal and grating pitch) were cleaned and lubricated

- Vertical slit encoders were double checked (without moving them) to exclude that Karabo errors are coming from them.

- Motors of Mirrors were inspected (without dismounting) to check if some strange noise is created during motion. The SA3 M2 Tx motor was very noisy at 0.035 speed and not anymore at 0.03. 

- Settings of acceleration and velocity was optimised together with EEE (Bernard). The noise at SA3 M2 Tx was disappearing even with 0.035 speed.

- M1 and M2 chillers had service (water filling) and were then set on again before closing the tunnel. For M5 and M6, cooling is off.

- Piezo controller for M1 was disconnected and removed. Therefore, the M1 piezos are unavailable at the moment. This was agreed with the experiments after it was found some instabilities in the beam position (beam was moving by itself sometime). 

- PBLMs were checked: https://in.xfel.eu/elog/XRO+Beam+Commissioning/76

Inst Dept Ramp up

- SA3 M2 RY was not moving. This took several hours to be solved. Temprary explanation: stepcounter value changed without any physical movement of the motor and later on, encoder was thought to be wrongly calibrated and thus adjusted. As a result, the motor position is lost and needs to be fiducialised again in the alignment.

- The performance of "Closed loop" and "Backlash Correction" was tested. The result is that the TY motors need to remain in open loop and with 'Backlash Correction' activated (value 2 microns). This is increasing the reproducibility of the positioning. The other motors could be used in closed loop if required, but then the Backlash Correction has to be deactivated.

- SA3 M6 RY encoder has an incorrect calibration at the moment. Please refer to the motor position only. We will work on a solution asap.

- The vertical slits (SCS, SQS, SXP) were checked and they move correctly.

- Several positions were fiducialised, that could be used as a starting point for Instruments fine alignment:
SXP 9mrad (8.9mrad) mono he premirror 937eV 
SXP 9mrad (8.9mrad) unfocused
SCS 9mrad (8.9 mrad) unfocused
SCS 9 mrad (8.3mrad) unfocused
SQS 9mrad (8.7mrad) unfocused
SQS 20mrad (18.5mrad) unfocused

- SEPS interlock was succefully tested: https://in.xfel.eu/elog/XRO+Beam+Commissioning/112