12. SCS Expert Startup

This section is for experts only and details the instruction to set the DSSC in operation after it was resinstalled or after a long period of shutdown.

12.1. Chiller

12.1.1. Bypass

The silicone oil absorbs moisture in the air over time. When cooling this leads to the formation of ice crystal in the pipe and inside the DSSC cooling blocks which can prevent DSSC cooling operation.

To prevent this the first thing is to bypass the DSSC and operate the chiller at +45C overnight.

To do this, put the bypass in place, configure the chiller locally, increase the hard limit and run the chiller with valve opened.

12.1.2. Normal operation settings

After the bypass operation, the original settings have to be put back. They can be found in: https://rtd.xfel.eu/docs/eee-plc-framework/en/latest/softdevices/SD_CHILLERJULABO.html with the exception of the setting for E-PROG H=55C which should be H=34.40C instead for this particular chiller.

Also the hard limit as to be put back to 40C.

When the chiller is interlocked, the ramp goes to 0 C/min which is not the smallest ramp as one would expect but the highest ramp speed possible. It has to be put back to 1 C/min before the chiller is started.

12.2. MPOD

Check in the rack room that the power enable green switch button on the 4 MPOD power supply are on.

12.3. AON

From the DSSC_Main scene, in the Automatic Power Panel frame, open the Manual Mode scene. In that scene, type aon and press on to start the automatic on channels.

This takes about 3 to 5 min to complete. U704 channel powering the PPT device should reach ~1.5 A.

12.4. SIB

The next step is to look at the SIB status. Switch the Experiment OK to on. More information on the SIB are accessible on the See more scene.

SIB state of 5 means ready for cooling. Set the chiller setpoint to -18 C.