LC Startup

For each start up of a new user group on ID23-2, the following checklist ought to be followed. The entire list could take between 20-30 minutes.

An LCStartup macro is installed, it should run the quick realign + the centrebeam actions and save motor positions in sybil (/users/opid23/data/LCStartupOH) for spec(opt) and lid233 (/users/opid23/data/LCStartupEH) for spec(exp). To use it, write LCStartup in spec(exp) once the search has been done in the experimental hutch.

IMPORTANT: The microfocus capability of ID23-2 makes the end-station non-standard and a specialised instrument. Please stress this to the users when you introduce them to the line!! In order to get the most out of the beamline the users will need to take special care during data collection for radiation damage and any eventual beam and sample movements. They will need to regularly check the beam position between data sets (around every 30 minutes for < 20 micron crystals and less frequently for larger samples). See below or in the User Guide for the procedure to check this.

Beam stability is strongly correlated with the temperature stability in the experimental hutch. Make sure the temperature is kept stable by minimising how many times users go in/out of the hutch (use the sample changer!) and by keeping the door shut at all times.

Helium Pressure in the KB vessel.

The focusing mirrors are operate under a weak helium overpressure. The pressure on the KB vessel can be read from a pressure sensor (blue device at the left side of the KB vessel), it should be around 985-1000 mbar. The helium cylinder is near the optic hutch electronic rack. Please check both of them and write the value on the logbook.

If the helium cylinder is empty, ask John Surr (working hours) or the floor operator (25 25, outside working hours or during WE) on how to get a new one.

Change proposal number

One of the first things to do is change to the new users proposal number in ProDC.

Check the Optics Hutch and the Undulator

After a machine day (normally Tuesdays) the optics hutch may not be closed and the undulators may be fully open. Search and close the optics hutch OH like an experimental hutch (2 search buttons: one near front end and one between the two beam tubes). If the undulator is open (use idappli to check under ID Control [under Commands menu]), the U20.2 should be closed to 11.50 mm. The other undulator (U35) is used by ID23-1 for MAD experiments and the gap depends on the edge being used: DO NOT MOVE IT.

Optimise the beam intensity in Experimental Hutch

Close the experimental hutch and optimise the beam using mxCuBE  ( push the "Beam Realign" button on the hutch tab); in some situations, repeated "Beam realign" in a short period of time can lead to beam instabilities.

Check Beam Position

Put the YAG screen in place, go to zoom 4 and focus (step size : 0.01 in mxCuBE) to see the surface clearly (the "3 click centering" can be used as well), then open the Safety shutter and fast shutter (mxCuBE). Check that the X-ray beam intersects the centre of rotation, visualised by the red cross indicating the beam center. This is important as the three-click centering algorithm uses this position. To bring beam to the cross, do a "beam realign" (if necessary, ie if intensity is too low or beam is drifted horizontally by more than ~ 30 µm) before clicking on "Centre". Check that the backstop/collimator is not cutting the beam.

Beam size is defined by the mirror focusing and not by the slits in the slitbox. It is better to let s1v and s1h wide open (around 3 mm gap) and to close and to use s2v and s2h (0.05 to 0.5 mm, 0.2 being a good compromise)  as cleaning slits rather than as beam defining slits.

Check position of the cryohead

There should be an alignment tool in the experimental hutch for the nozzle of the cryojet (attached by wire to the cryostream). Use the eye of a master if you cannot find this tool. Show the setting to the users and stimulate them to fine-tune it if they would like to do so or have data quality problems. An experiment on data quality from different cryo to sample distances should be enough to warrant checking.

Please record the local contact data and intervention record

ID23-2 tool box list

 - YAG 22 mm

- YAG 24.5 mm

- Cr2O3 powder on a nylon loop

- W wire pasted on a pin

- Goniometerhead key

- Goniometerheads

- Phi nozzle

- Korsolex

- Glasses

- Vial pusher

- Long tongs

- 1 30 cm long ruler

- 1 50cm long ruler

- 2 baskets with 10 samples in each