Crystal search with beam by a vertical scan (for expert user)

The purpose of this method is to try to localize with the X-ray beam an invisible crystal in a loop. The crystal is supposed to be already almost centered. To start, rotate the loop to be edge on. When it is done, move down the backlight and use spec(exp) to set the commands.

1-mccdon (will define the detector as a counter and allow the fast shutter triggering)

2- go to "mccdmenu" to set the main parameters such as the proper file path for your experiment, the file prefix (which should finish with a " _ "), the first image number, and to decide if you wish or not to save the diffraction patterns. I advise to save the images to be able to display them after the search scan.

3- ct (to check if you will take an image with marCCD and the fast shutter will be open when you will take an image) with the safety shutter closed. If it is not working, write "udo id232marscan" in the spec(exp) window and restart from step 1.

4- use 10 % transmission , switch on the front light, open the safety shutter (in mxCuBE)

5- dscan phiz -0.01 0.01 5 1

6- look at all the individual images (you can use on the marCCD display application the + and - button to go from one image to another one) , you can display one line on a diffraction spot and look for the maximum intensity. The image is corresponding to one position in phiz: grab this position from the scan table in spec(exp) and move phiz to it. Take an image snapshot with mxCuBE to visualize the position.

7- mccdoff on spec(exp) (to remove the detector from the counter list)

8- in mxCuBE, move phi by -90 degree and start the 3 click centring procedure. The second click will be with loop edge on, click on the red cross.