Mounting of the minikappa

 

If mounting the minikappa freshly on the minidiff, make sure to switch off the DPAP(s) for the kappa1 and kappa2 motors.

 

Calibration of the minikappa

 

for the translation calibration, remove the cryo stream.

 

the GONIOMETER TRANSLATION CALIBRATION is needed to make sure that the sample does NOT move out of the cryo during a rotation. This procedure together with the GONIOMETER ROTATION CALIBRATION needs to be done ONLY

      during the START-UP of the beamline

      if the minikappa has been unmounted

 

on the control PC (e.g. p1-id29) make sure that within the file /users/opidxy/STAC/config/BCM.dat the two following lines are correct (if you change anything, save the old file to BCM.dat.date):

      I)  BCM_PLUGIN BMC_PLUGIN_esrf_safe

     II)  SPECVERSION lid292:exp (or the equivalent for any other beamline)

 

run the program by typing STAC into a x-terminal on the control PC.

 

if you really want to do the full calibration (i.e. I) Translation Calibration and II) Rotation Calibration, you need to activate these 2 tabs in SPEC first under the tab OPTIONS

  

  • GONIOMETER TRANSLATION CALIBRATION (Gonio TransCalib):

        you need to have an alignment device that allows you to carefully centre (e.g. an acupuncture needle mounted in a pin)

      1. initialise motors

      2. move (0;0;0)

      3. centre tip (3 click centering) very carefully (do this at zoom 6; do NOT change the focus!)

      4. reset translation

      the next three steps need to be repeated for every phi translation made

      5. set phi translation

         (do this for phi = 90, 180 and 270 degree)

      6. centre tip

      7. get translation

      8. set kappa translation

         (do this for kappa = 80, 160 and 240 degree)

      9. centre tip

    10. get translation

    11. calculate (if nothing is selected, everything will be taken for the calculation)

                 these are the values to check:

                            I           DIFF TO CURRENT should be ≤ 0.7º

                            II          the calculated axis for phi should be close to x=0; y=0; z=1

                            III         RECONSTRUCTION ERROR should be less than 0.012 mm

     

     12. UPDATE when everything is fine.

 

 

  • GONIOMETER ROTATION CALIBRATION (Gonio RotCalib):

 

     1. initialise motors

     2. move (0;0;0)

     3. centre crystal (3 click centering) very carefully

     4. collect four subsequent images (oscillation start musst be 0)

easiest is to use the automatically generated mosflm.inp or XDS.INP files. If you like to do the
indexing manually, make sure that you generate also the bestfile.par (which is needed by STAC).

     5. index the images

     6. open the xxx.mat (when using MOSFLM) or the CORRECT.LP (when using XDS) into the space

     7. move (0;0;P)

     8. make sure that the oscillation start is 0 and repeat steps 3.-6.

     9. move (0;K;P)

   10. make sure that the oscillation start is 0 and repeat steps 3.-6.

   11. move (O;K;P)

   12. here the oscillation start corresponds to the value of O; repeat steps 3.-6.

   13. CALCULATE

            these are the values to check:

                  I           the calculated axes for phi and omega should be close to x=0; y=0; z=1

                  II          the calculated angle should be close to calibration values (∆ ≤ 0.7º)

                  III         DIFF TO CURRENT should be ≤ 0.7º

 

   14. UPDATE

 

  • RE-ORIENTATION CALCULATION

 

    1. mount a crystal

    2. centre crystal (3 click centering) very carefully

    3. collect four subsequent images

    4. index the images

    5. read in the xxx.sav file from the MOSFLM output and press LOAD

    the current angles and the translation plus the OM (orientation matrix) will be filled in automatically.

    6. NEXT (you know will automatically jump to the VECTOR EVALUATION tab)

    7. select whatever orientation you would like to have and press MvSel

    8. start data collection or press NEXT to calculate a strategy calculation.