Manual_MonoGratingSelection

Select a different grating of the Monochromator

Ask the assistance of a beamline scientist the first time you need to do this procedure, since you can seriously damage the grating if you do not follow the procedure properly!

Check here the Energy Ranges of the four spherical gratings of the Monochromator: The Beamline
 

     
1 ScanEnergy Check that this VI is not operative (stop all the scanning VI which read the energy such as scan energy, ScanXPS..). The arrow should be white. If you see that the arrow is white, it is OK. If the arrow appears broken, check again, find and stop the VI still running.
2 MainPanel.vi CLOSE FRONT END
3 MANUAL OPERATION Go next to the Monochromator Chamber (big Chamber along the beamline). You will find on the floor below the chamber, a small controller with a black wheel, where LIFT and DOWN positions are marked.
Follow these steps:

STEP1: LIFT the piston by rotating slowly the small wheel from down to lift position and checking the pressure on the manometer (from 4.5 bar to 0 bar). At the end of this operation visually check that the piston has lifeted

STEP2: MOVE manually the grating by moving the linear motion from the position of SG2 to the position of SG3 (as marked on the linear motion scale). The bellow can make some noise, do not worry.

STEP3: Push DOWN again the piston by rotating slowly the small wheel from lift to down position checking the pressure on the manometer (from 0 to 4.5 bar). At the end of this operation visually check that the piston is down again.
     
     
4 MainPanel.vi Select the new grating clicking on the rectangle with the name of the grating and choosing the grating from the drop-down menu which will appear [e.g. SG3 (5)]and Press =>

Read the energy. If mono homing is ok you should read ABOUT -348 eV or -326

Select the energy (in the range of the grating you have selected!) you want to use and then press MOVE (this may take 1.5-2 minutes!!!)
5 SetEneryandUndulator.vi Select the new grating in the Calculator field
6 MotorControl.VI

Press ==>.

Select: Element: POSTHORA and Action: Pitch

Read. You should read a value between -45000 and -55000.

Move to the value corresponding to the new garting selected.
SG1-XPS ...............OLD:-45087 old/ -48800
SG2-XPS -46100 OLD: -48000 old/ -51300
SG3-XPS -44100 OLD:-46939 old/ -50400
SG4-XPS .............OLD: -47250 old/ ...............

 
7 MainPanel.VI OPEN FRONT END


NOT FOR USERS:

NOT FOR USERS Monohome GALIL.vi
(NOT FOR USERS)

STEP1: Select pre-mirror angle, run the VI (press =>) and then press GO (wait that the red light becomes green).    This may take several minutes (typically 2 minutes). If, after 10 minutes the Mirror is still moving, stop the MONO HOME VI and try to do the Mono homing of the mirror again. {ONLY FOR BACH BL STAFF: The last time that the mirror angle was stuck during a mono home SG3->SG2: start: MA=87.43, STEP=311801. The position were was stuck: energy=542.8, MA=86.988, Step=274246}      Sg2->Sg1 (After M energy reads -82 eV)

You have to move the mirror (first) and the grating (second) in order to reach the limit switch. Don't move the grating first, otherwise you may crash the monochromator optics. 

NOTE: Sg3->Sg2 (After M energy reads +218.72 eV; Mirror Angle=85.823; Mirror Position=174717)
Sg2->Sg3 (After M energy reads +422.24 eV; Mirror Angle=85.8; Mirror Position=174739)

STEP2: Select grating angle, run the VI (press =>) and then press GO (wait that the red light becomes green). This may take several minutes (typically 1 minute for G). If, after 10 minutes the Grating is still moving, stop the MONO HOME VI and try to do the Mono homing of the Grating again. At the end of this operation, read the energy (ENERGY CONTROL GALIL VI): both grating and pre-mirror will be at about 84 and the energy reads -348 eV (with SG3) or -326 (with SG2).      NOTE: Sg3->Sg2 (After G energy reads -326 eV; Grating Angle=84.045; Grating Position=58727); Sg2->Sg3 (After G energy reads -348 eV; Grating Angle=84.097; Grating Position=58730)

Last Updated on Monday, 02 October 2017 12:26