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HowTo&Troubleshooting

TROUBLESHOOTING

.:. Hardware Troubleshooting

.:. Software  Troubleshooting

BEAMLINE PROCEDURES

:. How to select a different grating of the monochromator
.:. How to switch the Undulator
.:. How to open the Beamline (BL open/close.VI)
.:. How to close the Beamline (BL open/close.VI)
.:. How to set the required energy resolution (XPS resolution.VI)
.:. How to switch the Branchline from A to B
.:. Restart the Beamline Control System: see Manual and this document

ENDSTATION PROCEDURES

.:. Sample Transfer (only if authorized)
.:. How to perform Sputtering
.:. How to perform LEED
.:. How to perform TEY XAS
.:. How to perform PEY XAS
.:. How to perform XPS
.:. Evaporation: see Manual
.:. ComIXS BAFFLES: Manual
.:. Positions (see Manual section)
.:. Data Analysis: see Manual
.:. How to make the tuning adjustment of the STP300/400 SEIKO SEIKI PUMP to controller
 

 




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 MonoGratingNumber.vi 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.
The pressure meter is localized at the feet of the monochromator, on the left (SISSI beamline side), towards the front end.
Localize the linear motion.

Follow these steps:

STEP0: check that  the pressure meter reads 4.5.

STEP1: LIFT the piston by rotating slowly the small wheel from down to lift position, until the end (there is a small offset: you have to go a little bit more than the lift position until the wheel will stop), 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 and that the pressure meter reads 0.

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 a little bit before the down position (on the line marked manually) checking the pressure on the manometer (from 0 to 4.5 bar). DO NOT GO BEYOND THIS POSITION!!!! GOING ABOVE 4.5 bar can damage seriously the monochromator and the beamline vacuum. At the end of this operation visually check that the piston is down again.
4 MonoGratingNumber.vi Select the grating clicking on the grey rectangle with the name of the grating (in the picture SG2) and choosing the grating from the drop-down menu which will appear [e.g. SG3 (5)]and Press =>
     
6 Monohome GALIL.vi

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)

7 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 several minutes!!!)
8 SetEneryandUndulator.vi Select the new grating in the Calculator field
9 MotorControl.VI

CHACK POSITION ON THE CERAMIC at y=(26.1 or) 27 (the beam on the sample  is usually left bottom edge of the marker on the ceramic)

Press ==>.

Select: Element: POSTHORA and Action: Pitch

Read. You should read a value between -45000 and -48000.

Move to the value corresponding to the new garting selected.
GRATING NEW
 
OLD VALUES
SG1-XPS -44900 (check) -48800
SG2-XPS -48300/V=-7500 -51300
SG3-XPS -46000/V=-7800 -50400
SG4-XPS   -46150? Value to be checked

 
10 MainPanel.VI OPEN FRONT END

Switch the Undulator

The two undulators cannot be used simultaneously!!! When one of them is in use (gap below 100 mm) the other must be at the maximum gap (100 mm) and zero phase and zero tapering. If both gaps are below 100 mm a beam dump will occur and all beamlines will loose the beam!
. Check here (The Beamline) the Energy Ranges of the two Undulators

 

 
8.1 HE
OPERATIONAL
ID081 gap < 100 ID082 gap= 100 ENT slit-Y=-4.2

(encoder=+9.7)
PREVER-Pitch=about 150 (this value may be different!!)
8.2 LE OPERATIONAL ID082 gap < 100 ID081 gap= 100 ENT slit-Y=+117.5

(encoder=+131.4)
PREVER-Pitch=about -50 (this value may be different, but -200 is the typical shift from HE to LE)

 

DETAILED PROCCEDURE. FROM HE TO LE (Ask the assistance of a beamline scientist the first time you need to do this procedure!!!):

1 FEopenclose.VI. Close FE
2 082BACH Connect to Firefox and select the link ( 082BACH ) in the Bookmark Toolbar. As a fist action, open the gap of the undulator you are using (8.1) to 100 mm. Refresh the internet browser from time to time to follow the opening.

NOTE: Only when both Undulators are at 100 mm, you can close the gap of the undulator that you want to use (8.2) to 50 mm. Check in Firefox Bookmark Toolbar link 082BACH that the undulator has been switched. NOTE: after the injection the Control room closes the gap of the last used undulator. Therefore if you change the undulator during the injection, you will need to open again to 100 mm the undulator you were using!!!! A general rule is ALWAYS CHECK what is the gap of the 2 undulators before trying to move the gap with a Labview VI (e.g. SetEnergy&Undulator.VI).

3 Main Panel
or
Motor control.VI
Select: Element: Entrance slit and Action: Y
Read. You should read User Units=-4.2 and Encoder=+9.7 for the HE undulator 8.1. Set the value: +117.5 (if you want to switch to the LE undulator 8.2) in the Go to position (User units) box and press Move.

Read. If there is some message Overwrite or restore, check if the two values are close (e.g. saved value 114 read value 116 and press Overwrite in this case, which is the most likely case.) If the two values are very different then press restore.
Read again. If the vaue is not 117.5 move again Entr Slit Y to 117.5. Tou should read User Units=+117.5, Encoder=+131.4 for the LE undulator 8.2

4 MainPanel.vi Set PreVERT PITCH.  Set a value which is 200 lower than the pitch you have read and you were using for first harmonics with HE und.
5 SetEnergyandUndulator.VI Change in the menu HEund to LEund and eventually also the mono grating if you previously changed also mono grating. Set the energy you need with Set energy and Undulator using 1st harmonic. Press => and then press Calculate, before pressing move. If everything works you should read a value between 19.01 and 50.

IMPORTANT! Before pressing MOVE ALWAYS CHECK what is the gap of the 2 undulators at this link BACH082): Both undulators should be at 100, especially the undulator you are NOT using MUST BE at 100, because SetEnergyandUndulator.VI will close the new undulator you are using). If by mistake the gaps of both undulators are closed below 100 mm a beam dump will occur!!!

IMPORTANT! Before pressing MOVE ALWAYS check that In Mono grating number.VI the right MONO grating is selected, especially if the compuer was restared (in thius case you will find EMPTY) or you have changed the grating.

6 MainPanel.vi Open FE. Change the scale of the keithley Io-7
7 ScanEnergyGALIL TEST.VI Select YES and Scan energy around the value you set.
8 MainPanel.vi Check that teh energy is on top of the harmonic or set it there
9 MainPanel.vi Optimize PREVert
Set PreVERT at the maximum value


Monochromator zero Order

ONLY FOR BACH staff!!!
NOTE: Remember to close the valve of the COMIX spectrometer and to switch off the voltages of the analyser.
After setting the 0 order do a monohome positioning. This should be done ONLY by BACH BL STAFF. For monohome You have to move the mirror (first) and the grating (second) in order to reach the limit switch. 

Mirror move absolute and Grating move absolute should be moved using BCS starting frkom the Mono webpage GALIL (link on the BACH pc Firefox tabs), then select browsing. While moving monitor the position by opening a new window where you select MIRROR position and GRATING position.



SG1 0 order:  PM=270312; SG 295700
SG2 0 order:  PM=269900; SG 295900
SG3 0 order:  PM=411451; SG 436200
SG4 0 order:  PM=410750; SG 431200 (August 2014)

OLD SG4: PM=411544; SG 437150(o 431200)









How to open the beamline

Before you can use the photons, the beamline needs some time to thermalise. It is good practice to open the beamline half an hour before starting the experiments.
1) OPEN ALL THE BL VALVES (EXCEPT FOR THE LAST BL VALVE A, the last three BL valves of the BRANCH B and teh PINHOLE valve C) using the MainPanel.vi
2) OPEN THE FRONT END using the MainPanel.vi

FRONT ENDNote: the FE can be opened only if the Beamline Control System (BCS) finds a safe light path which means that the Beamline (BL) valves have to be opened at least up to the monochromator before opening the FE.

To open the FE, the general user is advised to use always the Main Panel.VI or FEopenclose.VI, the procedure is the same.
PROCEDURE A: If you are using the Main Panel, always close the pop up window when the FE has been opened (RED), otherwise you will not be able to use the other functions of the Main Panel.

PROCEDURE B:
1) FEopenclose.VI.
# FEopenclose.VI. To Open FE: Select Open, Press inside the circle until a point appears, Press=>)
# FEopenclose.VI. To Close FE: Select Close, Press inside the circle until a point appears, Press=>)

IMPORTANT NOTES: The FE connects the straight section of the storage ring (hosting the two undulators of BACH) with the beamline. Three are the elements of interest for the user (ordered from the source to the beamline):
the FE shutter, the FE stopper and the FE last valve.
In order to carry the light to the sample in experimental chamber, all these three elements need to be opened in a well-established order:
1. The FE (last) valve
2. The FE stopper
3. The FE shutter.
In order to close the FE these elements have to be closed in the opposite direction (1. The FE shutter, 2. The FE stopper, 3. The FE (last) valve.
Using MainPanel.VI it is possible to see if these valves are open (red) or close (green).

The Machine shutter and the Machine valve are located just befor the FE. Using BL BACH Monitor.VI it is possible to see if these valves are open (red) or close (green). Alternatively check at BACH BCS ). These two elements are not controllable by the user. If you find them closed (GREEN) you have to call the control room (8262 or 8263) to open them.

BEAMLINE

The beamline is made of subsequent sections made of different optical elements separated by pneumatic valves. You can see all the valves and optical elements (INTERNAL LINK: here ).
NOTE: For XAS and XPS general users are always using Branchline A. Branchlines B is used for TIME RESOLVED EXPERIMENTS. In order to open the valves of the BL you must use Main Panel.VI or BL Valve Control.VI (folder: Beamline). The convenction is that the name of the valve refers to the element following the valve itself.
If you are insecure about opening a valve, please check if the pressure before and after that valve is OK using BL Pressure Survey.VI (folder: Beamline). The pressure in the Main Chamber should be checked on the ion gauge controller on the platform.

PROCEDURE A: From the Main Panel.VI or using BL valve Control.VI, the procedure is the same.
All valves of the BL are open (BRANCH A), except for the last valve between the XPS/XAS experimental chamber and the last mirror of the BL. In order to open it, press on the rectangle "Close" and the word "OPEN" will appear. Then press inside the white circle on the right and then press on the arrow pointing right at the top right of the VI. You will hear the noise of the pneumatic valve opening. The last 3 valves of the BRANCHLINE B (future XMCD branchline) have to remain  closed in this case.
If you are using the Main Panel, always close the pop up window when the valve has been opened (Using the arrow pointing up, close to the arrow pointing right)  otherwise you will not be able to use the other functions of the Main Panel.

PROCEDURE A: BL valve Control.VI. Open a valve (Select Control, Press inside the circle besides (on the right) the valve which has to be opened until a point appears, Press=>). All valves of the BL are open (BRANCH A), except for the last valve between the XPS/XAS experimental chamber and the last mirror of the BL. In order to open it, press on the rectangle "Close" and the word "open" will appear. Then press inside the white circle on the right and then press on the arrow at the top right of the VI. You will hear the noise of the pneumatic valve opening. The last 3 valves of the BRANCHLINE B (future XMCD branchline) have to remain  closed in this case.





How to close the beamline

1) CLOSE THE LAST BEAMLINE VALVE (using the Mian Panel.vi)
2) SWITCH OFF THE MCP (using XPS ON OFF USERS.VI). Check the XPS is off on the XPS power supply on the rack (red lights OFF).
3) CLOSE THE FRONT END (using the Mian Panel.vi)
4) CLOSE THE OUTPUT first and then the INPUT water inlet of the EVAPORATOR water cooling system (only in case you are using evaporators)

When you finish expeiments and go home, you have to close the beamline, as it is forbidden to leave the beamline open unattended. In particular the water cooling of the evaporators cannot be left unattended!

How to select the required energy resolution

The BACH monochromator has both the entrance and the exit slit. These two elements are important in the determination of the energy resolution of the photon beam delivered by the monochromator. In order to check the resolution the user can utilize the ENERGY Resolution.VI or XPS Resolution.VI. In this VI it is necessary to set the grating in use, the energy of interest and the opening of the two slits (and the pass energy for XPS). The VI returns the theoretical (very close to the actual) resolution and the resolving power. These VIs are just calculators and can be used any time!

Then, using the MAIN PANEL.vi set the chosen opening of the ENTRANCE SLIT and EXIT SLIT. When you change the enrance slit opening the beamline will take ~30 minutes to stabilize, so you can observe some energy shifts..It would be better not changing the ENTRANCE SLIT very often unless necessary.

The Pass energy will be set by Scan XPS 2008.VI before XPS scans.
The STEP for XPS scans is usually set 1/3 or even a lille bit less than 1/3 of the total resolution. Only a finite number of steps can be choosen because they depend on the pass energy and the number of channels (16) of the MCP. The acquisition program will set the possible step closer to the value chosen by the user.



How to perform Sputtering

1) DANGER: Close the last BL valve and be make sure that it is closed (read BL BACH Monitor or BL valve control: the last valve should be green).

2)Switch off XPS using XPS on/off. Make sure the XPS is off by looking at the red leds (which should be off) on the CAEN Power Supply modules.

3)Set the sample in the sputtering position

4)Switch on the power supply. Switch on the filament and slowly increase the current to the operating value written on the power supply (2.85 A).

5)Switch on the high voltage and set the electron energy to 120 eV and emission current to 10 mA (in case it does not reach 10, very slowly increase the filament current, monitoring at the same time the current and the emission: be careful that the filament current should in any case remain below 3 Amp!!!!). Do not touch the focus and be sure that the energy (last button) is at 0 keV.

6)DANGER: Insert the Argon (p=1.2x10-6 mbar) (BL valve closed! XPS off!!!!)

7)Finally set the required energy (0.5-3 keV) for the sputtering.

TRUOBLESHOOTING: If it is not possible to raise the energy above 0.6 keV in the Sputtering Power Controller, check if the Extractor pin (n.2) is grounded (towards external shield of the ion gun). It should not be grounded! If a finite resistance is present, let some current flow trough this pin and ground until it is again isolated. ASK BEAMLINE SCIENTST FOR ASSISTANCE!
 

 

 


How to perform XAS measurements

During the alignment of the beamline, in the energy selection and, of course, in the measurements it is always better to have the best possible statistics. One important setting concerns the gain of the electrometers or amplifiers (the Keithleys) used to collect both I0 (address 25) and IS (address 24). In fact, these instruments convert small currents (down to fA) to voltages that are then read by the acquisition board close to the main beamline computer.

TEY

IN BRIEF:

  • Remote PreAmp IS connected (if the sample is not grounded!)
  • TEY COUNTER SETTINGS: I0=ON;IS=ON;IREL=ON

    PRACTICAL PROCEDURE:
    0. MainPanel.VI to set the required Energy Resolution by selecting the appropriate opening of the Entarnce and Exit slit.
    Press =>. Select the Element (Entrance Slit), the Action (Opening). Set the value (absolute) between 10 and 50 and press MOVE. Select the Element (Exit Slit), the Action (Opening). Set the value (absolute) between 10 and 50 and press MOVE.

    1. Remote PreAmp. Check that there is overload between the BNC pin and the ground. If there is overload and no finite resistance, connect the Remote PreAmp to the BNC.
    CAUTION!!! Before connecting the Keithley Remote PreAmp (see picture: more details) to the BNC on top of themanipulator to collect Is signal, check that there is overload between the BNC pin and the ground. If there is a finite resistance you can seriously damage the keithley!!! For the same reason ALWAYS disconnect the Remote PreAmp from the BNC, after having pressed OFF (on the main panel under the blue ligth, the blue ligth will get off) when you need to transfer the sample because the transfer arm grounds the sample. In anycase contact BL staff for more information.

    2. Set Energy and Undulator.VI. Select an energy about 10 eV higher then the position of the edges you want to measure. Use First harmonic when possible (for linear horizontal polarization at 2.0 GeV up to about 730 eV, at 2.4 GeV up to about 800 ?eV) or second harmonic. In order to see if you can use the fist harmonic, use Set Energy and Undulator and try to Calculate the Ideal gap before pressing Set ID and E. If you find Ideal gap as a value between 19.1 and 49.9 then the 1st harmonic can be used. Otherwise choose the 2nd harmonic. The third harmonic has more intensity, but it is usually too steep to perform XAS.

    3. Main Panel. VI (or Keithley Initialise 6430.VI) Initialise both 24 and 25 to the best scale .Select the the lowest rangepossible without causing an overflow to ensure best accuracy and resolution. The signal saturates at 1.05.
    For example, initialise both I0 (and IS) first to 1x10-6. Then read the counters using Counter read all.VI. Finally set the optimal scale (for instance if you read Io=4x10-9 on top of the harmonic, you should initialise the address=25 to 1x10-8.possible without causing an overflow to ensure best accuracy and resolution (more details).

    4. Scan Energy GALIL.VI. a) Counter Setting: Check that both I0 (and eventually IS and IREL for TEY if the sample is insulated) are selected (ON).
    Note: all the scanning VI (Scan energy, scan motor, scan XPS, scan resonant XPS,..) have to be STOPPED before using Counter setting.
    (b) The ENERGY STEP depends on the energy and grating. One good starting value can be 0.15 eV. However, if the monochromator is not able to perform regular steps, this means that the chosen step is too small. Typical CYCLES per point is from 5 to 35. DO NOT USE NUMBER OF CYCLES HIGHER THAN 35.
    The scan will be saved point by point: even if the VI is stopped before the end of the scan, the scan will be saved.

     

    PEY

    IN BRIEF:

  • Remote PreAmp IS OFF. 2) Remote PreAmp IS disconnected. 3) Ground cable connected.
  • PEY: COUNTER SETTINGS: I0=ON;XPS=ON (time=1000 or more);IS=OFF;IREL=OFF.
    Note: all the scanning VI (Scan energy, scan motor, scan XPS, scan resonant XPS,..)have to be STOPPED before using Counter setting.VI

    PRACTICAL PROCEDURE:
    0. MainPanel. VI to set the required Energy Resolution.
    Press =>. Select the Element (Entrance Slit), the Action (Opening). Set the value (absolute) between 10 and 50 and press MOVE. Select the Element (Exit Slit), the Action (Opening). Set the value (absolute) between 10 and 50 and press MOVE.

    1. Set Energy and Undulator.VI . Select an energy about 10 eV higher then the position of the edges you want to measure. Use First harmonic when possible (at 2.0 GeV up to about 730 eV, at 2.4 GeV up to about 800 ?eV) or second harmonic.

    2. Keithley Initialise 6430.VI. Initialise both 24 and 25 to the best scale .Select the the lowest rangepossible without causing an overflow to ensure best accuracy and resolution. The signal saturates at 1.05.
    For example, initialise both I0 first to 1x10-6. Then read the counters using Counter read all.VI. Finally set the optimal scale (for instance if you read Io=4x10-9 on top of the harmonic, you should initialise the address=25 to 1x10-8.possible without causing an overflow to ensure best accuracy and resolution (more details).

    3. XPS onoff.VI: Turn ON XPS. (Select ON, Press inside the circle until a point appears, Press=>). Then Press OK in the Popup window and wait until the green buttom gets red).

    4. XPS Survey.VI. Select the secondary electrons: Max KE=30;PE=90;Time=1000; Run the VI and when the KE has been set, press STOP.

    5. Scan Energy GALIL.VI. (a) 1. Counter Setting.VI. Check that both I0 and XPS are selected (ON).
    Note: all the scanning VI (Scan energy, scan motor, scan XPS, scan resonant XPS,..) have to be STOPPED before using Counter setting.VI.
    (b) Energy step depends on the energy and grating. One good starting value can be 0.15 eV. However, if the monochromator is not able to perform regular steps, this means that the chosen step is too small. Typical Cycles per point is 5. The scan will be saved point by point: even if the VI is stopped before the end of the scan, the scan will be saved..


 

How to perform XPS measurements

IN BRIEF: Remote PreAmp of IS OFF and disconnected.
Ground the sample: Ground cable connected.
COUNTER SETTINGS: I0=ON;IS=OFF;IREL=OFF;XPS=OFF



DETAILED PROCEDURE:

0. Set the Entrance slit and Exit slit opening with the MAIN PANEL.VI (or for expert users from Motor Control.VI) to set the required Energy Resolution.
Press =>. Select the Element (Entrance Slit), the Action (Opening). Set the value (absolute) between 10 and 50 and press MOVE. Select the Element (Exit Slit), the Action (Opening). Set the value (absolute) between 10 and 50 and press MOVE.

1. XPS onoff.VI has to be ON. (Select ON, Press inside the circle until a point appears, Press=>). Then Press OK in the Popup window and wait until the green buttom gets red).

2. Switch OFF the Remote PreAmp of IS (if it was connected)

3. Disconnect the Remote PreAmp of IS from the BNC of the manipulator.

4. Connect the Ground cable to the BNC of the manipulator in order to ground the sample.

Note that for XPS the Keithley is not a good ground. Therefore also in this case disconnect the Remote PreAmp from the BNC, after having pressed OFF (on the main panel under the blue light, the blue light will get off) and connect a ground cable to the BNC.

5. Counter Setting.VI. Check that only I0 is selected (ON) in the Counter Setting.VI (while XPS, IS and IREL must be OFF).

Note: all the scanning VI (Scan energy, scan motor, scan XPS, scan resonant XPS,..) have to be STOPPED before using Counter setting.VI

6. Align the beam on the sample using the TV screen, by moving X and Z with Y=25 and theta=180&deg. Some reference XYZtheta positions (center of the VG sample holder) of the manipulator are:

x=23.2; y=26.7; z=9.45; theta=180° -NORMAL INCIDENCE (SG3 grating)

x=25.9; y=29.72; z=9.45; theta=240° -NORMAL EMISSION (SG3 grating)

7.Set Energy and Undulator.VI. Use First harmonic when possible (at 2.0 GeV up to about 720 eV, at 2.4 GeV up to about 800-900 eV) or third harmonic for higher energies.

8.Scan XPS 2008.VI. Make a wide scan. Pass Energy can be selected from 5 to 90 eV. Typical time is 1000 (1 sec per point). The delta will be automatically chosen by the program (the value closest to the step set by the user compatible with the selected pass energy). Minimum Kinetic energy is 30 eV (default operation mode). On special request the operational mode of the analyser can be changed (by changing the CAEN connections-hardware) to measure kinetic energies between 0 eV and 100 eV (Low Energy Mode).

9.XPS Survey.VI. Optimize the Y and or change the angle. Set maximum kinetic energy, pass energy and time=500 to select a core level that you want to follow, the VI will show you in real time a window with the core level (the energy window will be proportional to the pass energy). For flat samples Y is around 25. You can then rotate to normal emission (theta=240°) while following the chosen core level count rate. You will need to adjust X and Y if the sample is not mounted at the horizontal center of the sample holder).




How to perform LEED

1) DANGER: Move the sample in the LEED position in the following order: Move first the angle, then x, then move the LEED forward towards the sample, then move the y, always monitoring the sample holder distance from the CF63 lateral window in front of the gate valve. The final distance of the top screw on the sample hoder should be few mm from the LEED. DANGER: Be careful while moving the y or the LEED or the rotation: you can damage seriously the LEED if the sample holder touches the instrument. Be also very careful after you finish the LEED measurement: before performing any rotation move the y to 20 and retract the LEED. Always use the CAMERA n.3 to monitor the position of the sample holder!

2) Switch on the LEED. Set Operate. Press ON on the filament. Wait until it reaches the operating current.

3) Press ON on the SCREEN Hi Voltage. Wait until it reaches the operating current.

4) If you want to use the remote control for the energy press save/remote.

5) When you finish switch OFF the screen, then switch OFF the filament, then press down the switch off button on the "Setting" panel for 2-3 second until on the screen the message "you can switch off the LEED" appears. Switch off the power switch.

6)DANGER: Move the y to lower values, move the LEED backwards,then move the angle, always monitoring the sample holder distance from the CF63 lateral window in front of the gate valve.


 


Working distance from sample 18 mm

Beam energy: 5 eV to 750 eV

Beam current: 2 μA at 100 eV and 0.5 mm beam size

Beam size from 1 mm to 250 μm - adjusted by Wehnelt potential, limited by exchangeable aperture down to 50 μm

Electron source Tungsten-2% Thoriated filament standard, single crystal

Bakeability Under vacuum, 250 degree C maximum

LEED Degassing Procedure

Before using the LEED, ask the beamline scientist if the instrument was degassed after the last bake out.

Check that the 3 connectors are plugged on the instrument.

To degass the LEED. The pressure in the main chamber has to be in the 10-10 mbar. Ask the beamline scientist for assistance. If you already know the instrument: Set the controller on Programming (Prog.) instead of Operating. Set the filament to 1 A and press on. Wait until it reaches 1 A, then increase the filament by 0.2 A every 5 minutes, until you reach the operating current (2.6A), while the pressure remains below 5x10-9 mbar. Wait for 1-2 hours, until the filamenet is completely degassed.


 

 


Sample holder transfer

ONLY for users who are already familiar with the transfer procedure. Users are not allowed to do this procedure for the first time without the assistance of a beamline scientist.

INSERT THE SAMPLE IN THE LOAD LOCK
1)Check that the Gate valve between load lock and prep is fully closed
2)Switch OFF the Pfeiffer Gauge of the load lock (controller is under the platform, below the prep chamber)
3)Stop the Turbo of the load lock
3)Close the big Valve between scroll and turbo
4)Wait until the frequency of the Turbo gets below 300-400 (10 min) and then open VERY slowly the venting valve (eventually connected to N2 flux). Monitor the frequency of the turbo and check that it is going SLOWLY down to 0
5)When the Turbo frequency is 0 open the loaad lock fast entry door and CLOSE the N2 flux!
6)Insert the sample holder fully inside on the pins of the load lock transfer arm, using the transfer tool (usually located on one of the tables of the computer room)
7)Close the venting valve. Unlock the spring of the transfer tool by rotating it by 90 degree clockwise and close the door (only after you have closed CLOSE the N2 flux!)
8)Open the valve between the scroll and the main and wait 1 minute until you do not hear any noise from the scroll. If you still hear noise check that the air venting valve is closed!
9)Switch the turbo ON and when the turbo reaches 1500, switch on the Pfeiffer gauge

TRANSFER THE SAMPLE FROM LOAD LOCK to PREP
1) Wait until the pressure in the load lock is <5x10-7 mbar
2) Open the gate valve between load lock and prep and fully retract the transfer arm of the prep chamber.
3)Rotate the sample holder vertically by rotating it anticlockwise (looking from the transfer arm) by 90 degree (BE CAREFUL! the pins of the load lock transfer arm, which initially are horizontal pointing towards you, at the end of the rotation will be vertical and pointing up, otherwise the sample holder will fall down!)
4)Transfer the sample in the prep and rotate the sample back clockwise by -90 degree. Move the transfer arm of the load lock to the end (transfer position).
5)Move the transfer arm of the load lock to the end which is the transfer position (be careful that the transfer arm of the prep is fully retracted). Then move the transfer arm of the prep forwards until the pin of the prep transfer arm enters inside the hole of the sample holder. Once you hook the sample holder on the transfer arm of the prep and retract completely the transfer arm of the load lock
6) Close the gate valve between the prep and the load lock

 

TRANSFER THE SAMPLE FROM PREP to MAIN
0)Important: First switch OFF the IS Keithley (top one) and disconnect the Keithley Remote PreAmp from the Manipulator BNC.
1)Set the Main manip at the Transfer positions (very precisely!):
x=33; y=10; z=25.0 (1.9); theta=178.5°
2)Set TV camera channel 2 (TRANSFER)
3) Fully open the gate valve between main and prep
4)Move the sample holder to the main with the sample holder vertical with the sample facing the beam (same position of the transfer from loadlock to prep). If necessary adjust the length of the driving bars
5)When you reach the main chamber, make sure that the sample holder is perfectly vertical by looking from the CF38 window in the main. If you are completely sure that is is vertical, slowly enter with the sample holder inside the manipulator pins to the end.
6)Unlock the spring by rotating the transfer arm clockwise by 90 degree. When the spring from vertical will get horizontal below the sample holder
7) Retract the transfer arm very slowly making sure that the sample holder does not come out again and then completely retract the transfer arm to the prep chamber you can extract the transfer arm.
8)Close the gate valve between main and prep (only to the end without squeezing)

TRANSFER THE SAMPLE FROM MAIN to PREP
0)Important: First switch OFF the IS Keithley (top one) and disconnect the Keithley Remote PreAmp from the Manipulator BNC.
1)Set the Main manip at the Transfer positions (very precisely!)
x=33; y=10; z=25.0 (1.9); theta=178.5°
2)Set TV camera channel 2 (TRANSFER)
3) Fully open (to the end) the gate valve between main and prep
4)Move the transfer arm to the main with the golden spring towards the LEED. If necessary adjust the length of the driving bars.
5)When you reach the main chamber, make sure that the transfer arm is perfectly vertical by looking from the CF38 window in the main. If you are completely sure that is is vertical, slowly enter with the transfer arm pin inside the sample holder hole to the end until you feel that the spring has hooked the sample.
6) Retract the transfer arm very slowly by keeping it perfectly vertical (do not rotate the transfer arm, otherwise the spring will get unlocked and the sample holder will fall down!) making sure that the sample holder comes out and then completely retract the transfer arm to the prep chamber
7)When you can see the sample holder inside the prep chamber close the gate valve between main and prep (only to the end without squeezing)

TRANSFER THE SAMPLE FROM PREP to LOAD LOCK
1) Check that the pressure in the load lock is <5x10-7 mbar
2) Open the gate valve between load lock and prep and fully retract the transfer arm of the prep chamber.
3)Rotate the sample holder vertically with the sample facing the diamond scraper.
4)Move the transfer arm of the load lock to the end, which is the transfer position (be careful that the transfer arm of the prep is fully retracted). Then move the transfer arm of the prep forwards until the 2 pins of the loadlock transfer arm enter COMPLETELY inside the holes of the sample holder.
5)Unlock the spring by rotating the PREP transfer arm by 90 degree. When the spring from vertical will get horizontal (above the sample holder) you can extract the PREP transfer arm
6) Rotate the transfer arm of the load lock by 90 degree (sample holder will be vertical) and retract completely the transfer arm of the load lock. Close the gate valve between the prep and the load lock


How to switch the branchline (e.g. from A to B)

Only for beamline staff. This procedure is not inteded for users.
IMPORTANT! Before starting to move check that the value in 082 BCS: CENTRAL PEM1 HEIDENHEIM_20 ASSEZ is different from 0 and the STATUS iS 0 (AND NOT 8).
IF STATUS is 8 and encoder is 0 you need to call Michele Turcinovich and ask to reboot the ENCODER (it is not necessary to restart the bcs).
 

1. POSTHORA. Z. Read. It should be UserUnits=-23 (UPDATED GEN2011. NOTE: THE OLD VALUE WAS -26), Encoder +23 (Branchline A)

2. POSTHORB. Z. Read. It should be UserUnits=-63 (OLD VALUE WAS -66), Encoder +23 (Branchline A). If OVERWRITE or RESTORE message appears, it is likely you have to select OVERWRITE.

3. POSTHORB. Z. Move UserUnits to -15 (OLD VALUE WAS -18), Encoder XX (OLD VALUE was -22) (Branchline B).

4. POSTHORA. Z. Read. A message OVERWRITE/RESTORE will appear. Press Overwrite. Now you should read: UserUnits=+22 (THIS IS THE OLD VALUE, TO BE UPDATED), Encoder -22 (OLD VALUE, TO BE UPDATED!)(Branchline A). If OVERWRITE or RESTORE message appears, it is likely you have to select OVERWRITE.

FROM A TO C:
1. POSTHORA. Z. Read. It should be UserUnits=-23 (UPDATED GEN2011. NOTE: THE OLD VALUE WAS -26), Encoder +23 (Branchline A)
2. POSTHORA. Z. Move User Units to 0 (zero). Enc=0.

FROM C TO A
1. POSTHORA. Z. Read. It should be UserUnits=0 Encoder 0 (Branchline C)
2. POSTHORA. Z. Move User Units to -23 (zero). Enc=+23.

Before starting to move check that the value in 082 BCS: CENTRAL PEM1 HEIDENHEIM_20 ASSEZ is different from 0 and the STATUS iS 0 (AND NOT 8).
IF STATUS is 8 and encoder is 0 you need to call Michele Turcinovich and ask to reboot the ENCODER (not the bcs).
 

 


Hardware Troubleshooting

The Shutter is closed and it cannot be opened

You can check the Status of the FE valves here (BL BACH Monitor.VI):
or here: BACH BCS. Note that the valves are green when closed, red when open.

a) Try opening FE by the MainPanel.VI or the FE openclose.VI (how)..

b) Check if there is beam at the following link Machine Status: http://www.elettra.trieste.it/accelerator/machine_status.php

c) Check if the water fluxes of SM1, SM2, Entrance Slit at the very end of the beamline, after the monochromator, on the left are ok. If they are too low, adjust the levels (ask asap to your local contact to show you the position of these water gauges and flux regulator!).

In case the water flux is low, the corresponding element in the BACH BCS will be RED (Sph.Mirr.1,Sph.Mirr.2, Entr. Slit). If in normal operation they are GREEN.
See also: http://www.tasc.infm.it/research/bach/external.php#Troubleshooting

d) Check that all BL valves are open (in particular the first valve close to the front end)

e) Check the pressure of Sph.Mirr.1. The gauge is not working well and from time to time it needs to be restarted. Call the beamline scientists.

f) Check that the Gamma Monitor and that FE Hutch has been searched: BACS Supervisor Panel (Front-end hutch status,Stopper FE status,Gamma monitor,Ring shutter opening)

The FE is open, but there is no signal


      a) Check if there is beam at the following link Machine Status.

      b)Check that all BL valves are open (from the MainPanel.vi, press BL valves and then press the arrow to read the status)

      c)Check that the Machine shutter and the Machine valve are open (RED) (link: BACH BCS). These two elements are not controllable by the user. If you find them close you have to call the control room (8262 or 8263) to open them.

      d)Check that the Keithley (e.g. 25, reading Io) have been switched on using the VI Keithely Initialize 6430 inside the folder Counters. The first time initialise it at 10-6 (check first that entrance and exit slits are less than 50 micron). Then read Io using Counter read All.VI and select the more appropriate scale.


Io or Is are very noisy.


      Try to fix the preamplifier to the BNC(MHV) of the amnipulator using some aluminum foil in order to ensure a good electrical contact between the BNC of the manipulator and the preamp. Sometimes the weigh of the preamplifier losens the contact inside the MHV and small mechanical vibrations create electric noise. If this is not eough contact the BL scientist.

      Try to change the scale of the keithley. E.g. If you measure 3x10-9, set the scale to 10-8.

It is not possible to raise the energy above 0.6 keV in the Sputtering Power Controller.

      Solution: Check if the Extractor pin (n.2) is grounded (towards external shield of the ion gun). It should not be grounded! If a finite resistance is present, let some current flow trough this pin and ground until it is again isolated.

RECOVER FROM A POWER CUT

If there is a programmed powercut:

1) LIFT the MONO GRATING UP.
2) Switch OFF all the MULTIVACS of the ion pumps and gauges
3) Switch off all the motor controls
4) switch off all the PCs, including the MONO PC (ON1 and ON2, ask Roberto Borghes)
5) FE rack switch off by the the software instrument group (Billè, Turcinovich, Chenda, Borghes)

After the power recovery:
1) Check that all ION PUMPS are up and running. You might have to open the beamline racks.
2) Only if you are sure that the pressure id 10-8 or less, switch on the gauges.
3) MAIN CHAMBER: main turbo and turbo cart, Manip turbo cart and scroll; PREP: turbo+scroll
4) Check all valves along the beamline. Open them when p<10-9 mbar everywhere
5) In the FE racks: everything should be switched ON by the software instrument group (Billè, Turcinovich, Chenda, Borghes)

Run: MOTOR READ ALL.VI
Run: MOTOR RESTORE SPEED.VI

In the acquisition PC you will need to select again the MONO GRATING NUMBER and maybe to run again the MONO HOME procedure.

Some ref. values (June 24 2011):
PREHOR pitch=5606.9;Rll=0,x=-998.486(==enc);z=2.023
PREVER pitch=377.9 (enc=-9.365);Roll=-4.2,x=0.5;z=-0.235
ENT SLIT open=30 (enc 786.5); Y=-4.2
EX SLIT open=30 (enc=1048)
POSTHORA pitch=-46941.9;Rll=0,;z=-23.12
POSTHORB pitch=-67799.5;Rll=0,;z=-63

POSTVERA pitch=-8000.9;Roll=0.4
POSTVERA pitch=-6996.9;Roll=0.403
RIXS=-21.999

Heideneim controller switched off (power failure).

      Solution: Press ENT. Then move up and down the pin.

Seiko seiki STP300/400 controller (e.g. prep chamber) needs to be tuned (power failure).


.:. How to make the tuning adjustment of the STP300/400 SEIKO SEIKI PUMP to controller
The procedure (PDF file) can be found HERE.


 

Software Troubleshooting

The Monochromator does not move and does not read correctly.

In this case always contact first the bamline staff. Only in case you are authorized by the beamline staff, you can perform the following operations:

For some reason, during the experiments, did you open the 082-MONO browser window located on the Firefox bookmark toolbar? CLOSE IT!!!It is important that this window is not open during energy control and energy scans. Keeping this window open can cause serious interferences during the operation of the monochromator. In this case, closing the window browser can already solve the problems.

PROCEDURE FOR THE RESTART:
      a) STOP all the running VIs .
      b) CHECK that all the VIs have been stopped by monitoring the MONO Grating Number.VI. If you see that the arrow is white, it is OK. If the arrow appears broken, check again, there is one VI still running.
      c) CLICK on the FIREFOX internet browser bookmark horizontal toolbar to the link to MONO082 (from any computer of the beamline).
The link is http://192.168.203.8:8080/
First click on the MONITORING page. If this page takes a lot of time to be loaded and at the end all the paraeters are zero and you read TIME OUT, then this means that you have to restart the MONO. Go back to the previous page  http://192.168.203.8:8080/
Here you will find a web ink to RESTART the software of the MONO. Click. Confirm that you want restart. Wait until the operation is done (90 seconds).
      d) CLOSE!! the MONO082 browser window. This is very important because keeping this window open can cause  problems during the operation of the monochromator!
      e) Use ENERGY CONTROL.VI to read the energy. If the reading is ok the operation has been successful. You can try to move the energy by some eV to have a cnfirmation that the monochromator software now works again.

Problem with the BCS.

      If it is impossible to communicate with the BCS, the BCS might need to be restarted or rebooted.
If the WEB is not working, do not reboot the BCS since the problem may be different! Always contact the local contact of the beamline first. If you are sure that the problem is really due to the BCS system call one of the person of the Software Group (Turcinovich, Billè, Chenda, Borghes, Pugliese):
      A list of the person of the Elettra Software Group which is available during the weekends (REPERIBILI) can be found at this link: http://elog/NewElogBook/logbook/rep.asp.
For the reboot (ONLY FOR AUTHORIZED PEOPLE): read this PDF document: BCS RESTART. For BACH: stop082, start082, reboot082
AFTER the reboot it is necessary to run the following VIs:
1) MONO GRATING NUMBER. VI: select the grating
2) RESTORE MOTOR SPEED
3) MOTOR READ ALL (press RESTORE in case you get an error)
4) MONO HOME. VI

BCS not working. Beamline valves cannot be closed

If you just need to close the last BL valve of the branch A, there is a manual gate valve (black actuator) just after the main chamber, before the last mirror.
Otherwise contact the beamline staff by phone.
ONLY FOR AUTHORIZED PEOPLE: There is another possibility, setting  all VACOs, both those relative to the frontend and those
relative to the beamline, are switched to the "LOCALE" mode, turning the corresponding key and then closing the valves. The FRONT END VALVES need to be closed and opened in a all these three elements need to be opened in a well-established order. Failing to follow this procedure will cause PERMANET DAMAGE to the FE stopper which will be burned under the direct photon beam.

TO OPEN the FRONT END open the following elements, following EXACTLY this order:
1. The FE (last) valve. 2. The FE stopper. 3. The FE shutter.
TO CLOSE the FRONT END:these elements have to be closed in the opposite direction. Close the following elements, following EXACTLY this order:
1. The FE shutter, 2. The FE stopper, 3. The FE (last) valve.

LabView is in Edit mode (it is not possible to write the number inside the VI)

      Click TAB some times untile the arrow symbol for the cursor appears again

The PC asks for a username and a password

      For the Acquisition PC, the username and password are written on the small paper fixed on the black case of the PC tower
      For the Analysis PC the username and password are written on a tape on top of the monitor

Overwrite or restore? An Error Message pops up

An Error Message pops up on the monitor of the Data Acquisitin PC, asking if you want to overwrite or restore. Even if the default choice is overwrite, 99.9% of the times it is better to press RESTORE, especially when the error message is about the ENTRANCE/EXIT SLIT OPENING positions.
In case of doubts, always press RESTORE!!!

1) The Beamline Control system is in time out and reads encoder=0. So, since encoder=0 means a different user unit value than the last value which was set, this erro message appears. It is the case when the user was NOT moving the SLIT OPENING or anything, but only reading its value or the user was doing an XPS or energy scan. Typically the two values (saved value and read value which appear in the error message) are very different (e.g. 30 and 50 for the entrance slit opening). Always press RESTORE in this case. If, by mistake, you have pressed OVERWRITE, contact asap the beamline scientist in order to restore the old values of the user units, otherwise you will be working with wrond settings.

2)In a very few cases, the typical case is when the users moves the Entrance slit "Y" position (NOT the opening!) to switch the undulator, it is necessary to press OVERWRITE.

This happens when the user is moving a motor (e.g. the Y), the motor does not reach the final position, but one step before. So the position read using the encoder is the one corresponding to the last step of the motor, but not the position that the motor was supposed to reach. In this case the two values (saved value and read value which appear in the error message) are very close (e.g. if you were moving the Y from +117.5 to -4.2, the error message says that the saved value is -4.6 and the read vale is -4.2). In this case, press OVERWRITE. Then READ again. The error message will likely appear again and then press again OVERWRITE.

3)(NOT FOR USERS) ONLY when the beamline scientist is switching the BRANCHLINE : In this case the rigth choice should be pressing OVERWRITE. However read the paragraph on HOW to SWITCH the branchline first.

The Acquisition PC or LABVIEW has to be restarted

      Always contact the local contact of the beamline first.
      You need to log (username and password are written on the PC (either on the monitor or on the tower case).
      Then in the desktop you will find a ling to the Manager.VI For Users or to a Folder named "User BACH Commands". Inside you will find all the VIs that you need to start again inside the SUBFOLODERS. The MAINPANEL.VI is on the desktop.
      MAINPANEL.VI in the desktop (runt it, then (1) select again the right grating, (2) in Counter Settings set again the channels you were using, the default reads only Io)
      MONOCHROMATOR folder: MonoGratingNumber.VI (select the right grating and press the arrow to run the VI) and SetEnergyandUndulator.VI;
      ANALYSER folder: XPSOnOff_Users (the analyser will be in the same status ON or OFF it was before the restart), XPSsurvey;XPS resolution.VI
      SCANNING folder: scanXPS2008.VI, scanEnergyGalil TEST.VI (note: the first time the path that you read is wrong, but as soon as you start a scanning with the right parameters, the VI will automatically save the data in the last used folder, with a progressive number, so there is no need to write manually the path. Eventually you can write manually the path of the data folder if you want to recall the scanning parameters of some previous scans)

      Other useful VIs (in case the MainPanel VI gives problems) can be:
MOTORS folder: MotorControl ;
COUNTERS folder: CounterSettings.VI (set the counters you were using (Io, Is or XPS) to be ON or OFF and run the VI)
FRONTEND folder: FEopenclse;
BEAMLINE folder: BLopenclose;
SCANNING folder: ScanMotor;
MONOCHROMATOR folder: EnergyControlGalil;
COUNTERS: KeithleyInitialise6430, CounterSettings, CounterReadAll...


      !!!VERY VERY IMPORTANT!!!!! After the restart of the PC IT IS NECESSARY to select again the grating of the MONOCHROMATOR. Use the MonoGratingNumber.VI: you will find that the option EMPTY is selected. Insted select the last grating you were using and then press the arrow (play the VI).
    *

      !!!VERY VERY IMPORTANT!!!!!After the restart of the PC IT IS NECESSARY to select again the right parameters in SetEnergyandUndulator (2.0 or 2.4 GeV, Linear Horizontal, First Harmonic, Grating..), because the default values can be different!
      NOTE: In the scanning VI it will be necessary to insert manually the parameters (initial, final, step,..). Once you have measured again the scan, you will be again able to recal the old files and parameters.

IGOR PROCEDURES:

The Igor procedure files to plot BACH data (the yellow panel) are installed on the acquisition PC of the beamline. If Igor or the PC crashes, it is possible to recover the yellow panel by doing the following:
1. Open IgorPro
2. Data-->Load Waves-->Load BACH_BCS (..the yellow panel will pop up)
3. Browse the folder by clicking on Data folder

The Energy or Motor scan are slow and I0 reads 0 every 2 or 3 points

Stop the scan and initialize again the keithley (i.e. set again the range of the keithley from the Main panel).

The regions of the ScanEnergy.VI or ScanResonantXPS.VI or other macros have to be deleted

Click with the right button of the mouse on the tab that you want to delete. Select DataOperation-->Delete element/ delete all elements /delete previous element

 


How to make the tuning adjustment of the STP300/400 SEIKO SEIKI PUMP to controller

Download procedure

 

 

Last Updated on Thursday, 13 September 2018 12:57