Manual_XAS

Pagina 2 di 2


PEY (OLD PROCEDURE FOR VSW-NOT AVAILABLE ANYMORE!)--see Manual Scienta3000 or Manual Channeltron

IN BRIEF (OLD!!!):

  • 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.

    Ultima modifica il Venerdì, 29 Settembre 2023 12:28