How to change GATT Gas Attenuator to Neon

  1. From the SASE3 Photon Beam Transport SA3_MAIN main panel, open the SASE3 Gas Attenuator.

    ../../_images/SA3_MAIN.svg

  2. From the SASE3 Gas Attenuator G_ATT_03 main panel, click on Pause Injection (not Stop injection). The Process Status on top will changed to PAUSED.

    Then open the SASE3 Gas Attenuator System Setup G_ATT_01 panel by clicking on 01 - System Settings/Pset= f(Attenuation).

    ../../_images/G_ATT_03.svg

  3. From the SASE Gas Attenuator System Set-Up G_ATT_01 panel, open the Central Gas Injection Module Control panel G_ATT_CGI panel by clicking on CGI Module Control Panel.

    ../../_images/G_ATT_01.svg

  4. From the Central Gas Injection Module Control panel G_ATT_CGI panel, open the Extended panel by clicking on Extended Panel.

    ../../_images/G_ATT_CGI.svg

  5. In the Extended Panel G_ATT - CGI Extended one can see the Gas Manifold with 5 different incoming gas lines consisting of 2 large gas line, Ar and N2, and 3 minican gas line.

    ../../_images/G_ATT_CGI_Extended.svg

    Labels of the minican gas line are not necessarily correct and one needs to know which minican gas line is the Neon gas line. The pressure indicates if minican is empty.

    1. Switch N2 Mode to Off.
    2. Switch Ne Mode to On if this is the right minican.
    3. Evacuate the gas manifold by switch on the membrane pump and opening the valve at the bottom of the gas manifold.
    4. Pump down the gas manifold for 3 to 5 minutes.
    5. Switch off the membrane pump. It will automatically switch off the valve.
    6. Open the Ne valve.

  6. From the Central Gas Injection Module Control panel G_ATT_CGI panel, select the adequate shutoff valve according to the orifice size.

    ../../_images/G_ATT_CGI.svg
    1. Set Control Mode to be 1.
    2. Select the Analog S.P. (set) to a value between 4.5 to 14 mA. Below 4.0 mA the shutoff valve should remain closed. The maximum opening is obtained for a value of 20 mA.
    3. Regulate the Analog S.P. to get the right Neon absorption in the spectrum. Switch to a different shutoff valve orifice size if the value goes outside the range of 4.5 to 14mA with the current orifice size.

How to change GATT Gas Attenuator back to N2 with 2mbar

  1. From the Central Gas Injection Module Control panel G_ATT_CGI panel, set the Analog S.P. (set) of the currently used shutoff valve to 0 to close it. Then close Shutoff valve.

    ../../_images/G_ATT_CGI.svg

  2. From the Extended Panel G_ATT - CGI Extended, switch the currently used minican Ne Mode to Off and switch the ‘N2 Mode’ to ‘On’.

    ../../_images/G_ATT_CGI_Extended.svg

  3. Use the Automatic GAS Exchange to On and click on PumpPurgetoN2. This procedure will pump down and purge the gas manifold a few times. The procedure takes about 15 min. Wait for the N2 exchange to be finished as indicated in the status box below.

  4. Switch Automatic Gas Exchange to Off.

  5. From the SASE3 Gas Attenuator G_ATT_03 main panel, go to 2mbar.

    ../../_images/G_ATT_03.svg