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• From lclshome -> User Dev Displays panel.
• Run one of the matlab scripts xalRunModel or xalGetModel.

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    xalGetModel. !image:xalGetModel.jpg|thumbnail!

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      Select a beamline. For example, select "*Cathode to Dump*" This runs the LCLS "Full Machine" model, from the LCLS Cathode to the main Dump. See [Why are all models from Cathode to some location|#whysameloc]. !image:selectabeamline.jpg|thumbnail!

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      Select whether to "*Run extant machine or design model? (x/d) \[d\]:*". Running the "design" model (choice "d") causes the XAL model to be run with the element setpoint values in the model input files. Those design setpoint values are, [to the extent possible, identical to the MAD design|#modeldiffs]. Running the "extant" model (choice "x") will cause the model execution to first replace the design values of beamline devices, with the actual readback values, as acquired through EPICS and AIDA, prior to running the envelope tracker. That is, "extant" is equivalent to what was called "DATABASE" in the SLC modelling system; it describes the extant machine at the time the model is run. !image:xalGetModelextant|thumbnail! Extant model run stages are as follows:

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      1) "Initial Twiss" is displayed. Check the initial conditions which will be used for the model run. These are presently taken from the SLC marker point 80. You can check these at any time with AIDAWeb ([MARK:VX80:80//twiss MODE=5|https://seal.slac.stanford.edu/aidaweb/dispatchQuery?Query=MARK%3AVX00%3A80%2F%2Ftwiss+MODE%3D5&Query+Action=Get+Data]; the values are Energy (GeV), psix, betax (m), alphax , etax (m), etax', psiy, betay (m), alphay, etay (m), etay') !image:extantinitconditions.jpg|thumbnail! If these appear fine, then confirm to continue.

    • 2) "Run " LEM 'Lite'". This will calculate and display the fudge factors and predicted energy. When it has completed, check in particular that the final energy at the undulator (see Energy comlumn, and the row of output labelled "BSY") is reasonable, e.g. 9.25 GeV.
      If energy appears fine, then confirm to continue.
    • 3) "Run XAL machine model." This can take up to a minute to execute, so please be patient.
    • 4) "Create MAD patch file". This stage is always entered, you don't need to do anything. It only takes a moment to create these.
    • 5) "Run XML writer." This is where the file containing the model results to be uploaded to Oracle, is created. This also takes half a minute or so.
      When it has completed, you should see that 3 files have been created: Eg

      Code Block
      /u1/lcls/physics/onlinemodel/xal/xalElements_20090120_115855.xml created /u1/lcls/physics/onlinemodel/xal/xalDevices_20090120_115855.xml created /u1/lcls/physics/onlinemodel/xal/xalModel_20090120_115855.mat created

• • xalGetModel

Model Notes

Anchor
whysameloc whysameloc

Why are all models from Cathode to some location?

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