• Excel spreadsheet for the FEL settings is here.
  • Common trajectory latest values for the X-ray mirrors are here.


Is there an issue? Escalation Path

  • Issue concerns X-ray beam delivery: see here
  • Issue concerns ECS: see here
  • Prepare the hutch for the shift (done 1h before the actual start time)
    • open the grafana dashboards located here (requires UNIX login/pwd) to access beam owner, energies and coatings
    • no gate valve in the trajectory
      • check in the vacuum windows that no gate valves from the NEH to the MEC hutch are IN (red)
      • it is ok that the DG2 STP 1 is IN
      • it is ok that the GL window is IN in MEC

    • open the rolling status and confirm that no devices upstream the hutch obstructs the beam

      op.rs()

    • insert yag3 to provide a photon terminator before TCC prior to send any beam in the hutch

      op.yag3.insert()
    • confirm that the chamber is loaded with targets and being pumped down to be ready at the start of the shift
    • search the hutch but leave SH6 IN (you are not the beam owner yet)
  • 15 min before the shift begins, call ACR at x2151 to check
    • look at current ACR beam operator on shift here
    • confirm photon energy
    • confirm pulse energy
    • confirm pulse duration
    • confirm beam mode
    • confirm multiplexing mode
    • ask for an e-loss scan
  • transition to beam ownership
    • ACR calls you to confirm they are tweaking the beam for you
    • confirm with ACR that MR1L0 and MR2L0 have the right coating following this page
      • if moving the mirror yourself, then open MR1L0 and MR2L0 HOMS GUI located in the mechome > LCLS tab > HOMS overview button
      • set the coatings to the appropriate material as a function fo the photon energy as per the page from above
  •  getting ready to accept the beam:
    • close DG2 STP 1
    • make sure the reference laser is out (check in the rolling status)
    • confirm the target chamber is pumped down
    • insert the Be window IN the beamline
    • search H6 if not already searched
    • remove SH6 OUT of the beamline
  • beamline alignment
    • ACR calls you to confirm beam is ready for alignment

    • force close the pulse picker to make sure it does not let the beam propagate to the hutch yet

      op.pp.close()
    • check MR1L3 mirror OUT (-6000) position (XCS mirror)
    • check the XPP slits (slit1) are open (20mm, 20 mm) in the rolling status
    • open the mirror settings located here
    • confirm bending values for MR1L0 and MR2L0 (advanced)

    • insert YAG0

      op.yag0.insert()
    • confirm FEL beam is on the cross for the OUT position (undeflected beam)
    • confirm the shape of the beam is round (advanced)
    • set the MR1L4 coating as per this page
    • insert MR1L4
    • confirm FEL beam is on the cross for the IN position (deflected beam)

    • insert YAG1

      op.yag1.insert()

    • remove YAG0

      op.yag0.remove()

    • remove all Si attenuators (send full energy beam)

      op.SiT(1)

    • open the pulse picker

      op.pp.open()
    • fine tune the pitch of MR1L4 to center the beam on YAG1

    • insert YAG3

      op.yag3.insert()
    • remove hutch Be CRL (Mechome > Beamline > Beamline CRL(hutch))

    • open slit 2

      op.slit2.move(5)

    • remove YAG1

      op.yag1.remove()
    • fine tune the pitch of MR1L4 to center the beam on YAG3
    • to adjust the height using the YAG3 red cross centered at (265, 282), call ACR, and for a 200 mic motion on the yag, ask them to move 200/4 mic up or down.
      • you could set SiT(0.2) to not saturate the image
      • you could set 10 images averaged to get a cleaner picture
    • log the mirror settings in our table here
    • confirm photon energy and lens stack to use and log the change of stack in the paper document for Be CRL log
    • insert the Be lenses with these parameters
      • set 1: 9 keV, 9 x 300 mic, f = 3.96 m, Y = 2.8816 mm
      • set 2: 17 keV, 10 x 100 mic, f = 4.4243 m, Y = 29.52 mm
      • set 3: 22 keV, 9 x 50 mic, f = 3.904 m, Y = ?
  • once they are done tuning
    • timing check
      • turn off laser triggers

      • go to the titanium foil:

        op.ti()
      • move hutch CRL out

      • set slit4 to 400 mic: 

        op.slit4.move(0.4)

      • send full beam on titanium: 

        op.SiT(1)

      • set the EVR to 10 Hz settings: 

        op.lpl_check_timing(rate='10Hz')
      • set vertical division to 10 mV/div on oscilloscope Lecroy 1
      • once you see the signal of the X-rays, set 100 sweep to average the signal
      • save it on memory 2
      • set back sweeps to 1 on channel 2
      • move target about 0.8-1 mm negative to target the Al frame
      • turn on the LPL trigger on, event code 43 for 10Hz
      • once you see the signal of the LPL, set 100 sweep to average the signal

      • move timing to overlap the LPL with the memory trace 2 using the python command

        op.nstiming.mvr(2e-9)

        to move the LPL 2 ns later than the FEL, but this is just an example! Move it (or not) by the necessary amount to overlap best the rising edges of the beams.

      • save the current value as our t0, using hte python command 

        op.nstiming.save_t0()
      • once timed, set 100 sweep to average the signal and save the trace on memory 3
      • take a screenshot and put it in the elog
      • move back the hutch Be CRL
      • set the slits back to data-taking move size

      • set the EVR to single shot settings: 

        op.lpl_check_timing(rate='single')
      • set the scope Lecroy 1 channel 2 voltage/div to the maximum (1V/div) to be able to observe the shot on the diode and monitor the timing
    • laser

      • select the laser pulse shape

        meclas.LPL.psmenu()
L3

        to choose pulse shape : 8ns flat top, max 80J

      • start by optimizing the conversion efficiency

        meclas.LPL.SHG_opt() 

      • finish by optimizing the pulse shape

        meclas.LPL.psefc10Hz(numIterQ=150)
    • detector 
      • confirm LPL event code is either 182 or 43 (precaution)

      • in python, set event sequencer to 120 Hz:

        op.x.start_seq(120)
      • aadd the detectors you want a pedestal for, remove any VISAR or slow cameras and allocate the DAQ

      • in a random DAQ terminal, execute

        takepeds

        and follow instructions

      • after takepeds is done, execute 

        makepeds -r xxx -u yourusername -q milano

        with xxx being the run number and yourusername being the user name of the person who extract the pedestal, then follow instructions

      • shutdown the DAQ (don't need to 'restartdaq'), reallocate and confirm the pedestal has been applied
      • alight Ge spectrometer 
      • check 4 Quads with calibrant sample (CeO2) for q range

1 Comment

  1. Eric M Galtier

    For the JJ slits, we need to be able to 0 them, otherwise the width readback is not from the center but is an absolute value, which we don't need. At the moment, I have hardcoded in our script the 0 width, to provide an idea of the width, and display a monitor value on the rollingstatus.