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- 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
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open the rolling status and confirm that no devices upstream the hutch obstructs the beam
Code Block language py theme RDark linenumbers true op.rs()
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insert yag3 to provide a photon terminator before TCC prior to send any beam in the hutch
Code Block language py theme RDark linenumbers true 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
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force close the pulse picker to make sure it does not let the beam propagate to the hutch yet
Code Block language py theme RDark linenumbers true 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)
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insert YAG0
Code Block language py theme RDark linenumbers true 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)
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insert YAG1
Code Block language py theme RDark linenumbers true op.yag1.insert()
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remove YAG0
Code Block language py theme RDark linenumbers true op.yag0.remove()
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remove all Si attenuators (send full energy beam)
Code Block language py theme RDark linenumbers true op.SiT(1)
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open the pulse picker
Code Block language py theme RDark linenumbers true op.pp.open()
- fine tune the pitch of MR1L4 to center the beam on YAG1
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insert YAG3
Code Block language py theme RDark linenumbers true op.yag3.insert()
- remove hutch Be CRL (Mechome > Beamline > Beamline CRL(hutch))
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open slit 2
Code Block language py theme RDark linenumbers true op.slit2.move(5)
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remove YAG1
Code Block language py theme RDark linenumbers true 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
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go to the titanium foil:
Code Block language py theme RDark linenumbers true op.ti()
- move hutch CRL out
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set slit4 to 400 mic:
Code Block language py theme RDark linenumbers true op.slit4.move(0.4)
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send full beam on titanium:
Code Block language py theme RDark linenumbers true op.SiT(1)
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set the EVR to 10 Hz settings:
Code Block language py theme RDark linenumbers true 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
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move timing to overlap the LPL with the memory trace 2 using the python command
Code Block language py theme RDark linenumbers true 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.
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save the current value as our t0, using hte python command
Code Block language py theme RDark linenumbers true 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
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set the EVR to single shot settings:
Code Block language py theme RDark linenumbers true 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
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select the laser pulse shape
Code Block language py theme RDark linenumbers true meclas.LPL.psmenu() L3
to choose pulse shape : 8ns flat top, max 80J
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start by optimizing the conversion efficiency
Code Block language py theme RDark linenumbers true meclas.LPL.SHG_opt()
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finish by optimizing the pulse shape
Code Block language py theme RDark linenumbers true meclas.LPL.psefc10Hz(numIterQ=150)
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- detector
- confirm LPL event code is either 182 or 43 (precaution)
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in python, set event sequencer to 120 Hz:
Code Block language py theme RDark linenumbers true op.x.start_seq(120)
- aadd the detectors you want a pedestal for, remove any VISAR or slow cameras and allocate the DAQ
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in a random DAQ terminal, execute
Code Block language bash theme RDark linenumbers true takepeds
and follow instructions
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after takepeds is done, execute
Code Block language bash theme RDark linenumbers true 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
- timing check