Excel spreadsheet for the FEL settings is here.
Is there an issue? Escalation Path
- Prepare the hutch for the shift (done 1h before the actual start time)
insert yag3 to provide a photon terminator before TCC prior to send any beam in the hutch
op.yag3.insert()
- search the hutch but leave SH6 IN (you are not the beam owner yet)
- getting ready to accept the beam:
- close DG2 STP 1
- confirm the target chamber is pumped down
- insert the Be window IN the beamline
- 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
insert YAG0
op.yag0.insert()
- confirm FEL beam is on the cross for the OUT position (undeflected beam)
- 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 = ?
- timing check if 1st shift of the beamtime
- 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 the 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)
- add 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
- check 4 Quads with calibrant sample (CeO2) for q range
- turn off laser triggers