Beam through entire system
Align HFP chamber to beam
Collect images of beam on diff pumping YAG
Collect images of beam on beam viewing paddle
Align Diagnostics chamber to beam
Collect images of beam on upstream diff pumping YAG
Collect images of beam on downstream HiRes beam screen
Align laser to beam - rough
FEL beam OFF
Insert mirror
Align beam, collecting images as necessary
Remove mirror before beam back ON
Pulse energy monitor
Offline testing of pressure, magnet current, detector voltages, data acq
Setup with appropriate pressure – observe signal
Correlate signal with FEE pulse energy monitors
Attenuate beam with gas attenuator & verify operation
Vary pressure and tabulate response
Shutter operation
View beam at Diagnostics chamber downsream HiRes beam screen
Beam OFF, shutter open
Insert shutter to nominal position
Beam ON, find beam on YAGs & center beam in shutter
Close shutter – observe beam screen
Pulse shutter – use pulse energy monitor to pick 1 Hz ?
Slit operation
View beam at Diagnostics chamber downstream HiRes beam screen
Monitor pulse energy with pulse energy monitor
Scan one slit blade at a time to find center of beam
Mask beam to varying degrees, watch for intensity variations between FEE and AMO
monitors
Open slits back open
KB optics
Focus optics for HFP interaction point
Insert KB optics into beam (nominal position)
Align chambers to KB optics
Heavily attenuated beam – check alignment & adjust
Imprint beam into beam focus verification paddle & view with microscope
Vary focal length between HFP and diagnostics chamber – dble check alignment
Repeat beam imprinting after focal length variation
Dynamic beam focus studies using Jacek’s set-up
HFP iTOF
Apply voltages to iTOF lenses
Apply voltages to iTOF detector (dark counts, off-line)
Acquire spectra using residual gas, either from background pressure or gas jet
leakage – optimize voltages
Vary acceleration, extraction voltages to define operational space
Gas jet optimization & operation (see below)
Pulsed extraction voltage operation – effects on spectra
HFP gas jet
st
Optimize throughout of gas by varying position of gas jet (off-line 1 )
Optimize timing of gas nozzle valve to LCLS using iTOF
Vary sample density via nozzle withdrawl, backing pressure variation to see effect on
signal, alignment, etc
HFP electron TOFs
Apply voltages to lenses
Apply voltages to eTOF detectors (dark counts, off-line)
Measure low KE electrons (Ne photoelectrons)
Optimize positions of all five TOFs
Optimize voltages on detectors
Optimize voltages on lenses (iterating these three)
Measure high KE electrons (Ne Augers)
Optimize voltages on lenses for maximum resolution, count rate
Measure moderate KE electrons (Ar Augers ?)
Optimize pressure for given focal volume – see broadening from charge ?
iTOF pulsed extraction operation – timing & effect on KE resolution
HFP Focus verification paddle
Remove iTOF & top eTOF to install focus verification paddle
Ensure limits are set to prevent damage to adjacent eTOFs
Imprint unfocussed beam and view with the microscope
Imprint focused beam & view with microscope
Move out of focus (chamber & paddle motion) & view
Optimize focusing
HFP vTOF (velocity map imaging TOF)
Replace iTOF with vTOF
Acquire signal using atomic sample (low extraction voltage)
Optimize position, voltages
Change to molecular sample (N2?) & acquire signal (high extraction voltage)
Optimize position, voltages
Try pulsed extraction voltage mode – image ?
Coincident measurements of N2 with vTOF
Diagnostics Beam Screens
Position downstream screen in beam
Measure samples of beam screen info for statistical analysis
Software available for position and extent determination?
Position upstream screen in beam – still see it on downstream screen ?
Measure samples of beam screen info from both screens
Diagnostics Magnetic Bottle
Current applied to solenoid – field ?
Voltages on detector – dark counts & image ?
Look for signal with high residual pressure from needle
Optimize position of the permanent magnet – looking at image
Optimize solenoid magnets
Optimize gas delivery
Spectra of low KE electrons
Spectra of high KE electrons
Test retarding field – tune solenoid magnets
Measure KE of electrons versus photon energy
Change focus to diagnostics position & repeat electron measurements
Diagnostics gas delivery
Optimize position of the needle in the beam
Optimize backing pressure for different foci
Effect of needle position on resolution of spectrometer
Laser
Bring laser beam into diagnostics chamber
Focus into interaction region of magnetic bottle
Overlap with FEL beam spatially/temporally
Measure side-bands – varying intensity & timing
nd
2 or third harmonic ?
Bring laser beam into HFP chamber
Focus into interaction region of electron spectrometers
Overlap with FEL beam spatially/temporally
Measure side-bands – varying intensity & timing
nd
rd
2 or 3 Harmonics & repeat
Diagnostics gas detector studies (Moeller)
Attach another gas detector to the instrument
Measure response at variety of different attenuator settings
HFP focusing studies (Jacek)
Replace ion TOF with camera mount
Install YAG screen on diagnostics paddle
Attenuate LCLS beam
Make measurements as function of position
Tune focusing of optics
Change focus to diagnostics chamber & measure
Return focus to HFP chamber & verify repeatability
HFP focusing studies (wavefront sensor)
Attenuate beam to prevent damage
Focus beam in HFP interaction region
Measure wavefront
Tune optics through iteraction
Verify with YAG screen diagnostic
HFP damage studies (Hau Riege)
Install sample(s) on beam focus paddle
Expose to single or multiple shots at various locations
Change attenuation & repeat
Change samples & repeat
HFP mTOF
Replace iTOF with mTOF
Acquire signals using atomic sample (low extraction voltage)
Optimize position, voltages
Change to molecular sample (N2?) & acquire signal (high extraction voltage)
Optimize position, voltages
Try pulsed extraction voltage mode – image ?
Coincident measurements of N2 with mTOF