Beam Through Entire System
- 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
- Optimize throughout of gas by varying position of gas jet (off-line 1st)
- 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
- 2nd 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
- 2nd or 3rd 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