Present: Michele Bergamaschi, Fern Pannell, Arthur Clairembaud, Marlene Turner, Patric Muggli, Nikita Zena van Gils, Luca Ranc (zoom)

Discussion points:

• Three positions of screens: out/in beamdump/in screen
• Should there be a double foil or two separate foils? fluence, beamsize and more spot considerations. If single foil, one needs to ensure that reflection is dumped in a safe place.
• Estimate ~4000 events per plunger
  • may need high statistics to pull signal out, events to be designated carefully
  • need to find energy. PM: there we need to have a clear strategy. Maybe start at 10m, then decrease slowly to guess energy range.
  • injection efficiency needs to be close to 100%
    • there will likely always be an unknown at where injection actually occurs.
• Spectrometer magnets can only be set to image in one plane when the plasma ends earlier than 9.5 m
• Screen retraction, screens retract towards aisle side, but still stick in--> laser will cause diffraction
  • proton beam halo may also interact with holder and cause additional background
  • shimming is an ~1hr intervention
• May plungers be used to study e-beam/plasma interaction?
  • when laser beam dump is inserted upstream, screen will block e-beam
• Spectrometer background
  • to be studied carefully during the SSM run (including changes)
  • biggest worry is that signal wont be visible
  • should know beforehand where optimum electron beam positions on the screen are. trade off between dispersion and background.