Run2c BI review

Friday 5 Sept 2025, 10:30 → 12:00 Europe/Zurich

Present: E. Belli, T. Lefevre, P. Muggli, C. Pakuza, M. Turner 

 

 

Proton beamline: 

·       Eleonora to verify the position of all BPMs along the proton beamline

·       For monitoring the event-to-event proton beam alignment, 4 BPMs are needed, 2 between the last magnetic element and the first plasma source, and 2 after the second plasma source upstream the spectrometer dipole. 1 BPM is already installed just before the merging point with the 18 MeV line, 1 another BPM has to be added.  Marlene to verify the BPM position so that the distance between these 2 BPMs is maximum (for better alignment accuracy) and not too close to the plasma entrance (possible issues when plasma)

·       Two BTVs needed for proton beam alignment upstream of the first plasma entrance (since the two vapor sources will be angled and because of the 150 MeV line injection magnet). These screens will also be used for laser beam alignment (laser beam needs to be on the same vector as the proton beam, only Chromox screens can be used). Need to be positioned after the last magnetic element and the distance between them should be maximum (for better alignment accuracy).

·       Eleonora to specify which and how many BTVs are needed to validate proton beam optics and the waist size and location.

 

18 MeV electron beamline:

·       Eleonora to check position of BPMs/correctors after the quadrupoles in the 18 MeV line (in Run2b the assembly was installed before magnets)

·       BTV.450074 after initial triplet will be used for position and emittance measurements (quadrupole scan)

·     BTV.450111 after first dipole magnet will be used for position and energy spectrum measurements (e.g. when setting up the gun). Need to confirm that the energy resolution is sufficient (given the beta function and dispersion).

·       Eleonora to specify which BTVs are needed to validate electron beam optics and the waist size and location.

·       ICTs are preferrable to a Faraday cup for charge measurements  request an ICT and define its position along the beamline

·       To be defined if a bunch length monitor is needed

 

General comments:

·       all screens that are used for alignment need to have position accuracy and reproducibility (number to be specified by the experimental team)

·       all screens that are used for streak cameras also need angle accuracy and reproducibility (number to be specified by the experimental team)

·       YAG screens can be used to measure beamsizes on the order of 100 um --> expansion volume screen can potentially also be used for size measurements

 

To be discussed:

·       150 MeV electron beam line (in particular bunch length monitors)

·       Experimental area (after the 2nd plasma source)

·       Test bench for commissioning