LUXE fortnightly meeting

Europe/Berlin
ATLAS meeting room, 1C/O1.310

ATLAS meeting room, 1C/O1.310

Beate Heinemann (DESY and Freiburg University), Matthew Wing (UCL)
Description
Remote Vidyo connection: https://vidyoportal.cern.ch/join/fJTg4XgY9EHN

Short summary of meeting

  1. Florian reported verbally progress on the accelerator. There is now a first 3D CAT model. The lattice is basically final. The CDR is making good progress and should be ready in about 2 weeks.
    • there was a discussion about how much we need to focus the electron beam towards the IP. The current default is 5 um but we want to underwstand better the scientific motivation for 5 vs 10 vs 3 um. This will be studied by Tony H and Ben K. For the brem photon case Sasha has demonstrated that the relevant spot size at the IP is not affected as long as it is below 20 um.
  2. Sasha reported on background estimates. With the current design he implemented in Geant there is too much background by about 5 orders of magnitude. The most problematic background (coming from photons hitting the beam dump) before the IP can be reduced by changing the beam dump, e.g. moving it further away from the beampipe and/or increasing the hole left for the beampipe. This is very high priority. A smaller background source comes from photons hitting the beampipe after the IP, this can likely be suppressed with combination of tracking and calorimeter we have. But we can also reduce it by increasing the beampipe. Gianluca sees a similarly large background in FLUKA. He is trying to put a collimator right after teh tungsten foil to collimate photons and reduce the problem that way. 
  3. Matt reported verbally on the laser setup he and Gianluca suggest. He will write it up in more detail in an appendix of the LOI, including a table of all relevant parameter requirements as well as enviornmental (room) requirements (similar as laid out in the document by Ishay Pomerantz attached to the agenda).
    • there was a discussion about the polarisation. Matt commented we can have any. For the science case we should include comments on the polarisation
    • the simulation we have now has been done with parameters that differ from those by Matt. Need to understand impact ASAP. Need full table of relevant parameters.
  4. AOB: Massimo and Beate will try to get the document into a state where it can be considered good enough to circulate within LUXE for comments by next Tuesday (July 9th). 

 

Actions:

  • Tony and Ben: study impact of spot size for electron-laser interaction
  • Matt: provide more information about laser in appendix and finalize LOI laser chapter, including costs, space requirements etc.
  • Ben and Matt; study impact of laser frequency (3omega vs 2omega)
  • Beate and Massimo: continue to improve LOI to put full draft together by July 9th
  • Florian, Sasha and Ginaluca: improve beamline design to reduce background and then reevaluate background

 

There are minutes attached to this event. Show them.
    • 12:00 12:05
      News 5m
      Speakers: Beate Heinemann (DESY and Freiburg University), Dr Massimo Altarelli (Max-Planck-Institut Structure and Dynamics of Matter)
    • 12:05 12:15
      Accelerator News 10m
      Speaker: Dr Florian Burkart (DESY)
    • 12:20 12:40
      Background Studies with Geant 20m
      Speaker: Oleksandr Borysov (DESY)
      Slides
    • 12:40 13:00
      Laser 20m
      Speakers: Ishay Ponerantz (Tel Aviv University), Matt Zepf (HIJ)
      document
    • 13:15 13:25
      AoB 10m