Tour-de-Table

Thursday 1 Dec 2016, 14:30 → 15:30 Europe/Zurich

6/2-004 (CERN)

Participants: Edu, Juergen, Yanliang, Raul, Andrea, Dominik, Daniel

Tour-de-table:

• Edu: Progresses in two-beam tuning. 90% of the machines reached 100% luminosity, in the 1-beam tuning. Two-beam machines: 90% machines 90% Luminosity. 40 iterations used in the 1-beam tuning, 24 for the two-beam tuning. Daniel suggests to start working on the 380 GeV design. Beam-beam feedback at IP is necessary. Offsetting the two beams to center them, might underestimate the luminosity achieved by the feedback at convergence.
• Juergen: THz source, studying the impact of a foil using geant4, that could be easier than using a comb. Collimators might be needed. 
• Yanliang:CLIC RTML rebaselining, 380 GeV. Problems with CSR simulations (memory leak?). Scan of the longest bunch length. Longer bunch length induces non-linearities in the longitudinal phase space, T566 terms. 3 TeV, BBA requires 1% emittance measurement. The geometry of the measurement station could be problematic, because one needs to measure the two axes.
• Raul: CLIC Drive Beam recombination complex. 150 micron emittance is the budget, he's obtained slightly off results: 199. Last efforts were devoted to the optimization of the injection section CR2. Rematching of the optics was needed, adding 4 sextupoles to the line. Injection of CR2 is pretty delicate. Daniel remembers that we will need to delay some train by few millimeters (~2 mm), for beam loading compensation in the ML. This should be kept into account.
• Andrea: ILC simulations of the ILC main linac for Z-boson calibration runs.
• Dominik: 380 GeV CLIC BDS. Photon tracking to the IP.