LHC Beam Operation workshop - Evian 2011

Session

Session 7: Limitations

13 Dec 2011, 15:45

Royal Hotel

Presentation materials

paper

SESSION_7_summaryEvian.docx

SESSION_7_summaryEvian.pdf

32. Impedance effects on beam stability

Nicolas Mounet

13/12/2011, 15:45

What was expected? What did we learn and what are the limitations from impedance? Effect of tight collimation settings, 25 ns vs 50 ns and 4 vs 3.5 TeV

33. Beam induced heating

Benoit Salvant

13/12/2011, 16:10

What were the expected heat loads? Review of the observations on temperature increases / outgassing for kickers, collimators, etc. Anything around the corner? Next limitations? What is the expected effect of bunch length (with the measured bunch spectrum)? Can we explain the observed heat loads by impedance effects? Mitigation measures 25 ns vs 50 ns and 4 vs 3.5 TeV

34. E-cloud effects

Giovanni Rumolo

13/12/2011, 16:35

What were the expected heat loads/stability limits? What did we learn and what are the limitations from e-cloud in terms of beam stability, heat load? Comparison with measurements: heat load vs. RF stable phase shift, SEY and reflectivity from heat load and pressure rise data. Effect of scrubbing run and requirements on SEY to operate the machine with 25 and 50 ns at 3.5 and at 4 TeV

35. e-cloud & vacuum instabilities

Giuseppe Bregliozzi

13/12/2011, 17:00

Vacuum and cryogenics observations: 25 ns vs 50 ns. Can e-cloud explain everything? Effects observed at TDI, experiments, triplets, impact on background, Estimations for a scrubbing run for 25 ns operation, Shall we have a scrubbing period at 25 ns to operate at 50 ns? Shall we have a scrubbing fill after every technical stop? Interplay with cryogenics and potential solution or mitigation measures

42. Luminosity lifetime - protons

Giulia Papotti

13/12/2011, 17:25

What did we learn and do we have a good model? What were the predictions (in particular LR)? Is beam-beam the only responsible for blow-up and luminosity lifetime? What did we learn and what are the limitations from beam-beam? Impact of separation (luminosity leveling), working point, crossing angle, 25 vs. 50 ns