Future studies (SPS)

1. Future studies (SPS) • Simulations • Simulation of main quadrupoles QD and QF (SEY threshold) • E-cloud monitors (including the holes) • COLDEX – meeting with TE/VSC colleagues to define the needs (Thursday) • Instability thresholds with all chambers (MBB, MBA, QD, QF, SS1, SS2)? • Experimental activities at SPS (scrubbing run 2014 + MDs – see next slide) • 25 ns beam(standard and BCMS) • Recover 2012 performance • Push performance to maximum intensity (possibly higher brightness thanks to the PSB-PS larger longitudinal emittance transfer), • Monitor scrubbing process based on e-cloud observables (liners, beam lifetime, emittances, tune shift along the train, chromaticity needed to stabilise). • Characterization of the a-C coated cell. In-situ SEY measurements device with pickup • Doublet beam, full set up (need to set up slower acceleration cycle, Q20 and Q26) • High Bandwidth Feedback System tests on single bunches of a multi-bunch beam (using directly data with ECI, if possible) • Test 8b + 4e scheme (e-cloud efficient ?) • COLDEX measurements with cold a-C coating (probably in 2015?) • LIU-SPS TDR: electron cloud part in the process of being written Electron cloud meeting, 17/02/2014

2. Injectorschedule 2014 Electron cloud meeting, 17/02/2014

3. Future studies (LHC) • Simulations (no experiments in 2014) • Simulation of all SAMs and semi-SAMs (SEY threshold) • Comparison with heat load data to determine • Evolution of SEY • Present value of SEY • Heat load in dispersion suppressor to determine fractions of e-cloud in arc dipoles and quads  meeting with TE/CRG colleagues • Comparison with stable phase shift measurements including the contribution from arc quads + SAMs + semi-SAMs • Extract all the heat load data from ITs (2011 – 2013) • Define a strategy to determine the scrubbing history with both 50 and 25 ns beams (simulations of some selected points) • Project for Summer student submitted  need tool for analysis ready • Simulation of higher order magnets (sextupoles, octupoles) • Do we need to include also the drifts in all our comparisons with heat load data? (usually cryostats include long drift portions) • Holes in the beam screen: effect in dipoles ? • E-cloud in BSRT undulator chamber: Can we change the magnetic field and measure heat load?  dependence of e-cloud on magnetic field • Stability with different octupole polarities and e-cloud distributions from PyECLOUD (to explain “hunchback instability”) Electron cloud meeting, 17/02/2014

4. Future studies (PS) • Simulations • Simulation of the new e-cloud monitors in SS98 (expected signal) • Instability simulations ?  self-consistent approach needed, maybe start with concatenating PyECLOUD and HEADTAIL (how easy through PyHEADTAIL?) • Experimental activities at PS • Measurements with the new monitors installed (25 and 50 ns, different bunch lengths over the last part of the cycle) • Cover higher intensities, up to LIU values, if achievable after LS1 with the new longitudinal feedback • More instability data? • New Technical student will start in March 2014  Annalisa Romano Electron cloud meeting, 17/02/2014

5. Future studies (Miscellaneous) • More LHC studies • BGV, MKI, TDI, BSRT undulator … • CLIC damping rings • Check electron cloud in the electron ring for the rebaselining? (possible resonant values for which there could be electron accumulation even in electron ring) • Check for cyclotron resonances in wigglers? (scan in magnetic field between -2.5 and 2.5 T) • FCC • Define possible electron cloud issues in the FCC and injector chambers (defined by magnet and resistive wall constraints) • Scan over bunch intensities and spacings under consideration Electron cloud meeting, 17/02/2014