1. Few slides from J. Fox’ talk in last November’s LARP meeting LARP CM15 02.11.2010

2. Wolfgang Hofle BE/RFLARP CM15 02.11.20102

3. Wolfgang Hofle BE/RFLARP CM15 02.11.20103

4. Wolfgang Hofle BE/RFLARP CM15 02.11.20104

5. Wolfgang Hofle BE/RFLARP CM15 02.11.20105

6. Constraints for design of new pick-ups and kickers for the wide band ecloud feedback current tapered stripline pick-up has limitation in frequency due to TE 11 cut-off around 1.6 GHz  goal: extend bandwidth with future new pick-up W. Hofle, CERN Wolfgang Hofle BE/RF6LARP CM15 02.11.2010

7. Example of “TMC” instability  milder losses (10 to 20 % of the bunch is lost before the first BCT measurement point)  losses also correlated to max of vertical signal  oscillation profile is rather similar before losses  oscillations are quickly decaying after the intensity decrease B. Salvant et al. signals from pick-up not corrected for transfer functions

8. Motivation for new pick-up extend transverse diagnostics to beyond 1.6 GHz non-linear phase response of existing wide band pick-ups (BPWs) not optimal for feedback with time domain sampling Wolfgang Hofle BE/RF8LARP CM15 02.11.2010 TMCI: extends beyond 1.6 GHzecloud: spurious signals at 1.6 GHz

9. Wolfgang Hofle BE/RFLARP CM15 02.11.20109 L Beam  = 2 L/c  ^ |Z T (  )|  … ZTZT Frequency Domain Z T (  ) = Z T j sin(  ) e -j  /2 ^ f=1/(2  ) load or short gating on 1 st pulse Proposed long strip line as new pick-up sampling only the first pulse results in flat frequency response maximum bunch length 5 ns  L > 0.75 m for separation of pulses several striplines can be arranged in vacuum chamber (circumference)

10. Wolfgang Hofle BE/RFLARP CM15 02.11.201010 SPS aperture

11. Wolfgang Hofle BE/RFLARP CM15 02.11.201011 Pick-up close to QD installing pick-up at QD with circular aperture high vertical beta function (~100 m) frequency reach: 83 mm diameter: cut-off: 2.1 GHz can make aperture smaller than current BPW pick-ups Pick-up close to bends MBB: flat more rectangular chamber: cut-off frequency of relevant TE mode (132 mm width): 1.2 GHz not good for pick-up, but possibly for kicker if bandwidth < 1 GHz Scenario under discussion: - new pick-up as CERN project, use high power feed throughs in order to also be able to use it as a kicker for prototype tests - design study / construction of a kicker as a joint LARP/CERN effort pick-up for installation in shutdown 2012-2013 ready for feed back demonstrator in 2013 Included in LIU project proposal at CERN

12. RF, low radiation special instrumentation no RF infrastructure extraction CNGS/LHC injection slow extraction radiation high current transverse FB extraction LHC

14. current layout SPS LSS3 space available for transverse feedbacks

15. 3 4 2 23 4 800 MHz future layout (option 1) SPS LSS3 QD PU BPW space available for transverse feedbacks QD

16. Wolfgang Hofle BE/RFLARP CM15 02.11.201016 Travelling wave cavity in SPS LSS3

17. Wolfgang Hofle BE/RFLARP CM15 02.11.201017 Current location of device used as kicker

18. Wolfgang Hofle BE/RFLARP CM15 02.11.201018 Current location of device used as kicker

19. Wolfgang Hofle BE/RFLARP CM15 02.11.201019 Short straight section at QF’s: flat chamber

20. Wolfgang Hofle BE/RFLARP CM15 02.11.201020 Free space in dispersion suppressor

21. Wolfgang Hofle BE/RFLARP CM15 02.11.201021 Issues: Layout in SPS LSS3 Option 1: 200 MHz TWC: 2x2, 2x3, 2x4 space for pick-ups close to QD’s preserved  study needed if all pick-ups & kickers for the future system can be put into dispersion suppressor; combine with study for movement of current damper from LSS2 to LSS3 and TWC upgrade location fixes aperture ! Option 2: TWC’s have more sections, no space left for pick-ups Current: 200 MHz TWC: 2x4, 2x5 space in LSS3 (straight section) used for pick-ups space in dispersion suppressor for kickers

22. Wolfgang Hofle BE/RFLARP CM15 02.11.201022 Study items for new pick-up and kicker kick strength / bandwidth must come from simulations aperture, where are we going to install it equipment we want to put in the tunnel for final system is physical centering of the beam in the pick-up required ? is “electronic” centering possible ? kicker: what are we going to use, set of short strip lines ?

23. LARP CM15 02.11.2010