1 / 10

Physics Requirements for the LCLS-II Feedback Systems

Physics Requirements for the LCLS-II Feedback Systems. Henrik Loos March 20, 2013. Overview. PRD 060-103-035-00 “Controls Requirements for LCLS-II Feedback Systems” Based on LCLS-I document Updated with LCLS-II machine layout Transverse feedbacks Longitudinal feedback Other feedbacks.

diamond
Download Presentation

Physics Requirements for the LCLS-II Feedback Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Physics Requirements for theLCLS-II Feedback Systems Henrik Loos March 20, 2013

  2. Overview LCLS-II Accelerator Physics Meeting / March 20, 2013 • PRD 060-103-035-00 “Controls Requirements for LCLS-II Feedback Systems” • Based on LCLS-I document • Updated with LCLS-II machine layout • Transverse feedbacks • Longitudinal feedback • Other feedbacks

  3. Transverse Feedbacks LCLS-II Accelerator Physics Meeting / March 20, 2013 Identical functionality to LCLS-I Modified to accommodate differences in machine layout • Gun launch • Injector launch • X-band cavity launch • L2 launch • L3 launch • Sector 18-19 launch (feedback sectors) • Bypass launch • LTU2 launch • Undulator launch (soft and hard, fast feedback/120 Hz)

  4. Transverse Feedback Locations Steering Loop BPMs Laser CER detectors β σ for 0.5 µm ε GUN 300m 80µm 60m 40µm 20m 20µm 10m 100µm 35m 70µm 50m 40µm L0 HXU DL2 SXU L2 L3 X L1 BYP DL1 BC1 BC2 • Injector/L1 BPMs need <10 µm resolution for 10% σ • L2/L3/BYP/DL2 BPMs need <5 µm resolution for 10% σ • Und BPMs need <2 µm resolution for 10% σ • For low charge BPM resolution 10x worse, σ 2x smaller LCLS-II Accelerator Physics Meeting / March 20, 2013

  5. Transverse Feedback Details LCLS-II Accelerator Physics Meeting / March 20, 2013

  6. Longitudinal Feedback Steering Loop BPMs Laser CER detectors sz1 sz2 V0 GUN d0 d1 d2 d3 1 2 V1 V2 V3 L0 HXU DL2 SXU L2 L3 X L1 BYP DL1 BC1 BC2 • Same basic layout as LCLS-I • Independent loops, but can be cascaded • 2 energy only loops (DL1, DL2) • 2 energy & bunch length loops (BC1 & BC2) • L3 energy alternate measurement BYP if D2B inserted LCLS-II Accelerator Physics Meeting / March 20, 2013

  7. Longitudinal Feedback Details • Energy measurement 10-4 (BCs), 10-5 (BYP, DL2) • Bunch length measurement (LCLS-I) <3% at 1.5kA LCLS-II Accelerator Physics Meeting / March 20, 2013

  8. L1B Phase & Amplitude Abstraction Schemes LCLS-II Accelerator Physics Meeting / March 20, 2013 • 2 klystrons for L1 (K11-1 & 2) • L1 phase only 16° • Phase only (like L2) • Klystrons in saturation • Adjust amplitude with opposing phases (±24°) • No amp, 0.08° phase jitter/station • Combined 0.045% & 0.057° • Phase & Amplitude • LLRF feedback for amp & phase • Keep phases at common L1 phase, adjust amplitudes • 0.025% & 0.025° amp & phase jitter/station • Combined 0.018% & 0.018° • Stable L1 energy profile during chirp scan • Energy scan w/o phase change and klystron kicks

  9. Other Feedbacks • Same VCC position and bunch charge as LCLS-I • TCAV0 feedback never implemented for LCLS-I, TCAV3 still is Matlab feedback • Bunch charge measurement <0.06% (LCLS-I), absolute value from toroid cross-check LCLS-II Accelerator Physics Meeting / March 20, 2013

  10. Common Feedback Controls Requirements LCLS-II Accelerator Physics Meeting / March 20, 2013 • Essentially the same as for LCLS-I • Select feedback rate • Separate loops for individual timing pattern (data slots) • Pulse averaging on each data slot • History buffer of ~1000 pulses • Dedicated network for 120 Hz (FCOM) • Less than 8 ms feedback response time for 120 Hz • Beam pulse identification for measurements • Actuators with data slot dependent set points

More Related