1 / 11

Damping of instability with octupoles

Damping of instability with octupoles. How much tune spread we can introduce with octupole correctors? How is it effective with space charge? 3. How much tune spread do we need with space charge? 4. Does it introduce significant beam loss due to octupole resonances?. Octupole correctors.

zeno
Download Presentation

Damping of instability with octupoles

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. Damping of instability with octupoles • How much tune spread we can introduce with octupole correctors? • How is it effective with space charge? 3. How much tune spread do we need with space charge? 4. Does it introduce significant beam loss due to octupole resonances?

  2. Octupole correctors 4H and 4V N=292 turns, I=10A (I_max=20A) Octupole: 150 [T/m^3] for I=10 A or 300 [T/m^3] for I_max=20A Corresponding tune spread (rough estimate) : 0.006 (I=10A) 0.013 (I=20A)

  3. Re(Z) for full 14-kicker system (May 2002) Impedance model (EK) used in simulations January- June’02

  4. Effect of octupoles – full beam

  5. Tune spreads Red – negative (10 A) Y octupoles (b_y=10m) Black- positive (20 A) Y octupoles Green – negative (10 A) X octupoles (b_x=11m)

  6. Tune spread (10 and 20 Amp positive y-octup.)

  7. Tune spread (10 Amp octupoles)

  8. Effect of octupoles – full beam

  9. 10 Amp positive Y-oct. – 1060-turn painting 1MHz 12MHz

  10. 17 Amp positive Y-oct., 1060-turn painting 1MHz 12MHz

  11. Halo after 1060-turn injection Blue – no impedance Black – impedance, no octupole correctors (halo due to instability) Red – 10A positive y-octupoles Pink – 17A positive y-octupoles Green- 40A positive y-octupoles

More Related