Rf considerations for the dedm ring
This presentation is the property of its rightful owner.
Sponsored Links
1 / 9

RF considerations for the dEDM ring PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on
  • Presentation posted in: General

RF considerations for the dEDM ring. Require coherent longitudinal oscillations with synchrotron tune around 0.2 Superconducting RF needed to produce such a tune. Cannot modulate RF phase at 0.2*frev so need another cavity with frequency offset from a revolution line by 0.2*frev

Download Presentation

RF considerations for the dEDM ring

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Rf considerations for the dedm ring

RF considerations for the dEDM ring

Require coherent longitudinal oscillations with synchrotron

tune around 0.2

Superconducting RF needed to produce such a tune.

Cannot modulate RF phase at 0.2*frev so need another cavity

with frequency offset from a revolution line by 0.2*frev

With superconducting RF all amplitudes and phases vary

slowly compared to synchrotron oscillations and an adiabatic

excitation is required


Longitudinal dynamics

Longitudinal dynamics

Thin lens equations of motion for energy deviation on turn n just before

entering the cavity at time

Initially, consider only two voltage terms

The approximation is only for analytic work


Analytic considerations

Analytic considerations

Set so that

Where

Next set the momentum variable to

Dynamics are described by the hamiltonian

Where


Analytic considerations 2

Analytic considerations 2

Now go over to action (J) angle () variables that rotate at

The new hamiltonian is

where small or fast terms have been dropped. Going back to Cartesian

Final hamiltonian


Analytic considerations 3

Analytic considerations 3

Final hamiltonian

Fixed points where , and stable when

Plot of as

is raised with fixed drive .

The stable fixed point

migrates to larger x.

This is fully adiabatic.


Analytic considerations 4

Analytic considerations 4

Intuitive picture of raising tune


Simulations

Simulations

Applied voltage.

360 MHz for main harmonic

drive at 176.3 MHz

2nd harmonic 720 MHz

Final bunches

Expect slight changes

with extended field

region.


Scaling laws for other rf frequencies

Scaling laws for other RF frequencies

Synchrotron tune is fixed by

Maximum velocity excursion

Inexpensive RF power in FM radio band and above 350 MHz

Cavities get larger as frequencies drop


Conclusions

Conclusions

  • Principle appears to be sound

  • Need to decide on frequencies and drive phases (90 .vs. 180)

  • Power and RF control considerations remain

  • Full system cost of 3 to 5 million dollars (fully loaded with, design, over head, etc. and assuming no surprises)


  • Login