Kicker Operating Margins

D. Johnson

March 3, 1993

All kicker specifications for integrated field and kicker angles are given for nominal extraction/injection design parameters.  The resultant conservative 4 mm beam-steel spearation at the Lambertsons for beams of 95% normalized emittance fo the 40 pi-mm-mr.   The maximum expected normalized emittance from Booster is 30 pi-mm-mr which reduces the beam size by roughly 14% thus increasing the margin of safety. 

The normal operating range should allow for at least a 10% increase in field strength which produces an extra 2 mm beam separation (5 mm for proton injection).  It is eplicitly assumed that there is a greater margin for reducing the field strenghth.   Considering the level of orbitcontrol in the MI through the Lambertsons and kickers shouls by <= 0.15 mm, the 10% margin appears inadequate.  Considerations on operational performance and reliability indicate that the kicker systems design should probide for and increased margin of safety of 20% over nominal depending on the results of a cost/engineering study.

Operation at the maximum of the range should not lead to any performance, reliabiliy or lifetime degradation.  Specifically, we would like to see:

10. % nominal operating (day to day tuning) range without any degradation to performance, reliability, or lifetime of the components
20. % operating margin above the nominal design specifications while accepting minimal degradation. The maximum allowed degradation should be defined as that which reduces the lifetime of components by 10%.

1. Proton Injection Kicker (MI-10)

Title 1 specified a 50 mm offset between the injected and circulating beam requiring 0.95 mr (0.281 kG-m integrated field). Thekicker was specified to have a nominal value of 0.309 kG-m integrated field giving a 1.5 mr kick.  This provides the cpability of removing a 60 mm spearation with an integrated field of 0.34 kG-m.  This margin should provide for adequate day to day tuneability.  However, this range should not produce any degridation. 

2.  Proton Extraction / Pbar Injection (MI-52):

The 150 Gev/c level of this kicke was specified to produce a 0.525 mr kick with an integrated field of 2.625 kG-m.  This produces a nominal separation of 24 mm at the entrance of the first Lambertson.   This separation is adequate considering the beam-steel separation of at least 4 mm in the design for a 40 pi-mm-mr beam.  A 10% operating margin would produce an extra 2 mm separation which would be used in day to day tuning.  

3.  Pbar Extraction (MI-62):

This kicker is required to operate only at the 150 GeV/c level of 2.625 kG-m integrated field to provide a 24 mm separation between circulating and extracted beam.  Again adequate beam-steel clearance of at least 4 mm has been provided utilizing the 40 pi-mm-mr beam emittance.  A 10% daily operating margin provides an additional 2 mm separation at the Lambertson. 

4. Proton Abort (MI-40):

This kicker is required to operate from 8.9 to 150 GeV/c.  The nominal design specified an integrated field level from .371 to 2.625 kG-m to produce a separation between the circulating and extracted beam of 55 mm at 8.9 GeV/c and 22 mm at 150 GeV/c.   Again adequate beam-steel clearance of at least 4 mm has been provided utilizing the 40 pi-mm-mr beam emittance.  A 10% daily operating margin provides an additional 2 mm of separation at the Lambertson.

5. TeV Proton Injection (TEV-F17):

The nominal design kicker angle of .381 mr is produced by a 1.906 kG-mr integrated field strength.  A 10%  operating margin as a day to day tuning range provides for an additional 2 mm separation at the injection Lambertson.  Steering dipoles in the injection line will be uitilized along with this kicker to assure the proper closure on to the closed orbit.  Experience with the present injecdtion kicker at E17 indicates a tuning range of 10% to keep Tevatron Closure.  Thus, this should be an accepatble range for the F17 kicker.

6. TeV Pbar Injection (TEV-E48):

The nominal design kicker angle was 0.35 mr produced by a 1.75 kG-m integrated field strength.  This field strength will meet the requirements for injection on 0% helix or 100% pbar helix with the current separator configuration.  The pbar helix is defined to be the polarity which puts the pbar orbit on the outside of the Tevatron through F0 and E48.  The kicker strength specification does not currently allow injection of pbars on the 100% proton helix (i.e. opposite polarity helix).  However, the current design requires roughly one third the D48 upgrade kicker strength.  Also, further investigation on the selected phase of the helix with respect to the Tevatron operation is required.  therefore, a 10% daily operating margin is acceptable at this time.

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