Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Introduction/Specifications Eric Prebys Proton Plan Manager

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Purpose of this Meeting We plan to replace the corrector system in the Booster. This is a major project, which is the last significant upgrade which is planned for the Booster. This system is the basis for the increased Booster efficiency required to meet the needs of the neutrino program through at least the middle of the next decade. We are on an aggressive schedule to install half of the correctors in 2006 and the remainder in 2007 If there are problems, we have to find them ASAP to have any hope of addressing them.

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Scope of the Review We’ll talk about  Specifications  Design  Power supplies  Production  Testing  Installation We won’t talk about  Control software  Integrated BPM’s

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Questions for the Committee (charge) 1.Are the magnetic specifications for the corrector packages well suited to the goals of controlling beam position and maximizing Booster efficiency? 2.Is the corrector design well matched to the magnetic specifications in terms of multipole strength, slew rate, field quality, and repetition rate (heat load)? 3.Have the magnetic measurements adequately demonstrated the acceptability of the corrector design and are the proposed production measurements adequate for quality assurance? 4.Are the power supplies and associated control hardware and control hardware appropriate for the requirements of the system? 5.Is the mechanical for the installation optimal? 6.Is the installation plan for the long straight correctors reasonable, given the eight week length of the 2007 shutdown? This should address all aspects of installation, including the corrector and power supply installation, cabling, cooling water, alignment, and quality control. 7.What are the biggest risks, in terms of procurement, remaining design, fabrication, and installation?

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Corrector magnets Purpose of Booster corrector system  Dipoles: Control beam position. Used in conjunction with collimation system to scrape beam halo Used to help maintain precise aperture below extraction septum  Quadrupoles: Maintain tune through cycle. Cancel harmonic resonances.  Skew Quadrupoles: Cancel coupled harmonic resonances.  Sextupoles: Control chromaticity to damp head tail instability Cancel harmonic resonances  Skew sextupoles: Cancel harmonic resonances

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Existing Corrector System Each of the 48 sub-periods in the Booster has an (original) trim package, containing  Horizontal and Vertical trim dipoles Low-  trims are operated DC –horizontal long straights –vertical short straights Recently, the high-  trims were upgraded to be controlled by individual ramped current controllers –Horizontal short straights –Vertical long straights –Important for controlling losses  Normal and skew quadrupoles Individual DC components for harmonic correction, added to A common ramp (one for each type) In addition, there are ramped sextupole correctors at discrete locations (3 normal, 2 skew)  Work together with small number of DC sextupoles in a manner similar to the quads

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Weaknesses of existing system Trim dipoles  Inadequate strength or slew rate to control beam position throughout cycle Quadrupoles  Inadequate strength to hold constant tune through cycle  Inadequate slew rate at transition Sextupoles  Strength adequate  Inadequate slew rate at transition  Discrete locations Result in emittance blow up Limit number of resonances which can be cancelled

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Resonance Correction* The Booster is susceptible to the following third order resonances: We currently try to correct these with sextupoles at a few discrete point in the ring. Putting sextupoles at every period will greatly improve our ability to cancel these resonances. *See A. Drozhdin, “Fermilab Booster Dynamic Aperture Simulation with new Injection/Extraction Schemes”, Correct with normal sextuples Correct with skew sextuples

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Beam Motion Beam Position at all periods around the ring relative to the position at injection. Traces plotted for 5 ms intervals. Vertical Horizontal

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Corrector Goals Specifications for new corrector system:  Position Control: Be able to produce 1 cm of beam motion at highest beam energy (8GeV). Be able to slew position 1 mm/ms up to the middle of the cycle. –Correct observed beam motion –Work in conjunction with collimation system  Tune Control: Maintain tune arbitrarily close to upper integer resonance throughout cycle. Be able to switch from full field plus to full field minus in ~1 ms in order to rapidly switch tunes at transition time.  Sextupoles Total strength consistent with existing system. Increase slew rate – to full field minus in ~1 ms in order to rapidly switch chromaticity at transition time.

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Meeting the Goals Aperture:  4.5” physical aperture  Fields good to 1% out to 40  ~ +-1.5” max Control system specifications:  Ramped control of ALL (6x48) elements  Closed orbit position correction through cycle  Time dependent harmonic correction in addition to global multipole control

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Evaluate Effect of Booster Improvements Calculate effect of various improvements based on increased acceptance: Use: Effective aperture reduction

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys Additional Effects Effect of quadrupoles  Better tune control  Not yet quantitatified Effect of increased number of sextupole  ~10% emittance reduction  Better harmonic correction not yet quantified

Booster Corrector Review, Oct. 10 th, 2006 E. Prebys 8:45 AMExecutive session (15 minutes) 9:00 AMIntroduction and magnet requirements (20 minutes) – Eric Prebys 9:20 AMMagnet design and production plan (40 minutes) – Dave Harding 10:00 AMMagnet measurements (35 minutes) – Phil Schlabach or George Velev 10:35 AMBreak (15 minutes) 10:50 AMPower supplies (20 minutes) – George Krafczyk or other EES designee 11:10 AMInstallation and safety (30 minutes) – Craig Drennan 11:40 AMConcluding questions and discussion (20 minutes) 12:00 AMExecutive session Lunch 1:30 PMCloseout (15 minutes) Agenda