1. SuperB Injection, RF stations, Vibration and Operations
John T. Seeman
for the SuperB Accelerator Team
2nd IRC Meeting
Rome
April 29-30, 2008

2. Outline
Injection
RF stations and power
Vibration
Operations

3. SuperB New Parameters
Beam-beam
transparency
conditions in red

4. Injection
Injection needs to provide 7 GeV polarized e- and 4 GeV e+, both with damped emittances. Would be good to allow opposite charges if needed.
Share linac facilities with the SPARX FEL project where appropriate.

5. SuperB footprint on Tor Vergata site
SuperB Ring (about 1800m)
SPARX
Roman Villa
100m
SuperB Injector (about 400m)
SuperB Main Building

6. Schematic injection layout
e- DR
7 GeV e- or e+
Spin rotator
e+ target
e- gun
polarized
1 GeV
4 GeV linac
1 GeV
4 GeV e+ or e-
e+ DR
~300 m
~20 Hz to make e- for SuperB HER
~40 Hz e- to make e+ for DR
~40 Hz e+ to SuperB LER
At 2x1010 ppp with single bunches, injector gives:
4x1011/sec e- and 8x1011/sec for e+
Good for 4x1036 then go to two bunches per pulse.

7. RF stations and power
The plan is to use the PEP-II RF stations without changes: klystrons, cavities, power supplies and controls.
15 PEP-II stations are available: 10 stations needed for initial operation. Hold in reserve 5 stations for upgrades to 2 x 1036.
Studies have been done for determination of total RF power needed including synchrotron radiation and Higher Order Modes (HOM) power for both rings.

8. RF power estimate Including synchrotron radiation, HOMs and RF power
with 50% klystron efficiency
A. Novokhatski
CDR parameters
New parameters

9. PEP-II RF Cavities Each cavity: 850 kV 500 kW 476 MHz HOM loads
Ceramic
windows
RF Cavities

10. B-Factory RF Klystrons (1.2 MW) under construction

11. Reuse of PEP-II Components
PEP-II turned off April 7, 2008, after producing 557 fb-1 for BaBar.
PEP-II is being transitioned into a Minimum Maintenance State (MMS) where hardware is preserved for future use. (i.e. magnets drained and dried, vacuum system vented to N2 and capped in a controlled manner, RF stations secured.)
A preview process has been formed to disperse equipment.
Most requests so far are for small components: power supplies, vacuum parts, computer-control hardware, diagnostics.
SuperB is a major requestor of components and is one of the major placeholders on the request list.

12. The PEP-II Collider

13. Vibration tolerances
Establishing low emittances in both rings (x and y) are essential for the successful operation of SuperB.
In addition, keeping the beams in collision transversely is also essential.
Potential mechanical vibration of the magnets (mostly quadrupoles and sextupoles) could affect both the emittances and beam collisions.
Studies have been done by the Super-B, ILC DR, and the NSLC-II Light Source teams to set vibration specifications. All of these rings have very similar specifications.

14. Vibration Tolerances All the same!
Typical measured vibration is at the 10 to 200 nm level at
frequencies above the feedback frequency of a few Hz.

15. Interaction Region Quadrupoles
Rough scale of
jitter tolerances:
Region of
concern
3 nm
Natural quietness easily spoiled by cultural noise
Final quads: tolerance ~10% IP beam size ~ 3 nm.
Rely on active methods to keep beams colliding
At low frequencies everything moves together and little feedback is needed.
10-1 1
102

16. Inertial stabilization R&D at SLAC one object, 6D, digital feedback
Side view
Inertial sensors
Schematic of the object to be stabilized
(ILC group: Himel et al)

17. Real Data from Test System
Feedback was turned on after 10 seconds.
RMS improved dramatically: damping 17 nm jitter to 0.33 nm!
Each SuperB IR quadrupole will have a damper like this one.
Thanks ILC!

18. Operations
The goal for SuperB operation is to run 10 months per year with 1 month accelerator tune-on and 9 months of beam delivery.
There will be about a 2 month shut-down each year for maintenance and accelerator improvements.
The upgrades to the accelerator to reach 2 to 4 x 1036 will be done during these shut-down periods.
The number of staff members and the skill sets needed to operate this accelerator are being studied and will be included in the TDR study.