1. BINP Tau-Charm Project Update E.Levichev, BINP, Novosibirsk
SuperB Workshop
LAL, Orsay, February 15-18, 2009

2. Topics: 1. Novosibirsk CT Project briefly 2. IR design 3. FF and QD0 4
Topics: 1. Novosibirsk CT Project briefly 2. IR design 3. FF and QD0 4. Polarization insertions

3. Layout Injection facility exists
Tunnel for the linac and the technical straight section of the factory is ready

4. Scientific case ► D-Dbar mixing
► CP violation searches in charm decays
► Rare and forbidden charm decays
► Standard Model tests in  leptons decays
► Searches for lepton flavor violation
► CP/T violation searches in t leptons decays
Requirements: L > 1034 cm-2 s-1, longitudinal polarization
► Production of the polarized anti-nucleons
Energy = 1 GeV with reduced luminosity

5. Specifications
► Variable energy Ecm= 3 – 4.5 GeV (from J/psi to charm baryons) (2 – 4.5 GeV?) ► L = 1÷2×1035 cm-2s-1 (crab-waist approach) ► e-s are polarized longitudinally at IP ► No energy asymmetry ► No beam monochromatization ► Energy calibration with medium accuracy is enough (Compton backscattering)

6. Main accelerator parameters
8 m of the SC wigglers with 20-cm-period are used to control the beam parameters at different energies

7. Luminosity
D.Shatilov

8. IR
 Old
A.Bogomyagkov
P.Piminov
New 

9. Last modifications Beta*x = 2 cm  3 cm (in QF1 Beta x = 800 m  350m)
Separation of the betas in SY & SX is better
–I between SY1 –SY2 & SX1-SX2 is designed with very high accuracy
Sextupole length L = 30  20 cm
Special weak sextupoles (~3% of the main ones) correct 4D DA very effectively
Special sextupoles open the energy bandwidth to ±2%
Chromaticity of Betas is intrinsically small for the telescope scheme and sextupoles are used to zero the chromaticity of Alphas (Betas’)

10. Parameters old/new
x 300 bunches = 1 x 1035

11. IR optics
L1/2 = 85 m

12. IR sextupole correction scheme

13. Telescope transformation
A.Bogomyagkov
Map:
Twiss transformation:
Transport notation:
Chromaticity:
Telescopic symmetry:
Sextupoles to cancel

14. Bandwidth
BW = ±2%

15. DA correction
P.Piminov

16. FF quadrupoles

17. QD0
Cosine SC quadrupole with short end coil region with optimized 6th and 10th integrated harmonics (<10-3)
Active quench protection system with heater
P.Vobly

18. QD0 main coils connection
Two additional current sources allows to compensate influence of the coils misalignment and manufacturing errors on the field with high accuracy. The tuning is done during the magnetic measurements.

19. QD0 assembling

20. Polarization insertion I
S.Nikitin
Central arc
Disadvantage: the scheme operates well only for the nominal energy.
At the nominal energy the magnets rotate the spin around the field direction by (2k+1), k is integer. Solenoids rotate the spin by /2 around the velocity vector: a polarization vector is longitudinal at IP and transverse outside the polarization insertion.

21. Polarization insertion II
Achromatic central arc
Advantage: the scheme is optimally tuned by the solenoids in the whole energy range!

22. Polarization insertion III
Arc
Achromatic arc
Longitudinal polarization degree, averaged on time and particle ensemble

23. Summary
► CT project interaction region is designed with parameters (bandwidth, dynamic aperture, crab sextupoles location, etc.) satisfied the project requirements
► Design of the final focus superconducting quadrupoles is started and preliminary configuration of the large aperture QD0, shared by both beams, with the required parameters is found
► New polarization insertion based on the achromatic arc is proposed. Solenoids allow to tune the polarization at IP in the wide energy range