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S.Kuroda ( KEK ). RTML ( Except Bunch Compressor ). Parameters and Layout Diagnostics and Beam Tuning Accelerator Physics Accelerator Components. Beam Parameters. Layout. Extraction from the DR ( ERTL/PRTL ). No vertical dogleg in ERTL because of the DR vertical position.
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S.Kuroda ( KEK ) RTML( Except Bunch Compressor ) Parameters and Layout Diagnostics and Beam Tuning Accelerator Physics Accelerator Components
Extraction from the DR ( ERTL/PRTL ) No vertical dogleg in ERTL because of the DR vertical position
Return Line ( ELTL/PLTL ) • Following the earth’s curvature in ML tunnel V correctors in each Q V dispersion matching by v correctors at both ends
Return Line ( ELTL/PLTL )(2) Geometry of the dog-leg defined in document EDMS: D*0969955 • Horizontal dogleg at the junction of ML and BDS, which is different in ELTL and PLTL due to positron target
Return Line ( ELTL/PLTL )(3) Mountain topography Flat topography
Turn Around • Horizontal dogleg • Vertical dogleg to adjust elevation to ML • 180-8 deg. turn around with dispersion matching( 8 deg. is needed for spin rotator ) • Bunch by bunch feed-forward. Time delay is 600 ns. z Spin Rotator x H-dogleg y V-dogleg z
Diagnostics • Cavity BPM • Laser Wire for emittance measurement
Beam Tuning • Dispersion Correction • Normal and skew Q in ERTL/PRTL in hx region • In pairs with –I --> No introduction of coupling • Normal Q in h/v dogleg of Turn Around • Coupling correction • 4 skew Qs in zero dispersion region downstream of ERTL/PRRTL and Spin Rotator
Beam Physics Issues • ISR Vertical emittance growth is negligible • Beam-Ion instability ( L.Wang, et al ) • < 2mPa
Beam Physics Issues (2) • Stray Field • Tolerance ( K.Kubo ) • 2nT for orbit jitter of 0.2sy • This can be corrected by fast feed-forward • Higher for emittance growth
Stray Field ( Measurement ) N.Solyak 2011
Beam Physics Issues (3) • Halo Formation from Scattering( S.M.Seletskiy ) • 2mPa 2e-6 of beam intensity < tolerance of 1e-5 • Space-Charge Effect • Incoherent space charge tune shift is O(0.15) in v • To be studied
Beam Physics Issues (4) • Emittance Preservation ( A. Latina )
Accelerator Components • Magnets • Vacuum • Requirement: < 2mPa
Summary and Work to Be Done • Lattice and optics design is almost done in TDR • Must be re-designed when the accelerator length is adjusted. • A few things of accelerator physics issue to be done? • Simulation study should be continued( emittance, ..) • Stray field measurement should be continued. • Space charge tune shift • …