150 likes | 161 Views
Collider Ring and IR – Optics Design for MEIC. Alex Bogacz. Figure-8 Collider Ring (electrons) Compact Arc with Low Emittance Dispersion〈H〉 Dispersive straight Asymmetric IR with conical FF quad (first) Pair of IRs with dispersion waves Chromaticity compensation
E N D
Collider Ring and IR – Optics Design for MEIC Alex Bogacz • Figure-8 Collider Ring (electrons) • Compact Arc with Low Emittance Dispersion〈H〉 • Dispersive straight • Asymmetric IR with conical FF quad (first) • Pair of IRs with dispersion waves • Chromaticity compensation • Natural Chromaticity Compensation - Arc and dispersive straight • ‘Compensation Block’ next to IR
Compact Figure-8 Collider Ring - layout 60 deg total ring circumference: 660 m
Electron Ring - Compact 2400 Arc dispersion suppressed with ‘missing dipoles’ 9 GeV phase adv./cell (Dfx= 1200, Dfy=1200) 2B/3 empty cells 2B/3 B/3 empty cells B/3 32 FODO cells, B 36 FODO cells, total arc length: 180 m 5 meter FODO cell Arc dipoles $Lb=150 cm $B=12.3 kG $ang=3.53 deg. Arc quadrupoles $Lb=50 cm $G= ±4.5 kG/cm
Electron Ring - Compact 2400 Arc No dispersion suppression 9 GeV phase adv./cell (Dfx= 1200, Dfy=1200) empty cells empty cells 36 FODO cells, B, total arc length: 180 m Arc dipoles $Lb=150 cm $B=11.6 kG $ang=3.33 deg. Arc quadrupoles $Lb=50 cm $G= ±4.5 kG/cm
Electron Ring - Dispersive Straight No dispersion suppression from the Arcs end 9 GeV phase adv./cell (Dfx= 1200, Dfy=1200) Arc 30 FODO cells, total length of the straight : 150 m quadrupoles $Lb=50 cm $G= ±4.5 kG/cm
IR Optics (6m + 6m ‘magnet free’ region) IP l * = 6m FF triplet : Q1 Q2 Q3 Q1 G[kG/cm] = 3.4 Q2 G[kG/cm] = -4.3 Q3 G[kG/cm] = 5.5
IR Optics – Beam Envelopes IP FF triplet l * = 6m • Asymmetric focusing (b*) for flat beams desirable, bx/by ~ 5 • Initial focusing of larger emittance plane results in minimized beam sizes in both planes • Manageable beam sizes on FF quads, sRMS ~ 3mm
IR Optics – Natural Chromaticity Q1 G[kG/cm] = 3.4 Q2 G[kG/cm] = -4.3 Q3 G[kG/cm] = 5.5 IP FF triplet : Q1 Q2 Q3 Natural Chromaticity: x=-139.1 y =-842.6
A pair of IRs - Anti-symmetric Dispersion Wave IP IP FF triplets FF triplets dispersion matching
A pair of IRs - Symmetric Dispersion Wave IP IP FF triplets FF triplets dispersion matching
Compensation Blocks symmetric dispersion wave anti-symmetric dispersion wave
Flexible Momentum Compaction Bend 4 × 450 rectangular bends singlet Q2 triplet Q5 Q4 Q3 triplet Q3 Q4 Q5
Same Bend Compensation Block inward bends Inward bends
Opposing Bend Compensation Block outward bends Inward bends
Conical First FF Quad IR? Pawel Nadel-Turonski