Berkeley Lab Generic Presentation

1
Asymmetric IR?
Alex Bogacz May 22, 2009

• Asymmetric in
• final focusing (different b in hor/vert)
• beam emiiance aspect ratio (hor/ver) flat
  beams
• energies (ions/electrons)
• longitudinal layout magnet free region
  longer on one side of the IP
• Options for large magnet free IR design (9 m
  9 m)

2
Longitudinally asymmetric detector
9o
Caldwell-type detector (see arXivhep-ex/
0407053v1)
CLAS12 space (fixed target program) 10 meter on
ion side Initial EIC detector cartoon about 8
meter on ion side
3
Magnet free region beam sizes
beta function evolution in a drift space
s - distance from the IP
beta function at the first FF quad (distance l
from the IP)
4
60 GeV Ions - IR (half)
b 5 mm
solenoid
IP
9 m
FF triplet
FF quads Lb50/100/50 cm G18/-18/18 kG/cm
5
60 GeV Ions - IR (half)
b 5 mm
FF doublet
FF triplet
FF quads Lb50/100/50 cm G18/-18/18 kG/cm
FF quads Lb50/50/50/50 cm G23/-25/10/-10 kG/cm
9 m
9 m
6
60 GeV Ions - IR (half)
b 5 mm
b 5 mm
FF doublet
FF triplet
9 m
9 m
7
MEIC Parameter Table Medium Energy
Yuhong Zhang
8
Large magnet free region IR (9m 9m)
manageable beam sizes at the first FF quad
(distance l from the IP)
9
Large magnet free region IR (9m 9m)
manageable beam sizes at the first FF quad
(distance l from the IP)
10
Conclusions

• Longitudinally asymmetric IR has no advantage
• The longest distance between the IP and the first
  quad is critical for FF quad apertures
• (9m 3m) IR as challenging as (9m 9m) IR
• Triplet vs Doublet FF Optics
• Same magnet apertures required
• Triplet focusing more compact
• Doublet focusing more suitable for interleaved
  FFs for smaller beam crossing
• Flat beams favorable, ex/ey 10
• Beam-beam interaction
• Luminosity optimization
• Asymmetric focusing (b) for flat beams
  desirable, bx/by 10
• Initial focusing of larger emittance plane
  results in minimized beam sizes in both planes
• Manageable beam sizes on FF quads, sRMS 5mm