1. Integration of Detector Solenoid into the JLEIC ion collider ring
G.H. Wei, V.S. Morozov, Fanglei Lin
Y. Nosochkov (SLAC), M-H. Wang
JLEIC R&D Meeting, JLab, Nov 17, 2016
F. Lin

2. Outline
Detector Solenoid Issues
An Integration Scenario
Summary

3. Detector Solenoid Issues
JLEIC Detector solenoid
Length
4 m
Strength
< 3 T
Crossing Angle
50 mrad
Ion e
Effects
e ring
ion ring
Coherent orbit distortion N Y
Coupling resonances
Rotates beam planes at the IP
Breaks H & V dispersion free
Perturbation on lattice tune & W function
Breaks figure-8 spin symmetry

4. Coherent orbit distortion
Detector Solenoid 1 T: Closed orbit V: ~170 mm, H: ~30 mm
Detector Solenoid > 2 T: No closed orbit

5. Coupling of X and Y betatron motion
Coupling betas (beta12 and beta21) are about 5 % of the values of beta11 and beta22, which turn into the usual beta x and beta y without coupling.

6. Break of H & V dispersion-free
Left: detector solenoid off
Right: detector solenoid on

7. Perturbation on lattice tune & W function
Detector solenoid status: Left: off; Right: on IP IP

8. An Integration Scheme A scheme:
Two dipole correctors on each side of the IP are used to make closed orbit correction. Here not only the orbit offset but the orbit slope is corrected at the IP.
Anti-Solenoid & Skew quads or components to make decoupling.
4 Skew quads with 0.1 meter are enough for each sider 8

9. An Integration Scheme Simulation Model of detector solenoid
MADX: misalignment option
Slices Model
MADX:
1.6 m + IP m (1):
select,flag=error,class=SOLDETDS;
ealign, DX:=-0.08, DTHETA:=-0.05;
select,flag=error,pattern="SOLDETUS";
ealign, DTHETA:=-0.05; 9

10. An Integration Scheme
Slices Model
: Vertical Kick
: Edge effect

11. Correction of Coherent orbit distortion
Slice Model
MADX_ealign
Two Models have almost same results.

12. Decoupling
Coupling betas (beta12 and beta21) are about 5 % of the values of beta11 and beta22, which turn into the usual beta x and beta y without coupling.
After decoupling, the coupling betas (beta12 and beta21) can be controlled locally in the interaction region and compensated at the IP.
Before decoupling
After decoupling

13. Re-matching (Transport Line)
Re-matching of Transport Line Model for twiss parameters, dispersions.

14. Re-matching (Global)
y = 7.5
y = 5.5
x = 12.5
x = 8.5
Re-matching of Global Model. The vertical dispersion of < 0.2 m can be ignored.
Phase advances between FFQ and chromatic sextupoles are restored with differences < 

15. LHC – Vertical Dispersion & IBS Growth Rates
Frank Zimmermann, IBS in MAD-X, MAD-X Day,
LHC – Vertical Dispersion & IBS Growth Rates
Dy is generated by the crossing angles (285 mrad) at IP1 and 2, as well as by the detector fields at ALICE and LHC-B; the vertical dispersion is about 0.2 m
Dy [m]
Dx [m]
x dispersion
y dispersion
s [m]
s [m]
IBS growth rates
no crossing angles & detector fields
with crossing angles
+ detector fields
tl [h]
57.5
58.6
tx [h]
103.3
104.2
ty [h]
-2.9x106
436.1

16. JLEIC – Vertical Dispersion & IBS Growth Rates
with crossing angle & detector field
with crossing angle & detector field
& Vertical dispersion as LHC level
No crossing angle & detector field
with crossing angle & detector field
crossing angles
+ detector field +
Dy (LHC level)
tl [h]
5.824
5.809
5.687
tx [h]
0.444
0.446
ty [h]
22.538
21.958
7.630

17. JLEIC – Vertical Dispersion & IBS Growth Rates
Up to 1 TeV
JLEIC
No crossing angle & detector field
with crossing angle & detector field
crossing angles + detector field + Dy ~ 1 m
tl [h]
tx [h]
4.810
4.834
4.878
ty [h]
-6.83E+04
-1.01E+05
64.013
IBS growth rates LHC
no crossing angles & detector fields
with crossing angles
+ detector fields
tl [h]
57.5
58.6
tx [h]
103.3
104.2
ty [h]
-2.9x106
436.1

18. Chromaticity Correction (W function)
Left: w/o detector; Middle: uncorrected; Right: corrected

19. Dynamic Aperture Red Line: only bare lattice
Black Line: with detector solenoid
Dynamic aperture has a shrinking to 50 , but large enough

20. Summary
Based on a sliced solenoid model, a correction system for the JLEIC detector solenoid is designed.
β function, dispersion, linear chromaticity and W function are also re-matched by adjusting quadrupole and sextupole settings. the vertical dispersion is not 0 but it is < 0.2 m around the ring. Its influences on IBS and other items can be ignored.
The dynamic aperture with integration of detector solenoid has a shrinking to 50  of beam size, which is also vary large due to the required dynamic aperture of 10 .

21. Thank you
F. Lin

22. Vertical and horizontal orbit oscillations
DX max. : mm
DY max. : mm
MADX
ealign
1.6 m + IP m
4.0 m
Slice
Model
1 Slice
40 Slices
100 Slices
200 Slices

23. Detector Solenoid Issues
Coherent orbit distortion
Transverse betatron coupling
Dynamic effect
Coupling resonances
Rotates beam planes at the IP
Breaks Horizontal and vertical dispersion free
Perturbation on lattice tune & W function of the first order chromaticity compensation
Spin effect
Breaks figure 8 symmetry
Crab crossing
Complicates the design if crab cavities are installed in a coupled region

24. Vertical and horizontal orbit oscillations
DX : mm
DY : mm
MADX
ealign
1.6 m + IP m (1)
1.6 m + IP m (2)
4.0 m
Slices
Model
1 Slice
40 Slices
100 Slices
200 Slices
400 Slices
1.6 m + IP m (1):
select,flag=error,class=SOLDETDS;
ealign, DX:=-0.08, DTHETA:=-0.05;
select,flag=error,pattern="SOLDETUS";
ealign, DTHETA:=-0.05;
1.6 m + IP m (2):
select,flag=error,pattern="SOLDETUS";
ealign, DTHETA:=-0.05;
select,flag=error,class=SOLDETDS;
ealign, DX:=-0.08, DTHETA:=-0.05;