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

Outline Detector Solenoid Issues An Integration Scenario Summary

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

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

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.

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

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

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

An Integration Scheme Simulation Model of detector solenoid MADX: misalignment option Slices Model MADX: 1.6 m + IP + 2.4 m (1): select,flag=error,class=SOLDETDS; ealign, DX:=-0.08, DTHETA:=-0.05; select,flag=error,pattern="SOLDETUS"; ealign, DTHETA:=-0.05; 9

An Integration Scheme Slices Model : Vertical Kick : Edge effect

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

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

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

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 < 0.0002 

LHC – Vertical Dispersion & IBS Growth Rates Frank Zimmermann, IBS in MAD-X, MAD-X Day, 23.09.2005 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

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

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] 264.237 264.226 318.843 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

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

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

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 .

Thank you F. Lin

Vertical and horizontal orbit oscillations DX max. : mm DY max. : mm MADX ealign 1.6 m + IP + 2.4 m -0.17172 -2.27298 4.0 m -0.18462 -2.99203 Slice Model 1 Slice -0.0897 -2.99488 40 Slices -0.06063 -2.99576 100 Slices -0.05996 -2.99578 200 Slices

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

Vertical and horizontal orbit oscillations DX : mm DY : mm MADX ealign 1.6 m + IP + 2.4 m (1) -0.34345 -4.54597 1.6 m + IP + 2.4 m (2) -0.41505 -6.93988 4.0 m -0.36923 -5.98406 Slices Model 1 Slice -0.17940 -5.98977 40 Slices -0.12126 -5.99151 100 Slices -0.12021 -5.99154 200 Slices -0.11991 -5.99155 400 Slices -0.11976 1.6 m + IP + 2.4 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 + 2.4 m (2): select,flag=error,pattern="SOLDETUS"; ealign, DTHETA:=-0.05; select,flag=error,class=SOLDETDS; ealign, DX:=-0.08, DTHETA:=-0.05;