JLEIC High-Energy Ion IR Design: Options and Performance Vasiliy Morozov JLEIC Accelerator R&D Meeting January 10, 2019

100 GeV/c Ion IR Optics Pole-tip fields are limited to 6 T FFB Far-forward detection Geometric match and dispersion suppression ions 𝜎 𝑥/𝑦 =21.7/4.3 𝜇m 𝜎 𝑥 ′ / 𝑦 ′ =0.22 mrad 𝛽 𝑥/𝑦 =10/2 cm IP Secondary focus iBDS2 iBDS3 iBDS1 Δ 𝑥 𝑓𝑟 = 𝐷 𝑥 Δ(𝐵𝜌)/(𝐵𝜌) 𝜎 𝑥 ′ / 𝑦 ′ =16/50 𝜇rad 𝜎 𝑥/𝑦 =292/19 𝜇m 𝛽 𝑥/𝑦 =69/37 cm 𝐷 𝑥 =−0.95 m January 10, 2019 JLEIC Accelerator R&D Meeting

Modifying IR Design for 200 GeV/c Constraints Maximum pole-tip fields at 200 GeV/c of 6 T  4.6 T Minimum impact on the forward hadron tagging performance compared to the 100 GeV/c design Minimum impact on the luminosity performance compared to the 100 GeV/c design Minimum impact on the beam dynamics compared to the 100 GeV/c design Options explored Reduced FF Quad Apertures Doubled Detector Space and Halved Crossing Angle Doubled Quad Lengths 1.5x Quad Lengths and 2/3 Crossing Angle  January 10, 2019 JLEIC Accelerator R&D Meeting

Doubled Quad Lengths: pCDR Appendix Version (IR v1) Keep maximum 𝛽-functions at ~2500 m  same maximum beam size Quad apertures  6 T / 𝜕 𝐵 𝑦 𝜕𝑥 at 200 GeV/c = 85 / 152 / 196 mm (radius) 𝜃≡ Quad aperture / distance from IP to quad’s far end = 9.1 / 10.0 / 10.5 mrad 𝛽 𝑥,𝑦 ∗ = 18 / 2.15 cm  𝐿 𝐿 0 =0.72, 𝐷 𝑥 at roman pot = 0.97 m January 10, 2019 JLEIC Accelerator R&D Meeting

Performance Optimization at Lower Energies (IR v1) Cut first FFQ in half and use the halves as the first and second FFQs at lower energies Can run in this mode up to 65 GeV/c proton momentum 𝛽 𝑥,𝑦 ∗ = 7.5 / 2 cm  luminosity improvement by a factor of 𝐿 𝐿 0 = 1.15 (up to 𝑝 𝑝 = 65 GeV/c) January 10, 2019 JLEIC Accelerator R&D Meeting

200 GeV/c IR Design with 4.6 T Pole-Tip Fields (IR v2) 𝛽 𝑥,𝑦 ∗ 𝑜𝑙𝑑 = 10 2 cm  𝛽 𝑥,𝑦 ∗ 𝑛𝑒𝑤 = 𝟔 𝟏.𝟐 cm 𝛽 𝑥,𝑦 𝑚𝑎𝑥 𝑜𝑙𝑑 =2.5 km  𝛽 𝑥,𝑦 𝑚𝑎𝑥 𝑛𝑒𝑤 = 𝛽 𝑥,𝑦 ∗ 𝑜𝑙𝑑 𝛽 𝑥,𝑦 𝑚𝑎𝑥 𝑜𝑙𝑑 𝛽 𝑥,𝑦 ∗ 𝑛𝑒𝑤 =𝟒.𝟐 km Constraints 𝛽 𝑥,𝑦 𝑚𝑎𝑥 ≤4200 m  𝛽 𝑥,𝑦 ∗ =19/1.6 cm  𝐿 𝐿 0 =0.48 Secondary focus in both planes Quadrupole aperture: 𝜃≥10 mrad Quadrupole length ratios: 1:2:1 Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒 ≤4.6 T Serious problem: forward detection region extends beyond figure-8 crossing point Figure-8 crossing point Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a/b 2.11 4.6 −33.5 13.7 11.7 iQDS2 8.44 17.1 26.9 12.7 iQDS3 4.22 −16.3 28.2 10.7 January 10, 2019 JLEIC Accelerator R&D Meeting

200 GeV/c Downstream IR Design with 4.6 T Pole-Tip Fields (IR v3) Quadrupole doublet instead of a triplet Constraints 𝛽 𝑥,𝑦 𝑚𝑎𝑥 ≤4200 m  𝛽 𝑥,𝑦 ∗ =19.6/1.6 cm  𝐿 𝐿 0 =0.48 Secondary focus in both planes Quadrupole aperture: 𝜃≥10 mrad Equal quadrupole lengths Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒2 ≤4.6 T, 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒3 ≤6 T Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a/b 2.23 4.6 −37.5 12.3 10.3 iQDS2 4.45 26.4 17.5 10.0 January 10, 2019 JLEIC Accelerator R&D Meeting

200 GeV/c Upstream IR Design with 4.6 T Pole-Tip Fields (IR v3) Doublet instead of a triplet Constraints 𝛽 𝑥,𝑦 ∗ =19.6/1.6 cm Quadrupole aperture: 4 cm radius Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) iQUS1 2.86 4.6 −115 4 iQUS2 2.04 115 January 10, 2019 JLEIC Accelerator R&D Meeting

Complete 200 GeV/c IR Design (IR v3) January 10, 2019 JLEIC Accelerator R&D Meeting

Optimization for Operation at up to 100 GeV (IR v4) 𝛽 𝑥 𝑚𝑎𝑥 is limited by the DA, 𝛽 𝑦 𝑚𝑎𝑥 is limited by HG effect Constraints 𝛽 𝑥,𝑦 𝑚𝑎𝑥 ≤4200 m  𝛽 𝑥,𝑦 ∗ =8.0/1.3 cm  𝑳 𝑳 𝟎 =𝟎.𝟖𝟑 up to 100 GeV Secondary focus in both planes Quadrupole aperture: 𝜃≥10 mrad Varied lengths of the first two quads Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T at 100 GeV/c 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒2 ≤4.6 T, 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒3 ≤6 T at 200 GeV/c Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a 2.21 4.6 −49.7 9.3 10.1 iQDS1b 2.27 38.4 12.0 10.0 January 10, 2019 JLEIC Accelerator R&D Meeting

Optimization for Operation at up to 100 GeV (IR v5) Adjusting quad length/aperture does not help to increase 𝐿, reached thin-lens limit, must adjust 𝛽 ∗ Approximation used to obtain 𝛽 𝑥 𝑚𝑎𝑥 = 𝛽 𝑦 𝑚𝑎𝑥 of 4.2 km is not very accurate because triplet is not a thin lens. Constraints 𝑳 𝑳 𝟎 =𝟏.𝟎 up to 100 GeV  𝜷 𝒙 𝒎𝒂𝒙 = 𝜷 𝒚 𝒎𝒂𝒙 ≤𝟓𝟎𝟖𝟓 m  𝛽 𝑥,𝑦 ∗ =6.6/1.1 cm (ratio is fixed for a doublet) Secondary focus in both planes 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T at 100 GeV/c 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒2 ≤4.6 T, 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒3 ≤6 T at 200 GeV/c Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a 2.21 4.6 −49.7 9.3 10.1 iQDS1b 2.27 38.4 12.0 10.0 January 10, 2019 JLEIC Accelerator R&D Meeting

200 GeV/c IR Design with 4.6 T Pole-Tip Fields (IR v6) Constraints 𝜷 𝒙,𝒚 𝒎𝒂𝒙 ≤𝟒.𝟐 km  𝛽 𝑥,𝑦 ∗ =15.2/1.5 cm  𝑳 𝑳 𝟎 =𝟎.𝟓𝟕 Secondary focus in both planes Quadrupole aperture: 𝜽≥𝟖 mrad Equal quadrupole lengths Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒2 ≤4.6 T, 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒3 ≤6 T Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a/b 1.74 4.6 −51.4 9.0 8.2 iQDS2 3.49 37.1 12.4 8.0 January 10, 2019 JLEIC Accelerator R&D Meeting

200 GeV/c IR Design with 4.6 T Pole-Tip Fields (IR v7) Constraints 𝜷 𝒙,𝒚 𝒎𝒂𝒙 ≤𝟓 km  𝛽 𝑥,𝑦 ∗ =12.8/1.2 cm  𝑳 𝑳 𝟎 =𝟎.𝟔𝟕 Secondary focus in both planes Quadrupole aperture: 𝜽≥𝟖 mrad Equal quadrupole lengths Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒2 ≤4.6 T, 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒3 ≤6 T Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a/b 1.74 4.6 −51.4 9.0 8.2 iQDS2 3.49 37.1 12.4 8.0 January 10, 2019 JLEIC Accelerator R&D Meeting

200 GeV/c IR Design with 4.6 T Pole-Tip Fields (IR v8) To take advantage of the smaller 𝑦 emittance must flip polarities of the quads in the doublet, otherwise run into HG problem. Crab voltage 𝑉 𝑐𝑟𝑎𝑏 ∝ 1 𝛽 𝑥 𝑐𝑟𝑎𝑏 𝛽 𝑥 ∗ Constraints 𝜷 𝒙 𝒎𝒂𝒙 ≤𝟓 km, 𝜷 𝒚 𝒎𝒂𝒙 ≤𝟏𝟎 km,  𝛽 𝑥,𝑦 ∗ =1.3/8.2 cm  𝑳 𝑳 𝟎 =𝟎.𝟖𝟏 Secondary focus in both planes Quadrupole aperture: 𝜽≥𝟏𝟎 mrad Equal quadrupole lengths Quadrupole length adjustment: 𝐵 𝑝𝑜𝑙𝑒−𝑡𝑖𝑝 ≤4.6 T 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒2 ≤4.6 T, 𝐵 𝑑𝑖𝑝𝑜𝑙𝑒3 ≤6 T Quad L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) iQDS1a/b 2.21 4.6 37.8 12.2 10.2 iQDS2 4.43 −26.5 17.4 10.0 January 10, 2019 JLEIC Accelerator R&D Meeting

JLEIC Accelerator R&D Meeting Summary Version # of quads L (m) 𝑩 𝒑−𝒕 (T) 𝝏 𝑩 𝒚 /𝝏𝒙 (T/m) 𝑹 (cm) 𝜽 (mrad) 𝜷 𝒙,𝒚 𝒎𝒂𝒙 (m) 𝑳/ 𝑳 𝟎 1 3 2.4/4.8/2.4 6 − 70.4 39.4 /−30.7 8.5/13.8/16.9 9.1 2,500 1.15 / 0.72 (65/200 GeV) 2 4.22/8.44/4.22 4.6 − 33.5 17.1 /−16.3 13.7/26.9/28.2 10.7 4,200 0.48 (200 GeV) 4.45/4.45 −37.5/26.4 12.3/17.5 10.0 4 (2.21,2.27)/4.45 −49.7/38.4 9.3/12.0 0.83 (100 GeV) 5 5,100 1.0/0.58 (100/200 GeV) 3.49/3.49 −51.4/37.1 9.0/12.4 8.0 0.57 (200 GeV) 7 5,000 0.67 (200 GeV) 8 4.43/4.43 37.8/−26.5 12.2/17.4 5,000/10,000 0.81 (200 GeV) January 10, 2019 JLEIC Accelerator R&D Meeting