1. 24/01/08Energy deposition, LIUWG, Elena Wildner1 Upgrade phase 1: Energy deposition in the triplet Elena Wildner Francesco Cerutti Marco Mauri

2. 24/01/08 Energy deposition, LIUWG, Elena Wildner 2 Outline Nominal, IR1 and IR5 Some basic considerations The upgrade Phase I scenario Simulation results Continuation Conclusion

3. 24/01/08 Energy deposition, LIUWG, Elena Wildner 3 Work on the nominal insertion layout Energy deposition studies independently Fermilab, 2002 & CERN, 2007 (LHC report 633 and LHC note to appear) with MARS and FLUKA In addition comparisons have been made on representative toy model Agreement 5 % in coils 20% in iron Studies so far up to D1

4. 24/01/08 Energy deposition, LIUWG, Elena Wildner 4 Models of baseline IR1 and IR5 Courtesy C. Hoa Liner in Q1 and MCBX of thickness 6.5 mm (stainless steel) Length 31 m Magnet apertures 70 mm Half crossing angle 145.5  rad

5. 24/01/08 Energy deposition, LIUWG, Elena Wildner 5 Heat load along the triplet, “nominal” To limit the peaks in the superconducting coils: our first objective Luminosity= L0 (1 *10 34 cm -2 s -1 ) Q1 Q2a Q2b Q3 Courtesy C. Hoa Recommended limit

6. 24/01/08 Energy deposition, LIUWG, Elena Wildner 6 The scoring Cable  We make the binning for the scoring so that it corresponds to a minimum volume of equilibrium for the heat transport (cable transverse dimensions, with a length corresponding to the twist pitch of the cable) Total power deposited in the magnets  Important to know the volume of the magnet (the model has to be realistic) The power deposited per meter of magnet  Azimuthal integration of the power in the longitudinal bins Important for results to know how this is calculated and choose correct bin size!!! Length (L) 10 cm (twist pitch) Transverse area of cable (A) Scoring volume: A*L

7. 24/01/08 Energy deposition, LIUWG, Elena Wildner 7 Effect of Magnetic Field, nominal IR5

8. 24/01/08 Energy deposition, LIUWG, Elena Wildner 8 Effect of the TAS Q1, no TAS Q1, TAS 40 mm aperture ”Symmetric” upgrade layout

9. 24/01/08 Energy deposition, LIUWG, Elena Wildner 9 Effect of Crossing Angle, nominal IR5 Total Peaks

10. 24/01/08 Energy deposition, LIUWG, Elena Wildner 10 Basic considerations (summary) Beam Pipe  The beam pipe between magnets shields the front face of the downstream magnet  The experimental vacuum chamber before the TAS has to be properly integrated  We do not include the experimental vacuum chamber before the TAS in our calculations yet TAS  The TAS protects essentially the first quadrupole Magnetic field  The magnetic field is driving the deposited energy Mask  A mask outside the magnet aperture does not affect the energy deposited in the cable Crossing angle  The effect of the crossing angle is smaller than 20%

11. 24/01/08 Energy deposition, LIUWG, Elena Wildner 11 The layout, Phase I 9.40m7.80m 9.40m 41 m 130mm Q1 Q2a Q2b Q3 “Symmetric” IP1 Positive particle + FDDF TAS MagnetMQXC Configuration“Symmetric” Gradient [T/m]120 Aperture [mm]130 Peak Field [T]8.7 Layers2 LHC Project Report 1000: “A Solution for Phase- one Upgrade of the LHC Low-beta Quadrupoles Based on Nb-Ti”, J. P. Koutchouk, L. Rossi, E. Todesco For comparison: “Nominal” (L=L0) layout is about 30 m long. Half crossing angle: 220  rad, vertical

12. 24/01/08 Energy deposition, LIUWG, Elena Wildner 12 The Magnet/Field Model Courtesy: F. Borgnolutti 4 X MQXC 130 mm Aperture 270 mm Cold Mass outer diameter 570 mm

13. 24/01/08 Energy deposition, LIUWG, Elena Wildner 13 The magnet ends The magnets have in this first study the same length as the magnetic length: mechanical length = magnetic length No coil ends are modeled (the same transverse layout over the whole magnet) No 3D field or hard edge approximation

14. 24/01/08 Energy deposition, LIUWG, Elena Wildner 14 Beam pipe dimensioning Relation thickness (t) and diameter (D), valid for stainless steel: t = 0.0272D Example for 130 mm aperture quads ( 3.5 mm is the gap between coil and beam tube): OD = 130 mm - 3.5 mm = 126.5 mm Thickness of beam pipe according to formula: t= 3.45 mm ID = 126.5 mm – 2*3.45 mm = 119.6 mm

15. 24/01/08 Energy deposition, LIUWG, Elena Wildner 15 “Baseline”or “reference” case, no shielding Minimum thicknesses for mechanical considerations: Beam-Pipe 3.45 mm Beam-Screen 2 mm Ref. value for max energy deposition 4.3 mW/cm 3 Continuous beam-screen and pipe, no experimental vacuum pipes Q1 Q2a Q2b Q3 Peak in coils Luminosity = 2.5 L0

16. 24/01/08 Energy deposition, LIUWG, Elena Wildner 16 Azimuthal heat deposition pattern, Q2a  = 180/16

17. 24/01/08 Energy deposition, LIUWG, Elena Wildner 17 Beam-screen, case 3mm W-liner 108.2/2 OD = 119.6 mm – 2 * 0.7 mm – 2 * 3 mm = 112.2 mm ID = OD – 2 * 2 mm = 108.2 mm Necessary Gap Liner Beam-Screen thickness 102.61/2 Additional restriction on vertical aperture

18. 24/01/08 Energy deposition, LIUWG, Elena Wildner 18 Liner dimensioning Space CBT-BS [mm]0.7 Coil Aperture [mm]130 CBT Outer Diameter [mm]126.5 CBT thickness [mm]3.45 CBT Inner Diameter [mm]119.6 BS Outer Diameter [mm]112.2 BS Inner Diameter [mm]108.2 BS thickness [mm]2.0 Capillary Outer Diameter [mm]4.76 h max [mm]102.68 w [mm]11.1 S [mm]1.1 Liner thickness [mm]3.0 Width of liner [mm]17.44 h max = D i,CBT - 2*0.7-2*4.76 - 2*2.0 -2*s= D i,CBT - 14.92 - 2*s D i,BS = D i,CBT - 2*0.7-2*2.0 – 2*3.0= D i,CBT – 11.4 s= (D i,CBT /2 - 4.76/2-0.7)(1-Cos[  ]) w= (D i,CBT /2 - 4.76/2-0.7)(Sin[  ]) Width of liner: w - outer radius of Capillary = 22.2 mm - 4.76 mm  s w Liner Old Capillary Position Beam-pipe and beam-screen as thin as mechanically possible! Magnet aperture 130 mm same in all 4 magnets.

19. 24/01/08 Energy deposition, LIUWG, Elena Wildner 19 Adding a liner along the Triplet Continuous beam-screen and pipe, liner also between magnets Recommendation: 3 mm W shield up to Q2

20. 24/01/08 Energy deposition, LIUWG, Elena Wildner 20 Liner not covering entirely gap Q1-Q2 Liner 3mm W No shielding, only BS and BP Gap

21. 24/01/08 Energy deposition, LIUWG, Elena Wildner 21 Liner not covering entirely gap Q1-Q2 Shielding like for “nominal”: Peak due to 1.5 m “gap” Shield needed between magnets

22. 24/01/08 Energy deposition, LIUWG, Elena Wildner 22 Between the Q1 and the Q2 magnets 1.4 cm stainless steel (checked case) Critical region, must be shielded: 1.Coil end 2.BPM aperture Nominal Layout

23. 24/01/08 Energy deposition, LIUWG, Elena Wildner 23 TAS opening The TAS opening in the simulations is 55 mm (R. Ostojic, S. Fartoukh)

24. 24/01/08 Energy deposition, LIUWG, Elena Wildner 24 TAS, lateral and backwards scattering Normalization (L upgrade = 2.5 L 0 )

25. 24/01/08 Energy deposition, LIUWG, Elena Wildner 25 TAS, mechanical considerations Luminosity: 2.5 10 34 cm -2 s -1 TAS aperture: 55 cm Total power in TAS: 300 W Peak: 131 mW/cm 3 ± 7% Fluka - > Ansys

26. 24/01/08 Energy deposition, LIUWG, Elena Wildner 26 Continuation Choice of pipe sizes and absorbers for next iterations Model of the region between Q1 and Q2a to be refined 3D field of coil ends, mechanical lengths Corrector magnets to be implemented Including D1, TAN, D2 and Q4 Detailed experimental pipes also before TAS Detailed study on the beam particle distributions at the collisions Ions

27. 24/01/08 Energy deposition, LIUWG, Elena Wildner 27 Conclusion 1. The beam-pipe and the beam-screen thicknesses are enlarged (aperture increase): decreases energy deposition in coils! 2. For good coil protection, we propose to add a 3 mm tungsten sheet (or equivalent) around the beam screen up to the entry of the second quadrupole. 3. We need to design detailed shielding in the region close to the beam-pipe between Q1 and Q2a, according to point 2 above (BPM, RF-conncetion, interconnects…)

28. 24/01/08 Energy deposition, LIUWG, Elena Wildner 28 Thanks to R. Ostojic V. Baglin S. Fartoukh M. Karppinen S. Sgobba L. Tavian  And others… Alessio Mereghetti Joined team from 01/01/2008

29. 24/01/08 Energy deposition, LIUWG, Elena Wildner 29 Comparison, smaller aperture TAS The effect of 3 mm SS between magnets is important for peak in second quad The smaller TAS aperture shields better the entrance of the first quad