1. 31/07/08Review new IRs: Energy Deposition1 Energy Deposition in the New IRs Francesco Cerutti, Marco Mauri, Alessio Mereghetti, Ezio Todesco, Elena Wildner AB/ATB and AT/MCS With contributions from: Frank Borgnolutti, Jens Bruer, Alfredo Ferrari, Christine Hoa, Vasilis Vlachoudis and others

2. 31/07/08 Review new IRs: Energy Deposition 2 Outline Triplet Upgrade  Parametric approach The Art of Binning Results  Peak energy deposition  Influence of interconnections  Total loads  Particle Fluences Conclusions (Part 1) 110 mm aperture case: power deposition and dose in TAS Triplet and corrector package D1 TAN D2 Part One: General aspects triplet Part Two: A Shielding Option: thick Liner in Q1 Part Three: Particle fluences in electronics locations UJ56 Conclusions (Part 2 and 3)

3. 31/07/08 Review new IRs: Energy Deposition 3 The Triplet, Parametric Approach Aperture (mm) Gradient (T/m) L(Q1,Q3) (m) L(Q2a,b) (m) Total length (m) 901568.697.4636.2 1151259.988.4240.7 13011210.819.0443.6 14010411.419.4945.7 Total Length Q1 Q2a Q2b Q3 “Symmetric” IP1 TAS No Corrector in triplet Half Crossing angle 225  rad, vertical TAS aperture 55 mm Max (cable length) Actual gradient: 215 T/m TAS at 19 m, Q1 at 23 m (like actual)

4. 31/07/08 Review new IRs: Energy Deposition 4 The Magnet Cross Section

5. 31/07/08 Review new IRs: Energy Deposition 5 Parameter Space for Parametric Study Q1 Positioned at 23 m from the IP Gaps between magnets 1.3 m  Impacts the peak in energy deposition we get on the following magnet Symmetric triplet  All magnets have the same aperture  All magnets have the same gradient  Q1 and Q3 have the same length  Q2 is split in two parts of equal length Magnets have “costheta” design  Two layers We get one family of solutions: (Aperture, gradient, length linked) Different from latest “New Triplet” layout, small effect

6. 31/07/08 Review new IRs: Energy Deposition 6 Beam pipe/Beam Screen Dimensioning For the Cold Bore Tube (Beam Pipe):  Relation thickness (t) and diameter (D), valid for stainless steel (pressure vessel code, 25 bar ): t = 0.0272D For the Beam Screen:  Calculations gave the same minimum thickness for all cases (1 mm)  we have used 2 mm (similar as for the previous simulations of the upgraded triplet) Courtesy: G. Kirby, C. Rathjen Cold Bore Tube and Beam Screen act as shielding. For parametric study: get the minimum necessary thicknesses for the different cases chosen Aperture [mm] BP thickness [mm] BS thickness [mm] 902.42.0 1153.02.0 1303.42.0 1403.72.0

7. 31/07/08 Review new IRs: Energy Deposition 7 The Scoring for the Triplet Peak power in cable (quench)  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 (cryogenics)  The outer diameter of the magnets (cold mass) is the same The power deposited per meter of magnet  Azimuthal and radial integration of the power in the longitudinal bins Particle fluence/dose Transverse area of cable (A) Scoring volume: A*L Length (L) 10 cm (twist pitch)

8. 31/07/08 Review new IRs: Energy Deposition 8 The Bins and the Results The indicative value 4.3 mW/cm 3 (P. Limon, private communication) is valid for Rutherford cable in LHC main magnets, including contingency of a factor of 3! Cable bin For other cables and magnet designs, this value has to be revised. For dose calculations (for example cable, insulation and spacers) the bins have to be chosen to get the dose that in reality would damage the bulk material in the object (mechanical and electrical properties) Insulation

9. 31/07/08 Review new IRs: Energy Deposition 9 Peak Power Deposition I Power 100% increase 140 -> 90

10. 31/07/08 Review new IRs: Energy Deposition 10 Peak Power Deposition II Rescaling longitudinally shows that the pattern is similar! Large effect for Q1 & Q2a

11. 31/07/08 Review new IRs: Energy Deposition 11 Between the Magnets (1) The gaps between magnets cause a accumulation of non intercepted particles: peaks at the entrance of magnets (particles from IP collisions) Smaller gaps or shielding of interconnection region interesting Magnet1 Magnet2 IP The more smooth pattern is due to the magnetic field (spectrometric effect) Over all the magnet: Cable 1(red) twice the peaks of cable 2 (blue) => for correctors, for example, use inserts in aperture

12. 31/07/08 Review new IRs: Energy Deposition 12 Between the Magnets (2)

13. 31/07/08 Review new IRs: Energy Deposition 13 Peak Power Deposition III Large effect in Q1 & Q2a small in Q2b and Q3 Power

14. 31/07/08 Review new IRs: Energy Deposition 14 Total Heat Load Choice of beam screen thickness: redistribution of heat loads

15. 31/07/08 Review new IRs: Energy Deposition 15 Horizontal/Vertical Crossing Can we use our results to scale without re- computing?

16. 31/07/08 Review new IRs: Energy Deposition 16 Particle type Distribution, all 4 Magnets Fluence scored in the first cable over each magnet. Interactions from material inside aperture (Beam Screen and Beam pipe) Smallest (90mm) and largest (140 mm) aperture will be shown ParticleFraction [%] 90 mm140 mm photons 87.086.0 neutrons 6.07.8 electrons 3.53.3 positrons 2.52.3 pions 0.4 protons 0.15

17. 31/07/08 Review new IRs: Energy Deposition 17 Neutron Fluence 90mm/140mm Calculated for 300fb -1 integrated Luminosity

18. 31/07/08 Review new IRs: Energy Deposition 18 Neutron Spectra 90mm/140mm > 1 MeV neutrons most critical for damage

19. 31/07/08 Review new IRs: Energy Deposition 19 The Triplet Layout as of 30/07/08 110 mm aperture Parametric study

20. 31/07/08 Review new IRs: Energy Deposition 20 Summary, General Part (1) The deposited peak power (quench) decreases with the triplet length. Shorter triplets (smaller apertures) need more shielding (takes more aperture). The decrease with length is largest in Q1 and Q2, where we also have the highest peaks. The total heat load on the triplet is decreasing (up to 140 mm at least) with length: between 90 and 130 mm aperture we have 16 % less, including the beam screen. Pattern of energy deposition is similar for all lengths however not identical for the two insertions (1 and 5).

21. 31/07/08 Review new IRs: Energy Deposition 21 Summary, General Part (2) The distribution of particle types in Q1 is very similar for 90 and 140 mm. Spectra similar, ~1.5 time higher fluence for 90 mm than for 140 mm aperture Great care has to be taken for binning in cables for power deposition (quench) and for longevity of objects (dose calculations), studies ongoing

22. 31/07/08 Review new IRs: Energy Deposition 22 ENERGY DEPOSITION IN THE TAS-D2 REGION FOR A TRIPLET SHIELDING OPTION (THICK LINER IN Q1) power values referred to a 2.5 10 34 cm -2 s -1 luminosity time integrated values referred to a 100 fb -1 total luminosity

23. 31/07/08 Review new IRs: Energy Deposition 23 80 MGy/100fb -1  r=1cm x  =2 o x  z=2cm scoring grid 45mm TAS aperture -> 110mm triplet coil aperture TAS

24. 31/07/08 Review new IRs: Energy Deposition 24 TAS 55mm TAS aperture -> 130mm triplet coil aperture peak power 114 mW/cm 3 total power 325 W 45mm TAS aperture -> 110mm triplet coil aperture peak power 180 mW/cm 3 total power 385 W 34mm TAS aperture peak power 110 mW/cm 3 total power 184 W present LHC (L=L 0 ) N.V. Mokhov et al., LHC Project Report 633

25. 31/07/08 Review new IRs: Energy Deposition 25 TRIPLET AND CORRECTOR PACKAGE 110mm coil aperture Q1Q2aQ2bQ3 10mm thick additional liner 75mm residual aperture

26. 31/07/08 Review new IRs: Energy Deposition 26 TRIPLET AND CORRECTOR PACKAGE horizontal crossing 8.05 m from the IP face 0.25 m from the IP face

27. 31/07/08 Review new IRs: Energy Deposition 27 TRIPLET AND CORRECTOR PACKAGE vertical crossing 1.25 m from the IP face9.55 m from the IP face

28. 31/07/08 Review new IRs: Energy Deposition 28 TRIPLET AND CORRECTOR PACKAGE  r=2.5mm x  =2 o x  z=10cm scoring grid horizontal crossing  r=2.5mm x  =60 o x  z=10cm scoring grid mW/cm 3

29. 31/07/08 Review new IRs: Energy Deposition 29 TRIPLET AND CORRECTOR PACKAGE  r=2.5mm x  =2 o x  z=10cm scoring grid  r=2.5mm x  =360 o x  z=10cm scoring grid vertical crossing mW/cm 3

30. 31/07/08 Review new IRs: Energy Deposition 30 TRIPLET AND CORRECTOR PACKAGE BS included BS only BS included BS only 101 W +12.9 W in the interconnections (where BS is supposed to continue) in the rest 402 W @ 1.9 K BS included BS only BS included BS only 98 W +11.4 W in the interconnections (where BS is supposed to continue) in the rest 382 W @ 1.9 K

31. 31/07/08 Review new IRs: Energy Deposition 31 D1 180mm coil aperture in the warm bore tube 0.9 2.5 W 0.8 1.4 W

32. 31/07/08 Review new IRs: Energy Deposition 32 (present) TAN 187 MGy/100fb -1  x=2.5mm x  y =2.5mm x  z=5cm scoring grid 495 15 6 442 32 3 external tube inner Cu absorber internal tube

33. 31/07/08 Review new IRs: Energy Deposition 33 (present) TAN horizontal cuts at beam level

34. 31/07/08 Review new IRs: Energy Deposition 34 no TCTV, TCTH no TCLP (present) D2 in the coils (80 mm aperture)

35. 31/07/08 Review new IRs: Energy Deposition 35 OVERVIEW mW/cm 3 vertical plane

36. 31/07/08 Review new IRs: Energy Deposition 36 mW/cm 3 horizontal plane OVERVIEW

37. 31/07/08 Review new IRs: Energy Deposition 37 TRIPLET AND CORRECTOR PACKAGE 130mm coil aperture 8/13mm thick additional liner Q1Q2a Q2bQ3DC vertical crossing

38. 31/07/08 Review new IRs: Energy Deposition 38 Concrete shielding blocks IP5 TAS TripletD1 TAN UJ57 UJ56 courtesy of M. Fuerstner (SC/RP) with contribution of C. Hoa (AT/MCS) FLUKA model of IR5 (present LHC) ESTIMATION OF PARTICLE FLUENCES IN ELECTRONICS LOCATIONS

39. 31/07/08 Review new IRs: Energy Deposition 39 In UJ56, after a 2m concrete shielding, the high energy hadron fluence at beam level ranges from 1.3 10 9 up to 1.3 10 10 cm -2 /100fb -1 >20 MeV HADRON FLUENCE vertically averaged over the -60cm < y< 60cm interval (beam axis at y=0) cm -2 /100fb -1 relevant to single event errors

40. 31/07/08 Review new IRs: Energy Deposition 40 UPSTAIRS vertically averaged over the 220cm < y< 420cm interval (beam axis at y=0) Upstairs (sensitive electronics) high energy hadron fluence is in the range 1.2 - 3.6 10 9 cm -2 /100fb -1 T. Wijnands cm -2 /100fb -1

41. 31/07/08 Review new IRs: Energy Deposition 41 CONCLUSIONS The peak power deposition in the Phase 1 Upgrade triplet SC coils (110-130mm aperture) is expected to be decreased down to the design limit by a 10mm thick stainless steel liner all along the Q1 beam screen, if the interconnection lengths are not increased (unless the liner is extended along the interconnections too). The Q1 liner effectiveness is limited to the first half of the Q2a. Peaks lie on the crossing plane and change their position (up->down, outer->inner) in the Q2a. The larger the crossing angle, the higher the peak power density. A magnetic TAS can play a role closing the crossing angle. ~400 W the triplet toal load + ~100 W in the beam screen (about one half in the Q1 liner). Peak dose in the coils to be evaluated over a volume relevant to possible damage to the insulator. A corrector package on the non-IP side of a FDDF triplet is more significantly impacted for vertical crossing (peak at -90 o in the transverse plane). A large aperture SC D1 is not expected to quench. TAS and TAN thermomechanical stress to be evaluated from the available power deposition maps. Expected high energy hadron fluence in UJ56 (triplet electronics) is worrying for the present LHC at nominal luminosity (with ideal shielding without holes).