1. Beam Commissioning Marco Oriunno (SLAC), May 14, 2014 ALCW 2014, Fermilab Engineering Issues

2. 2 Possible Commissioning Scenarios The key requirements originate from a defined strategy for the commissioning BDS Commissioning, set by the physics requirements of the Machine and Detectors. Meanwhile we look at three possible engineering options: 1.w/ Detector 2.w/o Detector, only QF1 3.w/o Detector, QD0 and QF1

3. 3 Challenges and Opportunities Challenges Safety Issues, mainly radiation shielding for a credible beam loss scenario Engineering Issues: Cabling, supports of temporary Beam Instrumentation. Opportunities Detector-Machine Schedule decoupling Leverage on the Push-Pull concept Dedicated Machine Development phases Opportunity for additional small forward detectors: TOTEM in the high pseudo-rapidity region (  3÷5) of CMS

4. 4 Option #1: w/ Detector 1.QD0s in place with the corresponding L* 2.Full set of forward detectors (Beamcal, Lumical, etc.) 3.Probably starting with the Vertex detector in place …..the ATLAS and CMS experience need to be recalled 4.One of the two detectors must be always available for commissioning and Machine Development: How to decide which one, case by case, strictly planned? Impact on assembly and maintenance schedule of the detectors.

5. 5 Option #2: w/o Detector, only QF1 1.Only QF1s with a commissioning optics 2.A basic set of beam instrumentation able to characterize the beam delivery to the IP (BPM, Beam scanners, etc.) Option A Permanently integrated in the QF1s regions: minimum impact on schedule Option B Movable light skid pre-assembled with the required diagnostic. Option B cont. Services connection (Cables, Cooling, Cryo) set the critical path.

6. Push-Pull : Engineering Concept (Option #1 and #2) Detector Hall, Japanese Mountain Site e-e- LHe refrigerator and LHe2 for the QD0’s above level on metallic structure.

7. 7 Option #3: w/o Detector, QD0 and QF1 1.Spares QD0s in place with only one L* possible 2.A basic set of beam instrumentation able to characterize the beam delivery to the IP (BPM, Beam scanners, etc.) 1. Movable light skid pre-assembled with the required diagnostic. 2. Services connection (Cables, Cooling, Cryo) 3.Possibility of a small-bore/high field MRI solenoid around the IP for beam distortion studies.

8. 8 Option #3: w/o Detector, QD0 and QF1 1.In normal operations the FFS push-pull with the detectors together with interconnections (High Current Leads and Cryogenic) 2.If dedicated QDOs for commissioning are installed, Power supplies and Cryogenics require not trivial infrastructures. 3.The pumping and the cooling down define the critical path 4.It is eventually a place where the Hybrid FFS Design a-la CLIC has a strategic advantage.

9. 9 Interface QD0-QF1: Critical for Fast&Reliable Push-Pulls 1 m QF1 QD0 Kicker Cryogenic Penetration Vacuum Instrumentation

10. MSL - SLAC 10 20 R.L. Cu target in IP-14 m. Large pacman. µSv/1_train Dose limits Maximum dose - The maximum integrated dose per event is ~8 µSv << 30 mSv - The corresponding peak dose rate is ~140 mSv/h < 250 mSv/h 9 MW M.Santana, SLAC

11. 11 Pacmen 500 mm Iron 2,000 mm Concrete

12. 12 Shielding Wall

13. 13 IP 5 mrad ~40 mrad ~85 mrad Challenges: High precision, high occupancy,high radiation dose, fast read-out! LumiCal, BeamCal: compact sampling calorimeters, R M ~1 cm Further Physics Opportunities  Precise measurement o the Integrated Luminosity (ΔL/L ~ 10 -4 ).  Provide 2 photon veto.  BeamDiagnostics using beamstrahlung pairs.  Provide 2 photon veto.  BeamDiagnostics using beamstrahlung photons.

14. 14 Summary Need Machine and Detectors to work on the definition of BDS commissioning, which in turn will define the set of requirements for the engineering studies Three options under study cover the full range of possibility. 1.w/ Detector 2.w/o Detector, only QF1 3.w/o Detector, QD0 and QF1 All options have different challenges and opportunities

15. EXTRA SLIDES 15

16. 16 Cryogenic Layout : Two options Plan A : Cold Boxes are stationary. Cold Transfer lines to each detector. Reliability for push-pull. Not off-the-shelf. Plan B : Cold Boxes on the platform. Warm Transfer lines to each cold box. Vibrations, fringe field effects, space

17. CLID QD0 : Hybrid magnet Permanent magnet Why a an Hybrid magnet ? Limited space available for the magnet difficult to accommodate a cryostat Magnet aperture too small to wind a superconducting cables given the large forces and the small radius; Complex assembly, difficult to align and stabilize at the sub-nanometer level (different layers of coils, collars, thermal insulation, cryostat); Difficult integration of a conical post-collision line in a cryostat assembly.

18. ILC QD0 : Cold Mass 2K Helium (BNL) ~3.5 m Technology of the superconducting final focus magnets has been demonstrated by a series of short prototype multi-pole coils. QD0 magnet split into two coils to allow higher flexibility at lower energies. The quadrupoles closest to the IP are actually inside the detector solenoid. Actively shielded coil to control magnetic cross talk Additional large aperture anti-solenoid in the endcap region to avoid luminosity loss due to beam optics effects. Large aperture Detector Integrated Dipole (DID) used to reduce detector background at high beam energies or to minimize orbit deflections at low beam energies.

19. Magnetic Field compensations at IP, DID, antiDID QD 0 Pairs distributions at 3.5m from IP anti-DID ON anti-DID OFF IP Longitudinal field of the solenoid + Fringe field extending over QD0 -> coupling (x, y) (E,y) => beam size growth Radial field due to crossing angle -> orbit deviation, implying synchrotron radiation, Fringe field extending over QD0 -> no compensation of radial and longitudinal components, => non zero orbit at the IP Anti-DID field -> additional radial field deviating incoming particles. R. Versteege n

20. Site Delivery prior the start of the Detector Assembly