review of FCChh optics beam dynamics IPNO Orsay

review of FCC-hh optics & beam dynamics IPNO, Orsay, Paris 19 -20 November 2015 Reviewers: S. Fartoukh (CERN), O. Napoly (CEA), E. Todesco (CERN), F. Zimmermann (CERN, chair) 02/12/2015 Burkart 2020 project Euro. Cir. Col, grant agreement 654305 1 Work supported by the European Commission under the. F. HORIZON

review agenda Time (19. 11) 14: 00 -14: 20 -14: 40 -14: 50 -15: 05 -15: 20 -15: 40 -16: 10 -16: 30 -16: 45 -16: 55 -17: 10 -17: 30 -18: 00 -18: 30 length 20 min. 10 min. 15 min. 20 min. 30 min. 20 min. 15 min. 10 min. 15 min. 20 min. 30 min. title speaker Welcome and review goals Michael Benedikt Arc lattice, lattice integration Antoine Chance IR lattice Andrei Seryi Minimum separation of detectors Rob Appleby Collimation system requirements Stefano Redaelli Betatron& momentum coll. lattices Antoine Lachaize Collimation tracking & evaluation James Molson Discussion Coffee break Injection lattice section Florian Burkart Integration of RF Bernhard Holzer Extraction/dump lattice section Florian Burkart Errors, tolerances, corrections DA Barbara Dalena Overall layout & optimization Daniel Schulte Discussion Time (20. 11) 09: 00 -11: 00 length 120 min. title Executive session (closed) Speaker reviewers 02/12/2015 F. Burkart 2 Additional invitees: WP 2 and WP 3 participants, R. Aleksan (ECB chair)

review goals 1. review the design status and performance of all dedicated insertions 2. review the overall lattice integration and space allocation/optimization 3. review the performance of the integrated lattice in terms of dynamic aperture, error tolerances etc. 4. identify any areas with optimization potential and propose high-priority actions towards the next milestone, FCC week Rome in April 2016. 02/12/2015 F. Burkart 3

Review of FCC-hh optics & beam dynamics Extraction lattice section 19. / 20. November 2015 Input from M. Barnes, W. Bartmann, M. Benedikt, F. Burkart, B. Goddard, W. Herr, T. Kramer, A. Lechner, D. Schulte, L. Stoel 02/12/2015 F. Burkart 4

Outline • • Beam extraction concept and optics. Dilution kicker requirements. Beam dump line geometry. Conclusions 02/12/2015 F. Burkart 5

Extraction straight options Too tight. R 2 E. MKB parameters. 02/12/2015 Too tight. R 2 E. MKB parameters. F. Burkart 6

Concept • “Conventional” beam extraction system, 1 per beam. MKBH Kicker 0. 13 mrad Enlarged quadrupole Septum 1. 7 mrad, 1. 42 T MKBV Triple chamber quadrupole? Segmented kicker system Try to minimize frequency of asynch. dump by accepting a single switch erratic – Reduce beta function (in bending plane) at the kicker to limit the oscillation from an erratic – Increase beta function at septum to have better kick efficiency (trade off with septum width) and to have beam dilution for protection absorbers up- and downstream of the septum • Asymmetric in optics functions. 638 m central drift • • 02/12/2015 F. Burkart 7

HW parameters LHC scaled Kicker Septum T. m 2 - 22 19 - 284 Available system length m 100 200 Rise time us 3 - Flat top length us >340 mm 18/18 B. dl GFR h/v 02/12/2015 F. Burkart 18/18 Aim for 1 us due to absorber limits 8

To be studied • To be studied for FCC week in Rome: – Impact of ~ 1 sig oscillation for one turn on machine? • Beam-beam kick • Collimation system • Showers • …? – Impact on absorbers during a sweep (max. bunch separation required short kicker rise time). – Also interesting for segmentation of kicker system. 02/12/2015 F. Burkart 9

Beam dump line geometry 2. 5 km dump line 1. 4 km dump insertion Kicker Septum 2. 8 km collimation insertion 10 mrad bend Dilution • 2 – 2. 5 km dump line (for dilution system / drift) • 10 m diameter dump cavern • Need some physical separation between FCC tunnel and dump cavern – say 5 m. • Separation between FCC beam and dumped beam of about 15 -20 m after 2 km: Absorber – 10 mrad fixed deflection in dump line – Needs ~100 m of 16 T dipole at 167’ 000 Tm – Without 10 mrad, dumped beam is only about 0. 7 m separate in H from FCC circulating beam, after 2 km (collimation). 02/12/2015 F. Burkart 10

Beam dump line geometry “Baseline 2” 2. 6 km passive protection RF 1. 4 km dump insertion RF 2. 6 km passive protection • Septum bends in the vertical plane. • Long dump line would help dilution kicker. • Reduced radiation impact to electronics as only passive protection for failure cases. • Separation for dump block cavern needed. • Asymmetric optics for both sides of the LSS. • Might be better to have RF with injection. 19/11/2015 F. Burkart 11

Beam dump considerations Hydrodynamic tunneling simulation benchmark with Hi. Rad. Mat experiment and simulations with FCC beam parameters 02/12/2015 F. Burkart 12

Beam dump considerations Copper after the impact of 10 and 50 FCC bunches 90. 400 K Simulation results for FCC beam parameters show that the beam will penetrate ~ 300 m in Copper, assuming no dilution. Dilution required! 02/12/2015 F. Burkart 120. 000 K 13

Dilution pattern was evaluated as a function of dilution kicker magnet MKB parameters and energy deposition on the TDE. Fixed dilution frequency: • f = 50. 9 k. Hz • Maximum amplitude at the dump block: 80 cm • Bunch separation > 1. 8 mm • Branch separation: 4 cm • Max deflection: 0. 32 mrad • B. dl = 53 T. m Alternative with frequency change: • f = 20. 4 k. Hz – 42. 9 k. Hz • Bunch separation = 1. 9 mm constant • Branch separation = 4 cm • Max deflection = 0. 24 mrad • Max amplitude = 0. 59 m • Bdl = 39 Tm (2. 5 km dump line) Energy deposition studies by FLUKA (A. Lechner & P. Garcia) Max. temperature below ~ 1500 °C. 02/12/2015 F. Burkart 14

Dilution kicker system • Horizontal and vertical kicker system as in the LHC • ~45 horizontal kickers ~110 vertical kickers within ~ 300 m to be optimized • Challenging part of the extraction system as “full” beam rigidity to be handled. • Magnet aperture increases with system length due to beam deflection, reduced efficiency of the magnets. • Electronics close to the magnets no collimation close or upstream of the system. • Optimization started, increased lever arm (length of the dump line) would help the dilution kickers, additional help with quads in the dump line. Detailed studies discussed in the FCC dump meetings 02/12/2015 F. Burkart 15

Summary • “Conventional” beam extraction system, 1 per beam. • Optics for extraction asymmetric. Optics for combined extractions to be studied. • Dilution kicker magnet requirements studied - system is challenging. FCC beam will penetrate ~ 300 m in Copper without dilution. Failure modes to be studied. long lever arm / dump line would help the dilution kickers. • Study the impact on machine for sweep and 1 sigma oscillation. – Collimation – Showers in the arc – Impact on kickers, triggering lines… – Energy deposition on septum protection / absorbers. – Need for (and design of) sacrificial absorbers. • R 2 E to be studied. • Studies for Baseline 1 (extraction and beta-collimation) and Baseline 2 (separate collimation and extraction) to be followed up. • Baseline 2 preferred. 02/12/2015 F. Burkart 16

general remarks • enormous progress after only half a year of Euro. Cir. Col project • ultimate optics parameters appear within reach • tools and algorithms ready (IR debris, collimation efficiency, magnet errors, …) • now it is time to focus on the design details 02/12/2015 F. Burkart 17

Summary • • • Arc - choice of magnet aperture is a good starting point, but looks tight study implications of aperture on minimum injection energy further optimization of the filling factor (cell length [aperture!], phase advance per cell [60 o instead of 90 o? ], length of insertions, …) make a second iteration on interconnection length Collimation simulation tools are on good track assess length of the secondary collimator jaws confirm and possibly revise gap size with help of shower simulations attempt to introduce dispersion between primary and secondary collimators RF looks good - the dogleg may need substantial space 02/12/2015 F. Burkart 18

injection lattice comments: • several 100 beam transfers to fill the FCC recommendations: • insertions like these should be kept flexible enough to be used as phase trombone station 02/12/2015 F. Burkart 19

extraction lattice comments: • this is a challenging system recommendations and questions: • does the present optics solution fulfil the basic constraints for an extraction insertion? E. g. • p/2 phase advance between MKD and TCDQ See optics plot later. • large b function (>5 km) at the dump Influence of high beta at the dump is low (see FLUKA studies). 02/12/2015 F. Burkart 20

A. Lechner – FCC dump meeting https: //indico. cern. ch/event/446212/ 02/12/2015 F. Burkart 21

overall layout & optimization comments: • on good track for the arcs and the two main experimental IRs • more work and details needed for other IRs recommendations: • continue the excellent work 02/12/2015 F. Burkart 22

Preferred layout 02/12/2015 F. Burkart 23

What influences FCC extraction settings? • • • Extraction: – Small beta at MKD, big beta at Septum Asymmetric in optics. – Feasible MKB parameters. – 2. 8 km space for passive protection for extraction failures, TCDQ, TCDS, TPSGs Size / Positions to be defined. – 90 degree phase advance (MKD and TCDQ) – another 180 degrees to the next absorber stage. Dump: – Protection devices. – b of a few km. – Bunch separation: ~ 2 mm – Branch separation: ~ 4 cm Dump cavern: – > 5 m separation to circulating beam. Low radiation to kicker electronics. ? ? 02/12/2015 F. Burkart 24

Dump considerations • Dump block considerations: • R=1 m • Shielding: ~ 3 m (doubled from LHC) • Air / crane / catwalk / etc. : ~ 3 m • > 5 m wall between cavern and arc Distance between middle of dump block / circulating beam: >13 m Asymmetric dump block cavern? To be studied by CE. 02/12/2015 F. Burkart 25

Extraction with bend Not to scale 4. 2 km 90 degree Extraction failure absorbers / TCDQ MKB MSEh MKDv 2. 5 km 2. 3 km Separation with MSE and bend. 14 m separation after 1. 5 km but MKB would need 95 Tm. 02/12/2015 Bend into extra tunnel solution: + fast separation + no radiation to MKB electronics - ~ 2. 5 km extra tunnel per beam - 100 m 16 T bends in the dump line. - Bend protection needed. - Challenging MKB parameters. F. Burkart 26

“standard” extraction Not to scale 4. 2 km MKDv MSEh 0. 8 km 3. 15 km MKB arc Separation with septum and arc bending (14 m). Extraction failure absorbers / TCDQ w. o. bend: + only 0. 8 km extra tunnel per beam + relaxed MKB settings - “slow” separation - Radiation to MKB electronics? Shielding needed? 02/12/2015 F. Burkart 27

Extraction of both beams Not to scale 4. 2 km MKDv 0. 8 km MSEh MKB arc MKB 4. 8 m 02/12/2015 MSEv MKDh • Dump line under arc with MSEv. • Dump cavern under arc with MSEh. • Difficult tunnel geometry (? ) at the end of the ESS, to be checked with CE. F. Burkart 28

Extraction of both beams to the outside MKDv MSEh MKB MSEh Not to scale MKDv + only 0. 8 km extra tunnel per beam + no bend in the dump line + relaxed MKB settings + symmetric systems - slow separation - Radiation to MKB electronics? • pipe assembly – X pipe • triple aperture quad 02/12/2015 F. Burkart 29

Influence on MKB parameters Dilution pattern was evaluated as a function of dilution kicker magnet MKB parameters and energy deposition on the TDE. Fixed dilution frequency: wit • f = 50. 9 k. Hz h 3. 15 • Maximum amplitude at the dump block: 80 cm km • Bunch separation > 1. 8 mm lev er • Branch separation: 4 cm arm • Max deflection: 0. 32 mrad / 0. 254 mrad • B. dl = 53 Tm (2. 5 km DL) / 42 Tm Alternative with frequency change: • f = 20. 4 k. Hz – 42. 9 k. Hz • Max amplitude = 0. 59 m • Bunch separation = 1. 9 mm constant • Branch separation = 4 cm • Max deflection = 0. 24 mrad / 0. 19 mrad • Bdl = 39 Tm (2. 5 km DL) / 31. 7 Tm Energy deposition studies by FLUKA (A. Lechner & P. Garcia) Max. temperature below ~ 1500 °C. 02/12/2015 F. Burkart 30

Beam pipes (1/2) 4. 8 m 02/12/2015 3. 1 m 4. 8 m F. Burkart 31

Beam pipes (2/2) 0. 6 m 14 m 4. 8 m 02/12/2015 2. 5 m 4. 8 m F. Burkart 32

Optics for the ESS 02/12/2015 F. Burkart 33 Courtesy: L. Stoel

Optics for extraction 93. 6 deg TCDQ MKD 02/12/2015 MSE F. Burkart 34 Courtesy: L. Stoel

Quad in the dump line • Help the dilution kickers. • Reduce aperture in the MKBv. Not to scale 95 m 2. 5 cm MKBh ~ 45 modules 80 cm MKBv ~ 110 modules w. o. Quad w. Quad Schematic apertures Reduce aperture by a factor 2. 02/12/2015 F. Burkart Quad parameters: • 70 mm diameter aperture • g = 280 T/m • L = 6. 2 m 35

Comments / to be studied: – – – – – 02/12/2015 1 sigma oscillation sweep. Beam pipe at dump with > 80 cm radius. X – chamber and beam separation of a few sigma – vacuum issues? New septum concept. See Dani’s talk. Optics, beamsizes and positions for absorbers for extraction failures. See Linda’s talk next meeting. Dump cavern size. Beam dump window. Stable field time of MSE in case of a failure. Absorber requirements: • Prepare table with beam parameters, bunch separation and probability for failure cases for TCDS, TCDQ, etc. for FLUKA team. Impact of Quad on MKB parameters. F. Burkart 36

Thank you for your attention! 02/12/2015 F. Burkart 37