Status of the LHe C Ring Ring Basic

Status of the LHe. C Ring / Ring Basic Parameters I. ) Change of Energy 1. ) Base line … until now: Standard Parameters Optics Beam size Luminosity Protons Electrons 11 Np=1. 15*10 Ne=1. 4*1010 Ep=7 Te. V Ee=70 Ge. V nb=2808 Ip=582 m. A Ie=71 m. A βxp=180 cm βxe=12. 7 cm βyp=50 cm βye=7. 1 cm εxp=0. 5 nm rad εxe=7. 6 nm rad εyp=0. 5 nm rad εye=3. 8 nm rad σxp=30 μm σxe=30μm σyp=15. 8 μm σye=15. 8μm 32 8. 2*10 cm-2 s-1

Change in Electron Energy: 70 Ge. V 60 Ge. V Synchrotron Radiation: Energy loss per turn: Synchrotron Radiation Power: MW 1. 73 km 2. 7 km 75 Ge. V 120 73 70 Ge. V 90 56 60 Ge. V 50 30 50 Ge. V 23 14 * Smaller synchrotron radiation losses àUse to store more electron current à to increase luminosity Ie = 71 m. A 111 m. A Max Klein ρ=2700 m

Change in Electron Energy: 70 Ge. V 60 Ge. V Luminosity Ring & Performance Limit Design values limited by 50 MW available rf power --> For Ee ≈ 60 Ge. V we can scale: Standard Parameters Optics Beam size Luminosity Protons Electrons Np=1. 15*1011 Ne=1. 4*1010 Ep=7 Te. V Ee=60 Ge. V nb=2808 Ip=582 m. A Ie=111 m. A βxp=180 cm βxe=12. 7 cm βyp=50 cm βye=7. 1 cm εxp=0. 5 nm rad εxe=7. 6 nm rad εyp=0. 5 nm rad εye=3. 8 nm rad σxp=30 μm σxe=30μm σyp=15. 8 μm σye=15. 8μm 1. 3*10 33 cm-2 s-1

Change in Electron Energy: 70 Ge. V 60 Ge. V Beam Emittance LFODO, LHe. C = 1/2 LFODO, LHC ε depends on ρ and Energy … but ε = 5 nm seems to be reasonable 4 Miriam Fitterer

Change in Electron Energy: 70 Ge. V 60 Ge. V Beam Emittance requiring: possible but very challenging !! LHC Upgrade optics

Change in Electron Energy: 70 Ge. V 60 Ge. V Beam Emittance keeping cool … i. e. keep σe const relax the electron optics again requiring: What do we gain in this case ? relaxed separation scheme (dominated by e-emittance) evtl smaller crossing angle or 7. 5 sigma separation !!! remember

the crossing angle: in the end the source of many problems First parasitic crossing: s=3. 75 m βx F. Willeke βx S=3. 75 m 10 m 135 m βy σx σy 24 m 0. 07 m m 0. 11 m m p 98 m 1. 01 m 0. 61 m e m m Separation: 5σp + 5σe =0. 35 mm+ 5 mm ≈5. 5 mm X-angle ≈ 1. 4 mrad

Status of the LHe. C Ring / Ring Basic Parameters II. ) The CDR Topics & Experts : Lattice e-Ring: ✔ bypass geometry: H. Burkhardt ✔ ring lattice: M. Fitterer ✔ e-dynamics: “ & J. Jowett ✔ (damping partition) ✔ IR 1 degree: L. Thompson, R. Appleby ✔ IR 10 degree: “ , “ & A. Kling ? ? ?

Status of the LHe. C Ring / Ring Basic Parameters II. ) The CDR e-lattice: M. Fitterer LHe. C Protons Nbunch ➡ LFODO, LHe. C must be equal or a multiple/fraction of LFODO, LHC ➡ 2808 7 Te. V 70 Ge. V Ibeam 860 m. A 71 m. A εrms, x 0. 50 nm rad 7. 6 nm rad εrms, y 0. 50 nm rad 3. 8 nm rad Ebeam 6. 6 m long DFBMs every 9 m 106. 9 (= LFODO, LHC ) Electrons Natural choice: LFODO, LHe. C = LFODO, LHC ➡ too large emittance ➡

Arc Cell Design - Optics LFODO, LHe. C = 1/2 LFODO, LHC ➡ non-interference with LHC ➡ meets design parameters ➡ correction of natural chromaticity 10 M. Fitterer

Arc Cell Design Geometry antisymmetric cell geometry imposes constraints on element especially dipole position and length ➡ compromise between geometry and synchrotron radiation losses 11 M. Fitterer

Status of the LHe. C Ring / Ring Basic Parameters B. Nagorny R. Appleby & L. Thompson

Status of the LHe. C Ring / Ring Basic Parameters II. ) The CDR Topics & Experts : Interaction Region: ✔ layout, geometry & concept: ✔ proton optics 10 degree: ✔ p & e optics 1 degree: ✔ beam interaction: ! Parameter List: ✔ Synchrotron Light: ✔ Detector Geometry: ✔ Beam Pipe Layout: ! Magnet Design: B. Holzer, R. Appleby & L. Thompson W. Herr !! B. Holzer, O. Bruning, et al !! B. Nagorny (Power Specrtum, Ecrit etc U. Schneekloth, A. Pollini, P. Kostka et al “ “ S. Russenschuck et al !! ? ?

Status of the LHe. C Ring / Ring Basic Parameters Resume: looks good in general a lot of progress ( I mean A LOT ) some worries (magnets) main parameter list has to be re-established complete rematch of the beam optics needed never again change the main parameters !!!!!!!