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Bernhard Holzer, CERN-LHC Parameter Space for HL-LHC IR8 * IP5 IP1 IP2 IP8 LEB Meeting

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  • Bernhard Holzer, CERN-LHC Parameter Space for HL-LHC IR8

    *IP5IP1IP2IP8LEB Meeting

  • HL-LHC Parameter Table

  • Luminosity:*F * HF = geometric los factor (x-angle)H = hour glass effect

    LHC StandardHL-LHC 25nsHL-LHC 50ns

    Np1.15*10112.2*10113.5*1011nb280828081404*3 m3 -10 m3-10 mn3.75 m2.5 m3.0 m18 m7.6 m8.3 m

  • a large variety of beam optics studied & optimised in IP8

    bog_150_0100_0100_3000_3000.madx *(IP8) = 3m standard ATS, roundbog_150_0050_0200_3000_3000.madx *(IP8) = 3m standard ATS, flat_xybog_150_0050_0200hv_3000_3000.madx *(IP8) = 3m standard ATS, flat_yxbog_150_5500_5500_10000_10000.madx *(IP8) = 10m ATS_injectionbog_150_0400_0400_0500_0500.madx *(IP8) = 50cm ATS ions

    each optics has to be implemented into the overall LHC lattice & optics.

    IR8 optics, 3m, ATS matched

  • HL-LHC Luminosity in IR8LHC_Standard, *= 3m, = 3.75 rad HL-LHC, *= 3m, t = 50ns, = 3.0 rad HL-LHC, *= 3m, t = 25ns, = 2.5 rad HL-LHC, *= 10m, t = 25ns, = 2.5 rad nota bene: values refer to E = 7TeVThe optics foreseen in the HL-LHC concept fot to the expected Luminositybin IR8.

  • HL- LHC-IR8-Standard Lumi settings: envelopes refer to +/- 5 crossing angle vert. 100 rad * = 3.0 m, n =3.0 m, on_LHCb = 1.0 135 rad hor hor plane ... dominated by LHCb crossing effectneg polarity, sufficient sep. at 2, 3 encounter but cross over due to wrong LHCb polarityCrossing Angles and Loss Factor

  • vert. plane ... guarantees separation from encounter #2.Crossing Angles and Loss Factor: 3m OpticsHL- LHC-IR8-Standard Lumi settings: envelopes refer to +/- 5 crossing angle vert. 100 rad * = 3.0 m, n =3.0 m, on_LHCb = 1.0 135 rad hor

  • vert. plane ... guarantees separation from encounter #2.

    A vertical crossing angle of 100rad guarantees sufficient separation at all parasitic encounters =in a range of beam optics between 3 ... 10m.Crossing Angles and Loss Factor: 10m Optics

    HL- LHC-IR8-Standard Lumi settings: envelopes refer to +/- 5 crossing angle vert. 100 rad * = 10.0 m, n =3.5 m

  • HL- LHC-IR8-Standard Lumi settingscrossing angle vert. 100 rad * = 3.0 m, n =3.0 m, 135 rad hor Crossing Angle and Loss Factors*F * HF F 98 % H 0.998 Geometric Loss Factor:Hour Glass Effect... for nominal LHC parameters

  • HL- LHC-IR8-Standard Lumi settings: Aperture after LS2crossing angle vert. 100 rad * = 3.0 m, n =3.75 m on_LHCb = 1.0 135 rad hor n1 okCrossing Angles and Optics: Aperture

    Velo not included

  • HL- LHC-IR8-HL- Lumi settings: Aperture after LS2crossing angle vert. 100 rad * = 10.0 m, n =3.75 m on_LHCb = 1.0 135 rad hor n1 oknota bene:10m optics is NOT combined with ATS schemeCrossing Angles and Optics: Aperture

    Velo not included

  • Addendum

  • LHCb Polarity & Horizontal Crossing Angle

    collisions at IP, separation at paras. encounters #2,3collisions after LHCb compensator dipolecollisions at IP, separation at paras. encounters #2,3 via LHCbseparation after paras. encounters #3 via ext. bump LHC-IR8-Original Design:Combination of internal (LHCb-) angle and external angle

    LHCb = good (... negative kick on beam 1)LHCb = -1.0 ... -135 rad b1on_x8 = 0.0 ...........................................on_x8=0.275 -66rad

    horizontal plane

  • LHCb Polarity & Horizontal Crossing Angle

    collisions at IP, separation at all paras. encounters as the external bump overcompensatesthe effect of the LHCb dipole (nota bene: aperture need !!)LHC-IR8-Original Design:Combination of internal (LHCb-) angle and external angle

    LHCb = bad (... positive kick on beam 1)LHCb = +1.0 ... +135 rad b1on_x8 = +1.0 .. -235rade

    horizontal planeeff crossing angle = -100radLHCb

  • LHCb Polarity & Horizontal Crossing Angle

    Aperture: *=3.0m, n =3.75 rad

    LHCb = good LHCb = bad

  • eff crossing angle = -2.27 mradcollisions at IP, separation at all paras. encounters Injection: horizontal crossing-angle

    LHCb = good(... negative kick on beam 1)LHCb = -15.5 ... -2.1mrad b1on_x8 = +1.0 .. -170rad

    separation at IP via vert. 2mm sep bumphorizontal planevertical plane

  • eff crossing angle = +1.93 mradInjection: horizontal crossing-angle

    LHCb = bad(... positive kick on beam 1)LHCb = +15.5 ... +2.1mrad b1on_x8 = +1.0 .. -170rad

    horizontal planecollisions at IP avoided via vert. sep bumpdue to cross over effect separation at all paras. encounters not possible for 25ns operation

  • Injection: vertical crossing-angle

    LHCb = bad(... positive kick on beam 1)LHCb = +15.5 ... +2.1mrad on_sep8 = +1.0 ... x=2.0mmon_x8vi = 0.8 ...... y = 125 rad

    optimisation of crossing angle (keep it SMALL) y=107rad emittance (keep it SMALL) n =2.5closed orbit tolerance (keep it SMALL) 3.0mmcollisions at IP avoided via hor. sep bumpseparation ok at paras. encounters 2...4avoids crossing at IP and paras. encounters 1,2,3separates the beams from paras. encounters 4horizontal planevertical plane

  • crossing angle y=107rad emittance n =2.5closed orbit tolerance 3.0mmApertureInjection: vertical crossing-angle

    LHCb = bad(... positive kick on beam 1)LHCb = +15.5 ... +2.1mrad on_sep8 = +1.0 ... x=2.0mmon_x8vi = 0.8 ...... y = 125 rad

    default: cor=4mm, en=3.75optimistic (?): cor=2mm, en=2.5

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