LHC 2020 LHC 2030 LHC Highluminosity LHC HLLHC

LHCの長期計画の始まり 2020年 LHC高輝度化改造 2030年 LHC高エネルギー化改造？？ High-luminosity LHC (HL-LHC) High-energy LHC (HE-LHC) 4

CERN Physics Department news より Before defining the possible scenario, it is a good idea to introduce a few keywords that are used to define the various steps for the LHC. • The nominal LHC corresponds to the design energy (~ 14 Te. V) and peak luminosity of 1034 cm-2 s-1. It should allow the experiments to record an integrated luminosity of about 50 fb-1 per year. • The ultimate LHC corresponds to a peak luminosity of ~ 2 1034 cm-2 s-1 and should yield about 100 fb-1 per year. • The High-Luminosity LHC (HL-LHC) would offer a leveled luminosity of ~ 5 1034 cm-2 s-1 yielding about 300 fb-1 per year.

LHC phase-2 upgrade paths for IP 1 & 5 early separation (ES) J. -P. Koutchouk stronger triplet magnets D 0 dipole le g n a ll- ity a m s av c b cra • ultimate beam (1. 7 x 1011 p’s/bunch, 25 ns spacing), b* ~10 cm • early-separation dipoles in side detectors , crab cavities → hardware inside ATLAS & CMS detectors, first hadron crab cavities; off-d b stronger triplet magnets. F. Zimmermann le g n a ll- ity a m s av c b cra • ultimate LHC beam (1. 7 x 1011 p’s/bunch, 25 ns spacing) • b* ~10 cm • crab cavities with 60% higher voltage → first hadron crab cavities, off-d b-beat large Piwinski angle (LPA) F. Ruggiero, W. Scandale. F. Zimmermann full crab crossing (FCC) L. W. Evans, Scandale, larger-aperture triplet magnets low emittance (LE) R. Garoby stronger triplet magnets wire tor a s n e p com • • • いろいろなＯｐｔｉｏｎが検討されてきたが、振り出しに 11 p’s/bunch) (5 x 10戻っている。 • ultimate LHC beam (1. 7 x 1011 p’s/bunch, 25 ns spacing) 50 ns spacing, longer & more intense bunches b*~25 cm, no elements inside detectors long-range beam-beam wire compensation → novel operating regime for hadron colliders, beam generation • • b* ~10 cm smaller transverse emittance → constraint on new injectors, off-d b-beat

L. Rossi ES, low *, with leveling events/crossing 34 300 L～ 10× 10 run time N/A examples av. luminosity events/crossing run time L～ 5× 1034 LPA, long bunches, with leveling 300 2. 5 h N/A 150 2. 6 x 1034 s-1 cm-2 150 2. 5 h 14. 8 h av. luminosity 2. 6 x 1034 s-1 cm-2 events/crossing 75 34 L～ 2. 5× 10 run time 9. 9 h 2. 9 x 1034 s-1 cm-2 av. luminosity 1. 7 x 1034 s-1 cm-2 2. 6 x 1034 s-1 cm-2 75 26. 4 h assuming 5 h turn-around time

LHC upgradeのための技術開発 • High Gradient/Large Aperture の四重極磁 石の開発(Bpeak 13 -15 T)が必要： – 今のＬＨＣの線材（Nb. Ti）では無理 – 米国ＬＡＲＰ　（LHC Accelerator Research Program ）でNb 3 Snの開発が進む – KEK-CERNでNb 3 Alの開発 　　　　Technology Choice ~2014頃 現行のLHC inner triplet • Nb 3 Sn is becoming a reality (first LQ long -3. 6 m – quad 90 mm) • This year we expect a second test of LQ-1 and test of LQ-2 　　　　L. Rossi 17

クラブ空洞　 衝突点付近でバンチの向きを変えること で輝度を上げる。 ＫＥＫ-Ｂが唯一の実用例 BNL KEK CI/DL KEK SLAC JLAB 世界中の研究所で設計競争がはじまっている。 Crab Cavities: this is the best candidate for exploiting small (for around nominal only +15%). However it should be underlined that today Crab Cavities are not validated for LHC , not even conceptually: the issue of machine protection should be addressed with priority. SPSでの予備実験を検討。KEK-Bの クラブ空洞を使う可能性も検討 18

Layout of the new injectors SPS PS 2 SPL PS s. LHC として考えられていた新設Injector群 • 　Linac 4は建設開始 • 　将来大強度プロトンドライバーとして使うことも視野 L. Evans – EDMS Document 905931 建設着 Linac 4

Present accelerator complex 1976 1972 LHC beam route 1959 2/23/2021 LINAC 2 BOOSTER (PSB) PS SPS 22

HE-LHC “First Thoughts on a Higher-Energy LHC” Ralph Assmann, Roger Bailey, Oliver Brüning, Octavio Dominguez Sanchez, Gijs de Rijk, Miguel Jimenez, Steve Myers, Lucio Rossi, Laurent Tavian, Ezio Todesco, Frank Zimmermann Abstract: We report preliminary considerations for a higher-energy LHC (“HE-LHC”) with about 16. 5 Te. V beam energy and 20 -T dipole magnets. In particular we sketch the proposed principal parameters, luminosity optimization schemes, the new HE-LHC injector, the magnets required, cryogenics system, collimation issues, and requirements from the vacuum system. Table of Contents: 1. Parameters 2. Luminosity optimization 3. Injector 4. Magnets 5. Cryogenics studies 6. Vacuum system 7. Collimation issues 2/23/2021 Eu. CARD-Acc. Net mini-workshop on a higher-energy LHC “HE-LHC’ 10” – 14 -16 October ’ 10, Malta 24

HE-LHC 高磁場磁石の開発を今進めることは将来を • HL-LHCのための高磁場磁石の開発⇒　偏向磁石に使えば、LHCのエ ネルギーをあげることもできる。 　　　　　　　Higher Energy LHC (HE-LHC) • 2030年以降の将来計画として、今年からＣＥＲＮのofficial statement としてでてきている。 • HE-LHC Workshop 14 -16 October in Malta Nb 3 Sn + HTS magnets Sketch of the double aperture magnet with the iron yoke – Coils are in blue 25 Field in the coil (one pole shown) at 20 T operational field transmission line magnets of new injector

HE-LHC Provisional parameter list for LHC energy upgrade 33 Te. V centre-of-mass energy 2/23/2021 26

• Main issues HE-LHC L. Rossi: Fermilab でのトーク （2010年 7月29日） – high-field 20 -T dipole magnets based on Nb 3 Sn, Nb 3 Al, and HTS – high-gradient quadrupole magnets for arc and IR – fast cycling SC magnets for 1 -Te. V injector – emittance control in regime of strong SR damping and IBS – cryogenic handling of SR heat load (this looks manageable) – dynamic vacuum • Provisional dates – 2022 start of 20 -T magnet procurement – 2022 -30 building/preparing new 1. 3 -Te. V injector – 2030 -33 installation of HE-LHC ring in LHC tunnel → 2035年　実験開始? ? 2/23/2021 27

LHC nominal performance Nominal settings Beam energy (Te. V) 7. 0 Number of particles per bunch 1. 15 1011 Number of bunches per beam 2808 Crossing angle ( rad) 285 Norm transverse emittance ( m rad) 3. 75 Bunch length (cm) 7. 55 Beta function at IP 1, 2, 5, 8 (m) 0. 55, 10, 0. 55, 10 Derived parameters Luminosity in IP 1 & 5 (cm-2 s-1) 1034 Luminosity in IP 2 & 8 (cm-2 s-1)* ~5 1032 Transverse beam size at IP 1 & 5 ( m) 16. 7 Transverse beam size at IP 2 & 8 ( m) 70. 9 Stored energy per beam (MJ) 362 * Luminosity in IP 2 and 8 optimized as needed 2/23/2021 29

parameter symbol transverse emittance e [mm] 3. 75 1. 0 3. 75 protons per bunch Nb [1011] 1. 15 1. 7 4. 9 bunch spacing Dt [ns] 25 25 25 50 beam current I [A] 0. 58 0. 86 0. . 86 1. 22 Gauss Gauss Flat longitudinal profile nominal ultimate ES FCC LE LPA rms bunch length sz [cm] 7. 55 11. 8 beta* at IP 1&5 [m] 0. 55 0. 08 0. 1 0. 25 full crossing angle qc [mrad] 285 315 0 0 311 381 Piwinski parameter f=qcsz/(2*sx*) 0. 64 0. 75 0 0 3. 2 2. 0 1. 0 0. 86 0. 30 0. 99 1 2. 3 15. 5 16. 3 10. 7 19 44 294 309 403 22 14 2. 2 2. 0 4. 5 geometric reduction peak luminosity L [1034 cm-2 s-1] peak events per #ing initial lumi lifetime t. L [h] effective luminosity (Tturnaround=10 h) Leff [1034 cm-2 s-1] 0. 46 0. 91 2. 4 2. 5 Trun, opt [h] 21. 2 17. 0 6. 6 6. 4 9. 5 effective luminosity (Tturnaround=5 h) Leff [1034 cm-2 s-1] 0. 56 1. 15 3. 6 3. 7 3. 5 Trun, opt [h] 15. 0 12. 0 4. 6 4. 5 6. 7 e-c heat SEY=1. 4(1. 3) P [W/m] 1. 1 (0. 4) 1. 04(0. 6) 1. 0 (0. 6) 0. 4 (0. 1) SR heat load 4. 6 -20 K PSR [W/m] 0. 17 0. 25 0. 36 image current heat PIC [W/m] 0. 15 0. 33 0. 78 gas-s. 100 h (10 h) tb Pgas [W/m] 0. 04 (0. 4) 0. 06 (0. 6) 0. 06 (0. 56) 0. 09 (0. 9) extent luminous region sl [cm] 4. 5 4. 3 3. 7 1. 5 5. 3 D 0 + crab comment 古いパラメータ nominal ultimate wire comp.