Sp Spin in tr treatme atment nt at t th the IL ILC: ove - PowerPoint PPT Presentation

Sp Spin in tr treatme atment nt at t th the IL ILC: ove verview, rview, sta tatus, tus, needs ds and d ope pen n qu quest estions ions G. Moortgat-Pick (Uni Hamburg/DESY) 1

World ld-wide wide Even ent • On June 12 th ,2013, ILC TDR was published in Worldwide Event. • End of major phase in ILC development – now what? 2 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

LHC timeline 3 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Japanese Site for ILC - LCC Directorate official site visit Oct. 2013. 4 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Brock ck Sn Snowma wmass ss Su Summ mmar ary 5 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Brock ck Sn Snowma wmass ss Su Summ mmar ary 6 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

The L e LC physics ics off ffer er a and ch chal alle lenges es • Staged energy approach: – √s~240 GeV, `Higgs frontier ‘ – √s~350 GeV, `Top threshold ‘ – √s~500 GeV , `Top Yukawa‘ – ( √s=91 GeV, `EW Precision frontier ‘ ) – √s~1000 GeV, `Higgs potential‘ • Polarized beams and threshold scans: – impact on ‘quality’ (and quantity) – Something ‘new’ comp. to LHC analyses • Highest precision: precise spin treatment required 7 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

IL ILC Mac achin ine e Lay ay-ou out • About 30 km in first stage √s=500 GeV, crossing angle 2x7 mrad • High luminosity: 2x10 34 cm -2 s -1 • Running time: 75% per year • Beams: 2x10 10 /bunch, 1312 bunch/pulse, 5 Hz rep. rate for √s=350 and 500 GeV 8 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

ILC Ma IL Mach chine ine Ov Overvie erview Polarised Damping Rings electron source Ring to Main Linac (RTML) (inc. bunch compressors) e + Main Linac Beam Delivery Beam dump Polarised System (BDS) positron & physics source detectors σ x / σ y - 474 nm / 6 nm e - Main Linac Luminosity - 2×10 34 cm -2 s -1 Polarisation (e-/e+) - 80% / 30% not to scale 9 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

ILC LC Pa Paramet rameters ers 10 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Sc Scope pe req equirements: uirements: ICFA A LC LC Pa Parameter ameter • ‘Scope Document no.1’ (2003) and ‘no.2’ (2006): baseline – Full luminosity of 2x10 34 cm -2 s -1 – Beam energy stability and precision below tenth of percent level – Machine interface must allow measurements of beam energy and differential luminosity spectrum with similar accuracy – Electron beams with polarization of at least 80% within whole energy range • Options: – e+ polarization ~50% in whole energy range – GigaZ= high lumi run at the Z-pole/WW threshold: energy stability and calibration accuracy below tenth of percent level Exploitation of polarization needs particular treatment 11 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

El Elec ectron tron polarization larization • Similar as SLC e- source: but now for long trains and high RF power – DC gun: e- with 200keV – Laser: λ =790nm , based on TiSapph, – cw. Nd:Yag laser provides power 12 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Po Posit itron ron source ce • Choice: e+ via radiation from a helical undulator (because of higher yield, less rad. level, better DR accept., less target stress ) (Target processes: Olufemi Adeyemi) See Andriy’s and Friedrichs talks Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 13

Po Pola lariza rization:T tion:Tec echnic hnical al fa fact cts s I • P(e-) ~ 80-90% • P(e+) ( always yield ≥1.5 imposed ): Andriy Ushakov, √s=240 GeV: 120 GeV e- drive beam – Undulator with 231 m (K=0.92, λ =11.5 mm), collimator r=3.5 mm – P(e+)~ 40% Eb=175 GeV √s=350GeV: 175 GeV e- drive beam – Collimator with r=1.2 mm – P(e+)~ 56% √s=500GeV: 250 GeV e- drive beam – Undulator with 144 m, collimator r=0.7mm – P(e+)~59% 14 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Techn chnica ical l fa fact cts s II • P(e+) ( always yield ≥1.5 imposed ): √s=1 TeV: 500 GeV e- drive beam – Undulator with 176 m (K=2.5), collimator r=0.9mm – P(e+)~54% See Annika’s talk • Measurent of polarization: – Compton polarimetry (up- and down-stream): δ P/P=0.25% – Via WW-process (lumi-weighted!): δ P/P(e-)~0.1%, δ P/P(e+)~0.2-0.3% Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 15

Spin in sensit itive ive comp mpone nents ts • Spin rotator before / after damping rings • (Fast) helicity flipping of the e+ required: s ee Sabine’s talk 0 0 – Apply kicker at the damping system • Polarization measurement (polarimetry, lumi-weigthed) s ee Moritz and Annika’s talks • QED processes at beam-beam interaction s ee Tony’s talk Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 16

Bea eam-bea eam: m: strong ong fi fiel elds in in IR IR Tony Hartin Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 17

Sp Spin in Rotat ator or Sy Syst stem em Valentyn Kovalenko Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 18

e Posit itron ron Lin inac ac to Rin ing Bea eaml mlin ine 19 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

La Latti ttice ce Spin pin Fli Flippe pper Larisa Malysheva Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 20

BMAD: D: Sp Spin in Trac acki king g in in PL PLTR (u (up p to to spi pin fli lipp pper) er) 21 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Sp Spin in trac acki king: g: spin in fl flip ipper er Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 22

Post t DR DR Sp Spin in Rotato tor Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 23

X-Y Y Coupling upling Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 24

Emm mma Ro a Rotat ator: or: phas ase e spac ace e unchanged 25 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Sp Spin in rot otator ator an and em emittance ittance preservati eservation on • Depolarization <0.1% Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 26

Em Emitt ittance ance preservation eservation 27 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Re Resona sonant nt De Depolariz polarization ation • Unpolarized configuration highly desirable – Get systematics under control, etc. • Helical undulator radiation: always polarized – Question: if only medium/low polarization available possible to destroy polarization if no spin rotators are used before the DR? – No, since no complete decoherence! See study of Barber/ Malysheva • Proposal: use RF kickers to get resonant depolarization – Study done by Valentyn Kovalenko within this BMBF project together with M. Vogt, A. Wolski – Simple spin model used so far, but looks promising 28 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Re Resonant sonant De Depolarization polarization Valentyn Kovalenko Use oscillating magnetic field (kicker) Kicker field is ┴ beam axis Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 29

Anal alyti tica cal l ap approa oach ch 30 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Us Used ed (simple) imple) spin pin mo model del Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 31

Pr Prin inci cipal pal fe featur ature Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 32

Applica pplication tion to Re Real al la lattice ttice Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 33

Compar mparison ison co codes es SA SAMM+SPRINT M+SPRINT Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 34

Comp mparison arison wit ith an analyti alytica cal l ap appr proach oach 35 Eucard@Mainz 2/2014 Gudrid Moortgat-Pick

Influence fluence of bea eam m geo eometry metry First results indicate: • Feasibility of resonant depolarization technique at ILC Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 36

Op Open n is issues ues Not a complete list ( just as proposals for ‘To -do-list ): – Inclusion of effects of synchrotron radiation and radiation damping – Test of different spin models (?) – Inclusion of accurate spin tracking in damping ring – Linking different codes for different sections to provide full cradle-to-grave tracking code – Inclusion of non-Gaussian beams in beam-beam studies – …. Eucard@Mainz 2/2014 Gudrid Moortgat-Pick 37