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Some thoughts to stimulate Discussion. Detector Requirements from Physics. ep-physics the same detector needs to cover inclusive (ep -> e’X), semi-inclusive (ep -> e’hadron(s)X) and exclusive (ep -> e’p p) reactions energy variability p : 50 – 250/325 e : 4 - 20
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Some thoughts to stimulateDiscussion EICC @ Stony Brook, January 2010
Detector Requirements from Physics EICC @ Stony Brook, January 2010 • ep-physics • the same detector needs to cover inclusive (ep -> e’X), semi-inclusive (ep -> e’hadron(s)X) and exclusive (ep -> e’pp) reactions • energy variability p: 50 – 250/325 e: 4 - 20 • large acceptance absolutely crucial (both mid and forward-rapidity) • particle identification is crucial • e, p, K, p, n over wide momentum range and scattering angle • excellent secondary vertex resolution (charm) • particle detection to very low scattering angle • around 1o in e and p/A direction in contradiction to strong focusing quads close to IP • small systematic uncertainty (~1%/~3%) for e/p polarization measurements • very small systematic uncertainty (~1%) for luminosity measurement • eA-physics • requirements very similar to ep • challenge to tag the struck nucleus in exclusive and diffractive reactions. • difference in occupancy must be taken into account
Energies Simulated in RAPGAP EICC @ Stony Brook, January 2010
(M)eRHIC Luminosities Some luminosity numbers: for MeRHIC without CEC 4 x 250: 1x1032 cm-2s-1 for MeRHIC with CEC 4 x 250: 1x1033 cm-2s-1 for eRHIC with CEC: 20 x 325: 2.8x1033 cm-2s-1 30 x 325 with b* of 5cm: 1.4x1034 cm-2s-1 as the the luminosity does not depend on the energy of electron beam you can write it as for eRHIC with CEC: 2.8 1033* Ep/250 cm-2s-1 so you can easily scale it going to 20x100 for example so for MeRHIC assuming 50% operations efficiency one week corresponds to 0.5 * 604800(s in a week) * (1x1032 cm-2s-1) = 3*1037 cm-1 so 30pb-1 for eRHIC with CEC we collect in one week ~1fb anoperations efficiency of 50% is low, but conservative at this moment. For EIC systematic errors will be the limiting factor i.e., g1, FL,Dg, Dq EICC @ Stony Brook, January 2010
The √s vs. minimum luminosity landscape W2-dependence of c.s. neglected Diffraction exclusive DIS (PS & VM) electro-weak exclusive DIS (DVCS) H1/ZEUS: ~1031cm-2s-1 Hermes: 5x1031-1033 semi-inclusive DIS inclusive DIS 20x100 20x250 10x100 4x50 4x100 BNL S&T-Review, July 2009
Momentum vs. theta of scat. electron Proton Energy 50 GeV 100 GeV 250 GeV As more symmetric beam energies as more the scattered lepton goes forward Electron Energy 4 GeV10 GeV 20 GeV EICC @ Stony Brook, January 2010
pe: 0-1 GeV pe: 1-2GeV pe: 3-4GeV pe: 2-3GeV 4x50 Q2>1GeV2 20o after 1m ~35cm away from beam pipe 4x100 4x250 EICC @ Stony Brook, January 2010
Momentum vs. angle of pions • Whatdo we see: • For DIS: distribution is more “smeared” as energy balance becomes more symmetric • For diffractive: majority of pions at easily accessible angles, either forward or backward depending on proton/electron energy Same CM energy (63.3 GeV)
t for exclusive VM vsp’ angle t=(p4-p2)2 = 2[(mpin.mpout)-(EinEout - pzinpzout)] t=(p3–p1)2 = mρ2-Q2- 2(Eγ*Eρ-pxγ*pxρ-pyγ*pyρ-pzγ*pzρ) 4 x 50 4 x 100 • very strong correlation between • t and “recoiling” proton angle • Roman pots need to be very • well integrated in the lattice • resolution on t! 4 x 250 EICC @ Stony Brook, January 2010
IR-Design for MeRHIC IP-2 • no synchrotron shielding included • allows p and heavy ion decay product tagging • IP-2: height beam-pipe floor ~6’ (with digging ~10’) EICC @ Stony Brook, January 2010
First ideas for a detector concept Solenoid (4T) Dipole 3Tm Dipole 3Tm FPD FED // // ZDC • Dipoles needed to have good forward momentum resolution • Solenoid no magnetic field @ r ~ 0 • DIRC, RICH hadron identification p, K, p • high-threshold Cerenkov fast trigger for scattered lepton • radiation length very critical low lepton energies EICC @ Stony Brook, January 2010
MeRHIC Detector in Geant-3 Silicon Strip detector ala Zeus central tracking ala BaBar Drift Chambers Drift Chambers ala HERMES FDC EM-Calorimeter LeadGlas Dual-Radiator RICH ala HERMES High Threshold Cerenkov fast trigger on e’ e/h separation • DIRC: not shown because of cut; modeled following Babar • no hadronic calorimeter in barrel, because of vertical space @ IP-2 EICC @ Stony Brook, January 2010
BACKUP EICC @ Stony Brook, January 2010
ERL-based eRHIC Design 5 mm 5 mm 5 mm 5 mm 20 GeV e-beam 16 GeV e-beam Common vacuum chamber 12 GeV e-beam 8 GeV e-beam 2 x 200 m SRF linac 4 (5) GeV per pass 5 (4) passes (M)eRHIC detector Gap 5 mm total 0.3 T for 30 GeV Polarized e-gun 10-20 GeV e x 325 GeV p 130 GeV/u Au possibility of 30 GeV @ low current operation Beam dump MeRHIC detector Coherent e-cooler PHENIX STAR 4 to 5 vertically separated recirculating passes EICC @ Stony Brook, January 2010
Zeus @ HERA I EICC @ Stony Brook, January 2010
Zeus @ HERA II EICC @ Stony Brook, January 2010
Hera I vs. Hera II Focusing Quads close to IP Problem for forward acceptance EICC @ Stony Brook, January 2010
ELIC Detector/IR Layout by R. Ent solenoid ion FFQs dipole bending scattered protons “up” ions electrons IP with crossing angle electron FFQs Distance from IP to electron FFQ: 6 m to ion FFQ: 9m Modest electron final focusing quad field requirements quads can be made small EICC @ Stony Brook, January 2010
ELIC detector cartoon - Oct. 09 by R. Ent 8 meters (for scale) Offset IP? 140 degrees TOF HCAL ECAL Tracking DIRC HTCC RICH dipole dipole 1st (small) electron FF quad @ 6 m solenoid Additional electron detection (tracking, calorimetry) for low-Q2 physics not on cartoon Ion beam e beam EICC @ Stony Brook, January 2010
Event kinematics produced hadrons (p+) D I S 4x250 4x50 20x250 DIS: small theta important D I F F R A C T I V E without magnetic field EICC @ Stony Brook, January 2010