IR-Design 0.44 m Q5 D5 Q4 90 m 10 mrad m 3.67 mrad 60 m m 18.8 m 16.8 m 6.33 mrad 4 m Dipole © D.Trbojevic 30 GeV e GeV p 125 GeV/u ions eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 m and 10 mrad crossing angle E.C. Aschenauer EIC INT Program, Seattle Week 11 m Spinrotator

A detector integrated into IR E.C. Aschenauer EIC INT Program, Seattle Week 12 ZDC FPD  for ERL solution need not to measure electron polarization bunch by bunch  need still to integrate luminosity monitor  need still to integrate hadronic polarimeters, maybe at different IP FED space for e-polarimetry and luminosity measurements

Can we detect DVCS-protons and Au break up p E.C. Aschenauer EIC INT Program, Seattle Week 13  track the protons through solenoid, quads and dipole with hector  beam angular spread 0.1mrad at IR  Quads +/- 5mrad acceptance  Proton-beam: p’ z > 0.9p z  100 GeV: p t max < 0.45 GeV  t max < 0.2 GeV 2  Detector: acceptance starts Θ > 50mrad  need more work to find a way to cover intermediate range  solution could be to do the same as for the electrons swap the dipole and quads dipole and quads proton track  p=10% proton track  p=20% Equivalent to fragmenting protons from Au in Au optics (197/79:1 ~2.5:1) proton track  p=40%

Downstream dipole on ion beam line ONLY has several advantages Downstream dipole on ion beam line ONLY has several advantages – No synchrotron radiation – Electron quads can be placed close to IP – Dipole field not determined by electron energy – Positive particles are bent away from the electron beam – Long recoil baryon flight path gives access to low -t – Dipole does not interfere with RICH and forward calorimeters Excellent acceptance (hermeticity) Excellent acceptance (hermeticity) solenoid electron FFQs 100 mrad 0 mrad ion dipole w/ detectors (approximately to scale) ions electrons IP detectors ion FFQs 2+3 m 2 m exclusive mesons ° recoil baryons 4 on 30 GeV Q 2 > 10 GeV 2 Make use of a 100 mr crossing angle for ions! Slides Rolf Ent Jlab: Detector/IR cartoon E.C. Aschenauer EIC INT Program, Seattle Week 14