e.c. aschenauereic ew meeting, w&m, va, may 20101

EIC EW Meeting, W&M, VA, May 2010 1

An IR- and Detector Design for all the Stages of eRHIC

E.C. Aschenauer


eRHIC Scope

e-

e+

p

Unpolarized andpolarized leptons4-20 (30) GeV

Polarized light ions (He3) 215 GeV/u

Light ions (d,Si,Cu)Heavy ions (Au,U)50-100 (130) GeV/u

Polarized protons50-250 (325) GeV

Electron accelerator RHIC

70% e- beam polarization goalpolarized positrons?

Center mass energy range: √s=28-200 GeV; L~100-1000xHera

longitudinal and transverse polarisation for p/He-3 possible

e-

Mission: Studying the Physics of Strong Color Fields

E.C. Aschenauer


The Relativistic Heavy-Ion Collider @ BNL

E.C. Aschenauer

RHICBRAHMSPHOBOS

PHENIXSTAR

AGS

TANDEMS

v = 0.99995⋅c = 186,000 miles/sec

ERL Test Facility

12 o’clock proposed

RF

BOOSTER

LINACEBIS


The 1st/2nd incarnation of a staged eRHIC

E.C. Aschenauer

STAR

PH

EN

IX

3 pass 4 GeV ERL

Polarized

e-gun

Beamdump

MeRHICdetector

2 x 200 m SRF linac4 (5) GeV per pass5 (4) passes

4 to 5 vertically separatedrecirculating passes

Gap 5 mm total0.3 T for 30 GeV

5 mm

5 mm

5 mm

5 mm

20 GeV e-beam

16 GeV e-beam

12 GeV e-beam

8 GeV e-beam

Com

mon

vacu

um

ch

am

ber

10-20 GeV e x 325 GeV p

130 GeV/u Aupossibility of 30 GeV @

low current operation

STAR

PH

EN

IX

Polarized

e-gun

Beamdump

Cohere

nt

e-c

oole

r

eRHICdetector

WHY IP-12? have Experimental Hall @ IP-12 size of STAR

fully staged detector from MeRHIC to eRHIC vertical space much bigger (room for HCal) need to buy magnets only once can stage detector components, i.e. hadronic calorimeter no moving of components (IP2 IP12) systematics reduced same detector for all energies

MeRHICeRHIC with

CeC

p (A) e p (A) e

Energy, GeV250 (100

)4

325 (125)

20 <30

>

Number of bunches

111 166

Bunch intensity (u) , 1011 2.0

0.31

2.0 (3)

0.24

Bunch charge, nC

32 5 32 4

Beam current, mA

320 50 42050 <10

>

Normalized emittance, 1e-6 m, 95% for p / rms for e

15 73 1.2 25

Polarization, % 70 80 70 80

rms bunch length, cm

20 0.2 4.9 0.2

β*, cm 50 50 25 25

Luminosity, x 1033, cm-2s-1

0.1 -> 1 with CeC

2.8

5

STAR

ePH

EN

IX100m

|--------|

6 pass 2.5 GeV ERL C

ohere

nt

e-cooler

22.5 GeV

17.5GeV

12.5 GeV

7.5 GeV

Com

mon

vacu

um

ch

am

ber

27.5 GeV

2.5 GeV

Beam-dump

Polarized e-gun eRHIC

detector

25 GeV

20 GeV

15 GeV

10 GeV

Com

mon

vacu

um

ch

am

ber

30 GeV

5 GeV

0.1 GeV

The latest design of eRHIC

The mostcost

effective design

RHIC: 325 GeV p or 130 GeV/u Au

eRHIC staging all-in tunnel


© V. Litvinenko

LINAC SS and ARC Design

E.C. Aschenauer

1.27 m beam high

30 GeV e+ ring

30 GeV ERL 6 passes

HE ERL passesLE ERL passes

30 GeV 25 GeV20 GeV15 GeV 10 GeV 5 GeV

1.27 m beam highe+ ring

200 m ERL Linac

© V. Litvinenko


IR-Design

0.4

4 m

Q5D5

Q4

90 m

10 mrad 0.3

29 m

3.67 mrad

60 m10 20 30

0.1

88036 m

18.8

m

16.8

m

6.33 mrad

4 m

© D.Trbojevic

30 GeV e-

325 GeV p

125 GeV/u ions

eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 mand 10 mrad crossing angle

E.C. Aschenauer

m

Spin

rotator


eRHIC – Geometry high-lumi IR

1.6 m

1 32 4 5 6

0.85 m

7

10 mrad

5.4

cm

8.4

cm

10.4

cm

1 m

© D.Trbojevic

E.C. Aschenauer

Two designs of the IR exist for both low luminosity (~ 3x1033) and high luminosity (~ 2x1034) depends on distance IR to focusing quads

By using a crossing angle (and crab cavities), one can have energy-independent geometries for the IRs and no synchrotron radiation in the detectors

Big advantage in detecting particles at low angle can go as low as 0.75o at hadron side |h| < 5.5 Beam-p: y ~

6.2

m

eRHIC IR1

p /A e

Energy (max), GeV 325/130 20

Number of bunches 166 74 nsec

Bunch intensity (u) , 1011 2.0 0.24

Bunch charge, nC 32 4

Beam current, mA 420 50

Normalized emittance, 1e-6 m, 95% for p / rms for e

1.2 25

Polarization, % 70 80

rms bunch length, cm 4.9 0.2

β*, cm 5 5

Luminosity, cm-2s-1 1.46 x 1034

(including hour-glass effect h=0.851)

Luminosity for 30 GeV e-beam operation will be at 20% level


(M)eRHIC Luminosities

E.C. Aschenauer

Old Design: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

New Design:for eRHIC with CEC: 20 x 325 with b* of 5cm: 1.4x1034 cm-2s-1

as the the luminosity does not depend on the energy of electron beam youcan write it as for eRHIC (new design): 1.4 1034* Ep/325 cm-2s-1

so you can easily scale it going to 20x100 for example

so for eRHIC assuming 50% operations efficiency one week corresponds to0.5 * 604800(s in a week) * (1.4x1034 cm-2s-1) = 4*1039 cm-1 so 4000pb-1

an operations 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


Questions about QCD

Confinement of color, or why are there no free quarks and gluons at a long distance? A very hard question to answer

What is the quark-gluon structure inside a hadron?Probes to “see” and “locate” the quarks and gluons, withoutdisturbing them or interfering with their dynamics?

How do quarks and gluons form color neutral hadrons?Probes to “monitor” the hadronization process?

How to understand the spin of a hadron? Hadrons are a composite particle of quarks and gluons What is the physics behind the QCD mass scale?

E.C. Aschenauer

It represents the difference between QED and QCD Can’t “see” it directly, but, it is behind the answers to all these questions

The key to the solutionThe Gluon

Lets try to answer: What is the role of gluons and gluon self-interactions in nucleons and nuclei? What is the internal landscape of the nucleons?

What is the nature of the spin of the proton? What is the three-dimensional spatial landscape of nucleons?

What governs the transition of quarks and gluons into pions and nucleons?


The √s vs. minimum luminosity landscape

E.C. Aschenauer

semi-inclusive DIS

inclusive DIS

Diffraction

electro-weak

4x10010x100 20x100 20x250

exclusive DIS (DVCS)

exclusive DIS (PS & VM)

4x50

H1/ZEUS:~1031cm-2s-1

Hermes:5x1031-1033

W2-dependence of c.s. neglected


Detector Requirements from Physics

Detector must be multi-purpose Need the same detector for inclusive (ep -> e’X), semi-

inclusive (ep -> e’hadron(s)X), exclusive (ep -> e’pp) reactions and eA interactions

Able to run for different energies (and ep/A kinematics) to reduce systematic errors Ability to tag the struck nucleus in exclusive and diffractive

eA reactions Needs to have large acceptance

Cover both mid- and forward-rapidity particle detection to very low scattering angle; around 1o in e

and p/A direction particle identification is crucial

e, p, K, p, n over wide momentum range and scattering angle excellent secondary vertex resolution (charm)

small systematic uncertainty for e,p-beam polarization and luminosity measurement

E.C. Aschenauer


Momentum vs. theta of scat. electron

Proton Energy50 GeV 100 GeV 250 GeV

Ele

ctr

on

En

erg

y 4

GeV

1

0 G

eV

2

0 G

eV

E.C. Aschenauer

As more symmetricbeam energies

as more thescattered lepton

goes forward

EIC EW Meeting, W&M, VA, May 2010 14E.C. Aschenauer

4x50

4x100

4x250

pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV

No dependence on hadron beam energyQ2>0.1GeV2

4GeV >5o

10GeV >2o

20GeV >1o


Momentum vs. angle of pions

Same CM energy (63.3 GeV)

What do 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

E.C. Aschenauer

16

t for exclusive VM vs p’ angle

E.C. Aschenauer

EIC EW Meeting, W&M, VA, May 2010

4 x 50 4 x 100

4 x 250

very strong correlation between t and “recoiling” proton angle Roman pots need to be very well integrated in the lattice resolution on t!

t=(p4-p2)2 = 2[(mpin.mp

out)-(EinEout - pz

inpzout)] t=(p3–p1)2 = mρ

2-Q2 - 2(Eγ*Eρ-pxγ*px

ρ-pyγ*py

ρ-pz

γ*pzρ)


A detector integrated into IR

E.C. Aschenauer

ZDC

FPD

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

FED

a lot of space for polarimetryand luminositymeasurements


Can we detect DVCS-protons and Au break up p

E.C. Aschenauer

track the protons through solenoid, quads and dipole with hector

proton track Dp=10% proton track Dp=20%

proton track Dp=40%

Equivalent to fragmenting protonsfrom Au in Au optics (197/79:1 ~2.5:1)

DVCS proto

ns are

fine, need m

ore optim

izatio

n for b

reak-u

p proto

ns


eRHIC Detector in Geant-3

E.C. Aschenauer

DIRC: not shown because of cut; modeled following Babar no hadronic calorimeter in barrel yet

investigate ILC technology to combine mID with HCAL

Drift Chambers central tracking

ala BaBar

Silicon Stripdetectorala Zeus

EM-CalorimeterLeadGlas

High ThresholdCerenkov

fast trigger on e’e/h separation

Dual-Radiator RICH

ala HERMES

Drift Chambers ala HERMES FDC

Need to adopt G

eant-3 m

odel to new IR

conce

pt


MeRHIC Detector in Geant-3

E.C. Aschenauer


More Detector Concepts in the same framework

E.C. Aschenauer

Detector optimized fordiffractive physicsby Allen Caldwell

“eSTAR”


STAR @ RHIC

Heavy Flavor Tracker (2013)

Tracking: TPC

Forward Gem Tracker(2011)

Electromagnetic Calorimetry:BEMC+EEMC+FMS(-1 ≤ η ≤ 4)

Particle ID: TOF

Full azimuthal particle identification over a broad range in pseudorapidity

Upgrades:Muon Tracking Detector HLT

E.C. Aschenauer


Kinematics at 4+100

Scattered electron Scattered jet

4x100 open kinematics: scatters the electron and jet to mid-rapidityForward region (FMS): Electron either Q2 < 1 GeV, or very high x and Q2

Jet either very soft or very hardNote: current thinking has hadron in the blue beam: optimized for high x and Q2

E.C. Aschenauer


Current PHENIX Detector at RHIC

MPC 3.1 < | h | < 3.9 2.5o < Q < 5.2o Muon Arms 1.2 < | h | < 2.4 South: 12o < Q < 37o

North: 10o < Q < 37o

Central Arms | h | < 0.35 60o < Q < 110o

e-

electrons will not make it to the south muon arm to much material

would like to have hadrons in blue beam and leptons in yellow beam direction

E.C. Aschenauer


What will the current PheniX see4x100

pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV

4x100 4x100

Current PheniX detector not really useable for

DISacceptance not matched to DIS kinematics

BUT ….

E.C. Aschenauer


HCALEMCAL

Preshower

The new PheniX Spectrometer

Coverage in |h| =< 4 (2o < q < 30o) 0.1 < Q2 < 100 (5o – 175o) need an open geometry detector planes for next decadal plan

replace current central detector with a new one covering |h| =< 1replace South muon arm by a endcap spectrometer

60cm

2T SolenoidEMCAL

HCAL

Silicon TrackerVTX + 1 layer

Silicon TrackerFVTX

1.2 < h < 2.7 8o < q < 37o

North Muon Arm

RICH

68cm

IP

80cm

145cm

5o @ 2m 17.4 cm dy

E.C. Aschenauer

Summary:

the new PheniX detector can make

important measurements

in ep/eA

Lets integrate it fully into the design

and the next decadal plan


Summary

A lot of change/progress since the last EIC Collaboration meeting new eRHIC design more elegant and staging is very

naturaly included working on costing of the new version test many detector options eSTAR, ePHENIX and a

dedicated detectoreSTAR & ePHENIX look promising with some restrictions

need to adjust the dedicated detector design fully to the new IR design

will integrate luminosity and e/p-polarisation measurements on the next step

Need input from the EW community what is required for detector, machine and IR design

Submitted first detector LDRD to BNL high resolution vertex detector based on CMOS pixel

E.C. Aschenauer


Luminosities in electron-hadron collisions

ELIC

eRHIC IIeRHIC

e+A facilities© 2010 Plot by A.Accardi

excepteRHIC luminosity by V.

Litvinenko

HERA II

E.C. Aschenauer


Questions about QCD (biased list)

Confinement of color, or why there is no free quarks and gluons at a long distance? A very hard question to answer

What is the quark-gluon structure inside a hadron?Probes to “see” and “locate” the quarks and gluons, withoutdisturbing them or interfering with their dynamics?

How quarks and gluons form color neutral hadrons?Probes to “monitor” the hadronization process?

How to understand the spin of a hadron?A composite particle of quarks and gluons

What is the physics behind the QCD mass scale? …

E.C. Aschenauer

It represents the difference between QED and QCD Can’t “see” it directly, but, it is behind the answers to all these questions

The key to the solutionThe Gluon


Energies Simulated for kinematics

Beam EnergiesEe + Ep [GeV]

Center-of-mass Energy [GeV]

Events Produced

4+50 28.34+100 40.010+50 44.74+250 63.3

10+100 63.3 One million20+50 63.3

20+100 89.410+250 10020+250 141

E.C. Aschenauer

EIC EW Meeting, W&M, VA, May 2010 32E.C. Aschenauer

STAR

PH

EN

IX

2 x 200 m SRF linac4 (5) GeV per pass5 (4) passes

Polarized e-gun

Beamdump

4 to 5 vertically separatedrecirculating passes

Cohere

nt

e-c

oole

r

5 mm

5 mm

5 mm

5 mm

20 GeV e-beam

16 GeV e-beam

12 GeV e-beam

8 GeV e-beam

Com

mon

vacu

um

ch

am

ber


MeRH

IC

dete

ctor

10-20 GeV e x 325 GeV p 130 GeV/u Au

possibility of 30 GeV @low current operation

The 1st incarnation from a staged eRHIC


IR-Design for MeRHIC IP-2

E.C. Aschenauer

synchrotron shielding omitted allows p and heavy ion decay product tagging IP-2: height beam-pipe floor ~6’ (with digging ~10’)

limits detector design no HCal in central detector


eSTAR

ePH

EN

IX

eRHIC staging all-in tunnel energy of electron beam is increasing from 5 GeV to 30 GeV by building-up the linacs

2 SRF linac1 -> 5 GeV per pass4 (6) passes

Vertically separatedrecirculating passes.# of passes will be chosen to optimize eRHIC cost

Cohere

nt e-co

ole

r

5 mm

5 mm

5 mm

5 mm

20 GeV e-beam

15 GeV e-beam

10 GeV e-beam

5 GeV e-beam

Com

mon

vacu

um

ch

am

ber


eRHIC detector

inje

ctor

RHIC: 325 GeV p or 130 GeV/u Au

The mostcost

effective design

© V. Litvinenko

The latest design of eRHIC

E.C. Aschenauer

e.c. aschenauereic ew meeting, w&m, va, may 20101

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gev beam

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