Some thoughts about the IR-Design and Si-tracking E.C. AschenauerEIC Tracking R&D Meeting, March 20121.

EIC Tracking R&D Meeting, March 2012 1

Some thoughts about the IR-Design

and Si-tracking

E.C. Aschenauer

EIC Tracking R&D Meeting, March 2012

eSTAR

ePH

EN

IX

Cohere

nt

e-c

oole

r

New detector

30 G

eV

30 GeV

Linac

Linac 2

.45 G

eV

100 m

27.55 GeV

Bea

m

dum

p

Polarize

d e-g

un

0.6

GeV

E/Eo0.02000.10170.18330.26500.34670.42830.51000.59170.67330.75500.83670.91831.0000

0.9183 Eo

0.7550 Eo

0.5917 Eo

0.4286 Eo

0.1017 Eo

0.2650 Eo

0.8367 Eo

0.6733 Eo

0.5100 Eo

0.3467 Eo

Eo

0.1833 Eo

0.02 EoAll energies scale proportionally by

adding SRF cavities to the injector

All magnets would installed from the day one and we would be cranking power supplies up as

energy is increasing

Staging of eRHIC: Eo : 5 -> 30 GeV

2E.C. Aschenauer


eRHIC high-luminosity IR with b*=5 cm

E.C. Aschenauer

10 mrad crossing angle and crab-crossing High gradient (200 T/m) large aperture Nb3Sn focusing magnets Arranged free-field electron pass through the hadron triplet magnets Integration with the detector: efficient separation and registration of

low angle collision products Gentle bending of the electrons to avoid SR impact in the detector

Proton beam lattice© D.Trbojevic, B.Parker, S. Tepikian, J. Beebe-Wang

e

p

Nb3Sn

200 T/m

G.Ambrosio et al., IPAC’10

eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 mand 10 mrad crossing angle this is required for 1034 cm-2 s-1

Question to answer

How does this design need to be adapted for eSTAR/ePHENIX?

ATTENTION:

eRHIC clock will be changing to 75ns

EIC Tracking R&D Meeting, March 2012 4E.C. Aschenauer

IR-Design

All optimized for dedicated detectorHave +/-4.5m for main-detector roman pots / ZDC low Q2-taggerneed to be integrated in the IR design


Integration into Machine: IR-Design

E.C. Aschenauer

space for low-Q e-tagger

Outgoing electron direction currently under detailed design detect low Q2 scattered leptons want to use the vertical bend to separate very low-Q e’ from beam-electrons can make bend faster for outgoing beam faster separation for 0.1o<Q<1o will add calorimetry after the main detector


Kinematics of Breakup Neutrons

E.C. Aschenauer

Results from GEMINI++ for 50 GeV Au

by Thomas Ullrich+/-5mrad acceptance seems sufficient

Results:With an aperture of ±3 mrad we are in relative good shape• enough “detection” power for t > 0.025 GeV2

• below t ~ 0.02 GeV2 we have to look into photon detection‣ Is it needed?Question:• For some physics rejection power for incoherent is

needed ~104

How efficient can the ZDCs be made?


Diffractive Physics: p’ kinematics

5x250

5x100

5x50

E.C. Aschenauer

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

out)-(EinEout - pz

inpzout)]

“ Roman Pots” acceptance studies see later?

Diffraction:

p’

Simulations by J.H Lee


proton distribution in y vs x at s=20 m

25x250 5x50

E.C. Aschenauer

without quadrupole aperture limit

25x250 5x50

with quadrupole aperture limit


Accepted in“Roman Pot”(example) at s=20m

25x250 5x50

E.C. Aschenauer

25x250 5x50

GeneratedQuad aperture limitedRP (at 20m) accepted


Si-Vertex Detector RD Si-Vertex Detector

MAPS technology from IPHC concept as STAR-HFT, CBM, Alice, …

Barrel: 4 double sided layers @ 2.5. 5. 7.5 15. cm 10 sectors in FRapidity coverage: at least +/- 1chip 20mm x 30mm 1cm 300 pixel pitch 33 micron dual sided readout, one column 60 ms readout timeRadiation length 5 permill / layer (50mm Si) < 5mm Vertex resolution

Forward Disks: At least 4 single sided disks spaced in z starting from 20cmRadial extension 3 (19 mm pixel) to 12 cm (75 mm pixel), dual sided readout 300x200ns = readout time 60microsneed a 0.3xm region at each side of the wedge for readoutRadiation length 3 permill / layerwill explore new technology of stitching

E.C. Aschenauer

4.4cm

1.1cm pi/8

pixel size 75 mm 300 pixel

pixel size 19 mm


Our Goals What does the LDRD want to answer

quantify the chip behaviorlaser test stand at columbiatest stand with sources / cosmic at BNL

testbeams, i.e. new more radiation hard mimosa chips “build” prototype chips / wedge using stitching answer integrations questions, i.e. is anything else

than air cooling needed answer many questions by MC

what is the occupancy for the different layers in the barrel and in the forward directionwhat is the needed resolution of the TPC / Barrel Gem-tracker to track from inside out what intermediate detector is needed if we have to track outside insynchrotron radiation loaddo we have heavy fragments in the direction of the disksvertex finding efficiency depending on pt-cut off

E.C. Aschenauer


What was done till now Laser teststand at columbia working

first results on Si-chips available start to establish Si-pixel collaboration with STAR, CBM,

IPHC offer made to postdoc to work on this STAR will install test pixel detector this summer

will most likely get involved in this

E.C. Aschenauer


Simulation well ahead

E.C. Aschenauer

Pythia-event


Symmetric version with improved detector model

All FairRoot simulationsdone by Yulia Zoulkarneev

FairRoot has also a fast smearing generator, whichis based on the actual material budget

E.C. Aschenauer


Experiment Central Field Length Inner Diameter

ZEUS 1.8 T 2.8 m 0.86 m

H1 1.15T 3.6 m 1.6 m

BABAR 1.5T 3.46 m 1.4 m

BELLE 1.5T 3.0 m 1.7 m

GlueX 2.0T 3.5 m 1.85 m

ATLAS 2.0T 5.3 m 2.44 m

CMS 4.0T 13.0 m 5.9 m

PANDA(*design) 2.0T 4.9m 1.9 m

CLAS12(*design) 5.0T 1.19 m 0.96 m

Magnetic Field Considerations

E.C. Aschenauer

Solenoid Fields – Overview:

Suggest 4-5m long Solenoid with diameter ~3m and B-Field of ~3Tparticles with very small scattering angle need to be treated separately


“Easier” Solenoid Field – 2T vs. 4T?

• Intrinsic contribution ~ 1/B• Multiple scattering contribution ~ 1/B

p = 50 GeV p = 5 GeV

B=2T

B=4T

E.C. Aschenauer


Multiple scattering contribution


Multiple scattering contribution dominant at small angles (due to BT term in denominator) and small momenta

E.C. Aschenauer


dp/p angular dependence

Can improve resolution at forward angles by offsetting IP


E.C. Aschenauer


Solenoid and Dipole field


As expected, substantially improves resolutions at small angles

E.C. Aschenauer

EIC Tracking R&D Meeting, March 2012 20E.C. Aschenauer

BACKUP


Multiple scattering contribution:

Intrinsic contribution (first term):

..2cos

0136.0

3.0

1

p

plr

T

nL

z

B

4

720

'3.0

p

p

p2

nLB

r

T

• B=central field (T)

• σrφ=position resolution (m)

• L’=length of transverse path through field (m)

• N=number of measurements

• z = charge of particle

• L = total track length through detector (m)

• γ= angle of incidence w.r.t. normal of detector plane

• nr.l. = number of radiation lengths in detector

msc

intr

Assumptions: • circular detectors around interaction

point• nr.l. = 0.03 (from Hall D CDC)

Magnetic Field: Super simple resolution estimates

E.C. Aschenauer


What needs to be covered

E.C. Aschenauer

e’

t

(Q2)e

gL*

x+ξ x-ξ

H, H, E, E (x,ξ,t)

~~

, ,g p J/Y

p p’

Inclusive Reactions: Momentum/energy and angular resolution of e’ critical Very good electron id Moderate luminosity >1032 cm-1 s-1

Need low x ~10-4 high √s (Saturation and spin physics)

Semi-inclusive Reactions: Excellent particle ID: p,K,p separation over a wide range in h full F-coverage around g* Excellent vertex resolution Charm, bottom identification high luminosity >1033 cm-1 s-1 (5d binning (x,Q2,z, pt,F)) Need low x ~10-4 high √s

Exclusive Reactions: Exclusivity high rapidity coverage rapidity gap events high resolution in t Roman pots high luminosity >1033 cm-1 s-1 (4d binning (x,Q2,t,F))

Some thoughts about the IR-Design and Si-tracking E.C. AschenauerEIC Tracking R&D Meeting, March 20121.

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