- vertexing - tracking - summary

2004. 11. 10Very Large Detector Kick-off Meeting

- Vertexing - Tracking - Summary

Summary of Tracking DevicesFor Huge Detector

Jik Lee(SNU) for Hwanbae Park (KNU)Huge Detector Kickoff Meeting, Nov. 10

SLAC CERN

DESY

KEK


• Huge Detector: best optimized for “PFA” - excellent momentum resolution - good separation of clusters/tracks

SiVTX pixel(cold version)

HCAL(Pb(Fe)/scinti or digital)

W/Scinti ECAL

TPC

Si intermedi.-Trk

SC-coil

▣ Concepts of Huge Detector

SD TESLA Huge

Solenoid B(T) 5 4 3

Rin(m) 2.48 3.0 3.75

L(m) 5.8 9.2 8.4

Est(GJ) 1.4 2.3 1.2

Tracker Rmin (m) 0.2 0.36 0.40

Rmax(m) 1.25 1.62 2.05

σ(μm) 7 150 150

Nsample 5 200 220

dpt/pt2 3.9e-5 1.5e-4 1.1e-4

maximize BL2


▣ Vertexing Performance Requirements

• excellent spacepoint precision < 4 microns• impact parameter resolution ≤ 5µm 10µm/(p sin3/2 )• minimal multiple scattering 0.1 - 0.2% X0 or less per layer (transparency) • two track separation, occupancy 20 x 20 µm2 pixel size

• Charge Coupled Devices (CCD)• Monolithic Active Pixels (MAPs)• DEPleted Field Effect Transistor (DEPFET)• Silicon On Insulator (SOI)• Image Sensor with In-Situ Storage (ISIS)

pixelated type


▣ Beam StructuresBeam Structures

• Pileup over bunch train

• Or fast timing

• bx live: 3 10-5

power pulse

• Fast readouts: OK, no pileup

• Digital pipeline

• bx live: 5 10-3

warm

cold• readout speed• radiation hardness• occupancy


▣ Vertex Detector: CCDVertex Detector: CCD

• faster readout needed for cold machine - need to readout every 50 µs (20 times) during a train ~0.5% occupancy - use Column-Parallel CCD with low noise (increase readout speed ~50MHz)

• cryostat for operation at 200 K - could be unnecessary with fast readout

CP CCD

separate amplifier andreadout foreach column

LCFILCFICP CCDCP CCD

thin and mechanically stable ladder

400x750 pixels(20µmx20µm)


▣ Image Sensor with In-situ Storage (ISIS)Image Sensor with In-situ Storage (ISIS)

• 20 readouts/bunch train may be impossible due to beam –related RF pick up motivates delayed operation of detector for long bunch train:

• charge collection to photogate from 20-30 µm silicon, as in a conventional CCD• signal charge shifted into storage register every 50 µs, providing required time slicing• string of signal charges is stored during bunch train in a buried channel, avoiding charge-voltage conversion• totally noise-free charge storage, ready for readout in 200 ms of calm conditions between trains


▣ Vertex Detector: MAPS PrototypeVertex Detector: MAPS Prototype

• neutron irradiations - fluencies up to 1012 neutrons/cm2 are acceptable with considering LC requirements which is ~ 109 n/cm2/year • ionizing irradiations - tests up to a few 100kRad - exact sources of performance losses are under investigation (diode size and placements of the transistors are important parameters)

5% drop in charge at 1.5e12 n/cm2

▪ standard CMOS sensor technology - readout/sensor on one chip - signal is corrected from epi. layer▪ pixel size and precision ~ CCD


▣ Vertex Detector: DEPFET PrototypeVertex Detector: DEPFET Prototype

• thinning process for sensors established

800x104 mm800x104 mm2

- sensitive area 50µm thinned - fast signal to cope with high rate requirement - resolution of 9.5 μm

• complete clear no clear noise - (1 x clear) then sample 500x in 2.5ms - (clear + sample) 500x

for single pixel

▪ detector and amplification properties▪ fully sensitivity over whole bulk▪ very low noise operation at room temp.


• pair background hit at R=15mm is 1.7 times larger than that of 4T• background hits are decreased significantly at larger R

▣ Vertex Detector Issue

R(mm)

B(T)Pair background

(hit/mm2/train)

15 4 1.0

15 3 1.7

24 3 0.4

• configuration of R=20mm with silicon thickness < 70 µm satisfies the impact parameter resolution requirement: ≤ 5µm 10µm/(p sin3/2 )

• readout speed and rad. hardness• very thin detector

Y. Sugimoto


▣ Tracking Performance Requirements

• excellent momentum resolution - dilepton recoil mass for higgstrahlung process - end-point measurement for SUSY chains• excellent pattern recognition and 2 track resolution - high energy, high density jets• tolerant to high machine backgrounds -tracks in central tracker dominated by γγ events

• MWPC and pads - limited by positive ion feedback and MWPC response• MPGD’s (Micro Pattern Gas Detectors) - GEM (Gas Electron Multiplier) - MicroMEGAS (Micro Mesh GAS detector)

gaseous type (readout)


▣ TPC with GEM

• 50 µm Kapton foil for gas amplification• 5 µm copper coated on both sides• 70 µm holes, 140 µm pitch

• hexagonally aligned holes• multiple GEM structures - safer operation - more flexibility to optimize charge transfer

• GEM voltages up to 500 V yield 104 gas amplification


▣ TPC with GEM

• to reduce ion feedback -GEM with Micro Hole Strip Plate (MHSP)

• apply negative strip voltage ions collected on strips, electrons extracted from holes due to diffusion

IF is reduced by a factor of 4


▣ TPC with MicromeGAS

• a micromesh sustained by 50-100 µm high insulating pillars• multiplication takes place btw anode and mesh

S1

S2

• S1/S2 ~ Eamp/Edrift

- can choose gap/HV to have gain maximum - ion feedback suppressed by Edrift/Eamp


▣ TPC with MicromeGAS

Berkeley-Orsay-Saclay TPC

Readout

Detector

Field cage

pad layout: 1024 pads

• 50 cm drift, 1024 channels• tested up to 2T at Saclay - no gain drop with 55Fe

principle is proven but optimization to be done


▣ TPC Tracking Issue

• small structures (no ExB effects)• fast electron signal• intrinsic ion feedback suppression

• optimize novel gas amplification systems• ion feedback suppression• neutron backgrounds• optimize single point and double track resolution• demonstrate large system performance with control of systematics


▣ Intermediate and Forward Tracker

• located btw vtx and main tracker (GLC model) - 5 layers at r=9 to 37 cm - angular coverage |cosΘ|<0.9 - spatial resolution σ = 20μm - total amount of Si required: 10 m2

• improve momentum resolution• improve track finding efficiency• forward tracking

SET

• intermediate between vertex and central (IMT, SIT, FTD)• intermediate between central and calorimeters (FCH, SET)

• SIT + TPC + SOT


512ch 50um pitch sensor

1cm PIN Diode

For SDD R&D




Backside of SSD

PIN Diode array

▣ Intermediate Tracker

n+ implantedp-stop in atoll

via in hourglassreadout pad in staggering

guard ring

p+ implanted readout strip

N side P side


▣ Tracking Devices

ΔPt/pt2

Pt(GeV/c)

Y. Sugimoto

• Si Vertex Detector 5 layers, t=70µm, =3µm cos < 1 (non-realistic)

• Si Inner Tracker 3 layers (12, 24, 36 cm), t=300µm, =7 µm, cos<1 (non-realistic)

• TPC 40cm < R < 200cm, Z<235cm Ar gas, 220 samples, =150µm

• Si Outer Tracker R=205cm(barrel)/Z=250cm(EC), =7µm

detail (realistic) simulation studies are underway


▣ Vertexing/Tracking Issues

• R&D must be guided by continuing physics and simulation programs which can deliver the accuracy that the LC physics needs

- evaluate the tracking performance: backgrounds, occupancy studies, pattern recognition studies• demonstrate performance in large scale prototypes in cosmic ray and test beams studies with the magnetic field• vertex detector, tracker, calorimeters should be integrated for optimal jet reconstruction


Backup Slides


▣ Physics Performance

• end-point measurement for SUSY chains

GLC project report

- vertexing - tracking - summary

Documents

ccd vertex detector

trains vertex detector

ccd faster readout

delayed operation of

conventional ccd signal

clear noise

noisefree charge storage

charge collection