charged particle tracker for a rhic/eic joint detector

Charged Particle Tracker for

a RHIC/EIC joint detector

Detector layouts based on EIC and NLC Physics drivers Silicon detector technologies Simulations based on different layouts

Rene Bellwied, Wayne State University

RHIC/EIC joint detector discussion, BNL, Sept.19th

The EIC detector concept

The EIC parton detector concept

Magnetic field strength: ?

For comparison: two LC detector options

Both detector options have now all calorimetry inside the magnet.

Old

B = 5 T B = 3 T

Large detector option for LCD

Large detector option for LCD

Silicon detector option for LCD

Silicon detector option for LCD

Central tracker: Silicon Drift DetectorsFive layersRadiation length / layer = 0.5 %sigma_rphi = 7 m, sigma_rz = 10 m

            Layer Radii    Half-lengths             -----------    ------------              20.00 cm      26.67 cm              46.25 cm        61.67 cm              72.50 cm        96.67 cm              98.75 cm       131.67 cm             125.00 cm       166.67 cm

56 m2 SiliconWafer size: 10 by 10 cm # of Wafers: 6000 (incl. spares)# of Channels: 4,404,480 channels (260 m pitch)

Silicon detector option for LCD (small detector, high field B=5T)

Forward tracker: Silicon StripFive disks uniformly spaced in zRadiation length / layer = 1.0 % Double-sided with 90 degree stereo, sigma = 7m

Inner radii      Outer radii    Z position             -----------      -----------    ----------               4.0 cm           20.50 cm       27.1 cm               7.9 cm           46.75 cm       62.1 cm              11.7 cm           73.00 cm       97.1 cm              15.6 cm           99.25 cm      132.1 cm              19.5 cm          125.50 cm      167.1 cm           Vertex detector:CCD 5 layers uniformly spaced (r = 1.2 cm to 6.0 cm)  Half-length of layer 1 = 2.5 cm   Half-length of layers 2-5 = 12.5 cm   sigma_rphi = sigma_rz = 5 microns Radiation length / layer = 0.1 %      

The SCT Semiconductor Tracker

4 barrels9 wheels

9 wheels

5.6 m

1.04 m

1.53 m

4088 Modules

~ 61 m2 of silicon

15,392 silicon wafers

~ 6.3 million of readout channels

Barrel diameters:Barrel diameters:

B3: 568 mmB3: 568 mm

B4: 710 mmB4: 710 mm

B5: 854 mmB5: 854 mm

B6: 996 mmB6: 996 mm

9,648,128 strips = electronics channel

440 m2 of Si wafers, 210 m2 of Si sensors

CMS Silicon Detector

Physics Drivers (e.g. for NLC)

Technical Issues (1)

Technical Issues (2)

Technical Issues (3)

Stripixels:something new from BNL

(why ? SDD’s might be too slow)

Alternating Stripixel Detector (ASD) Interleaved Stripixel Detector (ISD)

Pseudo-3d readout with speed and resolution comparable to double-side strip detector

(Zheng Li, BNL report, Nov.2000)

The SVT in STARThe final device….The final device….

… and all its

connections

… and all its

connections

STAR-SVT characteristics

216 wafers (bi-directional drift) = 432 hybrids 3 barrels, r = 5, 10, 15 cm, 103,680 channels, 13,271,040 pixels 6 by 6 cm active area = max. 3 cm drift, 3 mm (inactive) guard area max. HV = 1500 V, max. drift time = 5 s, (TPC drift time = 50 s) anode pitch = 250 m, cathode pitch = 150 m SVT cost: $7M for 0.7m2 of silicon Radiation length: 1.4% per layer

0.3% silicon, 0.5% FEE (Front End Electronics), 0.6% cooling and support. Beryllium support structure. FEE placed beside wafers. Water cooling.

Typical SDD Resolution

Wafers: B and T dependence

Used at B=6T. B fields parallel to drift increase the resistance and slow the drift velocity.

The detectors work well up to 50oC but are also very T-dependent. T-variations of 0.10C cause a 10% drift velocity variation

Detectors are operated at room temperature in STAR.

We monitor these effect via MOS charge injectors

0 1 2 3 4 5 65.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

6.0

6.1

Drif

t V

eloc

ity (m

/ns)

Magnetic Field (T)

Present status of technology

STAR 4in. NTD material, 3 kcm, 280 m thick, 6.3 by 6.3 cm area 250 m readout pitch, 61,440 pixels per detector SINTEF produced 250 good wafers (70% yield)

ALICE 6in. NTD material, 2 kcm, 280 m thick, 280 m pitch CANBERRA produced around 100 prototypes, good yield

Future 6in. NTD, 150 micron thick, any pitch between 200-400 m 10 by 10 cm wafer

Silicon Drift Detector Features

Mature technology. <10 micron resolution achievable with $’s

and R&D. Easy along one axis (anodes). <0.5% radiation length/layer achievable if

FEE moved to edges. Low number of channels translates to low

cost silicon detectors with good resolution. Detector could be operated with air cooling

at room temperature

Expected Impact Parameter Resolution

Results for b/c tagging performance

Expected Momentum Resolution

SD Tracking efficiencies:For 100% hit efficiency: (97.3±0.10)%For 98% hit efficiency: (96.6±0.12)%For 90% hit efficiency: (92.7±0.16)%

Tracking efficiencies:For 100% hit efficiency: (95.3±0.13)%For 98% hit efficiency: (94.5±0.14)%For 90% hit efficiency: (89.5±0.20)%

LD

Tracking efficiencies LD vs. SD

SD For hit efficiency 100%:Missing energy = (5.7±0.4) GeV = (3.3±0.2)%Ghost energy = (4.8±0.4) GeV = (2.9±0.2)%

For hit efficiency 100%:Missing energy = (11.7±0.6) GeV = (7.1±0.3)%Ghost energy = (19.6±0.8) GeV = (13.1±0.6)%

LD

Missing and ghost energies

With the maximum of d3p distribution at ~(1.5-2)10-3, the data are consistentwith the earlier momentum resolution simulations (B. Schumm, VR, et al):

within a factor of ~2 in the momentum range of 0.5 GeV/c < pT < 20 GeV/c.

2225 /2500102 cGeVpp TTpT

Preliminary conclusions

Momentum resolution

With the existing 3d tracking and pattern recognition software (Mike Ronan et al.) the Silicon option has a slight advantage in tracking efficiency, shows less missing and ghost energy, and less ghost tracks)

R&D for Large Tracker Application

Improve position resolution to 5m Decrease anode pitch from 250 to 100m. Stiffen resistor chain and drift faster.

Improve radiation length Reduce wafer thickness from 300m to 150m Move FEE to edges or change from hybrid to SVX Air cooling vs. water cooling

Use 6in instead of 4in Silicon wafers to reduce #channels. More extensive radiation damage studies.

Detectors/FEE can withstand around 100 krad (,n) PASA is BIPOLAR (intrinsically rad. hard.) SCA can be produced in rad. hard process.

The CLEO detector

The CLEO calorimeter

CLEO II quadrant viewCalorimeter specs:7,800 Th doped CsI crystals(6,144 in barrel)Each crystal 5 by 5 by 30 cmAngular Resolution ~5-10 mrad

Barrel resolution:E/E (%) = 0.35/E0.75 + 1.9 - 0.1E

Endcap resolution:E/E (%) = 0.26/E + 2.5

= 2-3% for 1 GeV e- or