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

Silicon detector option for LCD

Central tracker: Silicon Drift Detectors Five layers Radiation length / layer = 0.5 % sigma_rphi = 7  m, sigma_rz = 10  m Layer Radii Half-lengths cm cm cm cm cm cm cm cm cm cm 56 m 2 Silicon Wafer 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 Strip Five disks uniformly spaced in z Radiation length / layer = 1.0 % Double-sided with 90 degree stereo, sigma = 7  m Inner radii Outer radii Z position cm cm 27.1 cm 7.9 cm cm 62.1 cm 11.7 cm cm 97.1 cm 15.6 cm cm cm 19.5 cm cm 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 barrels 9 wheels 5.6 m 1.04 m 1.53 m 4088 Modules ~ 61 m 2 of silicon 15,392 silicon wafers ~ 6.3 million of readout channels Barrel diameters: B3: 568 mm B4: 710 mm B5: 854 mm B6: 996 mm

9,648,128 strips = electronics channel 440 m 2 of Si wafers, 210 m 2 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 STAR 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 0.7m 2 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 50 o C but are also very T- dependent. T-variations of C cause a 10% drift velocity variation Detectors are operated at room temperature in STAR. We monitor these effect via MOS charge injectors

Present status of technology STAR 4in. NTD material, 3 k  cm, 280  m thick, 6.3 by 6.3 cm area 250  m readout pitch, 61,440 pixels per detector l SINTEF produced 250 good wafers (70% yield) ALICE 6in. NTD material, 2 k  cm, 280  m thick, 280  m pitch l CANBERRA produced around 100 prototypes, good yield Future 6in. NTD, 150 micron thick, any pitch between  m l 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 consistent with the earlier momentum resolution simulations (B. Schumm, VR, et al): within a factor of ~2 in the momentum range of 0.5 GeV/c < p T < 20 GeV/c. 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 5  m Decrease anode pitch from 250 to 100  m. Stiffen resistor chain and drift faster. Improve radiation length Reduce wafer thickness from 300  m to 150  m 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 view Calorimeter specs: 7,800 Th doped CsI crystals (6,144 in barrel) Each crystal 5 by 5 by 30 cm Angular Resolution ~5-10 mrad Barrel resolution:  E /E (%) = 0.35/E E Endcap resolution:  E /E (%) = 0.26/E = 2-3% for 1 GeV e - or 