R&D for SLHC detectors at PSI and Geneva CHIPP workshop on the high-energy frontier of particle physics Zürich 6. September 2006 R. Horisberger (Paul Scherrer Institut) A. Clark (University of Geneva)

Super LHC machine ~ 10x Luminosity various upgrade phases for LHC machine possible: phase 0/1 limited hardware upgrade  x cm -2 sec -1 phase 2 major hardware upgrade  10 x cm -2 sec -1 Present CMS/ATLAS tracking systems built for integrated fluence ~ 500 fb -1 Assume for SHLC operation 2500 fb -1 and L= 5x or 10x cm -2 sec -1 Tracker upgrade stage should be available in 2013/14 With 4 years of qualification / production  3-4 years of R&D ! Little time! SLHC challenge: Data rates & Radiation Damage

230 min.bias collisions in bunch ~ particles in |  |  3.2 mostly low p T tracks N ch (|y|  0.5) Expected SLHC Environment ATLAS

ATLAS & CMS had several internal workshops to study and address the new challenge e.g. CMS Conclusions Design & built new ~200 m 2 Silicon Pixel Tracker for SLHC with: - Momentum resolution - Material budget - Tracking efficiency equal or better than present tracker under LHC conditions need L1 trigger from tracking system

LHCSLHC Silicon Pixel Detector Occupancy: ~ 1 m 2 Data 0-Sup: yes yes Silicon Strip Detector Occupancy:1-4%10-40% ~ 220 m 2 Data 0-Sup: no no CMS Silicon Tracker Present Silicon Strip Tracker (SST) needs replacement with zero- suppressed Pixel Tracker Pixel / Strixel / Striplets name not clear defined, depends on L/W

W. Smith, U. Wisconsin, July 16, 2005 CMS SLHC Workshop: Trigger Considerations - 6 From DAQ TDR Note limited rejection power (slope) without tracker information CMS Muon Rate at L = CMS Muon Rate at L = New CMS Pixel Tracker needs trigger capability !

CMS Detector Replacements Inner Tracker30 MChf Outer Tracker90 MChf Level 1 Trigger20 MChf DAQ10 MChf Other Front Ends10 MChf Infrastructure15 MChf Total175 MChf Materials Cost for Collaboration (CORE) Across collaboration ~ 900 FTE SLHC Pixel Tracker J. Nash, CMS Electronics Coordinator

SLHC needs consistent professional work on several areas: Radiation damage on silicon sensors RD50 low power electronics conception & design CMOS 0.25  m  0.13  m ?? high bandwidth controls & data readout replace TTC system 40MHz AOH readout low cost design / low cost fabrication of pixel modules low mass power distribution scheme serial powering rad. hard regulators low mass cooling low mass construction less material  more alignment low mass cabling very high bandwidth serial protocols

Current consumption: Analog: Strips  reduce noise Pixels  speed (timewalk) Digital: Information processing (data flow) ~ fluence Reduce power by : - Technology - CMOS 0.25   0.13  digital: yes analog: no - Architecture choice Pixel ROC Power/cm 2 : ALICE 100% ATLAS 72% CMS 31% - Custom protocols TBM05 ~ 1/6 power of TBM03 abandon LVDS for 5cm distance  custom protocol LCDS (Low Current Differential Swing) Power consumption~ material budget

Potential Common R&D Power –Target DC-DC conversion –Serial powering also an option A new control system for the LHC experiements –Replace the TTC system –Some current prototypes “gbt” being developed in MIC –Vital that CMS/ATLAS requirements are well defined as input to this development Top down, not bottom up system design J. Nash, CMS Electronics Coordinator

R&D II Optical Links –Radiation of components –Interfaces to control system IP blocks for 130nm –Build a radiation tolerant library in next generation CMOS technology –Potentially create some useful building blocks for development of next generation ASICs J. Nash, CMS Electronics Coordinator

To do list for Super LHC tracker: 1) Adapt and modify present pixel detector and its technology for SLHC operation at small radii ( r = 7 – 20cm ) 2) Develop and design new low cost, pixel technologies for medium ( r = 20 – 50cm ) and large radii ( r = cm )

PSI / ETHZ / Uni ZH / Uni BS have developed bulk of present pixel detector and has aquired following expertises: Micro-bump bonding (develop 18  In-bumps) TEM,LMN,LNS CMOS Read Out Chip design ( ~ 55 Chips PSI) ROC testing ( ~ 30K ROC tested by ETHZ ) Silicon sensor design & semiconductor simulation (PSI) Sensor testbeams at CERN (Univ. ZH, PSI) LHC rate ROC testbeams (PSI,  E1 beam line) Pixel module assembly (PSI / ETHZ) Pixel module qualification (U. Langenegger et al. ETHZ) Low mass mechanics & Cooling (Univ. ZH) System Integration & Cabling (PSI) CH Pixel Team is likely to perform task number 1) and be helpful to CMS collaboration for task 2) with selected contributions due to its unique pixel experience. e.g.  Pixel ROC evolution to high LHC rates  Low cost bump – bonding

Time-stamp buffer Depth: 12 data buffer Depth: 32 marker bits indicate start of new event set fast double column OR hit data column drain mechanism pixel unit cells: 2x80 sketch of a double column double column double pixels 32 data buffers 12 time stamp buffers double column interface 7.8mm 9.8mm CMS Pixel ROC: Column Drain Architecture SLHC rate data losses dominated by finite buffer sizes !  chip size !

H.C. Kästli 4th CMS Workshop for SLHC Perugia, Measurement in X-ray box LHC (10 34 cm -2 s -1 ): 11cm 7cm 4cm Very high photon fluence up to 300MHz/cm 2 Single chip sensor No TBM -> short readout times, readout losses negligible (see later) Simulation agrees very well with measurement

H.C. Kästli 4th CMS Workshop for SLHC Perugia, Contributions to data loss LHC (10 34 cm -2 s -1 ): 11cm 7cm 4cm Entirely dominated by timestamp buffer overflows In experiment also data buffer overflow (higher pixel multiplicity) Steep rise of inefficiency due to buffer limitations

H.C. Kästli 4th CMS Workshop for SLHC Perugia, Doubling the buffer size 0.4mm mounting screw whole new ROC size Doubling the buffer size in current 0.25  m ROC results in an increase of the periphery of 800  m just possible No R&D needed. Design ready in 1 month

CMS pixel modules need to be replaced. ( r=4cm every ) LHC  SLHC has probably no sharp step in luminosity Can improve rate capability of present pixel modules by: - increase buffer size in ROC periphery (factor 2 in 0.25  m CMOS ) - extra data buffer in redesigned TBM with parallel ROC read out scheme Replaced modules would be fully compatible with present system.  allows operation of present pixel system at L ~ 3x10 34 cm -2 sec -1 Evolutionary upgrade of CMS pixel modules Present TBM Read Out Scheme Future TBM Read Out Scheme

C4NP Low Cost Bumping Injection Molded Solder (IBM & Süss) Mold IMS Principle IMS allows bump 75  size and pitch of 150  200  thick wafers processed so far Wafer costs (300mm) ~ 150 $

ATLAS SCT barrel

Upgrade Activities - status 2015

ID Straw-man Layout (4 SS layers) 3 Pixel Layers 14,32,48  Sectors 5,12,18 R Location 4 Short strip layers 22,32,40,48  Sectors 27,38,49,60 R Location 2 Long Strip layers 32,40  Sectors 75,95 R Location Moderator

Current upgrade Activities - UniGe Existing: Design and prototype of ABCD-N readout chip for silicon strips (0.13 micron technology) Under investigation: Pixel b-layer replacement Study of relative merits of short strips and large pixels in the intermediate radius region (r = cm) Study of relative merits of a “barrel” design as compared with a “stave” design Interest in future development of cost- effective large pixel systems

Summary & Conclusions SLHC operations implies construction of new all silicon pixel tracker For installation in 2014/15 this implies early R&D now ! Common R&D projects ATLAS / CMS are almost mandatory ! Strong emphasis on low cost design and production must be given Evolutionary upgrade of CMS pixel modules for LHC luminosity up to ~ 3 x cm -2 sec -1 is well possible !

Power Dissipation of Pixel ROC’s ROC architecture and designs have considerable influence on actual power dissipation 3 chips in same 0.25  technology for same LHC environment # Pixels / chip Pixel area [ m  2 ] Idig [mA] Iana [mA] Power/ chip [mW] Power/ pixel  W] Power density [ mW/cm 2 ] ALICE819221’ ATLAS288020’ CMS416015’ Average power density of pixel chips = 330 mW/cm 2 CMS no on-chip regulators