Regina Demina, Hadron collider workshop, FNAL, October 16-18, SLHC tracking issues Regina Demina, University of Rochester International Workshop on Future Hadron Colliders: Physics, Detectors, Machines

Regina Demina, Hadron collider workshop, FNAL, October 16-18, 20032OutlineOutline Accelerator upgrade stages Requirements on tracking Radiation hard R&D Electronics issues System integration issues Summary AI=action item (to be addressed in future workshops)

Regina Demina, Hadron collider workshop, FNAL, October 16-18, LHC upgrade stages LHC performance: 7 TeV beam Beam-beam tune spread E11 p/bunch L= 1E34 cm -1 s -1 Phase 0: max performance w/o hardware changes to the LHC Increase B to 9 T  E to 7.54 TeV Increase bunch intensity to 1.7E11p/bunch  L=2.3E34 O. Brüning et al., “LHC Luminosity and Energy Upgrade: a Feasibility Report”, LHC Project Report

Regina Demina, Hadron collider workshop, FNAL, October 16-18, LHC upgrade stages Phase 1: max performance while keeping the LHC arcs  * = 0.5  0.25 m Crossing angle 300  rad  425  rad (essential at decreased b* to minimize long range collisions) Bunch intensity at 1.7 E11  L =3.3 E34 cm -2 s -1 Bunch crossing interval 25  12.5 ns Increased intensity and other modifications L=4.7 E34 cm -2 s -1 Phase 2: max performance with major hardware changes to LHC Modify injectors Superconduct magnets for SPS (injection E  1TeV) Mech and dynamic aperture changes  x2 in L L= 1.0 E35 cm -2 s -1 by 2015 New superconducting dipoles E  14 TeV (a lot more R&D is needed) – not considered in this discussion

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Tracking in SuperLHC 1. Radiation damage Design luminosity =10xLHC Running time = ½ LHC (5 years) Radiation dose = 5xLHC Inner layers of SiTrk (r=20cm) are expected to be operated at bias voltage 600V after 10 years of LHC SuperLHC  3kV (?!) 1.Need replacement 2.Need improved more rad hard technology 3.The goal is to maintain tracking and b- tagging performance

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Tracking in SuperLHC 2. Granularity With collider energy and/or luminosity increase the emphasis shifts towards higher energy jets. Energetic jets are more collimated  need higher granularity A.I. Local occupancy is more critical. Need to understand for typical jet E for objects at the threshold of sensitivity (e.g. use 7 th heavy quark M Q production model) ADC Strips R=20 cm 7% of tracks in 500 GeV jets have merged hits 2.5% of tracks in 100 GeV jets

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Possible detector configuration What to replace? Most likely 100% of the tracking system Lifetime (no relation to radiation damage) of Si systems so far <~3-4 years, LHC=8-10 years Increase granularity Electronics compatibility To fix all the problems that are not known now Scaling law radiation 1/r 2 R<20 cm – new technology 20<R<60 cm – pixels R>60 – microstrips (with some technology pushing)

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Directions in Tracking R&D Use of defect engineering silicon E.g. DOFZ is now used for ATLAS pixels, possibility for CMS 3D and new biasing schemes New sensor materials Significant success with CVD diamonds Cryogenic Silicon Tracker development Lazarus effect – x10 increase in rad hardness Monolithic pixel detectors Sensor+readout on the same silicon substrate (no bump bonding)

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Why now? CMS SiTrk detectors design time line RD2 report – 1994 CMS technical proposal RD20 report RD48 report – 1997 Start construction phase 2003 Start data taking 2007 = years SuperLHC start data taking 2015 RD?? report =2001 RD50 is formed 10/02 to address the needs of Super LHC

Regina Demina, Hadron collider workshop, FNAL, October 16-18, RD50RD50 Approved by CERN 06/ institutions, 5 from US (Fermilab, Purdue, Rutgers, Syracuse, BNL) Areas of research Material engineering Oxygenation, si carbite Device engineering Pad, 3D, thin detectors Rad hard technologies used for LHC are not completely characterized

Regina Demina, Hadron collider workshop, FNAL, October 16-18, RD50RD50

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Radiation damage – microscopic defects

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Radiation damage Leakage current grows with rad dose P-type impurities concentration increases, sensor goes through n  p type inversion and then depletion voltage grows indefinitely Annealing Reverse annealing

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Oxygen enriched silicon DOFZ (Diffusion Oxygenated Float Zone) O: cm -3 Introduced to HEP in 1999 Slows down V depl growth after type inversion Reverse annealing delayed and saturated at high fluences

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Device Engineering: 3D detectors Electrodes: Narrow columns along detector thickness 3D Diameter ~10  m, distance  m Lower Vdepl Thicker detector possible Fast signal

Regina Demina, Hadron collider workshop, FNAL, October 16-18, CVD diamonds Good progress lately Main issues charge collection distance reached 250 um S/N = 8/1 Very radiation hard Resolution improves (!) after 2E15 p/cm -2 Pretty

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Electronics issues 0.25 um  0.13 um 0.25 um might not be available on SLHC time scale or even worse only few vendors will be left 0.13 um – more rad hard Tracker in L1 trigger Binary? – ATLAS experience will tell Power supplies (why do they always become an issue) AI’s: Cost of 0.13 um development is very high must managed cooperatively Power consumption at 80 MHz Signal level At ~1V every welder in your neighborhood is your signal

Regina Demina, Hadron collider workshop, FNAL, October 16-18, System integration issues Large complex systems cannot be treated just as the sum of the parts Installed in experiment detector systems exhibit features not present in laboratory testing Commissioning is becoming a lengthy process years Why we are never able to get to b-tagging efficiency seen in Monte Carlo?

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Examples of “integration issues” SuSy will jump at you after 2-3 weeks of LHC data taking Not the first two weeks Susy? No, calorimeter noise Silicon tracker (WSMT)  calorimeter “cross talk” Welders DØ

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Examples of “integration issues” CDF L00 – signal carried by analogue cables Readout the whole L00 Fit pedestals with Chebyshev polynomials Another interesting story Resonance Lorentz force  wirebond breaks

Regina Demina, Hadron collider workshop, FNAL, October 16-18, AI on integration A lot of experience gained by Tevatron on integration and commissioning of large detector systems Statistics of failure modes (e.g. 12% of a system lot due to poor cable connection) grounding Documentation System integration is a worthy R&D project

Regina Demina, Hadron collider workshop, FNAL, October 16-18, SummarySummary LHC upgrades will deliver x10 in L and possibly x2 in energy Most likely entire tracking systems of both high Pt experiments will have to be replaced Requirements to tracking upgrades Radiation hardness Higher granularity Fast response R&D program has started: RD50 – silicon detectors RD42 – good progress with CVD diamonds Electronics: 0.25  0.13 um transition System integration must be given high priority

Regina Demina, Hadron collider workshop, FNAL, October 16-18, Action Items Understand local occupancy for typical jet E for objects at the threshold of sensitivity (e.g. use 7 th heavy quark M Q production model) Electronics: Cost of 0.13 um submissions Power consumption Signal and noise levels Integration Documentation of Tevatron experience R&D task