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Status of the R&Ds on Diamond Particle Detectors. Mara Bruzzi University of Florence - INFN Firenze. For the RD42 Collaboration November 6, 2002 - VERTEX2002. Outline of the Talk: Introduction 2001/2002 Milestones Status of PolyCrystalline Diamond Particle Detectors
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Status of the R&Ds on Diamond Particle Detectors Mara Bruzzi University of Florence - INFN Firenze For the RD42 Collaboration November 6, 2002 - VERTEX2002 • Outline of the Talk: • Introduction • 2001/2002 Milestones • Status of PolyCrystalline Diamond Particle Detectors • Single Crystal Diamond Particle Detectors • Summary and RD42 Plans M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
The RD42 Collaboration http://rd42.web.cern.ch/RD42/ M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Introduction LHC L~ 1034 cm-2s-1 in10 years: f ~ 1015 n/cm2 for pixels SLHCL~ 1035 cm-2s-1fast hadron f up to 1016 cm-2 Inner tracking layers must survive provide high precision tracking to tag b, t, Higgs • Diamond Properties: • Radiation hardness • Low Dielectric Constant Low Capacitance • Low Leakage Current Low readout noise • Room Temperature Operation , Fast signal collection time M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
2001/2002 Milestones Priorities of Research in 2001/2002 • Increase charge collection distance in a dedicated program with industry to > 250mm • Test the Tracking and radiation tolerance properties of the newest diamonds • Establish the performance of pixel detectors with radiation hard front-end chips from ATLAS and CMS • Establish the performance of large detectors • Test diamond trackers with LHC specific electronics (SCTA128 chip ) • Irradiate modules sensors and front-end chips together • Finalize the geometry and metalization of diamond LHC pixel detectors M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Status of PolyCrystalline Diamond Detectors • Chemical Vapour Deposition - DeBeers • Wafer diameter 5-6 inch • Metalization Cr/Au, Ti/Au, Ti/W new • 1V/mm Operation, Drift velocity saturated • Test procedure: dot strip pixel M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
R&D with DeBeers Ind. Diamond Latest Polycrystalline Diamonds Measured with a 90Sr Source • System Gain = 124 e/mV • QMP = 60mV = 7400e • Mean Charge = 76mV = 9400e • Source data well separated from 0 • Collection distance now 270mm • Most Probable Charge now 8000e • 99% of PH distribution now above 3000e • FWHM/MP ~ 0.95 Si has ~ 0.5 • This is diamond is available in large size The research program worked! M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
History of ccd progress Now M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Material Properties of PolyCrystalline Diamond • Grain-boundaries, dislocations, native defects in Polycrystalline Diamond: • limits carrier lifetime, mobility and charge collection distance • give rise to polarization and pumping effects • affect the radiation hardness ( spatial resolution improves, leakage current decrease, mean signal decreases ) Grain size: ~10-100mm Growth side of PolyDiamond produced by the Florence group State-of-art DeBeers PolyDiamond growth side after lapping M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Low quality t High quality T t ITSC t Basic Research on Defects in PolyCrystalline Diamond Thermally Stimulated Currents Analysis: TSC Vrev Native defects at grain boundaries: Main peak@520K + RT tail Et ~1eV, s ~ 10-12-10-19cm2, Nt ~ 1015-1019cm-3 M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Optimising CCE through Material Removal Columnar growth in PolyDiamond films Single-Crystal Line Picture from sample made in Florence Removal from growth () and substrate () Higher grain-boundary density on substrate M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Recent Tracking Studies - CERN Test beam setup • 100 GeV/c pion/muon beam • 7 planes of CVD diamond strip sensors each 2cmx2cm • 50mm pitch, no intermediate strips new metalization procedure • 2 additional diamond strip sensors for test • several silicon sensors for cross checks • strip electronics ( 2ms ): ENC ~100e + 14 e/pF M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Recent Tracking Studies Results • Uniform signals on all strips • Pedestal separated from “0” on all strips • 99% of entries above 2000e • Mean signal charge ~8640e • MP signal charge ~6500e .. Work in progress • Module with fully radiation hard SCTA128 electronics • Tested with Sr90 ready for beam test and irradiation • Charge distribution clearly separated from the noise S/N 8/1 • efficiency will be measured in test beams at 40MHz clock rate • Improve position resolution by measuring charge sharing between strips M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Radiation Hardness Signal to Noise Resolution • Dark Current decreases with fluence • S/N decreases at 2x1015cm-2 • Resolution improves at 2x1015 cm-2 M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Other Radiation Effects Pumping and Trapping f = 5x1014 n/cm2 • Pumping effect less evident • Defects at Et ~1eV partially removed or compensated f = 2.0x1015 n/cm2 M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Single Crystal CVD Diamond Particle Detectors • Single Crystal films produced by DeBeers: Microwave plasma-assisted CVD Homoepitaxial diamond films grown from HPHT synthetic diamond substrates. • Samples size: 390-690mm thick, 6mm diameter • Carrier mobility @ RT mn ~ 4500 cm2/Vs mh ~ 3800 cm2/Vs ~ factor 2 higher than for natural single-crystal diamond • Carrier lifetime: exceeds 2ms Dramatic improvement as compared with natural and polycrystalline CVD diamond (~ few ns) • Dislocation less than 106 cm-2 • Nitrogen content of the order of 1015cm-3 M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Performance of Single Crystal Diamond Detector New metalization ( Al, no carbide involved ) M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Single Crystal CVD Diamond Detector: CCE Charge Collection Distance ~ Device Thickness ( over 90-95%) ~ 100% Charge Collection Efficiency M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Single Crystal CVD Diamond Detector: Pumping Stable Signal, with no evidence of priming/polarization effects! Single Crystal Diamonds do not pump like polycrystalline material. M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Summary Polycrystalline Diamond I Charge collection 270mm collection distance MP signal 8000 e 99% of charge distribution above 3000e FWHM/MP 0.95 Tracking Results Operated a 7 plane telescope with 50mm pitch detectors high efficiency and tracking precision of 10-20mm Rad-hard SCTA128 electronics (DMILL ) built Source tests indicate high efficiency at 40MHz Beam test and irradiation this year Radiation Hardness dark current decreases with fluence some loss of S/N with fluence Resolution improves with fluence M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Summary Polycrystalline Diamond II Diamond Pixel Detectors Successfully tested ATLAS and CMS pixels patterns Bump-bonding yield 100% Excellent correlation between telescope and pixel data Reasonable spatial resolution attained Radiation hard chips just arrived Single Crystal Diamond: Future ? Material Characteristics mn ~ 4500 cm2/Vs , mh ~ 3800 cm2/Vs Carrier lifetime exceeds 2ms low native defect content Detector performance no pumping effect 100% charge collection efficiency over 550mm M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002
Future Plans of RD42 • Charge Collection • collection distance 300mm • improved uniformity • correlation between defects and detector performance • Radiation hardness of diamond trackers and pixel detectors • Irradiation with p, p, n up to 5x1015cm-2 • Beam tests with Diamond Trackers and Pixel detectors • Trackers with SCTA Electronics • Pixel detectors with ATLAS and CMS and rad hard elect. • Construct the full ATLAS diamond pixel module M.Bruzzi for RD42 Coll.- Status of R&D on Diamond Particle Detectors- Vertex2002, Hawaii, Nov.4-8, 2002