For the RD42 Collaboration 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 Diamond Properties: LHC L ~ 1034 cm-2s-1 in 10 years: f ~ 1015 n/cm2 for pixels SLHC L ~ 1035 cm-2s-1 fast 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
Priorities of Research in 2001/2002 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
Basic Research on Defects in PolyCrystalline Diamond Low quality High quality Thermally Stimulated Currents Analysis: TSC Vrev t T ITSC 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
Results .. Work in progress Recent Tracking Studies 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
Dark Current decreases with fluence S/N decreases at 2x1015cm-2 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
Polycrystalline Diamond I 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
Polycrystalline Diamond II Single Crystal Diamond: Future ? 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
collection distance 300mm improved uniformity 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