5th Super B Workshop Detector R&D Program – Plenary Session, May 9, 2007 – David W.G.S. Leith

We consider the detector presented in the CDR SUPERB Detector R & D. We consider the detector presented in the CDR    May 9, 2007 SuperB Detector R&D David Leith

Detector Layout BASELINE OPTION May 9, 2007 SuperB Detector R&D Below the mid-line we have our proposed detector. The upgrades are :- New beam pipe at small radius and reduced material thickness; a new inner layer vertex detector; a new drift chamber; End cap PID using TOF (if it passes physics review) and two versions of the DIRC system – one a simple replacement of the PMT’s, and the other a new focusing system with smaller mass and physical size, but requiring serious R&D and substantial costs; new forward electromagnetic calorimetry using LSO crystals; and a scintillator based muon system. OPTION May 9, 2007 SuperB Detector R&D David Leith

“What subsystems need R&D work” ? “Who is doing the work” ? and May 9, 2007 SuperB Detector R&D David Leith

Our friends from Pisa have been doing The Beam Pipe Our friends from Pisa have been doing nice work on a clever, low mass beam pipe that can also remove the heat from the layer 0 vertex detector chips. May 9, 2007 SuperB Detector R&D David Leith

Beam pipe 1.0 cm inner radius Be inner wall ≈ 4um inside Au coating 8 water cooled channels (0.3mm thick) Power ≈ 1kW Peek outer wall Outer radius ≈ 1.2cm Thermal simulation shows max T ≈ 55°C Issues Connection to rest of b.p. Be corrosion Outer wall may be required to be thermally conductive to cool pixels You saw this at our last workshop in Tor Vergata, and you will hear more this afternoon in the parallel sessions. May 9, 2007 SuperB Detector R&D David Leith

Vertex Detector silicon work . You will hear details of this work in the parallel sessions. The Italian groups are very well supported for the pixel R&D, and have a strong team working on a hard and important problem. May 9, 2007 SuperB Detector R&D David Leith

Layer0 striplets R&D issues Technology for Layer0 baseline striplet design well estabilshed Double sided Si strip detector 200 mm thick R&D confirms a clear S/N ~ 25. Readout speed and efficiency are not an issue with the expected background rate (safety factor x5 included) Possible gain in the total material budget for L0 with striplets (from 0.45%  0.35% X0) with some R&D on the connection between the silicon sensor and the readout electronics: May 9, 2007 SuperB Detector R&D David Leith

Layer0 MAPS R&D issues Extensive R&D needed CMOS Monolithic Active Pixels are a very promising “new device”, but so far have never been used in a real operating detector. Extensive R&D needed Fast readout architecture Sensor optimization Radiation hardness Mechanical issues: Sensor thinning, power, light cooling development. CMOS MAPS is an option for the ILC vertex detector  many aspects of the R&D are common. May 9, 2007 SuperB Detector R&D David Leith

Present Status on MAPS R&D (I) Very simple in-pixel readout developed by several groups with good efficiency & resolution performance Readout speed for large detector area is limited by the sequential readout. Trying to implement data sparsification at the detector periphery (column level) to improve speed. May 9, 2007 SuperB Detector R&D David Leith

Present Status on MAPS R&D (II) 3x3 matrix, full analog 4x4 matrix with sparsified readout Starting from the triple well MAPS design 6 test chips produced  8x8 matrix Sequential readout Readout Architecture data driven with sparsification and timestamp information is under development: Simulation under way to evaluate performance with the expected SuperB background rates. First small chip in production, medium size prototype in production by the end of 2007. Residual capacitive coupling between the digital lines and the sensor (C~10 aF !!!) is an issue: crosstalk observed. Shielding with metal planes inserted to cure the problem in the next chips in productions. May 9, 2007 SuperB Detector R&D David Leith

SLIM5 Collaboration The SLIM5 Collaboration has a quite detailed project plan to build a prototype of a thin silicon tracker (MAPS and thin silicon striplets modules) with LV1 trigger capabilities (based on Associative Memories). Important aspect of the project is to develop light mechanical and cooling structures for thin silicon modules to benefit of the very low material budget of the sensor itself. Test of the prototype tracker in a test beam in 2008 Several Italian Institutes involved in the project: Pisa (coordination), Pavia, Bergamo,Trieste, Torino, Trento, Bologna R&D project supported by the INFN and the Italian Ministry for Education, University and Research. May 9, 2007 SuperB Detector R&D David Leith

Drift Chamber You will hear a talk this afternoon on using a similar chamber design as that being proposed for the ILC. May 9, 2007 SuperB Detector R&D David Leith

DCH Basic technology adequate. Cannot reuse BaBar DCH because of aging M. Kelsey Basic technology adequate. Cannot reuse BaBar DCH because of aging Baseline: Same gas, same cell shape Carbon fiber endplates instead of Al to reduce thickness  Need to do complete background estimate Options/Issues to be studied: Miniaturization and relocation of readout electronics Critical for backward calorimetric coverage Conical endplate Further optimization of cell size/gas May 9, 2007 SuperB Detector R&D David Leith

Particle Identification System May 9, 2007 SuperB Detector R&D David Leith

SLAC Group B is working on : # 3-D focusing DIRC implementation; # very fast time measurement; # qualifying MCP PMT’s from various vendors; # behaviour of MCP PMT’s in high magnetic fields. May 9, 2007 SuperB Detector R&D David Leith

Our friends at BINP in Novosibirsk are working on MC simulations of forward PID, and evaluating the pros of having the extra information, and cons of the extra material. They are also doing serious R&D on aerogel and NaF radiators in proximity focusing geometries, And studying cathode lifetime of various MCP PMT’s under different geometries. May 9, 2007 SuperB Detector R&D David Leith

Our friends …. May 9, 2007 SuperB Detector R&D David Leith

Cherenkov Photons in Time and Pixel domains Cherenkov photons in time domain: 10 GeV/c electron beam data. ~ 200 pixels instrumented. Ring image is most narrow in the 3 x 12 mm pixel detector. Cherenkov ring in pixel domain: Burle 85011-501 Burle 85011-501 Hamamatsu H-8500 Hamamatsu H-9500 Burle 85011-501 Burle 85011-501 May 9, 2007 SuperB Detector R&D David Leith

Color tagging by measurement of photon propagation time f(l) vgroup = c0 / ngroup = c0 / [nphase – λ· dnphase / dλ] t = TOP = L / vgroup = L [nphase – λ· dnphase · dλ ] / c0 Time-of-Propagation dt/L = dTOP/L = l dl * | - d2n/dl2 | / c0 dt is pulse dispersion in time, length L, wavelength bandwidth dl, refraction index n(l) We have determined in Fused Silica: dt/L = dTOP/L ~ 40ps/meter. Our goal is to measure the color of the Cherenkov photon by timing ! May 9, 2007 SuperB Detector R&D David Leith

Conclusions We have demonstrated that we can correct the chromatic error of qC This is the first RICH detector which has been able to do this. Expected N0 and Npe is comparable to BaBar DIRC for MaPMT H-9500. Expected improvement of the PID performance with 3x3mm pixels: ~20-30% compared to BaBar DIRC for pi/K separation, if we use H-9500 MaPMT. The main defense against the background at Super-B is to make (a) the expansion volume much smaller, which is possible only with highly pixilated photon detectors, and (b) use of faster detectors. Next test beam run: Add (a) ADC-based pixel interpolation, (b) 2-nd hodoscope after a bar, (c) ASIC-based readout on one MCP-PMT allowing a measurement of time and pulse height, (d) test of the TOF detector. May 9, 2007 SuperB Detector R&D David Leith

Timing at a level of s <15ps can start competing with the RICH techniques Example of various Super-B factory PID designs: Calculation done for Flight Path Length = 2m Recent progress in the TOF technique is driven by these advances: (a) fast Cherenkov light rather than a scintillation, (b) new detectors with small transit time spread sTTS, (c) fast electronics, and (d) new fast laser diodes for testing. May 9, 2007 SuperB Detector R&D David Leith

Conclusions Our present best results with the laser diode: - s ~ 12 ps for Npe = 50-60 (expected from 1cm thick Cherenkov radiator). - s TTS < 26 ps for Npe ~ 1. - Upper limit on the MCP-PMT contribution: s MCP-PMT < 6.5 ps. - TAC/ADC contribution to timing: s TAC_ADC < 3.2 ps. - Total electronics contribution at present: s Total_electronics~ 7.2 ps. (One has to be aware that the time-walk, due to variation of Npe, has to be corrected). May 9, 2007 SuperB Detector R&D David Leith

Electromagnetic Calorimeter                            May 9, 2007 SuperB Detector R&D David Leith

Electromagnetic Calorimeter You will hear more from David Hitlin on this work. He and Ren-Yuan Zhu are well supported at Caltech by a DOE Detector Development grant. Good LSO crystals are being fabricated, in production mode, by the Sichuan Institute of Piezoelectric and Acoustic-optic Technology (SIPAT), of good physical size, (120 mm X 80 mm), and a a fair price ( $ US 15 per cc). One 60 mm X 250 mm crystal has been recently made for SuperB. May 9, 2007 SuperB Detector R&D David Leith

SIC BGO CPI LYSO Saint-Gobain LYSO CTI LSO BGO, LSO & LYSO Samples 2.5 x 2.5 x 20 cm (18 X0) Bar SIC BGO CPI LYSO Saint-Gobain LYSO CTI LSO May 9, 2007 SuperB Detector R&D David Leith

LSO/LYSO ECAL Performance Less demanding to the environment because of small temperature coefficient. Radiation damage is less an issue as compared to other crystals. A better energy resolution, (E)/E, at low energies than L3 BGO and CMS PWO because of its high light output and low readout noise: 2.0 0.5 .001/E May 9, 2007 SuperB Detector R&D David Leith

Muon system   You will hear a talk this afternoon from, Gianluca Cavoto on a MINOS-type scintillator detector, more suited to the high rate environment than the present gas chambers used in BaBar. May 9, 2007 SuperB Detector R&D David Leith

We will hear from each of the groups So much for the overview of the detector R&D work, on specific systems; We will hear from each of the groups doing the work in the next parallel session. I would like to spend a moment now on how the group might self organize for the R&D, as a ‘provocation’ to assist the parallel session discussion on this topic. May 9, 2007 SuperB Detector R&D David Leith

How will the R&D be organized, and funded and reviewed/guided                          and finally choices be made ? May 9, 2007 SuperB Detector R&D David Leith

[i.e. scientists in each region will approach their own agencies and I believe that the R&D activities should proceed, at least for the next year, and until there is a fully formed, and well supported, collaboration – under local financial support [i.e. scientists in each region will approach their own agencies and propose support for the R&D that they wish to pursue]. May 9, 2007 SuperB Detector R&D David Leith

I think that it would be useful to SuperB to set up a high level review committee that looks at the SuperB detector technical needs, and to provide a priority list of R&D topics – both for the experiment, and for the supporting agencies [as we did in the beginning of BaBar]. May 9, 2007 SuperB Detector R&D David Leith

I believe it would be helpful - * if this committee planned a regular review of progress of the R&D activities, * performed a high level overlook of the machine backgrounds to be expected, and of the technical needs of the experiment, and … * provide advice to the SuperB collaboration leadership. May 9, 2007 SuperB Detector R&D David Leith

Eventually, there will be a formal collaboration structure, with its own governance, that will enable the required choices and decisions to manage the R&D program. May 9, 2007 SuperB Detector R&D David Leith

backup slides May 9, 2007 SuperB Detector R&D David Leith

Motivation to develop a new DIRC at Super-B Goal: - Super-B will have 100x higher luminosity Backgrounds are not yet understood, but they would scale with the luminosity if they are driven by the radiative Bhabhas DIRC needs to be smaller and faster: Focusing and smaller pixels can reduce the expansion volume by a factor of 7-10 ! Faster PMTs reduce a sensitivity to background. Additional benefit of the faster photon detectors: - Timing resolution improvement: s ~1.7ns (BaBar DIRC) -> s 150ps (~10x better) which allows a measurement of a photon color to correct the chromatic error of qc. Focusing mirror effect: Focusing eliminates effect of the bar thickness (contributes s ~ 4 mrads in BaBar DIRC) However, the spherical mirror introduces an aberration, so its benefit is smaller. May 9, 2007 SuperB Detector R&D David Leith

qC resolution and Chromatic correction All pixels: 3mm pixels only: Correction off: Correction on: Correction off: Correction on: s ~ 5.0 mrad sChrom + sPixel s ~ 5.1 mrad The chromatic correction starts working for Lpath > 2-3 meters due to a limited timing resolution of the present photon detectors. The maximum likelihood technique does better for short Lpath than other methods Holes in the uncorrected distributions are caused by the coarse pixilization, which also tends to worsen the resolution. In the corrected distributions this effect is removed because of the time correction. Smaller pixel size (3mm) helps to improve the Cherenkov angle resolution; it is our preferred choice. May 9, 2007 SuperB Detector R&D David Leith

Crystal Density: Radiation Length 1.5 X0 Cubic Samples: Hygroscopic Halides Non-hygroscopic CsI CsI(Na) CsI(Tl) NaI(Tl) PWO LSO LYSO BGO CeF3 BaF2 BaBar CsI(Tl) Full Size Crystals: BaBar CsI(Tl): 16 X0 L3 BGO: 22 X0 CMS PWO(Y): 25 X0 L3 BGO CMS PWO May 9, 2007 SuperB Detector R&D David Leith

Scintillation Light Decay Time Recorded with Agilent 6052A digital scope Fast Scintillators Slow Scintillators LSO LYSO May 9, 2007 SuperB Detector R&D David Leith

Light Output & Decay Kinetics Measured with Philips XP2254B PMT (multi-alkali cathode) p.e./MeV: LSO/LYSO is 6 & 230 times of BGO & PWO respectively Fast Scintillators Slow Scintillators LSO LYSO May 9, 2007 SuperB Detector R&D David Leith

LSO/LYSO ECAL Performance Less demanding to the environment because of small temperature coefficient. Radiation damage is less an issue as compared to other crystals. A better energy resolution, (E)/E, at low energies than L3 BGO and CMS PWO because of its high light output and low readout noise: 2.0 0.5 .001/E May 9, 2007 SuperB Detector R&D David Leith

Mass Produced Crystals NaI(Tl) CsI(Tl) CsI BaF2 BGO PWO(Y) LSO(Ce) GSO(Ce) Density (g/cm3) 3.67 4.51 4.89 7.13 8.3 7.40 6.71 Melting Point (ºC) 651 621 1280 1050 1123 2050 1950 Radiation Length (cm) 2.59 1.86 2.03 1.12 0.89 1.14 1.38 Molière Radius (cm) 4.13 3.57 3.10 2.23 2.00 2.07 Interaction Length (cm) 42.9 39.3 30.7 22.8 20.7 20.9 22.2 Refractive Index a 1.85 1.79 1.95 1.50 2.15 2.20 1.82 Hygroscopicity Yes Slight No Luminescence b (nm) (at peak) 410 550 420 310 300 220 480 425 402 440 Decay Time b (ns) 230 1250 30 6 630 0.9 10 40 60 Light Yield b,c (%) 100 165 3.6 1.1 36 3.4 21 0.29 .083 83 d(LY)/dT b (%/ ºC) -0.2 0.3 -1.3 -0.9 -2.7 -0.1 May 9, 2007 SuperB Detector R&D David Leith

Expected final performance at incidence angle of 90o Focusing DIRC prototype bandwidth: Prototype’s Npe_measured and Npe_expected are consistent within ~20%. Hamamatsu H-9500 MaPMTs: We expect N0 ~ 31 cm-1, which in turn gives Npe ~ 28 for 1.7 cm fused silica bar thickness, and somewhat better performance in pi/K separation than the present BaBar DIRC. Burle-Photonis MCP-PMT: We expect N0 ~ 22 cm-1 and Npe ~ 20 for B = 0kG. BaBar DIRC design: N0 ~ 30 cm-1 and Npe ~ 27. Expected performance of a final device: May 9, 2007 SuperB Detector R&D David Leith