Le nuove tecnologie del progetto RICH di LHCb

Transcription

1 Le nuove tecnologie del progetto RICH di LHCb costi e planning CSN1 Roma, 3 febbraio 2004 C.Matteuzzi CSN1 3 Febbraio

2 Overview Photodetector technology choice Current HPD status Status of bump-bonded assemblies Test beam Ageing tests Magnetic field studies Project cost and planning Schedule/milestones Mirrors technology choice Current mirror status Project cost and planning C.Matteuzzi CSN1 3 Febbraio

3 LHCb performance goals require:- 1) Minimum possible material in the acceptance and 2) Optimal use of the fringe field between VELO and the TT station for the trigger. C.Matteuzzi CSN1 3 Febbraio

4 Requirements of photodetector In total ~ 2.8 m 2 area to be equipped with photodetectors Requirements: Single Photon Sensitivity (wavelength range: 200nm - 600nm) 2.5 x 2.5 mm 2 granularity LHC speed electronics (25 ns peaking time, 40MHz readout) Active-area fraction ~ 70% or higher ~500,000 channels at affordable cost Operation in radiation environment (3kRad/year) Operation in a fringe magnetic field (2.5 mt) C.Matteuzzi CSN1 3 Febbraio

5 Photodetector decision Two photodetector options considered: Pixel HPD Multianode photomultiplier Autumn 2003: 2 HPDs received with 40MHz chip and high-temperature melting bump-bond process HPD has better intrinsic performance than MaPMT: 40% more photons detected from gas radiators Lower cost: 5.3MCHF cf 6.4MCHF (incl. readout) October 2003: following successful R&D programme for both options, the Pixel HPD was chosen HPD risks are acceptable 484 Pixel HPD + spares (550 HPDs ) C.Matteuzzi CSN1 3 Febbraio

6 Stages of HPD production Detector chip Canberra Bumpbonding VTT HCM DEP IBM Readout chip Packaging HPD encapsulation Ceramic carrier Brazing and gold-plating Kyocera Kyocera (gold)+dep (braz.) C.Matteuzzi CSN1 3 Febbraio

7 Stages of HPD production 80mm photocathode window Electron Optics: 20 kv 5 x demagnification Photo-cathode deposition and vacuum sealing Tube body assembly C.Matteuzzi CSN1 3 Febbraio

8 Status of bump bonding At the end of October a total of 22 assemblies received from VTT: 15 have 99.5% good bonds 4 have 98.5% good bonds 3 have well understood failures BUMP BONDING PROCESS IS NOW FINALIZED 6 from the 99.5% sample have been fully packaged. No bump degradation is observed. A total of 4 prototype tubes are being fabricated by DEP (delivery early February). A new batch of 24 assemblies from VTT will be processed and expected to be delivered February Part of the sample of 24 assemblies will be used for preproduction HPDs. C.Matteuzzi CSN1 3 Febbraio

9 Ageing tests of HPDs Intense LED photocathode illumination of a 10 MHz HPD 40% occupancy at 50 C for 1 month (Normal occupancy: ~1%) equivalent to 10 years of LHCb running Measurements made of: Dark counts Ion feedback (indicator of vacuum quality) Light response Photocathode quantum efficiency C.Matteuzzi CSN1 3 Febbraio

10 Ageing tests of HPDs No degradation of QE Dark current Ion feedback Light yield Light yield Dark counts Ion feedback Dark counts: slight decrease with time Ion feedback increases from 1-3% but recovers Photocathode HPD3 QE 500V with Diaphragm efficiency Before Aged HPD3 QE 10V without diaphragm After Center Center QE [%] 0.15 Midway Edge DEP QE [%] 0.15 Mid1 Mid2 Edge Wavelength [nm] Wavelength [nm] C.Matteuzzi CSN1 3 Febbraio

11 Beam tests 10 GeV electrons, pions,protons 3 HPDs (2 at 40MHz) radiators: air and aerogel Milano - ISS vessel RICH I prototype C.Matteuzzi CSN1 3 Febbraio

12 Radiator: air Cherenkov Rings 10 GeV/c electrons and pions Air radiator, single 40 MHz HPD Performance Cherenkov angles: Electrons Measured 23.6 ± 2.9 mrad Expected 23.7 mrad Pions Measured 18.5 ± 3.0 mrad Expected 19.1 mrad Detected photons: Electrons Measured 11.5 Expected 11.6 ± 0.7 p.e. detection efficiency confirms lab measured value of 88% C.Matteuzzi CSN1 3 Febbraio

13 Radiator: Aerogel In October 2003 aerogel samples with excellent clarity were exposed in a 10Gev/C π beam and the Cherenkov rings measured using 3HPDs. The results shown here are for a tile with:- Thickness(L) = 4.4 cm Refractive Index = Clarity(C) = µm 4 /cm A = 86% and Weight = 60.6 g Measurement of ring segments shows that ~9 photo-electrons per ring would be detected (at 100% acceptance), consistent with the performance given in the TDR. C.Matteuzzi CSN1 3 Febbraio

14 Magnetic field sensitivity Helmholz Coil HPD tube with shielding HPDs have to operate in maximum field at photon detector plane of 2.4 mt in RICH-1 and LED 0.8 mt in RICH-2 200mm Video out to Frame grabber C C D 20mm XY table C.Matteuzzi CSN1 3 Febbraio

15 50 Gauss longitudinal field Pinhole mask Mu-metal shield (20mm beyond photocathode) no loss of active area photocathode at 30G 4.8% loss at 50G 30 G (RICH TDR) CCD pixels 50 G (NEW) Pixel Chip CCD pixels CCD pixels C.Matteuzzi CSN1 3 Febbraio

16 HPD PLANNING AND SCHEDULES Bump bonding schedule at VTT Delivery and lead times Responsibilities, schedule and milestones C.Matteuzzi CSN1 3 Febbraio

17 Preliminary VTT production plan ID Task Name 1 ALICE production (including RI 2 ALICE mid 1st batch (55 ladder 3 ALICE small batch (32 ladders) 4 ALICE large batch (120 ladders 5 ALICE standard batch (36 ladde 6 ALICE large batch (82 ladders) 7 ALICE standard batch (60 ladde 8 ALICE standard batch (82 ladde 9 VTT Easter break 10 VTT summer holidays 11 VTT winter break 12 VTT Easter break 13 VTT summer holidays 14 LHCb production 15 LHCb standard batch (250 singl 16 LHCb standard batch (300 singl 17 LHCb standard batch (290 singl 18 LHCb standard batch (260 singl NovDe JanFebMa Ap Ma Jun Jul AugSepOc NovDe JanFe Ma Ap Ma Jun Jul AugSepOc NovDe C.Matteuzzi CSN1 3 Febbraio

18 Delivery and lead times 48 pixel chip wafers (IBM) : Order gone out. 20 weeks delivery time 50 sensor wafers (Canberra) : Order gone out. 15 weeks delivery time 1000 carriers (Kyocera) : Order imminent. ~10 weeks delivery time Bump bonding (VTT) : Preliminary schedule agreed between ALICE/LHCb. Under discussion with VTT. Packaging (HCM) : Await production quote 550 tubes (DEP) : Purchasing tender proceeding. 5 months lead time PREPRODUCTION / PRODUCTION READINESS REVIEW A sample of preproduction HPDs produced Oct 2004: System tests in test beam planned. HPD Production Readiness Review to come after the pre-production tubes have been tested, ~ 1 month before full HPD production starts C.Matteuzzi CSN1 3 Febbraio

19 Organization HPD Project N. Harnew HPD fabrication T.Gys HPD electronics K. Wyllie HPD series production CERN Institute responsibilities HPD component tests CERN & Institutes HPD characterization Edinburgh & Glasgow Level-0 & optical links Oxford Level-1 & ECS Cambridge HPD/Level-0 translator Genoa HV and LV Milano 1 technician from Milano (F.Chignoli) G. Pessina started to work on HV and LV distribution boards + 30% electronics technician (R.Bertoni) C.Matteuzzi CSN1 3 Febbraio

20 HPD implementation: RICH HPDs: 2 planes x 7 rows x 14 HPDs/row Design is quickly evolving (magnetic field shielding) Detailed mounting scheme still under discussion LEVEL-0 BOARDS HPD PLANE C.Matteuzzi CSN1 3 Febbraio

21 HPD implementation: RICH HPDs: 2 planes x 9 columns x 16 HPDs/column Mounting scheme well advanced (GENOVA responsibility) RICH-2 Production Readiness Review: January 2004 COLUMN ASSEMBLY SUPPORTING FRAME ASSEMBLY LOW VOLTAGE BUS LEVEL-0 BOARD COLUMN ASSEMBLY RAILS HIGH VOLTAGE BUS COLUMN FRAME C.Matteuzzi CSN1 3 Febbraio

22 HPD schedules Key dates: Bump bonding production starts May 2004 HPD production starts November 2004 HPD production completed July 2006 C.Matteuzzi CSN1 3 Febbraio

23 The mirrors of RICH-1 C.Matteuzzi CSN1 3 Febbraio

24 The Spherical Mirrors One mirror per quadrant, 820x600mm, is required. Two possible technologies were under consideration (after composite mirrors made in Milano were shown to move in C 6 F 12 atmosphere) Carbon Fibre + Epoxy composite 2mm thick (λ=0.4% and X 0 =1.0%) manufactured by Composite Mirror Applications (CMA) in the USA 3mm of Beryllium + 0.3mm of glass (λ=0.8% and X 0 =0.9%) from Russia. (However these mirrors can only be made half the required size (410x600mm 2 ) because of the fabrication process, implying the use of 2 per quadrant, and are more expensive than composite) The optical requirements are for high reflectivity at the relevant wavelengths and for 95% of the light from a test point source to fall within an image diameter of 2.5mm. C.Matteuzzi CSN1 3 Febbraio

25 The Spherical Mirrors The sample Beryllium mirror has excellent optical properties The CMA composite mirror has three aluminium mounting cups glued to the back. Fraction of lig ht (% ) Image diameter before and after the mounting cups are glued Fraction of lig ht (% ) Diameter (mm) Diameter (mm) C.Matteuzzi CSN1 3 Febbraio

26 Beryllium Mirrors The mirrors and a support structure on one edge can be cut from a single piece of beryllium. Support Calculations show that mounting the mirror at 8 to the vertical from one edge results in negligible deformation. A full sized mirror segment will now be ordered. The use of beryllium mirrors (along with the beam-pipe) has safety implications for LHCb which are regulated by CERN safety instruction IS No. 25 C.Matteuzzi CSN1 3 Febbraio

27 Costi C.Matteuzzi CSN1 3 Febbraio

28 HPD and readout costs (including spares) C.Matteuzzi CSN1 3 Febbraio

29 Summary of RICH project costs Compare: 9.57 MCHF in Reoptimization TDR - costed for MaPMT in RICH C.Matteuzzi CSN1 3 Febbraio

30 Stato delle gare Per 550 HPDs (DEP) : in preparazione, da mandare a fine febbraio 2004 Per aerogel: negoziamento del contratto in corso. Un primo contratto per una mini serie (circa 10 litri= 20 Keuro) sara mandato nel giro di una o due settimane Per schermo magnetico: in preparazione, partira in aprile-maggio (data di consegna dello schermo al CERN ottobre 2004) C.Matteuzzi CSN1 3 Febbraio

31 Richieste alla CSN1 Autorizzazione a partecipare alla gara per la produzione dei 550 HPDs 500 KSF (=13% del costo totale) con profilo temporale: 30% nel 2004 (sblocco dei 100 Keuro s.j.) 60% nel % nel 2006 C.Matteuzzi CSN1 3 Febbraio

32 Back-up slides C.Matteuzzi CSN1 3 Febbraio

33 Milano responsability RICH-2 overall magnetic shielding B field peak lower than 10 Gauss in the HPD volume 60 mm soft iron 5.5 tons on each side Must be delivered to CERN In october 2004 C.Matteuzzi CSN1 3 Febbraio

34 RICH2 Mechanics Status PRR (19 February 2003): Superstructure (RAL) Space frame Central Tube Photon funnel Entrance and exit window Quartz window Mirrors (CERN - Milano) Spherical and flat mirrors Reflectivity Coating PRR (23 January 2004): Overall magnetic shielding (Milano) Photon detector mechanics (Genova) C.Matteuzzi CSN1 3 Febbraio

35 Entrance and exit windows 7.2 x 5.6 m² 1+1 mm carbon 36 mm PMI Completed October x 6.6 m² 1+1 mm alu 40 mm PMI C.Matteuzzi CSN1 3 Febbraio

36 RICH-2 schedule for next year(s) March 2004: Dismount clean room April to October 2004: Mount superstructure November 2004: Mount clean room December to April 2005: Install mirrors mid May 2005: Transport to the pit Installation Schedule: RICH 2 at the pit 23 May to 3 June 2005 C.Matteuzzi CSN1 3 Febbraio

37 Readout System: Binary data HPD containing pixel chip Translator caver n counting room Level-0 board Level-1 board LV distribution Optical data links DAQ link HV distribution ECS slave ECS master C.Matteuzzi CSN1 3 Febbraio

38 Translator Electrical connection from HPD to Level-0 board ZIF PCB + flex cable Responsibilities: Genova Status: Specs (electrical & mechanical) defined Design underway Close interaction with Level-0 & mechanics design C.Matteuzzi CSN1 3 Febbraio

39 Mechanical Design Magnetic shields (each ~8 tonnes of Armco iron) Low mass spherical mirrors Quartz windows Seal directly to the VELO exit window Z(cm) Gas enclosure Glass secondary plane mirrors (outside the acceptance) C.Matteuzzi CSN1 3 Febbraio