May 5-10, Buénerd 1 THE AMS RICH COUNTER The AMS RICH collaboration: Bologna, Grenoble, Lisbon, Madrid, Maryland, Mexico M. Buénerd ISN Grenoble Plan AMS project RICH counter Prototype AMS

May 5-10, Buénerd 2 The AMS collaboration S.C.C. TING (MIT), PI UNAM

May 5-10, Buénerd 3 High statistics study of Cosmic Ray particles: Allowing sensitive search for : Primordial antimatter (primary goal of the project) : Dark matter (neutralino annihilation) : High energy gamma ray astronomy AMS Scientific Program on the ISS

May 5-10, Buénerd 4 The AMS & RICH calendar 1994 Approval of the project by NASA/DOE June 1998: Instrumental flight on the space shuttle DISCOVERY, 10 days : AMS02 design & construction for ISS phase: SC magnet+ECAL+RICH+TRD 2005: AMS02 launch & installation on the International Space Station ~ : Data taking

May 5-10, Buénerd 5 TOF Hodoscopes (TOF & dE/dX) Cryostat & SC Magnet (B = 1T) Tracker (P & dE/dX measurement) EMC (ID em particles) RICH (particle ID A<~25, Z<~25) TRD e + /p & e - /p Discrim P<300GeV/c - THE AMS SPECTROMETER VETO

May 5-10, Buénerd 6 THE AMS RICH COUNTER Rôle in AMS: Ion identification (A & Z) p/e - and p/e + discrimination Albedo particle rejection _

May 5-10, Buénerd 7 RICH design history : - First simulation works to evaluate the possible performances: see NIM A454(2000)476 - Study prototype, construction and operation (T.Thuillier et al., NIM A, in press, astro-ph/ ) : - (Iterations to) final design - Second generation prototype

May 5-10, Buénerd 8 Imaging technique & main design features Design drastically constrained by: - Volume - Weight (currently ~190kg) - Power consumption - Long term reliability of components - Magnetic field in the photodetector region Proximity focusing counter, photomultipliers 2 radiators for a maximum momentum range for particle identification (~1-13 GeV/c/nucleon) è

May 5-10, Buénerd 9 The isotopic abundance ratio 10 Be/ 9 Be depends on: - Time of confinement of CRs in galaxy - ISM density and galactic halo size 6 weeks counting è ~ events ! A.Bouchet et al,Nucl.Phys A668(2000) 7 Be 9 Be 10 Be Simulation of 10 Be detection

May 5-10, Buénerd 10 The RICH architecture ECAL hole Photodetectors Radiator(s) Conical mirror

May 5-10, Buénerd 11 Rich assembly (exploded view) AEROGEL radiator plane. Produced in Japan, Characterized in Mexico Support structure Madrid Structure Assembly (Bologna/Gavazzi) LOWER PANEL Photodetector plane 680 PMTs ~10 4 pixels of photosensors (Japan) Photon drift space Mirror made in USA (~13kg) Resp. Bologna Mech Design from Gavazzi Co, Italy NaF radiator ?

May 5-10, Buénerd 12 Bottom skin End beam Support beam Th. = 0.8 mm Th. = 1.0 mm Th. = 1.2 mm Shielding Grid Structure Courtesy G. Sardo, Gavazzi Space Co

May 5-10, Buénerd 13 Photomultipliers Requirements: Must stand high magnetic field (>~100 G) Multianode ~5x5mm pixels è Hamamatsu R7600-M16

May 5-10, Buénerd 14 PMT Hamamatsu R7600-M16 16 anodes~4.5x4.5mm 2 PC Boards, RO and HVD Flex (ible) support Integrated Circuit: AustriaMikroSystem Technology RICH photodetector and front end electronics assembly

May 5-10, Buénerd 15 Front end electronics Principle: Spectroscopy type charge preamplifier, 16 multiplexed channels, 2 gain (x1 & x5) modes

May 5-10, Buénerd 16 Prototype of detector module (16 pixel) PMT Readout electronics (16) Light guides Housing (half) shell

May 5-10, Buénerd 17 RICH prototype (2nd generation)

May 5-10, Buénerd 18 Rich detector plane Prototype  96 PMTs, 1536 pixels Prototype = ~½ module of final counter

May 5-10, Buénerd 19 Prototype experimental set-up (Cosmic ray configuration) MWPCs Scint illators Radiator AMS Proto DAQ Vacuum chamber Trigger electronics and MWPC readout PMT Matrix Cosmic  3 Radiators tested aerogels 1.03, 1.05, NaF

May 5-10, Buénerd 20 PMT array before light guide Installation Light guides installed Detection plane

May 5-10, Buénerd 21 Back view of proto 2 Readout lines (9 PMTs/line)

May 5-10, Buénerd 22 PMT matrix RO electronics Scintillators MWPC tracker Vacuum chamber Chamber lid LED Top view of the set-up

May 5-10, Buénerd 23 SUN Station VME BUS Tracker : MWPCs + delay line RO [CAMAC] Trigger : scintillators + PMTs [CAMAC] L. Gallin-Martel ISN Grenoble, AMS - CERN October 19 th 2001 PSPS PC2 RICH prototype DAQ setup

May 5-10, Buénerd 24 Readout and DAQ Each board (33PMTs): 1 DSP controlled FPGA + memory buffer 3 DAQ modes controlled by DSP: - calibration: pedestal calibrated and tabulated - RAW: 2 gains and all channels stored - REDUCED : gain mode selection and channel reduction

May 5-10, Buénerd 25 Prototype performances in Cosmic Ray tests Example of (muon) event measured in CR tests Particle hit on LG+PMT

May 5-10, Buénerd 26 Velocity resolution Reconstructed  spectrum Only a resolution estimate since no measurement of the incident momentum of particles. Aerogel radiator n=1.03 MC simulation ° Data Resolution per hit: Measured: MC : è (  ) event  (Z=1) Contribution from mwpc tracker being reduced

May 5-10, Buénerd 27 Next steps -Technical tests : Vacuum, thermal, vibrations - Ion beam test at CERN on next october - Detector modules assembly will start on next January Counter assembly finalized by end of 2003.

May 5-10, Buénerd 28 Summary & Conclusion The AMS RICH is fully designed End-to-end tests of the prototypes have been performed successfully. Radiators (aerogels 1.03/05, NaF), PMTs, Light guides, FE and RO electronics, processing algorithms, provide the expected results (See talk by F. Barao). The forthcoming in-beam tests with ions at CERN on october will complete the tests. è The AMS RICH is on the tracks…. for flying on the ISS.

May 5-10, Buénerd 29 Reject Albedo particles (prototype inefficiency < ) Discriminate e + /p & e - /pbar (p < ~12 GeV/c) Identify nuclei or elements: What the RICH will do: Cosmic Ray studies with the RICH Assuming  P/P~1%

May 5-10, Buénerd 30 Electronics settings PMTs grouped by 11 (10) / flex  ped  ~ 4.3 = 69  /Q  ~ 0.47

May 5-10, Buénerd 31 Raw data vs simulation

May 5-10, Buénerd 32 Noise Aerogel 1.03 run 3  s delayed trigger El noise ~ hit/chan DC ~ hit/chan

May 5-10, Buénerd 33 Proto_1 Z separation Z separation obtained with proto 1 at GSI with 1GeV/n 12 C beam

May 5-10, Buénerd 34 Proto_1  (z) resolution  resolution obtained with proto 1 at GSI with 1GeV/n 12 C beam.

May 5-10, Buénerd 35 Field map at PMTs

May 5-10, Buénerd 36 From simulation results: Mass rangeA< ~30 Charge rangeZ< ~25 Momentum rangeP< ~15 GeV/c Assuming  P/P~1% The upper bounds quoted for A and Z are asymptotic limits What ion mass and charge ID range with the RICH ?