Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 1

THE CHERENKOV IMAGER of THE CHERENKOV IMAGER of the AMS02 EXPERIMENTthe AMS02 EXPERIMENT

The AMS RICH collaboration: Bologna, Grenoble, Lisbon, Madrid, Maryland, Mexico

M. BuénerdM. BuénerdLPSC GrenobleLPSC Grenoble

AMS

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 2

PLAN

The AMS02 spectrometer

Physics program

The Cherenkov imager

In-beam test results

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 3

Capabilities of the spectrometer

Measure particle energy from ~ 0.4 GeV/n up to ~ 1 TeV/n

Discriminate lepton-hadron

HE ray measurement

Identify ions or elements

over the largest possible energy range

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 4

AMS Scientific Program on the ISS

• High statistics study of the Cosmic Ray particles flux:

Allowing sensitive search for :

• Primordial antimatter (primary goal of the project):

• Dark matter (neutralino annihilation):

• High energy gamma ray astronomy

,...)C,He( 124

)X.... X,e X,p

nuclei) Antimatter Be,unstable 30, Z& 16A ions p, ,p ,(e 10

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 5

Main purpose:

• The only AMS detector dedicated to

Isotope identification (A & Z)

Also (redundant) :• p/e- and p/e+ discrimination

• Albedo particle rejection

_

The AMS Cherenkov imager

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 6

The isotopic abundance ratio 10Be/ 9Be depends on:

- Time of confinement of CRs in galaxy- ISM density and galactic halo size

6 weeks counting ~ 200000 events !

A.Bouchet et al,Nucl.Phys A668(2000)7Be 9Be 10Be

Simulation of 10Be detection

isomax

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 7

The RICH inside AMS

ECAL

Photodetectorplane (680 PMTs)

Radiator(s)

Conical mirror

AMS spectrometer NaF aerogelCherenkovRadiator

Photo- detectors

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 8

Sodium Fluoride

NaF, n = 1.33 thickness 5 mm

Aerogel n = 1.05 thickness 30 mm

Radiator plane

P range ~ 3-10GeV/c/n

P range ~ 1-4 GeV/c/n

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 9

4x4 Light Guides7.5x7.5mm2

PMT Hamamatsu R7900_M164x4 pixels (4.5x4.5mm2)

Front End Electronics: Charge preamplifier Track&hold +MPX 16 chan (x2gains)

ADC High voltage divider

Magnetic Shielding profile(Stray field up to 300G)

Photodetector cell

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 10

½ module of final detector

96 PMTs (1536 pixels) Light Guides FE+DAQ Radiators:

AGL 1.03 < n < 1.05 NaF n=1.33 (CR only)

The RICH prototype

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 11

with HE ion beam at CERNwith HE ion beam at CERN

Tests of the AMS RICH prototypeTests of the AMS RICH prototype

• Beam production principle*• Measurements • Results

* M. Buénerd and I. Efthymiopoulos, CERN report AB-2003-052

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 12

Multi-ion beam production

Incident SPS

- Pb ion beam(20GeV/c/n)- In ion beam(158GeV/c/n)

Productiontarget

Momentumanalysis

B

BCte x A/Z

Beam fragmentation BCte x beam A/Z

Example: A/Z=2 D, He, Li, Be, B, C,…, Si,.., Ca,…, 52Fe, ..

and beyond, but….

Testingdetector

Fewmrad

500m beam line

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 13

Intensity of ion beam fragments vs

Cosmic Ray flux

Cosmic Ray flux J.A. Simpson ARNS 33(1983)323

Beam fragments (A/Z=2)(From dE/dX scintillator ) Similarity of

the 2 spectra

controllableCR equivalent flux

~Nuclear charge Z

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 14

2 Runs

• October 2002: 20 GeV/nucleon 208Pb fragments A<~60 (z~30) 5 million events collected

• October 2003 : 158 GeV/nucleon 115Cd fragments A<115 (z=49)11 million events collected

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 15

Experimentalsetup

Prototype & RO electronics

MWPC

MWPC

dE/dXScintillatorsor Cherenkov

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 16

Close-up view of matrix with mirror

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 17

20GeV/n Cherenkov rings

Z2

3 6

>~16

>16

He

Li C

Si-P ?

~Fe ?

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 18

Velocity reconstruction 2002

spectra fittingRing fitting

nc 1 cos

Z=1 particlesZ=1 particlesAerogelRadiator Index Resol (x10- 3) Clarity (x10- 3)

Matsushita 1.03 0.71 7.9Matsushita 1.05 0.98 9.5Novosibirsk1.03 0.67 5.9

CIEMAT Madrid analysis

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 19

(Z) resolution 2002

Nγ in the ring ~

Z2

Limit set by pixel size

24

2

)10 8.0()1( )(

ZZ

Aerogel 1.03

CIEMAT Madrid analysis

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 20

Charge resolution 2002

(Z) < ~.2 up to Z=26

(n=1.05)

cZdxddN

sin 2 2

)1(exp ZN

NZ pe

Combining RICH+TRCKR

Courtesy M.Pohl, Geneva U.

Courtesy M. Pohl et al.

IndividualElement separation

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 21

2003 comparison of Aerogels

H (Nominal = 44 cm)

Test beam 2003 RESULTS (H = 33,5 cm)

TYPE SIZE

(Z=1, = 1) (Z=2, = 1)

PH. YIELD PH. YIELD

MAT 1.03 3 x 1 cm 11,0 ± 0.1 36,0 ± 0.1 (0.487 ± 0.006) x 10-3

NOV 1.03 1 x 3 cm 10,6 ± 0.1 34,7 ± 0.1 (0.468 ± 0.005) x 10-3

NOV 1.05 1 x 2.5 cm 14,6 ± 0.3 47,6 ± 0.1 (0.484 ± 0.007) x 10-3

Specific runs to compare the performances for radiators with different refraction index H = 33.5 cm (full contained rings)

ELECTEDELECTED

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 22

Cells integration

April 2004

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 23

coating

(Spares from the prototype used)

Finally:

680 PMT cellsASSEMBLED

POTTEDCOATEDTESTED SORTED

9 failures (3 due to PMT failure)

Ready for final counter integation

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 24

Summary

The study of the AMS RICH prototype with 20 & 158 GeV/n ions has allowed to:

1. Perform an end-to-end test of the instrument with a broad range of nuclear charges (1<Z<~49).

2. Measure the performances of the prototype:• Velocity resolution : / = 0.7 10-3 for Z=1 particles• Charge resolution : (Z) < 0.2 up to Z>~30

3. All the RICH prototype elements have been thoroughly tested (PMT cells, FE+RO electronics, reconstruction algorithms) and validated .

The final counter integration has started (end Nov 05).

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 25

AMS is an International CollaborationAMS is an International CollaborationNASA provides: Three shuttle flights and Mission Management at JSCNASA provides: Three shuttle flights and Mission Management at JSC

(S. Porter - Project Manager)(S. Porter - Project Manager)

USAA&M FLORIDA UNIV.JOHNS HOPKINS UNIV.MIT - CAMBRIDGENASA GODDARD SPACE FLIGHT CENTERNASA JOHNSON SPACE CENTERUNIV. OF MARYLAND-DEPRT OF PHYSICSUNIV. OF MARYLAND-E.W.S. S.CENTERYALE UNIV. - NEW HAVEN

MEXICO

UNAM

DENMARKUNIV. OF AARHUS

FINLAND

HELSINKI UNIV.UNIV. OF TURKU

FRANCEGAM MONTPELLIERLAPP ANNECYLPSC GRENOBLE

GERMANYRWTH-IRWTH-IIIMAX-PLANK INST.UNIV. OF KARLSRUHE

ITALYASICARSO TRIESTEIROE FLORENCEINFN & UNIV. OF BOLOGNAINFN & UNIV. OF MILANOINFN & UNIV. OF PERUGIAINFN & UNIV. OF PISAINFN & UNIV. OF ROMAINFN & UNIV. OF SIENA

NETHERLANDSESA-ESTECNIKHEFNLR

PORTUGALLAB. OF INSTRUM. LISBON

ROMANIAISSUNIV. OF BUCHAREST

RUSSIAI.K.I.ITEPKURCHATOV INST.MOSCOW STATE UNIV.

SPAINCIEMAT - MADRIDI.A.C. CANARIAS.

SWITZERLANDETH-ZURICHUNIV. OF GENEVA

CHINABISEE (Beijing)IEE (Beijing)IHEP (Beijing)SJTU (Shanghai)SEU (Nanjing)SYSU (Guangzhou)SDU (Jinan)

ACAD. SINICA (Taiwan)CSIST (Taiwan)NCU (Chung Li)NCKU (Tainan)NCTU (Hsinchu)NSPO (Hsinchu)

KOREAEWHAKYUNGPOOK NAT.UNIV.

50 universities, 500 participants

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 26

TOFHodoscopes(TOF & dE/dX)

Cryostat & SC Magnet

(B = 1T)

Tracker(P & dE/dX measurement)

EMC(ID em particles)

RICH(particle & isotope ID

A<~16 ?, Z<~25)

TRDe+/p & e-/p

Discrim P<300GeV/c

-

VETOskirt

THE AMS2 SPECTROMETER

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 27

2x

Dipole Coils2x6

Racetrack Coils

2,500 l Superfluid He

SC magnet in support structure

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 28

• What for ?• Which imaging technique ?• What radiator(s) ?• What photodetectors ?• What performances ?Prototype and test resultsPrototype and test results

The Cherenkov Imager

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 29

Largely dictated by constraints on: - Volume available (Shuttle cargo bay)- Weight (currently ~190kg) - Power consumption (currently ~150W) - Long term reliability of components - Magnetic field in the photodetector region- Isotropic flux (No point source like in accelerators)

• Proximity focusing counter, photomultipliers• 2 radiators for a maximum momentum range for isotope identification (~1-10 GeV/c/nucleon)

Which imaging technique ?

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 30

AEROGEL radiatorplane.Produced in Japan or Russia,Characterized at UNAM MexicoSupport structure made by CIEMAT Madrid

StructureAssembly(Bologna/Gavazzi)LOWER PANEL

Photodetector plane680 PMTs

~104 pixels of photosensors(Japan)

Photondrift space

Mirror made inUSA (~ 13kg)Resp. Bologna

Mech. Designby GavazziSpace, Italy

NaF radiator

Rich assembly (exploded view)

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 31

Selection of the ion sample

Z=2He

Z=82Pb beam

Z=8O

Z=20Ca

Z=50Zr

N

Z

Selec

tion

line

(A/Z

=Cte)

Changing the magnetic field in the beam line changes the ion mass/charge sampled Chart of the nuclides

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 32

The CERN H8 beam line

Productiontarget

Position (m)

RICH

MomentumAnalysis

Dispersiondipole

AnalysisDipoleAcceptance

collimators Imagecollimators

0-480 -420

-464

-352 -150 -80

TOF1

-26

NA45

Wall

/ /

Experimental area

Tracker

TOF

CREAM

P/P~1%

TOF2

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 33

Front end electronics

Principle: Spectroscopy type charge preamplifier, 16 multiplexed channels, 2 gain (x1 & x5) modes

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 34

To be cross checked with calibration from the ion charge distribution

3 pixels

PMT linearityPMT linearity measurementmeasurement

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 35

Team (night shift) at work

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 36

M.MartonModule coatingCoating

Aug 2004

Nov 30-Dec 5, 2004 RICH2004 Int. Workshop, Playa Del Carmen, Mexico M. Buénerd 37

Surface scattering