la biodola (isola delba) may 26, 2006the pamela experiment ready for flight o. adriani the pamela...

La Biodola (Isola d’Elba) May 26, 2006

The Pamela experiment ready for flight O. Adriani

The Pamela experiment ready for flight

Oscar Adriani – INFN Firenze, Università di Firenze

on behalf of the Pamela collaboration

Payload for Antimatter Matter Exploration and Light Nuclei

Astrophysics



Bari Florence Frascati

Italy:TriesteNaples Rome CNR, Florence

Moscow St. Petersburg

NMSU

GSFC

USA:

Russia:

India:

Mumbai

Germany:Siegen

Sweden:KTH, Stockholm



Pamela’s scientific objectives

Study antiparticles in cosmic raysSearch for antimatterSearch for dark matterStudy cosmic-ray propagationStudy solar physics and solar modulationStudy the electron spectrum (local

sources?)



o Long-term monitoring of the solar modulation of cosmic rays

o Energetic particles from the Sun (e+)o High-energy particles in the Earth magnetosphere

Antiproton flux 80 MeV - 190 GeVPositron flux 50 MeV – 270 GeVElectron flux up to 800 GeVProton flux up to 1000 GeVElectron/positron flux up to 2 TeVLight nuclei (up to Z=6) up to 500 GeV/nLight isotopes (D, 3He) up to 1 GeV/nAntinuclei search (sensitivity better than 10-7 in

He/He)

PAMELA Capabilities



Secondary production (upper and lower limits)

Simon et al.

Primary production annihilation (m() = 964 GeV, Ullio 2002)

Secondary production (CAPRICE94-based)

Bergström et al.

Unexplored Region

PAMELA energy range

AntiprotonsBlack holes / Dark Matter

Propagation / Dark Matter Extragalactic primordials



Unexplored Region

Secondary production ‘Leaky box model’ (Protheroe 1982)

Primary production annihilation (m() = 336 GeV

Baltz & Edsjö 1999)

Secondary production ‘Moskalenko + Strong model’ (1998) without reacceleration

PAMELA energy range

PositronsPropagation / Dark MatterCharge modulation effects



Secondary production (upper and lower limits)Simon et al.

Secondary production (CAPRICE94-based)Bergström et al.

Primary production annihilation (m() = 964 GeV)

Antiprotons

> 3.104 antiprotons 80 MeV/c - 190 GeV/c



Secondary production ‘Leaky box model’ (Protheroe 1982)

Primary production annihilation

m() = 336 GeV

Secondary production ‘Moskalenko + Strong model’ (1998) without reacceleration

Positrons

> 3.105 positrons 50 MeV/c - 270 GeV/c



Cosmic-ray Antimatter Search

He / He

Breq

GeVpGVR

)(

)()(

CR production ~O(10-

14)



Particle Number (3 yrs)

Energy Range

Protons 3.108 50 MeV – 1000 GeV

Antiprotons >3.104 80 MeV – 190 GeV

Electrons 6.106 50 MeV – 2 TeV

Positrons >3.105 50 MeV – 270 GeV

He 4.107 50 MeV/n – 500 GeV/n

Be 4.104 50 MeV/n – 500 GeV/n

C 4.105 50 MeV/n – 500 GeV/n

Antihelium Limit

7.10-8 80 MeV/n – 70 GeV/n

•‘Semi-Polar’ orbit (700) Low energy particles

•Wide energy range + 3 years mission Reliable measurements

Expected Fluxes in 3 Years



Earth observation

350 / 610 km

Inclination = 70.4o

Soyuz 2 launcher

Baikonur Cosmodrome

3 year mission

350 - 610 km

Pamela operational

During launch / orbital manoeuvres

Housed in an atmospheric pressure vessel

Temperature = 5oC ÷ 35oC

All subsystems must withstand launch vibrations!

Electronics must withstand up to ~3 krad

Resurs DK1Resurs DK1

Total mass ~ 470kg / 345W power budget

Satellite and orbitLaunch date: June 14-16, 2006



Geometrical Factor ~20.5 cm2sr

The PAMELA subdetectors1.

2 m

Mass ~450 kg Power ~360 W

)10(~ 4Op

p

)1.0(~ Oe

e

)200(~ Oe

p



Magnetic spectrometer (I)Si Tracker + magnet

•Rigidity measurement

•5 Nd-B-Fe magnet segments

•0.48T at the centre

•(13.2 x 16.2 cm2) x 44.5 cm high

•6 planes of 300m thick double sided Si detectors

•<3m resolution in bending view

•+/-10 MIP dynamic range (VA1 chips)



Momentum resolution 2003 Last beam-test of PAMELA flight model @ CERN-SPS40-150 GeV/c protons

Magnetic spectrometer (II)

MDR ~ 1 TV/c Multiple scattering

Nx & sx



Calorimeter (I)Si-W Calorimeter

• Measures energies of e±.

E/E = 15% / E1/2 + 5%

• Si-X / W / Si-Y structure.

• 22 Si / 21 W 16X0 / 0.90

• Imaging: EM - vs- hadronic discrimination, longitudinal and transverse shower profile

• Total number of channels 4224

• Wide dynamic range 1 - 1000 MIP

Calorimeter Requirements:• p/e+ selection eff. 90%• p rejection factor 105

• e- rejection factor 104



Calorimeter (II) Electron-Proton Separation

SPS TestBeam Data:p & e-

200 GeV/c



SPS Test Beam Data(p&e- up to 200 GeV)+ Simulation

Calorimeter (III) Electron identification efficiency

Test BeamSimulation

Proton contamination in the electron sample

Test Beam

Simulation

At 200 GeV:Proton rejection factor 2.3∙105

Electron selectionefficiency 90%



Trigger/Time of Flight (I)

Plastic scintillator + PMT

•Trigger

•Detection of albedo particles

• Particle identification (up to 1 GeV/c)

•dE/dx



Δ(Z=6)~0.26

Time Resolution

S1-S2 S1-S3

C 200 MeV/n 66 ps 68 ps

C 1200 MeV/n

75 ps 73 ps

Cr 500 MeV/n

71 ps 81 ps

C12 200 MeV/n

Δβ ~ 0.009

Trigger/Time of Flight (II)

Charge Resolution

Results from heavy ions beam test at GSI (2006)



Anticoincidence system

• Defines acceptance for tracks

• Plastic scintillator + PMT

Auxiliary detectors (I)



• Plastic scintillator: 482 mm x 482 mm x 10 mm• 6 PMT read-out • Dynamic range: 1 - 1000 MIP

• 2 x 18 3He proportional counters (polyethylene / Cd envelope)• 600 × 550 × 150 mm3

• n + 3He p + 3H + 765 keV

• O(10) more n in hadronic cascades than EM

Auxiliary detectors (II)

Shower Scintillator (S4)Neutron Counter



Trigger and Data RateOne orbitLevel 1 Trigger

TOF Scintillator Coincidence• S1 x S2 x S3• S2 x S3 12 Hz (G.F. = 20.5 cm2sr + background)

Calorimeter Self-trigger (Ee>0.3TeV)

10 mHz (G.F. = 600 cm2sr)Data Rate / Storage / Downlink

12 Hz x 5 kByte / event ~ 5 GB/day

Up to 20 GB daily on-boardDown-linked with a few ground connections per day

[PAMELA DAQ ~10% dead-time (10 ms)]



Detectors tested at PS / SPSTest facilities as Prototypes and in FM configuration

Mass/Thermal ModelsQualified, March-May 2003

Full Cycle of Vibration /Shock of the Flight Model passed at IABG/ Munich, January 2005

PAMELA Technological Model completed and delivered to Russia December 2003

PAMELA Flight Model delivered toTSSKB_Progress Factory in Samara (Russia) April 2005

PAMELA Status (≤2005)



On-ground muon results2005 acquisition of atmospheric particles during PAMELA test before delivering Check of spectrometer systematics with positive and negative muons

Preliminary results:- no efficiency correction- first-order alignment- no ETA p.f.a.

Preliminary!

Preliminary!



PAMELA Event

Ground Data Muon:2.8 GV



PAMELA Event

Ground DataHadron:6.6 GV



PAMELA Event

CalorimeterSelf Trigger

GF 400 cm2

sr



PAMELA Status (≥2005)

Pamela has been fully qualified in Samarafrom May, 2005 up to March, 2006•Cooling loop•Mechanical interfaces•Power supply tests•Interface with the Very High Speed

Radiolink (VRL)•Electrical tests

Many repeated tests have been done during 1 year

Pamela was accepted to be sent to the launch base (March 2006)



PAMELA Status (2006) (I)

Pamela was transported by airplane from Samara to Bajkonour on March 28, 2006

60 days work before launch

•Standalone tests•Insertion in the pressurized container•Electrical tests with the satellite•Test of the downlink



PAMELA Status (2006) (II)All the tests were successful (May 18, 2006)Pamela is ‘ready for flight’

Launch window: 14-16 June 2006

Next steps:4 days after the launch

1 switch on (nominal way – hot parts) for 4 hours

data downlink check of data in NTSOMZ receiving station

6 days after the launch: start of commissioning phasehot parts (6 days)cold parts (3 days)+test of various operating modes

17 days after the launchbeginning of physics data taking



• PAMELA is the first space experiment which will measure Antiprotons and Positrons to high energies (≥ 200GeV) with an unprecedented statistical precision

• PAMELA will set a new lower limit for finding Antihelium• PAMELA will look for Dark Matter candidates• PAMELA has collected ground cosmic-rays for various months at the

laboratories of Rome 2 University and at the Samara TSSKB-Progress factory

• All detectors are performing as designed and PAMELA seems able to achieve its scientific goals.

• Pamela has been delivered to Russia at the end of March 2005• PAMELA has successfully passed all the integrations tests with the Resurs-

DK1 Satellite at TSSKB-Progress factory in Samara• Pamela has been delivered to Bajkonour at the end of March 2006• PAMELA has successfully passed all the integrations tests with the Resurs-

DK1 Satellite at the launch base in Bajkonour and is ‘ready for flight’

• PAMELA will be launched in the 14-16 June 2006 time window

Conclusions

la biodola (isola delba) may 26, 2006the pamela experiment ready for flight o. adriani the pamela...

Documents

pamela flight model

biodola isola delba

pamela operational

pamela subdetectors

adriani calorimeter

w slide

adriani particlenumber

gevc slide