Isotopic composition [ACE] Solar Modulation [PAMELA,ULYSSES]

Results from PAMELA

Mirko BoezioINFN Trieste, Italy

On behalf of the PAMELA collaborationIndirect and Direct Detection of Dark Matter February 7th 2011

Mirko Boezio, IDDDM, Aspen, 2011/02/07

PAMELAPayload for Antimatter Matter Exploration and Light Nuclei Astrophysics


PAMELA Collaboration


PAMELA InstrumentGF ~21.5 cm2sr Mass: 470 kg

Size: 130x70x70 cm3


Design Performance Energy rangeAntiprotons 80 MeV - 190 GeV Positrons 50 MeV 300 GeV

Electrons up to 800 GeVProtons up to 1 TeV

Helium up to 400 GeV/n

Electrons+positrons up to 2 TeV ( by calorimeter)

Light Nuclei (Li/Be/B/C) up to 200 GeV/n AntiNuclei search sensitivity of 3x10-8 in He/HeMirko Boezio, IDDDM, Aspen, 2011/02/07


PAMELA

Launch15/06/06

16 Gigabytes trasmitted daily to GroundNTsOMZ Moscow


Orbit Characteristics Low-earth elliptical orbit 350 610 km Quasi-polar (70o inclination) SAA crossed Mirko Boezio, IDDDM, Aspen, 2011/02/07


S1 S2 S3NP SP

EQ EQOuter radiation beltInner radiation belt (SSA)


Subcutoff particlesMirko Boezio, IDDDM, Aspen, 2011/02/07


Main antenna in NTsOMZTrigger rate* ~25HzFraction of live time* ~ 75%Event size (compressed mode) ~5kB 25 Hz x 5 kB/ev ~ 10 GB/day(*outside radiation belts)Till ~now:~1400 days of data taking~20 TByte of raw data downlinked>2x109 triggers recorded and analyzedPAMELA milestones


Scientific goalsSearch for dark matter annihilation

Search for antihelium (primordial antimatter)Search for new Matter in the Universe (Strangelets?)

Study of cosmic-ray propagation (light nuclei and isotopes)Study of electron spectrum (local sources?)

Study solar physics and solar modulationStudy terrestrial magnetosphere


Dark MatterMirko Boezio, IDDDM, Aspen, 2011/02/07Indirect Detection


DM annihilationsDM particles are stable. They can annihilate in pairs.Primary annihilation channelsDecayFinal statesa=


Particle ID with PAMELAMirko Boezio, IDDDM, Aspen, 2011/02/07


Flight data: 0.763 GeV/cantiproton annihilation


Bending in spectrometer: sign of chargeIonisation energy loss (dE/dx): magnitude of chargeInteraction pattern in calorimeter: electron-like or proton-like, electron energy Time-of-flight: trigger, albedo rejection, mass determination (up to 1 GeV)Positron(NB: p/e+ ~103-4)Antiproton (NB: e-/p ~ 102)Antiproton / Positron Identification


Flight data: 14.7 GVInteracting nucleus(Z = 8)


Antiproton to proton ratio (0.06 GeV - 180 GeV)Donato et al. (PRL 102 (2009) 071301)Simon et al. (ApJ 499 (1998) 250)Ptuskin et al. (ApJ 642 (2006) 902) PRL 102, 051101 (2009) and PRL. 105, 121101 (2010)


Antiproton Flux (0.06 GeV - 180 GeV)Donato et al. (ApJ 563 (2001) 172)Ptuskin et al. (ApJ 642 (2006) 902) PRL. 105, 121101 (2010) Systematics errors included


Antiprotons inside SAAGalactic AntiprotonsAntiprotons below cutoff at equator

Galactic antiprotonsPAMELA trapped antiprotonsPreliminaryMirko Boezio, IDDDM, Aspen, 2011/02/07


Positron to Electron FractionSecondary production Moskalenko & Strong 98Adriani et al, Astropart. Phys. 34 (2010) 1 arXiv:1001.3522 [astro-ph.HE]


But antiprotons in CRs are in agreement with secondary productionUncertainties on: Secondary production (primary fluxes, cross section) Propagation models Electron spectrumA Challenging Puzzle for CR Physics


A Challenging Puzzle for CR PhysicsP.Blasi, PRL 103 (2009) 051104; arXiv:0903.2794Positrons (and electrons) produced as secondaries in the sources (e.g. SNR) where CRs are accelerated.I. Cholis et al., Phys. Rev. D 80 (2009) 123518; arXiv:0811.3641v1 Contribution from DM annihilation. D. Hooper, P. Blasi, and P. Serpico, JCAP 0901:025,2009; arXiv:0810.1527 Contribution from diffuse mature &nearby young pulsars.


G. Kane, R. Lu, and S. Watson, Phys.Lett.B681, 151 (2009); arXiv:0906.4765v3

A Challenging Puzzle for CR PhysicsT. Delahaye et al., A&A 501, 821(2009); arXiv: 0809.5268v3


Cosmic Ray SpectraCosmic-Ray Acceleration and Propagation in the Galaxy Mirko Boezio, IDDDM, Aspen, 2011/02/07


Diffusion Halo ModelMirko Boezio, IDDDM, Aspen, 2011/02/07


Proton and Helium Nuclei SpectraMirko Boezio, IDDDM, Aspen, 2011/02/07


Proton and Helium Nuclei SpectraGALPROPMirko Boezio, IDDDM, Aspen, 2011/02/07


Proton and Helium Nuclei SpectraMirko Boezio, IDDDM, Aspen, 2011/02/07


Boron and Carbon nuclei SpectraCarbonBoronMirko Boezio, IDDDM, Aspen, 2011/02/07


pdH isotopes separationMirko Boezio, IDDDM, Aspen, 2011/02/07


Positrons detectionWhere do positrons come from?Mostly locally within 1 Kpc, due to the energy losses by Synchrotron Radiation and Inverse ComptonTypical lifetime


PAMELA electron (e-) spectrume+ + e-e-Mirko Boezio, IDDDM, Aspen, 2011/02/07


PAMELA electron (e-) spectrumPreliminaryTracker basedCalorimeter basedMirko Boezio, IDDDM, Aspen, 2011/02/07


Theoretical uncertainties on standard positron fractionT. Delahaye et al., arXiv: 0809.5268v3 = 3.54 = 3.34Flux=A E-


PAMELA electron (e-) spectrumFlux=A E- = 3.18 0.05GALPROPprediction from e- fluxMirko Boezio, IDDDM, Aspen, 2011/02/07New Primary Contribution


Independently to the fit of the electron spectra, we also perform a 2 comparison between the expected positron fraction from GALPROP simulation and PAMELA measurement of the positron fraction.Confidence level, in parameter space (2;0) obtained from a fit of the electron spectra (red) and of the positron fraction (green). Cruces show the best-fit combination.

Interestingly, the best fit value for the two independent fit are very similar.Preliminarypositron fractionelectron spectrum Fit of electron spectrum90%95%99%Mirko Boezio, IDDDM, Aspen, 2011/02/07


Solar ModulationMirko Boezio, IDDDM, Aspen, 2011/02/07


Positron to Electron FractionSecondary production Moskalenko & Strong 98Adriani et al, Astropart. Phys. 34 (2010) 1 arXiv:1001.3522 [astro-ph.HE]


Solar Modulation of Galactic Cosmic RaysCourtesy of M. PotgieterPAMELA


PreliminaryTime Dependence of PAMELA Proton FluxMirko Boezio, IDDDM, Aspen, 2011/02/07


PreliminaryTime Dependence of PAMELA Electron (e-) FluxMirko Boezio, IDDDM, Aspen, 2011/02/07


Flux variation as a function of time for rigidities between 0.72 and 1.04 GVTime DependencePreliminary


Increase of the flux measured by PAMELA from July 2006 to December 2008Time DependencePreliminary


U.W. Langner, M.S. Potgieter, Advances in Space Research 34 (2004).PAMELA Electron to Positron Ratio and Theoretical ModelsPreliminary


Summary PAMELA ResultsMirko Boezio, IDDDM, Aspen, 2011/02/07 PAMELA Data


Summary PAMELA has been in orbit and studying cosmic rays for ~4.5 years. >109 triggers registered and >19 TB of data has been down-linked.

Antiproton-to-proton flux ratio and antiproton energy spectrum (~100 MeV - ~200 GeV) show no significant deviations from secondary production expectations. High energy positron fraction (>10 GeV) increases significantly (and unexpectedly!) with energy. Primary source?

The proton and helium nuclei spectra have been measured up to 1.2 TV. The observations challenge the current paradigm of cosmic ray acceleration and propagation.

The e- spectrum up to 600 GeV shows spectral features that may point to additional components.

Analysis ongoing to finalize the antiparticle measurements (positron flux, positron fraction), continuous study of solar modulation effects at low energy.

Waiting for AMS to compare contemporary measurements.



AMS-02 on ISSIn Orbit April 2011


The Completed AMS Detector on ISSTransition Radiation Detector (TRD) Silicon TrackerElectromagnetic Calorimeter (ECAL)MagnetRing Image Cerenkov Counter (RICH)Time of Flight Detector (TOF)Size: 3m x 3m x 3mWeight: 7 tons


AMS-02 new configuration


AMS S.C. Magnet:MDR 2.18 TV

AMS Perm. Magnet:MDR 2.14 TV


AMS Capability Space Part 2006




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Outer rb = elettroni. Piu` vicina alla terra. Si attraversa al polo sud perche` il satellite e` piu` lontano. 600km a sud 350km nord.La SSA e` unestenzione della fascia interna. Causata dal fatto che in centro del dipolo magnetico e` spostato rispetto al cetro della terra.

Counting rates along the orbit. Comparison between different detectors (tof scintillators, neutron detector, anticounters) allows to check detector behavior in the space environment. Conclusion: counting rates are consistent with satellite position along the orbit

Rate on S1, S2 S3:- Duration of a orbit- Environment: passage @ poles, equators and SSA

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Documents

Isotopic composition [ACE] Solar Modulation [PAMELA,ULYSSES]