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Nuclear Burning

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					  Why Does the Sun Shine?
• Sun ≡ Ball of H gas compressed by
  gravity → HEAT (not enough)
• HEAT → Nuclear fusion
     p + p → d + e+ + n + energy
           Solar Properties
    L☼= 3.8 x 1026 W = 2.4 x 1039 MeV/s

    M☼= 2 x 1030 kg =1057 Mp

Solar Fusion Cycle:
2e- + 4p → 4He + 2n + 26.7 MeV (thermal)
Rn = Neutrino rate = 2 L☼/26.7MeV = 1.8x1038 n/sec

Flux at earth = Rn/(4pR2) = 6x1010/cm2/sec
flux vs radius
Super Kamiokande Experiment
Neutrinos Point Back to the Sun!
The Story of Cosmic
       Rays

                      R. A. Millikan - 1925




Victor Hess – 1911
(Nobel prize 1936)
The Cosmic Ray Energy Spectrum

     • ~ E-3

     • “Knee”

     • “Ankle”




               Terrestrial Accelerators
        Sources

Stars




                                                   ??
                           Centaurus A
                           (CHANDRA X-ray image)


                                             UHECR


            Supernova
            acceleration
              GZK Cutoff




• p+g      p + p0 (Interaction with CMB)

        mp (MN +mp/2)
• Eth =               ~ 1020 eV
             2 Eg

• lint ~ 20 Mpc
Shower Detection
Pierre Auger Observatory
   (Malargue, Argentina)
New Result from Auger (2009)

				
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