Using the Westerbork radio observatory

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Using the Westerbork radio observatory to detect
UHE cosmic particles interacting on the Moon
J. Bacelar (KVI) O. Scholten (KVI) G. de Bruyn
(ASTRON) H. Falcke (ASTRON)
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UHE Cosmic-rays
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Experiments performed
Satellite FORTE Phys.Rev.D69(04)13008
Balloon ANITA Astro-phys./411007(2004) Ground RI
CE AstroP.Phys. 20(03)195
Moon GLUE Phys.Rev.Lett. 93(04)41101
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Askaryan effect Coherent Cherenkov emission
Experiment at SLAC with beams of 28.5 GeV
electrons And 1010 e-/bunch effective shower
energies 0.06-1.10 1019 eV
D. Saltzberg et al PRL 86 (2001) 2802
1 Jy 10-20 W/m2/MHz
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Askaryan effect Coherent Cherenkov emission
Experiment at SLAC with beams of 28.5 GeV
electrons And 1010 e-/bunch effective shower
energies 0.06-1.10 1019 eV
D. Saltzberg et al PRL 86 (2001) 2802
1 Jy 10-20 W/m2/MHz
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• Particle hits Moon (radius1700 km area 6p 106
  km2)
• Interacts protons within meters, V
• Askaryan effect -gt Coherent Cherenkov emission
• Shower development -gt
  including LPM effect
• Transmission through Moon material ?r 15m / ?
  GHz 7m (at 2.2 GHz)
• Transmissivity across Moon surface vacuum
  boundary

60 km _at_ 1021 eV 6 km _at_ 1024 eV
Vacuum
Moon n1.5-1.8
Spread emitted power density in a gaussian of
width ??c?/l Hadronic component ??c 2.5 (3/?)
3.50 (at 2.2 GHz) EM component ??c 2.5
(3/?)(4.1014 / E)1/3 0.0250
?c 560
?c
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• Particle hits Moon (radius1700 km area 6p 106
  km2)
• Interacts protons within meters, V
• Askaryan effect -gt Coherent Cherenkov emission
• Shower development -gt
  including LPM effect
• Transmission through Moon material ?r 15m / ?
  GHz 150 m (at 0.1 GHz)
• Transmissivity across Moon surface vacuum
  boundary

60 km _at_ 1021 eV 6 km _at_ 1024 eV
Spread emitted power density in a gaussian of
width ??c?/l Hadronic component ??c 2.5 (3/?)
750 (at 0.1 GHz) EM component ??c 2.5
(3/?)(4.1014 / E)1/3 0.50
?c
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ne Showers in ice above 1020 eV
EM Shower (80)
ne
e

• No photonuclear interactions
• Hadronic shower Long EM shower
• EM 36 cm/sqrt(E/1015 eV)
• Shower length 60 m (E/1019 eV)1/3
• (90 containment. Alvarez-Muniz Zas))

Hadronic Shower (20)
EM propagator Length LEM
EM --gt hadronic Shower (80)

• Photonuclear interactions
• Hadronic shower
• Delayed (by LEM) hadronic shower
• H 83 cm
• Shower length 30LH 25 m

ne
m
e
Hadronic Shower (20)
J. Alvarez-Muniz, E. Zas, P.L. B434
(98)396 Phys.Rev.D62(2000)63001.
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Shower Length

• 3 simple models
• EM (w/ LPM)
• Length E1/3
• (Alvarez-Muniz Zas)
• 1 km at 1022 eV
• Hadronic
• Length ln(E)
• Hybrid
• Initially EM, but
• g --gt hadrons
• 400 m at 1022 eV

Purely EM Purely Hadronic Dotted - hybrid
ne Energy (eV)
NOTE ??c 1/(l? )
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Results of calculations for cosmic rays
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Results of calculations for neutrinos
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Proposed Experiment
Use Westerbork radio observatory

• Advantages
• 117-175 MHz band
• 25 m diameter dishes
• 5 degree field of view
• 12-14 coincident receivers
• 100 hour observation time
• 40 M samples/sec (PuMa2)
• Polarization information

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Proposed Experiment
Use Westerbork radio observatory
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(No Transcript)
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Calc. limits GLUE
Published limits Rice,GLUE,FORTE
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Calc. limits GLUE
Published limits Rice,GLUE,FORTE
Theoretical predictions Active galactic
nuclei Astro.Phys.3(96)295 GZK induced
flux Phys.Rev.D64(04)93010 Topological
defects AstroPhys. J. 479(97)547
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Calc. limits GLUE
Published limits Rice,GLUE,FORTE
Predicted limits 45 days ANITA
Theoretical predictions Active galactic
nuclei Astro.Phys.3(96)295 GZK induced
flux Phys.Rev.D64(04)93010 Topological
defects AstroPhys. J. 479(97)547
Calc. limits 100 hours Westerbork
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Energy response
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Conclusions

• Westerbork observatory
• 14 radio antennas
• 117-175 MHz band
• PuMa 2 data acquisition mode
• Low background noise
• Large field of view
• Polarization information

• Within 100 hours observation competitive
  sensitivity to both cosmic rays and neutrino
  fluxes
• Energy threshold 1021 eV
• Polarization determines plane of incidence of
  original particle

Future Experiment with LOFAR