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Concept of the LORD experiment. V.Chechin for the LORD Collaboration. Layout of LORD. LORD Lunar Orbital Radio Detector. Moon. CR, neutrino. Multibeam inflatable parabolic antenna (D=5…25 m). 10 m. RF inflatable antennas. 5 m. Biconical feed antennas. satellite. Moon.
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Concept of the LORD experiment V.Chechin for the LORD Collaboration
Layout of LORD LORD Lunar Orbital Radio Detector Moon CR, neutrino Multibeam inflatable parabolic antenna (D=5…25 m)
10 m RF inflatable antennas 5 m Biconical feed antennas
satellite Moon
Trigger system thresholds Square Law Detectors Dscr BPF 1th Beam Dscr BPF LNA & Dscr BPF Dscr BPF 2th Beam Trigger Trigger Logic of 2th Beam LNA OR 3th Beam LNA Trigger Logic of 3th Beam
Basic parameters Number of beams M = 3 Satellite altitude h 5001000 km Antenna’s diameter D 1020 m System temperature T 300 K Beamwidth 0.1*0.1 Frequency range f 300700 MHz 4 channels with f 4050 MHz Time gate 20 ns Signal-to-noise ratio SNR 35
Calculation scheme Antenna: f Emin(SNR, kT, Seff, f) Geometry: h, RM Radiation field parameterization: R*E(W,f,cos) Transmission through rough interface Directional pattern Apertures (km2 ster) ACR, A & (W, Emin, f, h) Fluxes JCR, J Differential event rates JCR*ACR, J*A (1/eV/s) Integral event ratesJCR*ACRdW, J*AdW(1/s)
Angular apertures (ster) Total apertures (km2 ster)
Radiation field parametrization • The basic problem of finding the apertures is the calculation of the radiation field with allowance for its absorption and refraction on the rough interface as well as near-field effects. Instead of performing Monte Carlo simulations we used the known parametrization f02500 MHz. The function (f,W) for hadronic showers was found by fitting Monte Carlo results for ice in the form A+B log(W) and scaling from ice to lunar regolith For neutrino-produced showers, W<y>W Transmission coefficient with allowance for wave divergence and lunar surface roughness (Dq from 2 to 5 degree)
CR and NU apertures: SNR=4 Over whole visible surface LORD cosmic rays LORD10 neutrinos
COSMIC RAYS h=1000 km h=1000 km Diameter of parabolic antennas d=10 m Satellite altitude
COSMIC RAYS h=1000 km d=10 m h=1000 km d=10 m
Neutrino h=1000 km h=1000 km
LORD and LORD10 limits on flux 1 year LORD: azimuth=2p Eth=0.01V/m MHz LORD10: Eth=0.07V/m MHz azimuth=0.3 LORD10 Models: TD – topological defects; MPR – Mannheim, Proteroe, Rachen; WB – Waxman, Bahcal; GZK min: NpEp—2, max: NpEp—1
Torus parabolic multibeam antenna Frequency 3.7-4.2 GHz Gain 46 dBi Reflector size 7 m x 12.8m Beamwidth 1 x 2 degrees Arc Coverage 75 degrees Number of feeds 37
CR and NU apertures: SNR=3 Over whole visible area cosmic rays LORD neutrinos
CR and NU apertures: SNR=5 Over whole visible surface cosmic rays LORD neutrinos