Modern Status LUNAR ОRBITAL RADIO DETEKTOR V. A. Chechin, G.A. Gusev, B. N. Lomonosov, K. M. Pichkhadze, N.G. Poluhina, V. A. Ryabov, V. K. Sysoev, V. A. Tsarev e-mail gusev@sci.lebedev.ru ARENA 2008 JUNE 25-27, G.Gusev Russia: LPI, Lavochkin association
Method: detection of radio emission; the Moon as a target Scientific problems: The prime goal: detection of UHECR & UHEN with energy E > 1020 eV Additional goals: study of the Moon and its vicinity (EM environment, plasma, lunar seismic activity, etc.) Method: detection of radio emission; the Moon as a target Realization: within the LUNA-GLOB mission Collaboration: LPI, Lavochkin Association, MSU; Expected results : measurements of the CR flux near and above the GZK cut-off, detection of ultra-high energy neutrinos. ARENA 2008 JUNE 25-27, G.Gusev
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Optimization of the concept and configuration of the experiment Theoretical calculations and simulation of the generation and registration of radio emission in the different media Optimization of the concept and configuration of the experiment Simulation of the experiment (taking into account the scattering and reflection of the signal due to subregolith layer) Adjusting to the space platform, ballistics etc. Expected by-product results (lunar seismic activity, impacts of meteorites) ARENA 2008 JUNE 25-27, G.Gusev
The Moon as a target Rmoon = 1740 km Regolith: density 1.7 g / cm3 depth 1÷12 m, dielectric permitivity ε≈3 attenuation length ~ 15 m/ f (GHz); effective volume for Veff ~ 2105 (km.w.e.)3; neutrino detection Average surface temperature: from 107 C to -153 C ARENA 2008 JUNE 25-27, G.Gusev
CONCEPTUAL MODELING of the EXPERIMENT ARENA 2008 JUNE 25-27, G.Gusev
0.4·106 km2sr Full aperture, km2·sr Energy eV Full aperture for UHECR events 0.4·106 km2sr Full aperture, km2·sr Energy eV ARENA 2008 JUNE 25-27, G.Gusev
LORD limits on flux 1 year Eth = 0.01V/m MHz; f = 0.5; GHz 18/06/08
CONCEPTUAL DESIGN OF THE RADIO DETECTOR ARENA 2008 JUNE 25-27, G.Gusev
ARENA 2008 JUNE 25-27, G.Gusev
Monte Carlo Modeling of the Experiment Simulation of the event (Cherenkov emission) registration in t-representation taking into account models of antenna system (diagram, polarization), noises (thermal and galactic), digital system parameters ARENA 2008 JUNE 25-27, G.Gusev
Number of simulations) Experimental parameters Determination of threshold tension and transfer function Start of selection cycle Selection of event candidates with condition Addition of the signal with noise Number of simulations) Selection of events with trigger Primary parameters Candidates? no Useful event Forming of array of primary parameters with dimension [1 x NI] Secondary parameters With dimension [1 х Nin]: Digitizing of signals Forming of array of secondary parameters with dimension[1 x NI]: End of selection? no Algorithm ARENA 2008 JUNE 25-27, G.Gusev Exit
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Model study of the basic characteristics of the LORD experiment. f, MHz f, МHz Distribution in signal duration t, ns t, ns ARENA 2008 JUNE 25-27, G.Gusev
ARENA 2008 JUNE 25-27, G.Gusev
ARENA 2008 JUNE 25-27, G.Gusev
Taking into account the subregolith layer Retarded reflected signal vacuum Retarded reflected signal T = 2hcosθn/c Direct signal 1 CR 2 3 regolith ν h h θ ε≈3 ε≈6÷8 subregolith ARENA 2008 JUNE 25-27, G.Gusev
reflected direct The first example of the statistics for direct(blue) and reflected(red) signals (CR cascade) for the regolith depth is 1 m (without scattering on two interfaces) ARENA 2008 JUNE 25-27, G.Gusev
reflected direct Second example of the statistics for direct and reflected signals. Regolith depth is 10 m. For this regolith depth the statistics for reflected signal is two times smaller. ARENA 2008 JUNE 25-27, G.Gusev
A2 B2 direct reflected A1 B1 Registration of a signal in t-representation by 4 antennas with two orthogonal polarizations. ARENA 2008 JUNE 25-27, G.Gusev
Amplitude, μV Amplitude of the direct and reflected signals as a function of cascade energy. ARENA 2008 JUNE 25-27, G.Gusev
Currently a new platform is under construction. Universal platform for small-sized space vehicles LAVOCHKIN ASSOCIATION Currently a new platform is under construction. ARENA 2008 JUNE 25-27, G.Gusev
CONCLUSIONS 1. For CR spectrum E-3 statistics per year in the LORD experiment : for CR – one hundred events; for GZK neutrino (maximum flux model) – several units events. 2. Conception of radio detector (first generation) is developed and optimized. 3. There are principle possibilities for selection of the events from the radio pulse background and separation between CR and neutrino cascades. 4.The LORD experiment is included in LUNA-GLOB mission, to be launched at about 2012 year. ARENA 2008 JUNE 25-27, G.Gusev
THE END THANK YOU ARENA 2008 JUNE 25-27, G.Gusev
Some examples of lunar relief (from Apollo mission ) STUDY of the INFLUENCE of the MOON SURFACE RELIEF and FINITE DEPTH of the REGOLITH on DETECTION of RADIO EMISSION Some examples of lunar relief (from Apollo mission ) On the left photo one can see relatively flattish lunar surface and hills, for which the diffusion by small irregularities is not strong . On the other hand on the right photo one sees irregular stone big enough to destroy significantly mirror component of radio emission from cascade. ARENA 2008 JUNE 25-27, G.Gusev
1. In the case of small diffusion, duration of the signal is virtually the same as for ideally flat plane surface, amplitude decrease does not exceed 10%. 2. In the case of strong diffusion incident from below beam transforms into many quasi-mirror ray beams and diffusion component. Although the diffusion diminishes the signal amplitude (increasing threshold), but it increases angular aperture so that positive integral effect in statistics may be more, due to relatively small angular aperture and small penetration coefficient from regolith to vacuum for Cherenkov mechanism used in simulations. 3. We must take into account that in the case of more large angular aperture we have more large registration surface and more favourable conditions for the concordance with LORD antenna (effective distance, diagram and polarization). Also the scattering diminishes from below the range of registering primary particle energy, consequently the imprecision of energy measurements also diminishes. ARENA 2008 JUNE 25-27, G.Gusev
Lebedev short message on physics #10, 1984, p. 41. The schema of phase interferometer for EAS registration with effective area 1000 km^2. It consists of 5 transmitters and 20 receivers. For CR with spectrum E^-3 statistics per year about 1 event for energies E>5·10^20 eV Lebedev short message on physics #10, 1984, p. 41. 18/06/08
Background Processes for Radio Antarctic Muon and Neutrino Detector (RAMAND) A.F. Bogomolov, V.V. Bogorodsky, et al. Proc. 20 ICRC, v. 6, p.472 The curve 1 corresponds to radio pulse background spectrum at the Russian Vostok station, the curve 2 – at the Mirnii station (20 km from the cost) during good whether, the curve 3 – at the Mirnii during storm (23 m/sec). Here the σ is thermal noise rms for temperature about 3000ºC. 18/06/08