34 research outputs found
Optimized Trigger for Ultra-High-Energy Cosmic-Ray and Neutrino Observations with the Low Frequency Radio Array
When an ultra-high energy neutrino or cosmic ray strikes the Lunar surface a
radio-frequency pulse is emitted. We plan to use the LOFAR radio telescope to
detect these pulses. In this work we propose an efficient trigger
implementation for LOFAR optimized for the observation of short radio pulses.Comment: Submitted to Nuclear Instruments and Methods in Physics Research
Section
Free Energies and fluctuations for the unitary Brownian motion
We show that the Laplace transforms of traces of words in independent unitary Brownian motions converge towards an analytic function on a non trivial disc. These results allow one to study the asymptotic behavior of Wilson loops under the unitary Yang--Mills measure on the plane with a potential. The limiting objects obtained are shown to be characterized by equations analogue to Schwinger--Dyson's ones, named here after Makeenko and Migdal
Damage Spreading in Asymmetric Ising Spin Glasses
Spin glasses in dimensions 2, 3, 4 and mean field are studied numerically as a function of the
degree of asymmetry of the interactions between spins. Damage spreading data are used to assess the
effects on the spin glass ordering of introducing asymmetry in the couplings. In all dimensions the
critical temperature for damage spreading is rather insensitive to the asymmetry, but the spin glass
ordering is strongly suppressed by any finite degree of asymmetry. We discuss the physical
significance of the damage spreading parameter
Numerical methodology for proton exchange membrane fuel cell simulation using computational fluid dynamics technique
The mid-infrared channel of the EChO mission
International audienceThe Exoplanet Characterisation Observatory, EChO, is a dedicated space mission to investigate the physics and chemistry of Exoplanet atmospheres. Using the differential spectroscopy by transit method, it will provide simultaneously a complete spectrum in a wide wavelength range between 0.4mum and 16mum of the atmosphere of exoplanets. It has been selected by ESA in its M3 Cosmic Vision program for a phase A study. The payload is subdivided into 6 channels. The mid-infrared channel covers the spectral range between 5mum and 11mum. In order to optimize the instrument response and the science objectives, the bandpass is split in two using an internal dichroic. We present the opto-mechanical concept of the MWIR channel and the on-going detector development that drives the thermal and mechanical designs of the channel. The estimated end-to-end performance will also be presented
The mid-infrared channel of the EChO mission
International audienceThe Exoplanet Characterisation Observatory, EChO, is a dedicated space mission to investigate the physics and chemistry of Exoplanet atmospheres. Using the differential spectroscopy by transit method, it will provide simultaneously a complete spectrum in a wide wavelength range between 0.4mum and 16mum of the atmosphere of exoplanets. It has been selected by ESA in its M3 Cosmic Vision program for a phase A study. The payload is subdivided into 6 channels. The mid-infrared channel covers the spectral range between 5mum and 11mum. In order to optimize the instrument response and the science objectives, the bandpass is split in two using an internal dichroic. We present the opto-mechanical concept of the MWIR channel and the on-going detector development that drives the thermal and mechanical designs of the channel. The estimated end-to-end performance will also be presented
Laser-induced breakdown spectroscopy acoustic testing of the Mars 2020 microphone
The SuperCam instrument suite onboard the Mars 2020 rover will include the Mars Microphone, an experiment designed to record the sounds of the SuperCam laser strikes on rocks and also aeolian noise. In order to record shock waves produced by the laser blasts, the Mars Microphone must be able to record audio signals from 100âŻHz to 10âŻkHz on the surface of Mars, with a sensitivity sufficient to monitor a laser impact at distances up to 4âŻm. The Aarhus planetary simulator facility has been used to test the Mars 2020 rover microphone in a controlled Martian environment. The end-to-end tests performed in a 6âŻmbar CO2 atmosphere, with wind, and also with the microphone at â80°âŻC have demonstrated that the SuperCam/Mars Microphone requirements are satisfied. Tests were also performed on Martian soil simulant targets showing that the variation of the acoustic energy of the shock wave depends on the level of compaction of the target
The mid-infrared channel of the EChO mission
International audienceThe Exoplanet Characterisation Observatory, EChO, is a dedicated space mission to investigate the physics and chemistry of Exoplanet atmospheres. Using the differential spectroscopy by transit method, it will provide simultaneously a complete spectrum in a wide wavelength range between 0.4mum and 16mum of the atmosphere of exoplanets. It has been selected by ESA in its M3 Cosmic Vision program for a phase A study. The payload is subdivided into 6 channels. The mid-infrared channel covers the spectral range between 5mum and 11mum. In order to optimize the instrument response and the science objectives, the bandpass is split in two using an internal dichroic. We present the opto-mechanical concept of the MWIR channel and the on-going detector development that drives the thermal and mechanical designs of the channel. The estimated end-to-end performance will also be presented