0000000000348070
AUTHOR
M.b
Detection potential of the KM3NeT detector for high-energy neutrinos from the Fermi bubbles
A recent analysis of the Fermi Large Area Telescope data provided evidence for a high-intensity emission of high-energy gamma rays with a E-2 spectrum from two large areas, spanning 50 above and below the Galactic centre (the "Fermi bubbles"). A hadronic mechanism was proposed for this gamma-ray emission making the Fermi bubbles promising source candidates of high-energy neutrino emission. In this work Monte Carlo simulations regarding the detectability of high-energy neutrinos from the Fermi bubbles with the future multi-km(3) neutrino telescope KM3NeT in the Mediterranean Sea are presented. Under the hypothesis that the gamma-ray emission is completely due to hadronic processes, the resul…
Quantitative optical analysis of filler dispersion degree in MWCNT-epoxy nanocomposite
Recently developed methodology of quantitative analysis based on optical analysis of filler particles' area distributions is applied now to estimate the dispersion efficiency of multiwall carbon nanotubes in nanocomposite prepared by solution intercalation method. Experimental parameters of dispersing (temperature, duration and power level of ultrasonication) were optimized and the most effective experimental procedure was determined. The methodology of determination of dispersion parameter is proved by indirect method of light transmittance experiments. The nanocomposite specimens having lower dispersion parameter represented the highest transmittance over the nanocomposite specimens. 2011…
Expansion cone for the 3-inch PMTs of the KM3NeT optical modules
[EN] Detection of high-energy neutrinos from distant astrophysical sources will open a new window on the Universe. The detection principle exploits the measurement of Cherenkov light emitted by charged particles resulting from neutrino interactions in the matter containing the telescope. A novel multi-PMT digital optical module (DOM) was developed to contain 31 3-inch photomultiplier tubes (PMTs). In order to maximize the detector sensitivity, each PMT will be surrounded by an expansion cone which collects photons that would otherwise miss the photocathode. Results for various angles of incidence with respect to the PMT surface indicate an increase in collection efficiency by 30% on average…
Fast, high-efficiency Germanium quantum dot photodetectors
We present on high efficiency metal-insulator-semiconductor (MIS) photodetectors based on amorphous germanium quantum dots (QDs) embedded in a SiO2 matrix. High internal quantum efficiencies (IQE) were achieved across a broad wavelength range, with peak value reaching 700% at-10 V applied bias due to high internal photoconductive gain. The transient photoresponse behavior is also studied and it was found that the response time of the photodetector depends on the thickness of the QD layer. We also discuss the conduction mechanism which leads to the high photoconductive gain. © 2012 IEEE.