Search results for " Detectors"
showing 10 items of 2027 documents
Magnus expansion and the two-neutrino oscillations in matter
1990
We show that the Magnus expansion can help to deal with the problem of matter-neutrino oscillations in the nonadiabatic regime of the two-neutrino-flavor case. An analytic result for the electron-neutrino survival probability is derived in a quite simple way without reference to any particular electron density.
Prototype of an angular-selective photoelectron calibration source for the KATRIN experiment
2010
The method of direct neutrino mass determination based on the kinematics of tritium beta decay, which is adopted by the KATRIN experiment, makes use of a large, high-resolution electrostatic spectrometer with magnetic adiabatic collimation. In order to target a sensitivity on the neutrino mass of 0.2 eV/c^2, a detailed understanding of the electromagnetic properties of the electron spectrometer is essential, requiring comprehensive calibration measurements with dedicated electron sources. In this paper we report on a prototype of a photoelectron source providing a narrow energy spread and angular selectivity. Both are key properties for the characterisation of the spectrometer. The angular …
A semiconductor detector telescope electron spectrometer
1971
Abstract A simple d E d x+E type semiconductor detector telescope electron spectrometer featuring high detection efficiency and effective discrimination against γ-rays and heavy particles is described. The line shape of the spectrometer is better than that of a single detector of corresponding size; at 1 MeV, the peak-to-total ratio is approximately 0.8. The device is suited to the study of beta-ray spectra and conversion electron lines at energies above about 0.4 MeV.
Locust: C++ software for simulation of RF detection
2019
The Locust simulation package is a new C++ software tool developed to simulate the measurement of time-varying electromagnetic fields using RF detection techniques. Modularity and flexibility allow for arbitrary input signals, while concurrently supporting tight integration with physics-based simulations as input. External signals driven by the Kassiopeia particle tracking package are discussed, demonstrating conditional feedback between Locust and Kassiopeia during software execution. An application of the simulation to the Project 8 experiment is described. Locust is publicly available at https://github.com/project8/locust_mc.
ALEPH: a Detector for Electron-Positron Annihilations at LEP
1990
Process-centred Software Engineering Environments (PSEE) are the most recent generation of environments supporting software development activities. Most of PSEE are based on mechanisms promoting enforcement and automation of process activities. In this kind of mechanisms the process models are prescribed in a detailed and complete way. But the experience shows that supporting processes is more concerned with the flexibility of guidance offered during the process performance than with enforcement of a collection of predefined process models. In this paper, we present a solution to support strategic processes in a PSEE by providing a flexible guidance during process enactment.
Study of Microcalorimeters for Astrophysics Applications
2008
In the framework of the Italian Space Agency R&D project, which is focused on the development of microcalorimeters for applications on astrophysics, we are studying different methods for TES microcalorimeter production and developing simulations of various absorber performances. In this paper are presented preliminary results obtained with two different geometries: front back and planar on SiN membrane.
Collective flavor transitions of supernova neutrinos
2009
We give a very brief overview of collective effects in neutrino oscillations in core collapse supernovae where refractive effects of neutrinos on themselves can considerably modify flavor oscillations, with possible repercussions for future supernova neutrino detection. We discuss synchronized and bipolar oscillations, the role of energy and angular neutrino modes, as well as three-flavor effects. We close with a short summary and some open questions.
Search for dark matter in the Sun with the ANTARES neutrino telescope in the CMSSM and mUED frameworks
2012
ANTARES is the first neutrino telescope in the sea. It consists of a three-dimensional array of 885 photomultipliers to collect the Cherenkov light induced by relativistic muons produced in CC interactions of high energy neutrinos. One of the main scientific goals of the experiment is the search for dark matter. We present here the analysis of data taken during 2007 and 2008 to look for a WIMP signal in the Sun. WIMPs are one of the most popular scenarios to explain the dark matter content of the Universe. They would accumulate in massive objects like the Sun or the Galactic Center and their self-annihilation would produce (directly or indirectly) high energy neutrinos detectable by neutrin…
Flavor of cosmic neutrinos preserved by ultralight dark matter
2019
Within the standard propagation scenario, the flavor ratios of high-energy cosmic neutrinos at neutrino telescopes are expected to be around the democratic benchmark resulting from hadronic sources, $\left( 1 : 1 : 1 \right)_\oplus$. We show how the coupling of neutrinos to an ultralight dark matter complex scalar field would induce an effective neutrino mass that could lead to adiabatic neutrino propagation. This would result in the preservation at the detector of the production flavor composition of neutrinos at sources. This effect could lead to flavor ratios at detectors well outside the range predicted by the standard scenario of averaged oscillations. We also present an electroweak-in…
Search for neutrino emission from gamma-ray sources with the Antares Telescope
2012
ANTARES is the first undersea neutrino detector ever built and presently the neutrino telescope with the largest effective area operating in the Northern Hemisphere. A three- dimensional array of photomultiplier tubes detects the Cherenkov light induced by the muons produced in the interaction of high energy neutrinos with the matter surrounding the detector. The detection of astronomical neutrino sources is one of the main goals of ANTARES. The search for point-like neutrino sources with the ANTARES telescope is described and the preliminary results obtained with data collected from 2007 to 2010 are shown. No cosmic neutrino source has been observed and neutrino flux upper limits have been…