Search results for "methods [Diffusion Tensor Imaging]"
showing 10 items of 992 documents
Gas-silicon detector telescope for charged particle spectroscopy
1997
Abstract A gas-silicon detector telescope for charged particle spectroscopy has been constructed and tested. The lower detection limits were determined to be 155 keV for protons, 180 keV for deuterons and 350 keV for alpha particles. Typical energy resolution of the telescope measured for beta-delayed protons is 20 keV. Time resolution for the signals of the telescope was measured to be less than 10 ns. Examples of using the detector telescope in detection of beta-delayed proton activities are presented.
Measurements of the muon component of extensive air showers at 320m.w.e. underground
2003
Abstract The ALEPH detector at LEP has been supplemented with five scintillator telescopes to measure the muon component of cosmic ray air showers underground. The emphasis of the present analysis of a new data set is to measure coincidences over distances up to about 1 km which are sensitive to the forward production of hadronic interactions and the chemical composition of primary cosmic rays in the energy range around 1015 eV. First results indicate that the observed decoherence curve of muons is compatible with a light primary composition and the arrival directions of muons show no obvious clustering in galactic coordinates.
High energy gamma ray counterparts of astrophysical sources of ultra-high energy cosmic rays
2004
If ultra-high energy cosmic rays (UHECRs) are accelerated at astrophysical point sources, the identification of such sources can be achieved if there is some kind of radiation at observable wavelengths that may be associated with the acceleration and/or propagation processes. No radiation of this type has so far been detected or at least no such connection has been claimed. The process of photopion production during the propagation of UHECRs from the sources to the Earth results in the generation of charged and neutral pions. The neutral (charged) pions in turn decay to gamma quanta and electrons that initiate an electromagnetic cascade in the universal photon background. We calculate the f…
Investigation of the elastic and inelastic scattering of He-3 from Be-9 in the energy range 30-60 MeV
2018
We have measured the differential cross-sections for the elastic as well as inelastic scattering populating the 2.43[Formula: see text]MeV [Formula: see text] excited state in [Formula: see text] using [Formula: see text] beams at energies of 30, 40 and 47[Formula: see text]MeV on a [Formula: see text] target. The experimental results for the elastic scattering were analyzed within the framework of the optical model using the Woods–Saxon and double-folding potentials. The theoretical calculations for the concerned excited states were performed using the coupled-channel method. The optimal deformation parameters for the excited states of [Formula: see text] nucleus were extracted.
Rejection Power of A Horizontal Rpc Telescope For Left and Right Coming Cosmic Muons
1993
Abstract The possibility of performing neutrino astronomy by means of a detector above the ground depends critically on the feasibility of a rejection power on the order of 10 11 required to discriminate the enormous background of cosmic downward going muons from the signal of upward going muons produced by neutrinos. In order to check whether and how this rejection is obtainable, we have built in the Physics Department of the University of Bari a horizontal cosmic muon telescope (MINI) instrumented with resistive plate counters. By performing time-of-flight measurements, we have estimated the rejection power of our telescope for left and right coming cosmic muons. The rejection dependence …
THE UFFO SLEWING MIRROR TELESCOPE FOR EARLY OPTICAL OBSERVATION FROM GAMMA RAY BURSTS
2013
While some space born observatories, such as SWIFT and FERMI, have been operating, early observation of optical after grow of GRBs is still remained as an unexplored region. The Ultra-Fast Flash Observatory (UFFO) project is a space observatory for optical follow-ups of GRBs, aiming to explore the first 60 seconds of GRBs optical emission. Using fast moving mirrors to redirect our optical path rather than slewing the entire spacecraft, UFFO is utilized to catch early optical emissions from GRB within 1 sec. We have developed the UFFO Pathfinder Telescope which is going to be on board of the Lomonosov satellite and launched in middle of 2012. We will discuss about scientific potentials of t…
The INTEGRAL experiment
1998
The International Gamma-ray Astrophysics Laboratory (INTEGRAL) is conceived as the next logical step in gamma-ray astronomy after the US Compton Gamma-Ray Observatory (CGRO) and the French/Russian SIGMA mission. The INTEGRAL scientific payload consists of two main instruments (Imager and Spectrometer) and two monitor instruments (X-Ray Monitor and Optical Transient Camera). The INTEGRAL spectrometer "SPI" is optimized for detailed measurements of gamma-ray lines and mapping of diffuse sources. It combines a coded aperture mask with an array of large volume, high-purity germanium detectors. The detectors make precise measurements of the gamma-ray energies over the 20 keV-8 MeV energy range. …
A coded mask for γ-ray astronomy. Design and calibration
2003
Abstract The high-resolution γ-ray spectrometer (SPI) is one of the two main instruments on board the ESA INTEGRAL satellite successfully launched in October 2002. SPI uses coded aperture mask technique in order to have imaging capabilities at the energy band (20 keV–8 MeV) it will study celestial sources. The SPI imaging performance depends critically on the quality of the coded mask response and also on the precise knowledge of such response function. In this paper we present a general description of the SPI Coded Mask design together with its main features. Scientific impact of INTEGRAL SPI Coded Mask design on the instrument capabilities is also discussed. Results obtained for Mask cali…
Low energy collective modes of deformed superfluid nuclei within the finite amplitude method
2013
Background: The major challenge for nuclear theory is to describe and predict global properties and collective modes of atomic nuclei. Of particular interest is the response of the nucleus to a time-dependent external field that impacts the low-energy multipole and beta-decay strength. Purpose: We propose a method to compute low-lying collective modes in deformed nuclei within the finite amplitude method (FAM) based on the quasiparticle random-phase approximation (QRPA). By using the analytic property of the response function, we find the QRPA amplitudes by computing the residua of the FAM amplitudes by means of a contour integration around the QRPA poles in a complex frequency plane. Metho…
APXS and MIMOS IIA: Planetary and terrestrial applications
2011
Both Alpha Particle X-ray Spectrometer (APXS) and the Miniaturized Moessbauer Spectrometer (MIMOS II) have shown their performances in space missions and terrestrial applications. Taking advantage of the challenges of space missions both instruments have become very powerful tools, even small in mass and dimensions.