1,120 research outputs found
YODA++: A proposal for a semi-automatic space mission control
YODA++ is a proposal for a semi-automated data handling and analysis system for the PAMELA space experiment. The core of the routines have been developed to process a stream of raw data downlinked from the Resurs DK1 satellite (housing PAMELA) to the ground station in Moscow. Raw data consist of scientific data and are complemented by housekeeping information. Housekeeping information will be analyzed within a short time from download (1 h) in order to monitor the status of the experiment and to foreseen the mission acquisition planning. A prototype for the data visualization will run on an APACHE TOMCAT web application server, providing an off-line analysis tool using a browser and part of code for the system maintenance. Data retrieving development is in production phase, while a GUI interface for human friendly monitoring is on preliminary phase as well as a JavaServerPages/JavaServerFaces (JSP/JSF) web application facility. On a longer timescale (1â3 h from download) scientific data are analyzed. The data storage core will be a mix of CERNs ROOT files structure and MySQL as a relational database. YODA++ is currently being used in the integration and testing on ground of PAMELA data. 2005 Published by Elsevier Ltd on behalf of COSPAR
The ALTCRISS project on board the International Space Station
The Altcriss project aims to perform a long term survey of the radiation
environment on board the International Space Station. Measurements are being
performed with active and passive devices in different locations and
orientations of the Russian segment of the station. The goal is to perform a
detailed evaluation of the differences in particle fluence and nuclear
composition due to different shielding material and attitude of the station.
The Sileye-3/Alteino detector is used to identify nuclei up to Iron in the
energy range above 60 MeV/n. Several passive dosimeters (TLDs, CR39) are also
placed in the same location of Sileye-3 detector. Polyethylene shielding is
periodically interposed in front of the detectors to evaluate the effectiveness
of shielding on the nuclear component of the cosmic radiation. The project was
submitted to ESA in reply to the AO in the Life and Physical Science of 2004
and data taking began in December 2005. Dosimeters and data cards are rotated
every six months: up to now three launches of dosimeters and data cards have
been performed and have been returned with the end of expedition 12 and 13.Comment: Accepted for publication on Advances in Space Research
http://dx.doi.org/10.1016/j.asr.2007.04.03
Polarization Asymmetry In The Photodisintegration Of The Deuteron
The reaction ÂČ(Îł,p)n has been studied using a monochromatic and polarized gamma ray beam at energies E(Îł)=19.8, 29.0, 38.6, and 60.8 MeV. The beam of an intensity âŒ4Ă10â” Îł/sec was obtained by Compton back scattering of mode-locked laser light off electron bunches in the Adone storage ring. Photoneutron yields were measured at nine neutron angles thetanâ15, 30, 45, 60, 90, 120, 135, 150, and 165 deg in the center of mass (c.m.) for E(Îł)=19.8, 29.0, and 38.6 MeV, and at thetanâ30, 60, 90, 120, and 150 deg c.m. for E(Îł)=60.8 MeV. The polarization independent component Iâ(theta) of the differential cross section and the polarization dependent component PIâ(theta) were deduced and the angular distribution of the azimuthal asymmetry factor ÎŁ(theta)=Iâ(theta)/Iâ(theta) was obtained. An extensive comparison with theory has been carried out and the inclusion of corrections due to meson exchange currents and to Î-isobar configurations have been shown to be mandatory at energies E(Îł)âł40 MeV. Theoretical and experimental implications of intermediate energy deuteron photo- disintegration studies are discussed in some detail
SiPM: Characterizations, modelling and VLSI front-end dedicated development
In this work we describe the results of performance tests and measures of SiPM of several sizes (1Ă1, 3Ă3, 5Ă5) delivered from MEPHI. The SiPMs have been studied both in steady and pulsed stimuli. Aging and temperature behavior
are also discussed. Another test has been performed in order to obtain an electrical model of the SiPM to be used in analog simulations. Finally, a design of a pilot chip with 0.35 ÎŒm technology implementing a front-end for SiPM aimed to TOF applications with adjustable thresholds and very high dynamical range is described
Detection of the high energy component of Jovian electrons in Low Earth Orbit with the PAMELA experiment
The PAMELA experiment is devoted to the study of cosmic rays in Low Earth
Orbit with an apparatus optimized to perform a precise determination of the
galactic antimatter component of c.r. It is constituted by a number of
detectors built around a permanent magnet spectrometer. PAMELA was launched in
space on June 15th 2006 on board the Russian Resurs-DK1 satellite for a mission
duration of three years. The characteristics of the detectors, the long
lifetime and the orbit of the satellite, will allow to address several aspects
of cosmic-ray physics. In this work we discuss the observational capabilities
of PAMELA to detect the electron component above 50 MeV. The magnetic
spectrometer allows a detailed measurement of the energy spectrum of electrons
of galactic and Jovian origin. Long term measurements and correlations with
Earth-Jupiter 13 months synodic period will allow to separate these two
contributions and to measure the primary electron Jovian component, dominant in
the 50-70 MeV energy range. With this technique it will also be possible to
study the contribution to the electron spectrum of Jovian e- reaccelerated up
to 2 GeV at the Solar Wind Termination Shock.Comment: On behalf of PAMELA collaboration. Accepted for publication on
Advances in Space Researc
A calorimeter coupled with a magnetic spectrometer for the detection of primary cosmic antiprotons
A tracking calorimeter made of 3200 brass streamer tubes together with 3200 pick-up strips has been built to complement a magnetic spectrometer in order to detect cosmic antiprotons in space. The characteristics of such a calorimeter, the results of a preliminary test of a prototype as well as the properties of the whole apparatus are presented. The apparatus, designed to operate on a balloon at an altitude of about 40 km, can be considered as a second generation detector, capable in principle to solve the problem of the presence of low energy (â€1 Ge V/c) antiprotons in the cosmic rays which is still open because of the disagreement between the existent experimental data
Inner radiation belt source of helium and heavy hydrogen isotopes
Nuclear interactions between inner zone protons and atoms in the upper atmosphere provide the main source of energetic H and He isotopes nuclei in the radiation belt. This paper reports on the specified calculations of these isotope intensities using various inner zone proton intensity models (AP-8 and SAMPEX/PET PSB97), the atmosphere drift-averaged composition and density model MSIS-90, and cross-sections of the interaction processes from the GNASH nuclear model code. To calculate drift-averaged densities and energy losses of secondaries, the particles were tracked in the geomagnetic field (modelled through IGRF-95) by integrating numerically the equation of the motion. The calculations take into account the kinematics of nuclear interactions along the whole trajectory of trapped proton. The comparison with new data obtained from the experiments on board RESURS-04 and MITA satellites and with data from SAMPEX and CRRES satellites taken during different phases of solar activity shows that the upper atmosphere is a sufficient source for inner zone helium and heavy hydrogen isotopes. The calculation results are energy spectra and angular distributions of light nuclear isotopes in the inner radiation belt that may be used to develop helium inner radiation belt model and to evaluate their contribution to SEU (single event upset) rates
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