Browsing by Autor "Jose A. Bellido"

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DIFFERENTIAL SPECTRUM OF NEUTRONS AT CHACALTAYA-BOLIVIA
(American Institute of Physics, 2009) R. Mayta; Alessandro Zanini; R. Ticona; A. Velarde; C. J. Solano Salinas; Jose A. Bellido; David Wahl; Óscar Saavedra
We describe the Neutron Spectrometer Experiment installed at Chacaltaya Cosmic Rays Observatory (68° O, 16.2° S), located in Bolivia, at 5230 m.a.s.l. This experimental system is constituted by passive detectors which register the flux of neutrons, in an energy range of 10 KeV–20 MeV. Using the unfolding code BUNTO a peak around 1 MeV of the characteristic spectrum of neutrons was obtained. Experimental values, observed during April of 2008, are compared with similar ones carried out in 1997 at the same place, in order to look for eventual changes due to local atmosphere. A similar experiment was also carried up at the Laboratory of Testa Grigia‐Italy (45.56° N, 7.42° E,. 3480 m.a.l.s). Data of both stations allow us to compare the spectra in order to explain the difference of neutron flux of these two stations.
Simultaneous Observation of Solar Neutrons and Effects on Terrestrial Magnetic Field in Association with a Solar Flare
(American Institute of Physics, 2009) Wara Chamani; Rolando Ticona; Edgar Ricaldi; C. J. Solano Salinas; Jose A. Bellido; David Wahl; Óscar Saavedra
On November 2, 2003 at 17:03:00 UT a solar flare, registered by the GOES satellite, was also recorded by the Neutron Monitor (NM64) of Cosmic Ray Laboratory at Mount Chacaltaya. This flare affected the local geomagnetic field (F): there were variations in the intensity of the horizontal component (H), declination component (D) and vertical component (Z). Variations on these components, estimated as 71 nT, 10 deg. and 19 nT, respectively, have been observed with the Patacamaya’s Geomagnetic Observatory; as well as a net increased field (F), estimated as 66 nT, recorded by the Villa Remedios Geomagnetic Observatory. The duration of the magnetic and neutron signals was approximately 40 and 54 minutes, respectively, which shows that the flare was intense and with large emission of neutrons.
the Large Aperture GRB Observatory
(American Institute of Physics, 2009) X. Bertou; C. J. Solano Salinas; Jose A. Bellido; David Wahl; Óscar Saavedra
The Large Aperture GRB Observatory (LAGO) is aiming at the detection of the high energy (around 100 GeV) component of Gamma Ray Bursts, using the single particle technique in arrays of Water Cherenkov Detectors (WCD) in high mountain sites (Chacaltaya, Bolivia, 5300 m a.s.l., Pico Espejo, Venezuela, 4750 m a.s.l., Sierra Negra, Mexico, 4650 m a.s.l). WCD at high altitude offer a unique possibility of detecting low gamma fluxes in the 10 GeV -1 TeV range. The status of the Observatory and data collected from 2007 to date will be presented.