The Cosmic Ray Observatories at IGEF-UNAM. José Fco Valdés-Galicia- PI Octavio Musalem Alejandro Hurtado Luis Xavier Gonzalez Jesús Alvarez Bernardo Vargas Ernesto Ortiz Rocío García Marcos Anzorena. Neutron Monitor And Muon Telescope. Monitor Type 6-NM64
The Cosmic Ray Observatories
José Fco Valdés-Galicia- PI
Luis Xavier Gonzalez
Neutron Monitor And Muon Telescope
Monitor Type 6-NM64
Geographic Latitude = 19.33 °
W Longitude = 99.18 °
Altitude (asl) = 2274 m
Cutoff Rigidity = 8.23 GV
AÑO HELIOFÍSICO INTERNACIONAL (Naciones Unidas, 19 de febrero de 2007)
VESO (Instituto de Geofísica UNAM):
RIS Radio Interferómetro Solar (Investigaciones Solares y Planetarias)
MEXART (Mexican Array Radio Telescope)
Radiotelescopio de Centelleo Interplanetario (Física Espacial)
RC Observatorio de Rayos Cósmicos (Investigaciones Solares y Planetarias)
TEO Observatorio Geomagnético de Teoloyucan (Geomagnetismo y Exploración Geofísica)
From September 1, 1989 to December 31, 1996 upon request
EMBEDDED DATA ADQUISITION SYSTEM FOR
COSMIC RAY DETECTION
AMPLIFICATION AND DISCRIMINATION
EMBEDDED DATA ADQUISITION
Upgrading our Neutron Monitor
- Lead rings.
- Moderator material.
- Four high voltage and two low voltage power supplies.
- Miscellaneous components.
We have another station at Sierra Negra Volcano, 4580m asl
SOLAR NEUTRON TELESCOPE
PC are veto for protons
Energy is resolved by
peak signal height
Direction is resolved by
PC in coincidence w/plastic
World Network of Solar Neutron Telescopes
Graphical output of the simulation of a vertical impinging neutron of 500 MeV.
■ n + 12CSci → p+ Triggers four PRCs underneath the Sci (marked in red).
■ Production of low energy γby nuclear reaction inside the Sci
Solar Neutron Event on September 7, 2005
■ A strong solar flare occurred on Sept 7 2005
( X17.0, E= 17x10-1 erg cm2 seg-1).
■ Maximum at 17:40 UT (GOES),
■ Sierra Negra, was a suitable site to observe
solar neutrons 11:36:40 LT,
Solar zenith angle ~0°.
■ Clear excesses were recorded by
solar neutron channels, after the
hard X-ray peak time.
■ The statistical significance of the
a) Simulated solar neutron flux arriving vertically to the telescope
(mid-day incoming flux, zenith angle = 0°).
b) The real proportion of SNT counting rates during the event on Sept 7,
2005 at 17:36:40 UT (11:36:40 LT ~0° of zenith angle).
Sako, et. al., 2006, & Watanabe, et. al., 2007, based on the time evolution profile
observed at Chacaltaya, assuming a power law functional form, calculated the spectral
index α. First using an impulsive injection and then using the 4 MeV gamma ray profile
as injection function.
Sako (2007) used 1 hr (17:30 to 18:30 UT) data from the Sierra Negra SNT, a detector
simulation based on GEANT3, and the atmospheric neutron atenuation calculated
by Shibata (1994) to make an estimate of α.
Spectral index results were:α= 3.1 & 3.2.
Based on GEANT4, the neutron atmospheric atenuation of Dorman & Valdés-Galicia
(1999), and 45 minute data (17:30 to 18:15 UT) from the Sierra Negra SNT,
we recalculated α.
Conclusions for SNT work
■ The angular resolution of our SNT simulation is in very good agreement with real data taken during the event of September 7, 2005, constituting a validation of the simulation code.
■ From the simulation we may conclude that neutrons of ~1 GeV were observed.
■ Protons of at least 10GeV must have been produced. They were not observed as it was an east limb flare.
■ The spectral indexα of the september 7 2005 event is most likely close to 3.
THE FUTURE AT SIERRA NEGRA
PROTOTYPE NEXT WEEK
SSNT, NEXT MARCH IN TONANZINTLA,PUE