The data acquisition system of the Akeno Giant Air Shower Array (AGASA) is described. The AGASA array covers an area of about 100 km
2 and has been operated since 1990 to study the origin of ...extremely high energy cosmic rays. In the early stage of our experiment, AGASA was divided into four sub-arrays called branches for topographical reasons so that air showers were observed independently at each branch. In December 1995, we have improved the data acquisition system and unified the four branches into a single detection system. By this unification, the effective detection area of the AGASA increases by about 1.7 times in the early stage.
The purpose of The Telescope Array experiment is to identify origin of the ultra high energy cosmic rays. The Telescope Array is a hybrid detector consists of a surface detector array and air ...fluorescence detectors. This hybrid detector is observing extensive air showers to measure the energy spectrum, anisotropy and composition of Ultra High Energy Cosmic Rays. The detector construction has been completed in March 2008, and the hybrid observation with the full configuration has been running since that time. In this talk, the status of observation and our prospects are described.
The Telescope Arrayas Middle Drum fluorescence detector was instrumented with telescopes refurbished from the High Resolution Flyas Eyeas HiRes-1 site. The data observed by Middle Drum in monocular ...mode was analyzed via the HiRes-1 profile-constrained geometry reconstruction technique and utilized the same calibration techniques enabling a direct comparison of the energy spectra and energy scales between the two experiments. The spectrum measured using the Middle Drum telescopes is based on a three-year exposure collected between December 16, 2007 and December 16, 2010. The calculated difference between the spectrum of the Middle Drum observations and the published spectrum obtained by the data collected by the HiRes-1 site allows the HiRes-1 energy scale to be transferred to Middle Drum. The HiRes energy scale is applied to the entire Telescope Array by making a comparison between Middle Drum monocular events and hybrid events that triggered both Middle Drum and the Telescope Arrayas scintillator ground array.
Search for GeV GRBs with the INCA experiment Cabrera, R.; Castellina, A.; Ghia, P. L. ...
Astronomy & astrophysics. Supplement series,
09/1999, Letnik:
138, Številka:
3
Journal Article
Recenzirano
Odprti dostop
INCA is an air shower array located at Mount Chacaltaya in Bolivia, at 5200 m a.s.l., searching for Gamma Ray Bursts of energy $E>1$ GeV. The results presented here concern a GRB search made in ...correlation with 70 events recorded by BATSE since December 1996 to August 1998. For every burst, the INCA counting rate has been studied both during the BATSE detection time and in 2 hours around. No significant excess has been found in any of the trials. Assuming for the burst a power low energy spectrum extending up to 1 TeV with a slope $\alpha = -2$ and a time duration of 10 s, the obtained $1~{\rm GeV}\div 1~{\rm TeV}$ energy fluence upper limits range from $5.3 \ 10^{-5}~{\rm erg}~{\rm cm}^{-2}$ to $2.9 \ 10^{-2}~{\rm erg}~{\rm cm}^{-2}$ depending on the event zenith angle.
A small air-shower array at Mount Chacaltaya Kakimoto, F.; Ogio, S.; Shirasaki, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/1996, Letnik:
373, Številka:
2
Journal Article
Recenzirano
We have operated a small air-shower array at Mount Chacaltaya in Bolivia since September 1987 and have observed air showers with primary energies above 2.0 × 10
13 eV. This array consists of ...thirty-three unshielded scintillation detectors and a shielded scintillation detector. The unshielded detectors are installed over an almost flat field of approximately 8 × 10
3m
2 area, while the shielded detector is located at the array center. In the present paper, we report both the details and the operation of this array and the analysis method for the observed data. Furthermore, we have simulated air showers with a Monte Carlo technique. Then, analyzing these air showers, we examine the performance of our array, that is, the accuracy in determination of the electron sizes and the arrival directions of observed air showers.
We have developed a Monte Carlo program to simulate the extensive air showers (EASs) in short computing time and to study the chemical composition of cosmic rays at the knee region. This code is ...particularly applied to the
C
̌
erenkov experiment that measures the time structure of
C
̌
erenkov light from the EAS. There are many EAS programs available for public use. However, they are not adequate for simulating large number of air shower, since they deal with the very complex interaction algorithm and consume a lot of time. Therefore much faster program should be developed adequately for our purpose. In this report, we discuss the interaction model used in our Monte Carlo code and make a comparison with the accelerator data and the widely used Monte Carlo code, CORSIKA. In addition, we propose a parameterization method that describes the fluctuation of air shower development. Using this method, we can calculate air shower development 10
6 times faster than the CORSIKA simulation code.
Relativistic neutrons were observed by the neutron monitors at Mt. Chacaltaya and Mexico City and by the solar neutron telescopes at Chacaltaya and Mt. Sierra Negra in association with an X17.0 flare ...on 2005 September 7. The neutron signal continued for more than 20min with high statistical significance. Intense emissions of g-rays were also registered by INTEGRAL, and during the decay phase by RHESSI. We analyzed these data using the solar-flare magnetic-loop transport and interaction model of Hua et al. Hua, X.-M., Kozlovsky, B., Lingenfelter, R.E. et al. Angular and energy-dependent neutron emission from solar flare magnetic loops, Astrophys. J. Suppl. Ser. 140, 563-579, 2002, and found that the model could successfully fit the data with intermediate values of loop magnetic convergence and pitch-angle scattering parameters. These results indicate that solar neutrons were produced at the same time as the g-ray line emission and that ions were continuously accelerated at the emission site.
PDF
