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Investigation of Geomagnetic field effect on azimuth distribution of EAS events

Khakian Ghomi, M ; Sharif University of Technology | 2007

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  1. Type of Document: Article
  2. Publisher: Universidad Nacional Autonoma de Mexico , 2007
  3. Abstract:
  4. EAS events are developing in the last few 10 kilometers of their path in the atmosphere. But geomagnetic field has been extended until a few thousand kilometers around the Earth. This field deflects charged particles and the deflection is different for different directions and observers. These differences depend on the amount and direction of the geomagnetic field (a dipole inside the earth) and direction of the charged particle. It was accurately investigated for 100 TeV primary particles from H0 = 20, 000 kilometers from the center of the earth (BH = 0.03 * B 0) to the ground and it was observed that the deflection is less than 10-6 degrees in azimuth angle φ. Therefore we investigated the geomagnetic field effect on the secondary particles. We accumulated about 500,000 EAS events by a 4-fold array of water cherenkov detectors with a configuration of 6.08×6.08 m2 square. Distribution of the events shows a slight anisotropy ( 4%). We fitted a double harmonic function on the distribution, it is seen that the first harmonic is more important. Also we separated these data in 12, 5 degree intervals from 0 to 60 degrees. It is seen that: 1- In all of them, total structure is similar. 2- The zeroth harmonic (Constant number) obey well the dN = sin θ(cos θ + 2.4 sin θ) cosn θdθ. 3- The amplitude of the first harmonic is increasing until 35-40 interval and then it decreases. For the investigation of the geomagnetic field on the EAS events we simulated 220,000 events with the magnetic field at Tehran (Bx = 28.1, Bz = 38.4) and 40,000 events without magnetic field (Bx = Bz = 0), from 50 TeV to 5 PeV by CORSIKA code. Then we investigated the simulated events by the approach that there is an anisotropy in North-South direction due to angle between secondary charged particles and geomagnetic field direction (B = B xî + Bzk̂)
  5. Keywords:
  6. Anisotropy ; Charged particles ; Cosmic rays ; Harmonic analysis ; Harmonic functions ; Magnetic fields ; Tellurium compounds ; Azimuth angles ; First harmonic ; Geomagnetic fields ; Primary particles ; Secondary particles ; Simulated events ; Total structures ; Water Cherenkov detectors ; Geomagnetism
  7. Source: 30th International Cosmic Ray Conference, ICRC 2007, Merida, Yucatan, 3 July 2007 through 11 July 2007 ; Volume 4, Issue HE PART 1 , 2007 , Pages 11-14
  8. URL: https://inspirehep.net/literature/1371506