Speaker
Dr
Pierre-Simon Mangeard
(National Astronomical Research Institute of Thailand, Chiang Mai 50200, Thailand)
Description
Neutron monitors (NMs) are large ground-based instruments for precise time tracking of the variations in the Galactic cosmic ray (GCR) flux at GeV-range. NMs are counting the secondary particles (mostly neutrons) issued from the interaction of the cosmic rays in the atmosphere. The sensitivity to GCR variations depends on the geomagnetic cutoff at the location of measurement. Since late 2007, the Princess Sirindhorn Neutron Monitor (PSNM), at the summit of Doi Inthanon, Thailand's highest mountain (2565 m altitude), records the flux of galactic cosmic rays with the world’s highest vertical cutoff rigidity for a fixed station, 16.8 GV. We have developed Monte Carlo simulations of cosmic ray interactions in the atmosphere and in PSNM, and trace cosmic ray trajectories through Earth's magnetic field to model the cosmic ray suppression at low rigidity at the location of PSNM. The simulation shows a fairly good agreement with the data and the variations of the GCR spectrum, such as the solar modulation, can be investigated for the first time with a fixed NM at high rigidity. That expands the range in energy of the worldwide NM network's sensitivity.
Primary author
Dr
Pierre-Simon Mangeard
(National Astronomical Research Institute of Thailand, Chiang Mai 50200, Thailand)
Co-authors
Dr
Alejandro Sáiz
(Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 Thailand)
Prof.
David Ruffolo
(Department of Physics, Faculty of Science, Mahidol University, Bangkok 10400 Thailand)
Dr
Tanin Nutaro
(Department of Physics, Faculty of Science, Ubon Ratchathani University, Warin Chamrap, Ubon Ratchathani 34190, Thailand)
