Our Research

Cosmic rays are energetic particles (including electrons, protons, and heavier elements) produced in the galaxy by processes that are not fully understood. The propagation of these particles is influenced by magnetic fields in the solar wind and in the magnetosphere of the Earth.

Charged particles can be accelerated by magnetic forces on the sun to energies much greater than those from individual fusion reactions. Some of these particles interact with the Earth’s atmosphere creating a cascade of secondary particles, including neutrons, that make their way to the Earth’s surface. Neutron monitors are passive counters. Neutrons interact with a gas, either helium-3 (3He) or boron-trifloride (10BF3), inside a pressurized tube. The subsequent radioactive decay produces an alpha particle and the partner ionized nucleus. Cartoon shows the enriched boron reaction which produces a lithium ion. The ion and alpha particles are accelerated high potential difference maintained between an isolated central wire and the outer conducting surface of the tube. The resulting cascade produces a measurable pulse that is counted. These counts allow us to determine the flux of cosmic rays interacting with the earth’s atmosphere.

 

Picture illustrates the three-tube neutron monitors placing on the platform at the South Pole. Our collaborators (in red cloth) from University of Wisconsin-River  Falls stood nearby the platform .  Besides the neutron monitor, there are 12 tubes of bare neutron monitor.  The configurations are simply a neutron monitor tube without  the lead producer  or outer reflector in the standard  NM64 configuration.

Text Box: Latitude Survey 
Text Box: South Pole Neutron Monitor