Question

Describe what happens to molecular oxygen in the upper atmosphere when exposed to radiation at λ = 1030 – 1070 Å and radiation at λ = 1027 Å.  Description should include name of the process occurring and the type products (to include charge).

Answer 1

When a primary cosmic ray enters the atmosphere a cascade of elementary particles are produced
The cascade begins when the primary core collides with an atmospheric core (molecular oxygen) producing a nuclear reaction in which part of the energy is transformed into matter, creating new particles, especially pions.

The incident nucleus or the fragments resulting after this collision still traveling fast towards the ground again until another nuclear reaction takes place in more particles and so on occur. Sometimes some nuclear fragments reach the earth's surface. Pio neutral pions created disintegrate almost instantaneously, becoming two gamma rays. The charged pions pi + pi- can collide with other atmospheric core producing new particles or disintegrate into a muon and a neutrino. The muon has a half life of 2 millionths of a second (2 micros) after which disintegrates becoming an electron and two neutrinos. As the life of the muon so short you might think that none can live at ground level. However, due to its high speed (very close to that of light) are affected by relativistic time dilation and our reference system half-life is much higher. In fact, in almost all cascades initiated by cosmic rays, an important part of muons manage to reach the earth's surface. They are so pervasive that many of them reach depths of hundreds of meters underground, but, being charged particles leave a trail of ionization easily detectable. For this reason were the first detected secondary particles. On the other hand, neutrinos are created in the decay of pions and muons, despite being very numerous, they have a chance of interaction with matter extremely small so that went unnoticed in the pioneering experiments. Their penetration power is so great that can pass completely through the Earth.