Particle spray produced in Cloud chamber?

Reading an article just now, about the possibility of micro black holes being produced in particle collisions inside the Large Hadron Collider when it is running an experiment. I started thinking about the resultant spray of particles inside a cloud chamber, after a stationary particle has been smashed into by a high speed particle coming into the chamber from outside it.

1. These high speed particles originating from outside the cloud chamber, are they cosmic rays from deep space? or are these high speed particles themselves a result of the cascade effect of a cosmic ray collision in the upper atmosphere?

2. My main question really. Am I right in thinking, that if high speed particle collisions inside the cloud chamber can cause such a spray pattern, in the cloud chamber medium (alchohol I think?) Do these same collisions happen inside our own bodies all the time?