Does air pressure affect the range of alpha particles in air?

[regisz90]

Homework Statement

We have an alpha particle moving in the air (p=10^5 Pa). Its range is "d". What would be the range if the pressure was q=10 Pa only.

Homework Equations

x=d*(p/q) ?

The Attempt at a Solution

I think the particle is slowed down the more the more is the number of molecules in the air. And the number of molecules is proportional to the pressures (from the ideal gas law). It seems to be too easy that the range will be incresed by the quotient of the pressures.

 

[TSny]

I think it is that simple. For example, see equations (25) and (27) in this document:
http://www2.physics.ox.ac.uk/sites/default/files/Passage.pdf where n is the number of (air) molecules per unit volume.