A circulating charged particle under a magnetic field

[eurekameh]

http://imageshack.us/photo/my-images/543/unledyel.png/

This is a chamber, immersed in a magnetic field, containing circulating electrons shot into a gas. My question is: why is the direction of rotation for the electrons (as shown on the picture) clockwise and not counterclockwise? I am crossing v with B, which is directed outward of the page, and so, Fb is directed toward the center of the circle. However, with the direction of v and Fb known, I would think the electrons circulate counter-clockwise. Why is this not the case?

 

[sandy.bridge]

I applied the RHR and determined that the force on a positive charge is directed outwards from the balloon. Thus, the force reverses and points inwards for a negative charge.

 

[sandy.bridge]

Also, it doesn't look like their rotating about the centre axis clockwise at all. To me, it appears that the velocity vector points in the direction such that the particles go counter clockwise.