A velocity selector is a device used to obtain a beam of charged particles (ions) moving in a straight line path all with the same velocity (speed). The basic essentials of the device are as follows: Charged particles enter the device's opening and encounter mutually perpendicular electric and magnetic fields E and B. Those particles not deflected by the combined fields continue to travel along in a straight line path and pass through the device's exit opening, all of which are now traveling at the same velocity.
- Utilize vector cross-products -
a) With E pointing vertical downward and the particle' s velocity v as shown {for +q ) ... Identify and sketch the above described scenario identifying field lines and forces for B, Fc, and FB.
b) Validate by force equilibrium the speed v of the particles exiting the opening is given by: v = E/B
