I try to detect a flow of positive charged ions. These ions produce an electrical current in the order of 10^-12 Ampers. My question is that, what is the simplest set up for detecting these ions?
Charged particles traveling in vacuum and hitting a metal box, When an ion hits the metal box, its charge is neutralized by an electron jumping from the metal on to the ion . That leaves a space amongst the electrons in the metal, and the electrons in the wire shuffle along to fill it.