I am currently working on building an electric field mill. I am in the very early stages of building this and I have little experience on the subject, unfortunately. I understand the basics and came up with a formula to calculate the current with respect to time (this is AC current). Unfortunately, the magnitude of my current output will be at most on the order of a nanoamp. This is too small as the ammeter I have is much less sensitive. As I have read in a few papers, a charge amplifier is necessary. I don't know anything about them and have dozens of questions that I can't find answers to. Perhaps even a few key words would help me in the construction of this, but right now I am stuck. What I really want is a simple way to increase the current of my mill by a constant so that I can still use my setup to find the magnitude of electric fields with it. That's the dream at least. Any help would be appreciated, thank you.