Don't understand you question.

Do you mean an electrostatic field or the motion of electrons and ions?

 Hi Franz,

Many thanks for your participation. Yes, So we have a plasma source that ejects both ions and electrons which will at a distance away from the source pass through the electrostatic analyzer plates that have either +ve or -ve potential dependent on what you look at. Thus only electron, protons and ions with the right energy will reach the other end of the analyzer.

Would a model of the kinetic energy related to the potential across the radius of the plates be sufficient to describe the trajectory of the particles and resolve them?

Cheers,

Rad

Dear Radhwan,

as I can understand you have two problems together:

a) kinetic energy analysing in spatial relation  to your plates and 

b) amount of particles in spatial relation to your plates with plasma

For a) you need at least two measurements to get the speed of your particles.

the problem of b) is included in a) too. Best way to solve it, is to build an spatial mirror which shows the spatial amounts of charge. 

Hi Franz,

Many thanks for your answer.

I am actually getting the signal of the proton and ions passing through the plates on a fast scope. The signal is being captured using electron multiplier .

The analysis of the signal is what I am concerned about  and resolving the particles ions and protons on a -ve plate bias and electrons plus -ve ions with +ve plate's bias. The velocity of every peak is obtained simply by knowing the distance and time resolved on the scope. 

My question is which would be the best model to describe the trajectory of each particle as I already did that starting with a centripetal force on particles in electric field and naturally using the velocity afterward so you relate this to the velocity and kinetic energy. However, still wonder whether there is any other way in doing this. 

Cheers,

Radhwan

The "centripetal force"  ? Where? Do you use a rotation of your plasma or is it quiet?

What's about optical measurement by video? 

Dear Franz,

You may have missed what I mentioned in my previous explanation. The particles are passing through ESA which is a pair of curved plates each constituting a quarter circle with a voltage applied across(image enclosed). Thus you should start in describing your circular motion in an electric field. 

Cheers,

Rad