Low Energy Beam Observation

Abstract

My summer research project was to design and test a pico-ammeter to measure the intensity of ion beams in the Low Energy Beam and Ion Trap (LEBIT) Project. The picoammeter was built with the specification to measure currents ranging from 100 fA to 1 nA with good accuracy. To make accurate current measurements of such a low magnitude requires the use of two different circuits. The first being the Integrator circuit which sums the incoming current over a predetermined length of time and outputs a corresponding voltage. The second circuit is an amplifier that increases the magnitude of the voltage coming from the Integrator to a more standardized scale that can be read by the user interface. Specifically, the amplifier maps the current on to a base ten scale. When tested this circuit was able to measure a current as low as 100 femtoampseres with a 2 volt output. .