we have a lab view program that controls an electron gun (Kimball Physics) placed in a vacuum chamber and reads current from Keithley electrometer based on trigger and without trigger (normal). Electron gun strikes the metal/dielectric sample with stream of electrons as we sweep from electron energy level of 10 eV to 1000 eV in different number of steps and current flows from the sample towards electrometer. We have an external pulse generator that sends same duration pulse (Through Channel A and Channel B) to the electron gun (for pulsing electron gun) and to the electrometer respectively so that both are synchronized, and current is supposed to be read at the electrometer only when the external pulse is ON i.e. electrometer gets triggered. The external pulse is received at the electrometer TLINK connector for triggering it. The Pulse ON duration is 1 second and pulse OFF is 1 second. We keep the time delay between electron energy steps as 1 second so that beam energy changes are also synchronized with electrometer trigger.
For some reason, the data of current read from electrometer is not good. Although electrometer display shows status of Triggering while we run the code but still the data is not good. It seems like Lab View is not able to get current exactly at a time when electrometer triggers and electron GUN is also pulsed ON. I have attached my electrometer code, kindly see where I am doing mistake. I have tried reading data through oscilloscope triggering and it reads voltage but for some reason, electrometer current data is not good. Any help would be highly highly appreciated.
