Signal processing techniques in electron-atom collision studies

The signal processing devices can be configured to serve a wide range of applications in counting, time spectroscopy, energy spectroscopy, and coincidence measurements. Therefore, the optimization of signal processing units for different experimental studies is very important. Electron multiplier detectors such as channeltron (channel electron multiplier) and micro-channel plates have commonly used in atomic collision experiments. The requirement for low noise and stable sensitivity with these detectors is met by using a charge-sensitive pre-amplifier. The amplifier is one of the most important components in a pulse processing system for applications in counting, timing, or pulse amplitude (energy) spectroscopy. On the other hand, in counting applications, the analog input pulses that cross the discriminator threshold are converted to standard logic pulses at the output of the timing discriminator. These logic pulses can be counted in a counter/timer or in a multichannel scaler. When a timing application demands picosecond precision, a time-to-amplitude converter is a prime device. Time-to-amplitude converter can be used to identify coincident events between two detectors. The result is a rectangular output pulse with a width of a few microseconds and an amplitude that is proportional to the time interval between the start and stop pulses. This pulse is fed to an analog-to-digital converter or a multichannel analyser for pulse-height measurement. The characteristics and general operating principles of all these signal units have been explained in this thesis.