Abstract
In measuring the ionization efficiency curve by electron bombardment, mass analyzed ion counts have to be accumulated for successive values with a fixed interval of electron energy. For this purpose, a step voltage source for the electron acceleration was designed and constructed which can syndlronize the advancing of memory channels in a pulse height analyzer. The syncbronization and correspondence of theaccelerating voltages to the PHA channels were kept by generating a series of logic pulses in a time sequence. The pulses were generated and controlled by using a net wrok of about 30 digital IC's and 7 linear IC's. Performance tests have proved that the correspondence between the voltages and the channels is certainly kept and the combination. of the voltage source and the PHA system does work well with good accuracy in wide ranges of step times(0.1-50sec)and step voltages(0.01-0.5eV) .
