Patent Number: 062427474
Section: abstract

A method and apparatus is provided for controlling the operational parameters of a radio frequency (RF) linear accelerator (linac) (23) in an ion implanter (1). An operator or a higher level computer enters into an input device (10) the desired type of ions, the ionic valence value of ions, the extraction voltage of ion source (21), and the final energy value that is needed. Using internally stored numeric value calculation codes in parameter storage device (18), a control calculation device (11) simulates the ion beam acceleration or deceleration, and the anticipated dispersion of the ion beam, and calculates the RF linac operational parameters of amplitude, frequency and phase for obtaining an optimum transport efficiency. The parameter related to the amplitude is sent from control calculation device (11) to amplitude control device (12) which adjusts the amplitude of the output of RF power supply (15). The parameter related to the phase is sent to phase control device (13), which adjusts the phase of the output of RF power supply (15). The parameter related to the frequency is sent to frequency control device (14). Frequency control device (14) controls the output frequency of RF power supply (15) while it also controls the resonance frequency of RF resonator (23-1) of RF linac (23).