METHOD FOR SUPPLYING A PLURALITY OF REACTIVE PROCESS GASES TO A PROCESS LOCATION OF A PARTICLE BEAM SYSTEM

A system for supplying a process gas to a processing location 7 of a particle beam system 1 comprises a gas reservoir 63; a gas conduit 65; a pipe 69 located close to the processing location; a valve 67 provided between the gas conduit and the pipe; and a controller 71 configured to open and to close the valve to switch the system from a first mode of operation in which process gas is not supplied to the processing location to a second mode of operation in which process gas is supplied to the processing location. The controller can alternately open and close the valve in cycles, wherein each cycle includes a first duration in which the valve is open and a second duration in which the valve is closed, wherein a ratio between the first duration and the second duration can be changed.