the part there can also be a gauge to measure the pressure differential between the room and the inside of the chamber the main components inside a sample chamber in accordance with the present invention with the exception of the sample are the translation stages and the chuck the chuck can be a relatively simple vacuum system which can be mounted to the rotary stage and connected to a pump such as a carbon vane pump through a rotary or other appropriate connection the chuck can be smaller than or equal in size to the size of the part if the chuck protrudes past the part a small amount of chuck material may deposit on the edge or surface devices such as rotometers and mass flow controllers can be used to meter gas flow a system can for example use mass flow controllers with piezoelectric transducers to monitor gas flow on all lines except the auxiliary a power source and control panel can be rack mounted this can be a commercial unit useful for low pressure capacitively coupled discharges the rack can also contain the stage controller and the electronics for the mass flow controllers the introduction of reactive gas into the plasma can be controlled by a mass flow controller over a range for example of 2000 ml of cf 4 per minute to 0 05 ml per minute with an accuracy that may be in the range of u2212 2 0 with such a system it may be possible to go from for example 40 l min of cf 4 by using cf 4 in the main body of the plasma to 0 01 ml min using dilution there can be.