An apparatus for processing a substrate is provided. A processing chamber is provided. A substrate support for supporting the substrate is within the processing chamber. A gas inlet provides gas into the processing chamber. An exhaust pressure system exhausts gas around a periphery of the substrate, wherein the periphery around the substrate is divided into at least three parts, wherein the exhaust pressure system controls exhaust pressure to control a velocity of the gas over the substrate, wherein the exhaust pressure system provides at independent exhaust pressure control for each part of the periphery for the at least three parts.

An instrument producing a charged particle beam according to the present invention is provided with: a charged particle source; a plurality of first electrodes disposed along a direction of irradiation of charged particles from the charged particle source; a plurality of insulation members disposed between the first electrodes; and a housing mounted around the plurality of first electrodes. The housing is formed from an insulating solid material, and includes a plurality of second electrodes disposed at positions in proximity to the plurality of first electrodes. At least one of the plurality of second electrodes is electrically connected to at least one of the plurality of first electrodes, each of the plurality of second electrodes having the same potential as the potential of the proximate one of the first electrodes.

An apparatus for thermal ablation testing is provided. The apparatus comprises a chamber; an optically transparent window in the chamber; a sample holder inside the chamber; a test sample in the sample holder; a number of bare-wire thermocouples connected to the test sample, wherein the thermocouples generate temperature data in the form of voltage; a mass balance inside the chamber, wherein the mass balance is configured to hold the sample holder and dynamically detect changes in mass of the test sample; an external radiant heat source configured to heat the test sample through the window; a plasma source configured to generate a number of atomic species in the chamber; and a pyrometer directed at the test sample.