The high temperature gas reaction cell allows sample modification under high temperature and high pressure conditions.  The reaction cell is a small volume, quartz chamber with facility for gas introduction, purging and evacuation.  Maximum operating temperature is 1000  ͦ C.  Maximum operating pressure is 30 bar.  The accessory has integrated sample and gas handling allowing transfer under UHV conditions directly to the sample analysis chamber or via the surface science station, depending on which chamber the reaction cell has been mounted.