Beam Extraction System

Two electrodes (extraction and focusing) system is used to extract the beam at the right energy then to focus and match it with the beam optic to beam line components up to the analysing magnet or to an intermediate focusing lens. The system is designed in order to optimise the electrical field line as well as the pumping speed and cooling at the extraction region of the source. The working conditions are the following: the source is biased at the required voltage, the puller (extraction electrode) could be biased negatively in order to improve the beam extraction and achieve the required emittance. The intermediate electrode is biased positively. It will focus the beam and match it to the following optical component of the beam line. Each flange is water cooled. The gaps between electrodes are adjustable only when the source is vented.

The assembly is optimized in order to screen the insulators from the beam and secondary electrons. The extraction system includes also the pumping tank for a pumping system trough CF160 flanges. It will also have two CF40 ports for vacuum measurement. The outgoing flange will be CF100. The outlet straight section of the vacuum tank will be surrounded by a lead shield. The extraction system is serviceable by the customer using a special tool for positioning and alignment (provided).