NEC Faraday cups are designed for accurate measurement of ion beam intensity.
NEC manufactures various types of Faraday cups for a variety of applications involving the monitoring of ion beam currents. Our 3 standard models are:
The configuration of NEC Faraday cups varies from model to model dependent upon power rating and application requirements. However, all NEC Faraday cups are equipped with electron suppression assemblies and can be biased for accurate beam current readings. The suppressor is necessary to return secondary electrons, which affect the beam current readings. The cup is made of tantalum to limit neutron production.
All standard models utilize a molybdenum beam aperture that protects the insertion mechanism and assures proper operation of the suppression assembly.
The position of the Faraday cup is controlled by a pneumatic cylinder, which is actuated by air pressure. The motion is transmitted through a bellows seal to move the Faraday cup to one side of the beam path.
Below is a description of the three standard models. Custom cups based on any of these designs may be available upon request. Please contact NEC for more information.
The above beam power ratings are for a continuous beam with a diameter of 3mm or greater and with appropriate cooling.
A complete Faraday cup system includes a Faraday cup, a controller for actuation, and either a picoammeter or logarithmic amplifier for current reading. NEC offers a local controller and a remote controller, as well as log amps and picoammeters as needed. See the Related Documents below for further information on these accessories.