Abstract: An ion collector includes a Faraday collector having a conductive surface disposed substantially parallel to and spaced from the axis of an entering particle beam containing charged and uncharged particles. A grounded plate disposed in the path of the particle beam allows incoming uncharged particles to impinge thereupon. Preferably, the application of a suitable potential to the conductive plate manipulates incoming charged ions to impinge upon either the electron multiplier or the Faraday collector. The ion collector can further include an electron multiplier used in conjunction with the Faraday collector to allow separate modes of operation. Application of a suitable first potential to the electron multiplier can cause charged particles to be deflected directly to the Faraday collector in one mode, and application of a second potential can cause deflection of charged particles to the electron multiplier, with the effects of the uncharged particles on the output of the detector being minimized.