SECONDARY ION MASS SPECTROMETER

摘要

PURPOSE:To make it possible to measure secondary ions of positive and nega tive charge concurrently by providing an accelerating power supply positive charge secondary ions and a secondary electron multiplier, and together with an accelerating power supply for negative charge secondary ions and a secon dary electron multiplier. CONSTITUTION:Secondary ions 4 generated by the bombardment of ions 2 from an ion source 1 onto a sample 3 are introduced into an ion resonance field 12 surrounded byfour cylindrical electrodes 6 through a slit 5 and only the ions of the mass conforming to their resonance condition are emitted from a slit 7 by a high frequency electric field. And positive charge ions 33 among these ions are accelerated by a power supply 25 and injected into a secondary electron multiplier 21, and negative charge ions 34 are accelerated by a power supply 26 and injected into a secondary electron multiplier. The outputs from both the secondary electron multipliers are taken out through an amplifier 32 and 33 respectively, and thus a secondary ion mass spectrometer is constituted. Therefore, the positive and negative charge secondary ions can be measured concurrently without necessity of connection change-over.