JP2581695B

• Main Authors: MITAMURA SHIGEHIRO, OKUI YOSHIAKI
• Format: Patent
• Language: English
• Published: 12.02.1997
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To prevent the contamination by the secondary radioactive material generated except from a sample by utilizing a carbon graphite which has a low etching rate and ionization rate to prevent ions from coming into contact with the base and side walls of a vessel. CONSTITUTION:A bottomed cylindrical shielding member 3 formed of the carbon graphite is disposed in the lower part in the vessel. The gaseous argon ions A1, A5 biased from the sample S arrive at the base of the cylindrical shielding member 3 and the gaseous argon ions A2, A4 bounced from the surface of the sample S arrive at the peripheral wall of the cylindrical shielding member 3 and are so shielded as not to come into contact with the wall surface, etc., of the vessel 1. The cylindrical shielding member 3' enclosing ion beams is mounted to the exit port of an ion gun 2 to shield the spacing between the exit port and the side walls of the vessel 1. The evaporation or ionization of the elements except the sample S by receiving etching and the consequent hindrance of the analysis by vapor deposition on the sample S are, therefore, prevented.