GAS CHROMATOGRAPH MASS SPECTROMETER AND REDUCTION METHOD OF BACKGROUND USING IT

摘要

PROBLEM TO BE SOLVED: To provide a gas chromatograph mass spectrometer capable of removing fundamentally He*which is a main cause of a background originated in He. SOLUTION: An electron source 38 for He*ionization is provided between an ionization chamber 32 and QMF 36 disposed in a vacuum chamber 31 of an MS part 30, and He*emitted from the ionization chamber 32 is irradiated with electrons having proper energy, and thereby ionized into He+. Otherwise, a collision chamber is provided between the ionization chamber 32 and the QMF 36, and the collision chamber is filled with N2gas by a gas supply part, and He*emitted from the ionization chamber 32 is interacted with N2in the collision chamber, and thereby changed into He in the ground state. COPYRIGHT: (C)2006,JPO&NCIPI