| 摘要 |
PROBLEM TO BE SOLVED: To improve transmission efficiency of ions, reduce the background noise, and improve detectability by arranging a skimmer in an interface part and a mass filter of a mass selection part in such states as being shifted the ares and opposing them to a skimmer outlet side and a mass filter inlet side respectively by a curved ion beam guide. SOLUTION: An octupole 100 of an ion leans part 40 is formed into a curved shape so that its inlet side is approximately opposed to the outlet side of a skimmer cone 34 and its outlet side is approximately opposed to the inlet side of a Q pole 54 of a mass filter. Then, the octupole 100 is wholly bent so as to minimize the curvature. This constitution can suppress the sudden bend of the ion beam in the inlet and the outlet sides of the octupole 100 constituting an ion beam guide, reduce the loss of ions incident on the mass spectrometer part, and improve the SN ratio. The transmission efficiently of the ions can be improved by constituting the ion beam guide of an octupole having 8 electrodes. |
