| 摘要 |
PURPOSE:To increase the quantity of ions able to be taken out while bringing an ionization region near to an emission port by arranging disklike permanent magnets in the specific positonal relation, while interposing a filament and a trap electrode on both sides of an ionization chamber, therebetween. CONSTITUTION:A filament 2 and a trap electrode 3 are arranged on both sides of an ionization chamber 1, electron rays 4 are guided into the ionization chamber 1 through a passage port 5 to be trapped by a trap electrode 3 through the passage port 6, and produced sample ions are pushed out toward an emission port 8 by a repeller 7 to be drawn out by a drawer type electrode 9. And disklike magnets 11a and 11b are opposingly arranged outside of the electrode 3 while being shiftedly disposed so that the position l thereof may come on the side of the repeller 7. Accordingly electron rays 4 can be strongly focused near the passage port 5, while an electron ray trajectory inside of the ionization chamber 1 can be made to curve toward the emission port 8 thus making it possible to take out efficiently produced ions outside. |
