| 摘要 |
<p>An ion guide comprising: two opposing planar surfaces 2 & 4 of dielectric material; and an electrode arrangement disposed on each planar dielectric surface, each electrode arrangement including at least one, preferably planar, RF electrode 6a-6d, and also a number of planar DC electrodes 12a-12f. At least one of the RF electrodes is arranged to overhang an exposed portion 14 of the dielectric surface on which it is located such that there is no direct line of sight from an ion flow path 10 to said exposed portion 14. This shadowing results in a reduction in the charging-up of exposed dielectric surfaces, while the overall planar construction of the ion guide reduces the amount of collisions between neutral species and electrodes. Preferably, the dielectric surfaces are formed from planar printed circuit boards (PCBs) with the respective electrode arrangements being formed thereon by conventional micro-fabrication techniques.</p> |
