ELECTRODE SYSTEM OF LINEAR ION TRAP Russian patent published in 2012 - IPC H01J49/42 

FIELD: physics.

SUBSTANCE: electrode system of a linear ion trap has four electrodes, each pair oppositely located. Plains of symmetry of electrode pairs are perpendicular to each other. The system differs from prototype in that each electrode of at least one pair has in the cross section substantially the shape of an isosceles triangle. The vertex of the triangle is directed towards the longitudinal axis of the trap. The best result is achieved when angle between lateral sides of the triangle is 130°-152°, i.e, the angle between the working surfaces of the electrodes is 130°-152°. The width of the longitudinal slit for ejecting ions in such an electrode is less than 24% of the inscribed radius of the trap. The disclosed electrode system for a linear ion trap enables to achieve high resolution which is comparable with the resolution of ion traps of hyperbolic electrode section, i.e. significantly higher than can be achieved by the prototype ion trap. At the same time the working surface of electrodes in proposed system is composed of flat surfaces, which are placed at an angle whose vertex is directed towards the axis of the ion trap. Manufacturing of such electrodes is much simpler. An angle in the region of the slit of the electrode compensates for local weakening of the field.

EFFECT: higher resolution with simpler design.

3 cl, 7 dwg