Ion guides with RF diaphragm stacks
First Claim
1. An ion guide consisting of one or more apertured diaphragm stacks comprising apertured diaphragms arranged with small intermediate spaces and insulated from each other, alternately supplied with two phases of an RF voltage, wherein in at least one of the diaphragm stacks, each diaphragm has an aperture with two parallel sides and two sides formed of opposing hyperbolic indentations extending into the aperture and each diaphragm is rotated 90°
- with respect to adjacent diaphragms so that an RF quadrupole field is created within the at least one diaphragm stack.
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Accused Products
Abstract
The invention relates to RF voltage-operated ion guides based on stacked apertured diaphragms. The invention provides ion guides consisting of diaphragm stacks that permit the ion beam to be shaped in cross-section so that it corresponds to the acceptance profile of the subsequent section of the device, therefore yielding optimal ion transmission. For this purpose, at least some of the diaphragms in the diaphragm stacks do not have circular openings, but instead have openings which shape the cross section of the emerging ion beam in the desired manner. It is possible, for instance, to obtain elliptical beam cross sections, divided beams or beams focused to the shape of a fine thread at the output of the diaphragm stacks.
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Citations
14 Claims
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1. An ion guide consisting of one or more apertured diaphragm stacks comprising apertured diaphragms arranged with small intermediate spaces and insulated from each other, alternately supplied with two phases of an RF voltage, wherein in at least one of the diaphragm stacks, each diaphragm has an aperture with two parallel sides and two sides formed of opposing hyperbolic indentations extending into the aperture and each diaphragm is rotated 90°
- with respect to adjacent diaphragms so that an RF quadrupole field is created within the at least one diaphragm stack.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An ion guide consisting of an apertured diaphragm stack comprising a plurality of apertured diaphragms insulated from each other and alternately supplied with the phases of an RF voltage, wherein each of the plurality of diaphragms has an aperture with three indentations of hexapolar shape extending into the aperture and each diaphragm is rotated 90°
- with respect to adjacent diaphragms, so that an RF hexapole field is created within the apertured diaphragm stack.
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14. An ion guide consisting of an apertured diaphragm stack having an axis and comprised of a plurality of apertured diaphragms insulated from each other and alternately supplied with the phases of an RF voltage, wherein in the direction of the axis, the apertures in the diaphragms differ beginning with a wide opening, changing to an elongated opening, then to an opening having the shape of a peanut shell with indentations and then to two physically separate openings, so that a beam of ions entering the diaphragm stack along the axis is divided into two partial ion beams at the two separate openings.
Specification