| 摘要 |
<p>The invention relates to the combination of at least two multi-pole radio-frequency (RF) fields of different order defined by at least two multi-pole ion guides sharing a common axis. The hybrid device utilizes a higher order multi-pole field at the entrance of the device, the order determined by the number of poles, and transports ions into at least a second multi-pole field of lower order. The higher order multi-pole exhibits a wide phase space area acceptance at the entrance of the ion guide, which is particularly useful for ions having a broad kinetic energy and spatial spread, while each consecutive multi-pole field of progressively lower order exhibits enhanced focusing and produces a highly collimated ion beam at the exit of the device. The device can be operated over a wide range of pressures extending from 10 mbar to 10 -5 mbar. The hybrid ion guide can be operated in a continuous mode by applying RF voltages to generate mulitpole fields and DC gradients along the axis (cooling mode) or by superimposing periodic pulses for trapping and releasing ions regions of different field-order (bunching mode). The device can be used further as a collision cell in either mode or can be coupled to orthogonal TOF mass analyzers to enhance duty cycle.</p> |
