Hybrid generators and methods of using them
Certain embodiments described herein are directed to generators that can be used to sustain a plasma in a driven mode and in an oscillation mode and optionally in a hybrid mode. In some embodiments, the generator is configured to switch between the two modes during operation. In certain instances, the plasma may be ignited when the generator is in a driven mode and may be used to analyze samples when the generator is in an oscillation mode or driven mode or hybrid mode.
1. A generator configured to provide power to sustain an inductively coupled plasma in a torch body in a driven mode and in an oscillation mode, the generator comprising:
a circuit configured to electrically couple to an induction device and provide power to the induction device in the driven mode to sustain the inductively coupled plasma in the torch body in the driven mode and configured to provide power to the induction device in the oscillation mode to sustain the inductively coupled plasma in the torch body in the oscillation mode; and
a processor electrically coupled to the circuit and configured to switch operation of the circuit between the driven mode and the oscillation mode.
2. The generator of claim 1 , in which the circuit comprises a signal source configured to electrically couple to the induction device.
3. The generator of claim 2 , in which the signal source comprises at least one of a RF frequency synthesizer, a voltage controlled oscillator, and a switchable RF signal source.
4. The generator of claim 2 , in which the circuit comprises a feedback device configured to electrically couple to the induction device and be enabled during operation of the induction device in the oscillation mode.
5. The generator of claim 4 , in which the processor is configured to disable the feedback device during operation in the driven mode.
6. The generator of claim 4 , in which the processor is configured to enable the feedback device during operation in the oscillation mode.
7. The generator of claim 6 , in which the processor is configured to disable the signal source during operation in the oscillation mode.
8. The generator of claim 1 , in which the circuit is configured to provide impedance matching within about three RF cycles when operated in the oscillation mode.
9. The generator of claim 1 , in which the circuit is configured to provide a substantially constant frequency and amplitude to the induction device during operation in the driven mode.
10. The generator of claim 1 , in which the circuit is configured to provide a variable frequency and amplitude during operation in the oscillation mode.
11. The generator of claim 1 , in which the circuit comprises a driving circuit electrically coupled to the induction device and an oscillating circuit electrically coupled to the induction device.
12. The generator of claim 11 , further comprising a filter electrically coupled to the oscillating circuit and present between feedback devices of the oscillating circuit and the induction device.
13. The generator of claim 1 , further comprising a detector electrically coupled to the processor and configured to determine when the plasma is ignited.
14. The generator of claim 13 , in which the processor is configured to switch from the driven mode to the oscillation mode at any time after a plasma is detected by the detector.
15. The generator of claim 14 , further comprising a signal converter between the processor and the detector.
16. The generator of claim 1 , in which the circuit comprises at least one transistor configured to electrically couple to the induction device in the driven mode and in the oscillation mode.
17. The generator of claim 1 , in which the circuit comprises at least one transistor configured to electrically couple to the induction device in the driven mode and comprises at least one additional transistor configured to electrically couple to the induction device in the oscillation mode.
18. The generator of claim 17 , in which the processor is configured to disable the at least one transistor during operation in the oscillation mode.
19. The generator of claim 17 , in which the at least one transistor and the at least one additional transistor are both enabled in a hybrid mode.
20. The generator of claim 1 , in which the circuit is configured to electrically couple to an induction device that comprises an induction coil or a plate electrode.