Inductively coupled coil

Figure 4 shows schematically the STS Multiplex ICP etching system. The source plasma is generated by an inductively coupled coil supplied by a 1-3 kW 13.56 MHz RF generator. Another 13.56 MHz generator is used to power the platen electrode which allows independent control of the bias potential of the wafer relative to the source plasma. The wafer temperature is maintained at typically less than 80 C through temperature-controlled, pressurized helium supplied to the back of the wafer. Wafers may be either mechanically or electrostatically clamped to the platen electrode. Typical base pressures are in the 10 torr range. The system is equipped with an automatic pressure control valve which can operate in one of two modes. In fixed automatic pressure control (APC) mode, the APC position remains constant, and the chamber pressure is a function of gas flows and RF powers. In automatic APC mode, the APC valve adjusts to maintain the chamber pressure at a constant value. The tool has been developed... 

For transcutaneous neural implants, it is necessary to transfer power and wireless data simultaneously to the implant inside body from the external world. For this purpose, a single-band approach, in which wireless data are modulated on power carrier and sent through an inductive coupling coil, has been applied to most existing neural implants [112-115]. 

Near the outlet from the torch, at the end of the concentric tubes, a radio high-frequency coil produces a rapidly oscillating electromagnetic field in the flowing gas. The applied high-frequency field couples inductively with the electric fields of the electrons and ions in the plasma, hence the name inductively coupled plasma or ICP. 

Recently it has been shown that rotating coiled columns (RCC) can be successfully applied to the dynamic (flow-through) fractionation of HM in soils and sediments [1]. Since the flow rate of the extracting reagents in the RCC equipment is very similar to the sampling rate that is used in the pneumatic nebulization in inductively coupled plasma atomic emission spectrometer (ICP-AES), on-line coupling of these devices without any additional system seems to be possible. 

Inductively coupled plasma Plasmas generated by application of radiofrequency power to a nonresonant inductive coil and maintained by an inductive electromagnetic field. Low-pressure ICP is a high-density plasma source. 

Other configurations that are used include an concentric electrode setup in a tubular reactor, where the discharge still is capacitivily coupled. Also, inductive coupling has been used, with a coil surrounding the tubular reactor [146, 147]. 

Fig. 1. Typical a.c. plasma systems used for hydrogenation of semiconductor samples. A. In this aparatus, hydrogen is pumped through the quartz tube (Q) and a plasma excited by inductive coupling of 13.56 MHz r.f. power with a copper coil (c2). The sample rests on a graphite block (b) that is heated by 440 KHz power coupled by a second coil (cl). A pyrometer (P) measures the sample temperature. B. In this system, a high frequency oscillator is used for plasma excitation while the sample is heated in a tube furnace (Pearton et al., 1987).

The temperature of the inductively coupled plasma varies with the distance from the load coil and according to the setting of the ICP rf power and nebulizer gas flow rate. A typical profile of the plasma gas temperature along the torch axis as a function of distance from the load coil is shown in Figure 2.4. With increasing distance from the load coil and with a reduction of ICP rf power the gas plasma temperature decreases. 

The cross-sectional view of an inductively coupled plasma burner in Figure 21-12 shows two turns of a 27- or 41-MHz induction coil wrapped around the upper opening of the quartz apparatus. High-purity Ar gas is fed through the plasma gas inlet. After a spark from a Tesla coil ionizes Ar, free electrons are accelerated by the radio-frequency field. Electrons collide with atoms and transfer their energy to the entire gas. maintaining a temperature of 6 000 to 10 000 K. The quartz torch is protected from overheating by Ar coolant gas. 

An inductively coupled argon plasma eliminates many common interferences. The plasma is twice as hot as a conventional flame, and the residence time of analyte in the flame is about twice as long. Therefore, atomization is more complete and signal is enhanced. Formation of analyte oxides and hydroxides is negligible. The plasma is remarkably free of background radiation 15-35 mm above the load coil where sample emission is observed. 

In order to elucidate the details of the magnetization distribution in the bulk of the sample, several pick-up coils were used. They were inductively coupled with different parts of the crystal (Fig. 6). 

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