Spiral coils generate very powerful electromagnetic fields by operating with two different but simultaneous resonant behaviors. Quarter-wave resonance is established by adjusting the frequency (and wavelength) of a radiofrequency (RF) voltage source until the length of the spiral conductor is equal to ¼ of the wavelength of the alternating voltage. This generates an electromagnetic standing wave with at least one peak node and at least one null node. Inductive-capacitive (L/C) resonance is established by optimizing the thickness and width of the wire ribbon used to make the spiral coil. When inductance and capacitance are balanced, the current response will synchronize with the voltage input, creating in-phase behavior, minimal total impedance, and maximal power output. If two such coils are placed near each other, they will create an extremely powerful electromagnetic field between them, which can promote chemical and plasma reactions involving charged particles such as ions or plasma particles, possibly including nuclear fusion reactions.