Ignition characteristics of methane/air premixed mixture by microwave-enhanced laser-induced breakdown plasma.

A microwave-enhanced plasma generation technique was combined with laser-induced ignition to improve ignition characteristics. A locally intensified microwave field was formed near the laser-induced breakdown plasma. As the plasma absorbed the microwaves, the plasma emission intensity increased. The plasma lifetime could be controlled by changing the microwave oscillation duration. Furthermore, the microwave-enhanced laser-induced breakdown plasma improved the minimum ignition energy of the methane/air pre-mixture with just a small amount of absorbed microwave energy.