A gas laser oscillator having at least three discharge tubes disposed along the optical axis, and a spacer having an opening centered on the optical axis. The initiator is preferably 4-phenyl)-propionic acid N-hydroxysuccinimide ester or 2-bromo, 2-methyl-propionic acid N-hydroxysuccinimide ester. More specifically, each armrest is mounted to a rotary shaft comprising a spring that is used to raise the armrest. A biasing element urges the flow control member to the open or the closed position. A method and apparatus to treat a subterranean formation comprising a wellbore including introducing to a wellbore a tool in a region of low permeability or damage, treating the region of low permeability or damage with a fluid, introducing a diversion agent, and moving the tool to another region wherein the fluid comprises a tracer.