Efficient generation of extended plasma waveguides with the axicon ignitor-heater scheme

An efficient method for generating extended plasma waveguides is developed by using the axicon lens in conjunction with the ignitor-heater scheme. The short-pulse ignitor generates the seed electrons by multiphoton ionization, and the long-pulse heater expands the plasma by inverse bremsstrahlung heating and builds up the plasma density barrier by collisional ionization. A 1.2-cm-long plasma waveguide is generated in pure Ar gas with a total energy of only 100 mJ. Evolution of the plasma density profile is measured by time-resolved interferometry to show the waveguide forming process and how it can be optimized.