title: Design and characterization of supersonic nozzles for wide focus laser-plasma interactions.
abstract: In this work we optimize the contour of supersonic nozzles to produce long and stable gas jets suitable to be used in loose focus laser-plasma applications. The nozzle design method takes into account the inclusion of a boundary layer that increases the length of the usable gas jet. Two 8 mm supersonic nozzles were characterized, one with a Mach number of 3 and another with a Mach number of 6, using a Mach-Zehnder interferometer performed with a He:Ne 4 cm expanded laser beam. The experimental results confirm that the inclusion of the boundary layer produces an 8 mm constant longitudinal density profile for the nozzle with a Mach number of 6 (NM6) and a 4.5 mm constant longitudinal density profile for the nozzle with a Mach number of 3 (NM3).
authors.affiliation: GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
authors.forename: N
authors.initials: N
authors.lastname: Lemos
authors.forename: N
authors.initials: N
authors.lastname: Lopes
authors.forename: J M
authors.initials: JM
authors.lastname: Dias
authors.forename: F
authors.initials: F
authors.lastname: Viola
mesh_terms: D004867:Equipment Design / Q000379:methods*; D005740:Gases; D006358:Hot Temperature; D007368:Interferometry; D007834:Lasers; D014783:Viscosity
chemical_list: D005740:Gases