Extrude some tubing in a modeler (Silo is my first choice).

     The main extrusion would be the visible "neon".

     Nested just slightly inside would be an IDL emitter extrusion.  Uncheck visible in camera, and text-edit the prop file to set visible in reflection to zero.  This mesh will have intense ambient (7?  70?)

     Make a third extrusion along the same path, but with a diameter about 2.5 times that of the neon.  This third extrusion will be the glow aura, and use the double edge blend method of texturing. 

  

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5