At 0.9Ω, a dual, 2mm ID, parallel coil build, using either 29, 30 or 31 gauge Kanthal A1 wire, with a net 10mm leg length will produce a heat flux of 161, 227 and 322 mW/mm2 respectively.
Heat flux is the coil(s) radiant temperature, expressed in milliwatts per millimeter squared. Adjusting...