Price: 68.25
Product ID : W200
W200 Silver Ribbon, Thickness (in)=0.005, Width (in)=0.115, Thickness (mm)=0.127, Width (mm)=2.92, (ohms/cm)=0.00043
Description
More details on associated web pages:
Silver Wire and Ribbon - Filament and Heater Material
Silver wire and ribbon has the highest electrical and thermal conductivity of all metals. It is used to make lead wires for some mass spectrometer filaments and heaters.Filament & Heater Material
(Catalog A33)

Finnigan has routinely used 0.020" diameter copper in the past for this purpose.