Aluminum is an excellent target material for many reasons – it is reasonably inexpensive, light weight, strong, easy to machine, and also resistant to corrosion. Its high conductivity results in a skin depth only 25% larger than copper. It has a slightly lower temperature-coefficient than copper – 4200 ppm/°C vs. copper’s 4300 ppm/°C.

Anodized finishes, which are typically only a few microns thick, do not affect the performance of aluminum targets as long as the overall thickness of the aluminum is sufficient for the sensor frequency.

Aluminum alloys, such as AL6061, exhibit all of these benefits, but it is recommended to check the conductivity of any selected alloy.