17A-16 Tesla Coil

The tesla coil produces approximately 6 million volt discharges 200 times per second. Each discharge resonates in the radio frequency range somewhere in the region of 80kHz. The discharges emanate from the toroidal top-load and in all directions. However, with the aid of 'break-out' spikes located on the toroid or conductive spike connected to earth, it is to some extent possible to guide the path of the discharges.

This test consists of two activities:

Materials testing: high voltage electrostatic discharges will be directed through materials to simulate the effect of lightning strikes on the surface of Mars.

Electronics testing: computer and electronic equipment will be operated close to the coil to estimate its performance when operated in the vicinity of lightning strikes on the surface of Mars.

The first step is to set up the coil and then tune it until it is delivering stable discharges in an efficient manner.

For each material to be tested, the coil is powered off, the material is attached to the end of the probe, the coil is powered and the probe brought close to the toroid, so that continuous discharges pass through the material.

The assistant will catalogue each material, the duration of the electro-static discharge and any immediately observable changes, e.g. discolouration, combustion, etc. The material samples will be stored for future inspection.

Science background: Dust Devils on Mars produce strong electromagnetic emissions and could lead to arcing on equipment. Dust events on Earth caused by triboelectric charging of saltating and colliding sand and dust particles produce strong electric fields in terrestrial dust events, sometimes in excess of 100 kV/m. However, Martian dust devils can reach up to 7km height with a diameter of several hundreds of meters. The dust devils have up to 70 times the local atmospheric particle density (corresponding to concentrations of more than 10 billion particles per cubic meter). Due to the low atmospheric density, electrical discharge occurs at an electric field gradient between ∼5 and 20 kV/m on Mars, much lower than the ∼3,000kV/m on Earth.

Experimental Results