Some curious tests were made using X-Ray fluoroscopy screens that respond to very short wavelengths of UV... I mentioned in the past how Phantom streams were faintly visible positively and negatively charged streams that form well beyond the typical sparking distance of certain varieties of Pancake Coils, beyond the typical brush discharge. These screens light up slightly brighter than the phantoms, and do allow some of the effects to be photographed. The only drawback of the screens is that the surface charge on them allows the phantoms to more easily be converted into spark discharges, as is evident from some of the photos. But a hint of these unusual discharges is present on the following links. The power supply is a 28 watt 3.5kV 8mA neon with cap adjusted from .010 - .015 mfd. The discharge circuit contains a spark gap adjustable to 1/14400th of an inch increments, and a Pancake coil of 1 1/2 turns 1" wide copper ribbon for the primary and 200 turns of 31 AWG magnet wire in flat spiral form for the secondary, spaced .010" apart and insulated with a paraffin wax and paraffin oil mixture. The discharge ball is 1.5" in diameter and the apparent phantom length extends 10 - 12" or more from the ball depending on the spark gap length. By changing the gap length and charging voltage with the variac the thickness and forked natures of the streams changes in appearance, even with small increments. At certain intervals of adjusting the gap the streams are purely positive, and at other times negative near the brush and positive at the very extents.
Initial Photographs:
http://www.electrotherapymuseum.com/2010/PhantomFluoroscope1/index.htmShowing bombardment of screen at a distance from the discharge post:
http://www.electrotherapymuseum.com/2010/Phantoms2/Phantoms.htmJeff Behary
