Plasma 2

October 29, 2018 at 12:42 am

The Fusor has produced a few more plasmas.  See below video.


Plasma_run from Tom McCarthy on Vimeo.


What you’re seeing is a plasma inside the vacuum chamber.  The wires are the tungsten grid that’s connected to the high voltage supply.  Chamber at ~10 microns and begins at ~6 kV, 20 mA.


The colour of the plasma gives an idea of its elemental composition.  As it transitions from blue/grey to pink-red the concentration of deuterium in the chamber is increasing.  The high pitched whine that begins during the video is the turbopump starting up, which begins to further reduce the chamber pressure.  Air is removed and the small deuterium inflow causing the deuterium concentration to increase.  However, current or electron flow is required to sustain a plasma, and my HV power supply is limited in the voltage and current it can provide.  As the pressure drops, the power supply is maxed out and the plasma is extinguished.


I’ve found it difficult to stabilise a deuterium plasma.  Running an air plasma is easy, just turn on the roughing pump and power supply and it appears.  An air plasma is what’s seen at the start of the video.  Deuterium plasma (for fusion) requires higher voltages and lower pressures, which involves a lot of tweaking and finetuning.  I would be very surprised if fusion was not happening in the video above, but had no neutron detector set up at the time to prove this.


For now, I have to try and keep fiddling with the vacuum, electronics and gas systems until I can get some sort of stable operation/fusion.  The problems: 1. Can’t throttle turbopump finely enough, throttle valve too coarse.  2. Deuterium flow too low, too much constriction in the line (secondary to throttle problem) 3.  Neutron detector, He-3 tube not calibrated.