Confinement of deuterium ions and electrons with a static electromagnetic field
In a "normal" fusor an electric field heats ions to conditions suitable for nuclear fusion. Because most of the ions fall into the wires of the inner grid (and electrons collide with the wall), these fusors suffer from high conduction losses and do unfortunately not produce net energy. Would it be possible to design a new kind of fusor without this inner grid but that still confines the ions (and electrons) more or less in the centre?
Let's consider the following:
Fig. 1. Design of SEM fusor. (Shem)
It consists of:
When do deuterium D+ ions fuse?
If two D+ ions at the same but opposite speed collide head on, their speed must be at least 6,4E6 m/s in order to come at such a short distance from one each other that the strong nuclear force becomes larger than the repulse Coulomb force. (see temp.- speed calculations )
But because of i.a. tunneling this speed is lower: In euro-fusion.org, in hyperphysics and other sources a temperature of about 450E6 degrees C is mentioned for D-D fusion reaction to occur. This corresponds with a mean speed of about 2E6 m/s .
Confining D+ ions with speeds up to 3E6 m/s
In a field of 1,5 tesla deuterium ions with a speed of 1,4 E7 m/s move in circles with a radius of 0,2 m (see radius D+ ions in a magn. field ). So with this magnetic field it seems to be possible to avoid that the particles escape sidewards.
A positive charged sphere at 151 V and with a radius of 8 cm will stop a D+ particle with a speed of 3E6 m/s and an initial distance of 30 cm from the centre of the sphere. See calculation. So it seems to be possible to confine the fast D+ ions in the vertical directions with a static electric field.
The electrons, by the way, are a lot easier to confine, because of their smaller mass.
We use our simulation program to simulate the SEM fusor design:
D+ ions and electrons are generated, more or less in the centre region with random speeds in all directions up to 3E6 m/s. They interact with the static electromagnetic field and with each other according Coulomb's and Biot-Savart law (non relativistic). Leapfrog integration is used
Fig. 2. Screenshot of a simulation experiment.
This is a cross section in a vertical plane through the centre of the vacuum chamber; the three dimensional positions of the particles are projected in this plane. Old positions become black.
Result: both the deuterium ions and the electrons stay confined (up to speeds < 3,5E6 m/s)