I magnetic fusion this is achieved by applying magnetic fields. By this the particles are confined better and have more time to get to thermal equilibrium by collisions.

In a simple 0D model the actual question is the energy balance: what power goes into electrons and ions and what losses do they have.

You can also use an anode spot or "fireball" for the creation of high energetic ions, but this will not alter the temperature of the ions from the bulk plasma unless there are many collisions.

As I said in attached paper, it is very difficult to raise conventionally the ion temperature at big plasmas.

You can separate ions from electrons electrostatically and/or using magnetic field as example using a quadrupole, sending plasma jet again a perpenticular magnetic field. Then you can heat using RF, laser or other the ion separted part

I have problems also with light ions and heavy ions used in our plasma thrusters that we are building for the next test campaign of pulsotron device

Data Plasma Temperature and Radiation in Tokamak, ICF, HIF and Pulsotron

I just remembered a second possibility you can heat up the ions by ion cycloctron resonance heating.

Good idea Johannes!, I remembered that the polywell makes a similar system sending away electrons, but still it will be big amount of radiation. I supose that radiation power emitted by ions may be inverse proportional with ion weight with respect the electron, but I do not know Stefan Boltzmann constant for ions. Do you think that Boltzmann law can be rewritten as this?:

P=K2/M*sigma*T^4

Where M is the ion mass in kg and K2 is stefan-boltzmann constant * mass of electron in kg

sigma is plasma emissivity

Hello Javier,

no, actually I don't think that you can use Stefan-Boltzmann in this fashion, because this is the temperature dependent radiation power of a black body per surface area. I don't know how you get the mass factors of ions and electrons in there. This is a bulk property which cannot be easily extrapolated to single particles.

The radiation losses will be due to Bremsstrahlung if you just take the gyrations of the ions into account (as curved motion is accelerated motion). You can, however, rather conviniently calculate the energy losses due to radiation with the formula for synchrotron radiation (which is a special case of Bremsstrahlung) - you can find some information about that on Wikipedia:

http://en.wikipedia.org/wiki/Synchrotron_radiation

Thanks Johannes, Cyclotron radiation is very low if the plasma ions moves well below relativistics speed (a few keV), gamma is about 1, it does not means that elevated by 4th power. I think you should refer to Bremsstrahlung thermal emissions.

I think (I have not data about ion emissions, as usually it is said to be much lower than electron ones) that Bremsstrahlung depend on square of acceleration, that must depends on square of speed. But as example a Deuterium plasma with mass 3600 times higher than the electron the "plasma-with-heated-ion-only" emissions should be 1/3600 of the thermal equilibrium plasmas. If true it is a very good notice for fusion, because Bremsstrahlung seems to depends linearly with energy

Stefan Boltzmann is an experimental equation used for plasma in equilibrium, dominated mainly by electron emission.

What other radiation must us to considerer in ion only heated plasmas?

At the moment I think we have the most important radiation mechanisms for a fusion plasma.

You are right about Stefan-Boltzmann, of course you can apply it for plasma, but you have to take into account the WHOLE plasma, so it does not work for single particles (cyclotron emission or bremsstrahlung does). This is because the temperature goes into this equation and temperature, of course, is a statisical term. Hence you need a large number of particles for that - and, as you mentioned correctly, you need a thermodynamical equilibrium, because only here you can define a temperature in the statistical sense.

You are right, but remember that plasma emitts a lot when heating some electronvolts unless it is at very low pressure ones, I discovered it making tests

It depends on what emission you are referring to - optical emission?

This is clear as you always have a lot of recombination and/or deexcitation which produces photons as the electrons go to an energetically lower state.

I do not know if this helps or not. It as a proposal for soliton catalyzed fusion. I believe that there may already be some research in this area.

Data Soliton Mediated Nuclear Fusion