OK makes sense, so we are really operating as if we have no core at all with regards to field calculations.
Above Curie temperature - yes.
Below Curie temperature (e.g. 500C) some H field will still be needed to reach saturation, but less than for a cold iron (the H field is made by the DC coil and is expressed in ampturns/meter where the "meter" refers to the length of the magnetic circuit (rod + U).
So at the curie point we have fuel that is saturated and no longer is effected by skin depth, as you stated earlier.
Oh, it is still affected but much much less. Compare, the 50% attenuation skin depth of:
a) cold unsaturated iron at 1MHz is 1.56µm
b) cold saturated iron at 1MHz is 110µm
c) hot 770C iron at 1MHz is 340µm (at 100kHz is 1080µm)
But that is for iron conducting electric current, not magnetic flux, so it is not applicable.
Of course alternating magnetic flux in any conductor will induce electric eddy currents, but the attenuation of AC magnetic flux is very different from the attenuation of AC electric current.
Now the problem with the NMR bias field being part of the heater is that it will get cycled on and off, or pwm controlled if we went complicated.
Yes, that's why pure DC should be used.
I am thinking it maybe better to run an ON/OFF heating control cycle and just run the MHz drive signal when the heater is off and use a separate coil for the bias field,
A separate heating and bias coil can be used if the heating coils is wound in bucking bifilar mode so it does not contribute to the DC bias.
my reasoning on this is we don't need a strong bias field now (or do we still for Lorentz orbit ) and that will lower the NMR frequency,
Yes, the Lorentz confinement is still an issue but I'd suggest keeping the DC bias at 0.5T because that's what the patent recommended and 0.5T is square in the middle of the domain magnetization rotation zone mentioned in that NMR paper from Cyril.
but because we are using an E class amplifier which is more complicated to build tunable then if we stick to one center park frequency, all we need to do to tune this beast is vary the DC voltage/current on the bias coil to shift our NMR up and Down to hit out Class E frequency, so much easier to vary a voltage in mv steps than a frequency and associated amplifer to 0.001Hz
With other substances that would be very true, but as you can glean from that NMR paper, iron has its own internal magnetic hyperfine field of great density (~33T) that overshadows our weak 0.5T field and the resonance frequency will stay at 45.5MHz regardless whether we apply that 0.5T biasing field or not.
Now we are in a position to just choose a frequency say 1MHz and we can work out the bias field needed and the current and voltage variation to give us a 500KHz to 2 MHz swing for the NMR frequency, then with all the unknowns we should be able to find in this case the magic bias value for isotropic mutation at 1MHz or any other frequency we choose.
Again, Cyril's paper changes everything because we learn from it that the line width for non annealed iron is ±80kHz and for annealed iron it is ±25kHz. (impure Iron could be much less sharp though).
That small frequency deviation is well within the range of class E amplifiers.
So the next thing then is to find our static NMR chosen frequency, are the benefits for a higher frequency say 10MHz as opposed to a 900KHz frequency, apart from the different bias field strength.
Looks like nature made that decision for us and fixed the resonance frequency at 45.5MHz.
How do we control the speed of conversion? maybe by varying the MHz power, or is it done by off tuning as in the McFreey Device, or maybe we can control the amount of atoms being converted by controlling the skin depth.
I think just like in McFreey's device because each pulse is self quenching since the circulating fast electrons generate electric current that generates magnetic field that opposes the 0.5T confinement field.
I think we need to thrash this Lorentz orbit out a bit, we need an orbit small enough to keep the fast electrons inside the core? Why we already have Neutrons flying out, are fast electrons going to matter,
Yes because only electrons and positrons will generate our output electric current and neutrons will not. Neutrons are just deadly, if they are emitted at all.
and surely anyway if the atom that they come from is on the outside perimeter of the rod then they will surely be outside rod containment anyway.
Yes, but if the 0.5T containment field exists outside of the fuel rod (e.g. because the 0.5T DC solenoid is larger than the rod) the the path of such electron will be curved back into the rod.
Presumably it is these fast electrons that are our power out source, if so i can see we want as many contained as possible.
Fortunately their motion destroys their own confining magnetic field.
So our bias field now is only needed purely for the Lorentz orbit diameter.
Yes and also maybe to polarize iron in the middle of that domain rotation zone described in Cyril's paper
Then we need to know what needs to be prominent, our DC bias, lets say at the moment we went with 0.5T then how prominent do we want our MHz signal,
The frequency shift below 0.6T is proportional to (H
BIAS / 33.02T)
2 so it is very small
can we calculate how much energy or at what field strength the atom flips 180 Degrees.
I can't do that yet. Maybe Smudge can help.
So things we need to nail down & choose:
1) Bias Field strength Tesla's
2) Static NMR Frequency
3) Static NMR Frequency field strength +/- ?Tesla's or in terms of watts power would do.
4) 50Hz field strength +/- ? Tesla's or power in watts.
5) Fuel rod length and or diameter i could settle on 20mm diameter, but length is open for debate,
1) 0.5T just like in the patent AFAIR
2) 45.5MHz (must use Litz wire winding for that)
3) f
RESONANCE =1381564(H
BIAS - H
D - 33.02T). I don't know about the RF power and about the demagnetization field (H
D) for the particular dimensions of the fuel rod.
4) I don't know but I guesstimate not more that the DC bias field.
5) 20mm diameter feels fine. I cannot be certain because I do not know the energy of the fast electrons. If they are 1MeV then 20mm should be enough.
The size and proportions of the fuel rod determine its demagnetization field (H
D). Maybe Smudge can help us calculate it with an elongated ellipsoid formula for that shape.
Iron-57 is stable so it normally does not emit any fast electrons/positrons and thus their energies are not listed in literature, but the whole idea of this contraption is to destabilize iron and make it emit these charged particles.
Its neighbors, e.g. Iron-59 spontaneously emit 1.565MeV electrons, see:
http://www.periodictable.com/Isotopes/026.59/index.full.dm.htmlThe destabilization of nuclei through electrical means has been documented before, so it is not that far out. For example read up
here on Dysprosium
163Dy that is also normally stable but can be made unstable using non-nuclear (electronic) methods.
Is there any other way of making the orbit much smaller mm or so other than field strength.?
For given speed/energy of the electrons it is the only way.
We could be overestimating their speed/energy, though. For example Iron-55 decays only with 231keV and such small speed/energy of these fast electrons would result in smaller Lorentz orbits.
Isotope Energy Lorentz orbit diameter at 0.5T
------------------------------------------------------------------------
Fe
55 231keV 7.2mm
Fe
60 237keV 7.3mm
1000keV 19.0mm
Fe
54 1364keV 24.0mm
Fe
59 1565keV 26.8mm
Fe
53 2721keV 42.6mm
All of the above isotopes decay in Beta modes without any neutron emissions (see
here)
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Topic: Meyer-Mace Isotopic NMR Generator (Read 121142 times)
