Meyer-Mace Isotopic NMR Generator

The chart showing that zone shows the magnetization to be between 90% and 100% of saturation value

Yes.

so most of the ferromagnetic dipoles hence also nuclear dipoles are aligned.

No, take a look at the composite graph below. I marked the 5kG external field with a red line.
You can see that the red line is almost in the middle of the yellow domain rotation zone.
At 5kG the domain wall volume is at 67% of its maximum, thus not all domain dipoles are aligned with the external field (if they were then the domain wall volume would be zero)

Meyer-Mace Isotopic NMR Generator

Fe NMR.png (26.25 kB, 491x402 - viewed 4634 times.)

Verpies

Re: Meyer-Mace Isotropic NMR Generator « Reply #77 on: 2015-07-07, 01:51:38 »

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But the three coils shown in the patents have different requirements and are not connected as depicted in your diagrams.

These bucking coils produce the same flux pattern between them even when they are not grounded at the midpoint and are completely separated galvanically and having 4 terminals.

I am mystified by the axial RF drive coil. If my reasoning is correct and the nuclear dipoles are aligned along the magnetization axis then you need cross coupling to drive them.

Yes but as we can see from the graph above, at 0.5T, not all of the domain dipoles are aligned along the magnetization axis.
Also, any bucking fields from two segmented coaxial coils will tend to produce a radial flux (perpendicular to the fuel rod's major axis).

Note that all the nuclei are already precessing but at random phases so the net effect is zero. To pump them with RF you need to access their off-axis component that is rotating at their resonant frequency, not their on-axis component which is constant. They can then absorb energy over a number of cycles that tries to speed up the precession process, creating the torque to ultimately flip them through the desired angle. The on-axis RF magnetic field does not do this.

Yes, the on-axis parallel field cannot pump the nuclei ...but the external field that is parallel to the rod's axis is not parallel to the unaligned domain dipoles.

Ask yourself a question: At what value of the external field, the integral of the product of domain dipole magnitudes * sin θ, occurs?
(where θ denotes the angles between the domain dipoles and the external field).
Don't disregard the results from this Fe NMR paper, that concludes that domains first grow and later they rotate their magnetization vectors, as the external field increases.

Quote from: verpies on 2015-07-07, 01:35:59

Also I do wonder whether the patents reflect someone's aspirations rather than an accomplished and verified experiment.

I wonder, too. There is an article by Renaud de la Taille in "Science et Vie" nr.700 March 1976 ( pages 42-45 ), that features an actually built device...allegedly functioning.

Smudge

Re: Meyer-Mace Isotropic NMR Generator « Reply #78 on: 2015-07-07, 17:13:55 »

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No, take a look at the composite graph below. I marked the 5kG external field with a red line.
You can see that the red line is almost in the middle of the yellow domain rotation zone.
At 5kG the domain wall volume is at 67% of its maximum, thus not all domain dipoles are aligned with the external field (if they were then the domain wall volume would be zero)

IMO domain wall volume is not an indication of domain or dipole alignment, so you can have a significant number of domains (hence also wall volume) whose dipoles are almost aligned. Magnetization is a direct indication of dipole alignment. At 0.5T the magnetization is about 97% of its maximum, and that tells me most of the dipoles are aligned. That chart showing the different regions is common to most ferromagnetic materials.

Smudge

Peterae

Re: Meyer-Mace Isotropic NMR Generator « Reply #79 on: 2015-07-07, 20:58:53 »

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I started machining the mild steel frame today, using mild steel rod at the moment until i source the 18mm diameter pure iron.

In the patent he Chrome plates the mild steel frame, something i cannot do myself, any idea if this might be important as it may cost a bit, will need to get a quote when machined.

I need to start thinking about the wire connections to the iron rod, shall i extent the iron rod by 5mm beyond the mild steel frame, and tap each end for a screw terminal connection.

Also need to start thinking about coil construction/ bobbin sizes, coil turns and wire thickness for the following 5.

We have 5 things to wind

Heater winding somehow insulated electrically but allowing conductive heat to the iron rod, then insulated with Grumages 1000 Deg C insulation, with a thermocouple embedded, and then bobbins on top of this insulated layer.

1) Heater Coil
2) Bias coil
3) 45.5MHz 20 Turn coil
4) 50Hz AC 1
5) 50Hz AC 2

The heater coil i am wondering if this is best done using a non inductive way down the length of the iron rod instead of winding as if a coil axially down the length.

Anyway some calcs

so 90mm length of 20mm diameter iron rod weights 224g

specific heat of iron is 448 joules/kg

so 100 joules will raise our iron 1 Deg C

if our starting temperature is 20 Deg C and we want 700 Deg C then our temperature
difference is 680 Dec C and our energy required 100 * 680 or 68000 joules

if we were to raise this over 240 seconds then we get a power rating of 283 Watts joules/s of power

if we run the heater from 48V then we have a current of 5.9 Amps

The heater needs a resistance of R = V^2/P or 48^2/283 = 8.15 Ohms

I should now be able to work out my wire length and diameter once it's geometry is chosen.

« Last Edit: 2015-07-07, 22:19:16 by Peterae »

Verpies

Re: Meyer-Mace Isotropic NMR Generator « Reply #80 on: 2015-07-07, 22:50:07 »

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I started machining the mild steel frame today, using mild steel rod at the moment until i source the 18mm diameter pure iron.
In the patent he Chrome plates the mild steel frame, something i cannot do myself, any idea if this might be important as it may cost a bit, will need to get a quote when machined.

IMO Chrome does not matter and Iron does
What is your source for pure Iron rods? ...I'd like to know for myself (powder is not a problem)

I need to start thinking about the wire connections to the iron rod, shall i extent the iron rod by 5mm beyond the mild steel frame, and tap each end for a screw terminal connection.

I don't think this would affect anything negatively.

We have 5 things to wind
Heater winding somehow insulated electrically but allowing conductive heat to the iron rod, then insulated with Grumages 1000 Deg C insulation, with a thermocouple embedded.
The heater coil i am wondering if this is best done using a non inductive way down the length of the iron rod instead of winding as if a coil axially down the length.

IMO the heater winding should be wound in an non-inductive manner like this.
...but the heater winding does not have to be wound over the fuel rod at all. For example it could be wound over the U support structure.
Alternatively, the heater winding can be skipped altogether and the support structure can be heated with gas flame.

2) Bias coil
3) 45.5MHz 20 Turn coil
4) 50Hz AC 1
5) 50Hz AC 2

2) Should be much larger than the diameter of the fuel rod. The number of turns and amperage was calculated here.
3) I strongly recommend Litz wire for this one.
4 & 5) I'd go for 4Ω at 50Hz which gives the inductance of 4Ω/(6.28*50Hz) = ~13mH wound with thick wire like this.
...none of these 4 windings need to touch the fuel rod and they should be far away from the U support structure.

I hope Cyril will throw in some of his calculations and suggestions, too.

Meyer-Mace Isotopic NMR Generator

Mayer Heater.png (341.94 kB, 655x643 - viewed 1644 times.)

Meyer-Mace Isotopic NMR Generator

Bucking Gap.png (15.97 kB, 478x277 - viewed 2053 times.)

Peterae

Re: Meyer-Mace Isotropic NMR Generator « Reply #81 on: 2015-07-08, 06:35:22 »

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Wow thanks verpies for the fast response.
It maybe best and more energy efficient to heat the iron rod from within the rod, if it was a tube, for instance if the 20mm iron rod has a 5mm hole down the centre, then the heater can be inserted inside along with the temp sensor.

Waiting for a quote on the pure iron rod, not on order yet, once i find a viable source i will post the source.

Wow pure iron powder is available i think easier anyway, will research when get home from work

I have plenty to build for the moment.

If you guys can prove to me i need that 500 Watt amplifer using maths i am going to be much more willing to part with money

My iron internal rod length is 90mm long, see drawing in 2ND post, how far is far away from the iron support frame

Verpies

Re: Meyer-Mace Isotropic NMR Generator « Reply #82 on: 2015-07-08, 09:58:41 »

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It maybe best and more energy efficient to heat the iron rod from within the rod, if it was a tube, for instance if the 20mm iron rod has a 5mm hole down the centre, then the heater can be inserted inside along with the temp sensor.

It could but it would be too much of a departure from the patent. It would affect the reluctance of the rod and possibly reactions inside it.

Waiting for a quote on the pure iron rod, not on order yet, once i find a viable source i will post the source.

IMO pure iron begins at 99.5%

Wow pure iron powder is available i think easier anyway,

Yes it is easier but is it the same? (density, resistivity, reluctance, saturation...)
Powder can be packed inside a tube to create a make-shift rod.
Melting iron powder without contamination by the atmosphere and the crucible would be hard. Grumage would know better how feasible that is.

If you guys can prove to me i need that 500 Watt amplifier using maths i am going to be much more willing to part with money

I can't do that yet but the patent mentions 460W per mole of iron.
Calculating the electric skin effect is easy but the attenuation of AC magnetic flux inside iron - not so much.

My iron internal rod length is 90mm long, see drawing in 2ND post, how far is far away from the iron support frame

Depends how large the coil diameters are. 90mm length seems a little short for 4 windings.