[gianfranco]

Thank you for your assistance. I have now made two WINRAR archives and hope to be able to upload…. DONE!

Attached files

Basic_electrical_8.rar (25 B)  Basic_electrical_9.rar (24 B) 

[gianfranco]

AI, thanks for your comments & state of the art review. On a ship now, will reply next week.

Lerner, no problem here. All the software & computing facility is ready. If you let me have up to date current plots, I can easily repeat analyses in a very short time .

Still impossible to upload Excel files…

[gianfranco]

Unfortunately the system does not allow me to attach EXCEL filies…I could send them by email….

[gianfranco]

I have now completed a comprehensive study on the Electrical/Engineering aspects of the FF-1. It is too long for a post and I am enclosing a PDF file of it. I hope this work can be of help to clarify some technical issues. I shall post the companion computational excel files separately in another post.

Attached files

Post_5.pdf (399 B) 

[gianfranco]

“In your spreadsheet, you calculate that the capacitor voltage is still very high.”

I could not agree more with the theoretical observations of AI, whom I thank for his post and very useful information.

However I think that perhaps I did not stress enough three points that are fundamental to this work and will now attept to clarify a possible misunderstanding.

1) My work aimed at a possible definition of the LPP-1 machine as a two terminal load getting power from an external source.
2) My calculations are solely based on the EXPERIMENTAL DATA recovered by the current vs. time curve shown on Figure 3, page 12 of the document: “Theory and experimental program for p-B11 Fusion with the Dense Plasma Focus” by E.J. Lerner et Al.
3) The results are only valid from time 0 to time just before Pinch.

I enclose copy of Figure 3. The method I have used is as follows. I collected current data from the curve at 100 nS intervals. This data is listed on my spreadsheet, Sheet 2, column J. As shown in diagram “Current math”, this data is curve fitted by:

I = -0,0003t^2 + 1,3082t – 146,62

This expression is used to smooth out possible small errors in evaluating the curve of Figure 3 and is used to calculate current at intervals of 100 nS in Sheet 3, column B. Therefore it is the experiment itself that tells us that prior to Pinch, in that particular instance, the current out of the capacitor bank was 1.2 MA after 2100 nS and 100 kA after 200 nS.

Using the initial equivalent resistance and current values every 100 nS, the spreadsheet, Sheet 3, column D, calculates the residual voltage as follows:

V(t) = V(t-1) * EXP((-d(t))/(C * R(t-1))

In other words we approximate the voltage level at the begining of every 100 nS time period. Next resistance value is then calculated separately and written into column C. In my opinion, if the current data in Figure 3 is right, then the derived results should be right.

As far as the system inductance is concerned, the cited paper gives a total value (internal + external) of 50 nH. The equivalent resistance at the beginning of the discharge is calculated to be in the order of 0,5 Ohm: therefore the 100 nS delay before current starts rising significantly is fully justified.

To conclude, at least for this particular experiment, this work seems to show that the capacitor source feeding the cell after the switches saw, between switch closure and just prior to the pinch, that (very nonlinear) varying equivalent load resistance, that current variation and that voltage variation. This work does not see what happens afterwards, after the Pinch started.

Finally the fact that a very significant amount of energy seems to be left in the capactor bank is also confirmed by the LPP presentation of 10/12/2012.

Attached files

[gianfranco]

ELECTRODE COOLING. Electrode cooling could become much easier by reversing feed polarity to the Cell (assuming this is technically possible and allowed by the electrical connections of capacitor & switches).

With polarity reversal the Anode would be grounded and the troublesome alumina insulator would be eliminated. The Anode could be built from a solid cylindrical block of metal, flanged thru the top chamber wall to an external heat sink which could be convection cooled, air cooled or liquid cooled, according to technical convenience & engineering constraints.

The Cathode would become a “floating cathode”. The top wall of the chamber could be made with a thick circular plate of Teflon, for limited mechanical elasticity, covered by a plate of Alumina carrying as many “towers” as needed to hold as many cathode bars. The cathode bars would be made of thick tubing joined on top by the cathode joining ring, also made of tubing. On the ouside of the top wall we would have the electrical connections (negative) to each cathode tube. In addition half the cathode tubes would receive liquid coolant under pressure (non-toxic transformer oil). The coolant would reach the top cathode joining ring and tru it reach the other half of the cathode tubes which would then discharge the coolant back to the cooling system. Any convenient method could then be used to stabilize coolant temperature to the required value and perhaps obtain Energy Recovery.

For example a “solid” (no insulator) Beryllium Anode with a thermal length of 10 cm and with the tip at 1,100 °C (Berillium melting point 1287°C) will dissipate almost 5,5 kW if the cold end is kept at 10 °C. Thermal length measured from center length of Anode and cold end. A single hollow Berillium Cathode bar with a wall thickness of 3 mm and a thermal length of 10 cm, if cooled by a suitable flow of oil at 100°C could be easily be kept at 600°C while dissipating heat in excess of 10 kW.

BORON DUST PROBLEM. My proposal is to employ an injector and a getter. The injector will be served by a calibrated injector pump which will deliver a metered quantity of Boron powder to the injector. This arrangement limits the quantity of Boron into the Chamber. The getter is a simple metal ring fitted near the inner bottom of the chamber connected thru an insulator to a low power positive HV supply (30 kV is a good guess). At the beginning of a discharge cycle the injector will supply the limited quantity of Boron powder. At the end of the ignition cycle and during recovery (say at plus 20 uS) the HV PSU will switch on and the getter will easily capture both Boron dust at zero charge from the Anode and at negative (residual charge) from the cathode. It should not be difficult to automatically recover Boron dust after a convenient number of cycles, because extra Boron dust will be localized at the bottom of the chamber.

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