We need to continue to offer interesting ideas such as this one by Bob. I made a careful review of the power input versus temperature curve that just recently was posted in the MFMP blog. It appears that the curve does not have sufficient downward slope tendency to indicate entry into the negative resistance region needed for normal melt down progress.
On the other hand, if a sudden threshold is present where the onset of core generated power is extremely swift then an immediate negative slope could materialize at that threshold. This was not seen in Parkhomov's experiment so I need to be convinced that it actually happened at MFMP. Parkhomov's device behaved much as I was expecting and in a manner that suggests that it can be adequately controlled under the correct circumstances. Could it be that the MFMP team made modifications to the basic design that lead to the problem? The connector attached to the ceramic rod should facilitate measurements of the hydrogen pressure and allow plenty of variables to be adjusted. In many ways this appears to be a great idea. But, we also know that something went very wrong with the device at elevated temperatures that did not become apparent with Parkhomov's device. In the first Parkhomov experiment the input power versus temperature curve acted as I was expecting. As the power input increased the slope of that curve came very close to reaching a negative value within the region of interest. The lack of enough clean data points prevented me from determining how close it came, but the fact that the device remained stable with static drive steps proved to me at least that it did not enter into a negative resistance region of operation. This is characteristic of a stable type 1 device. A comparison of the MFMP device and Parkhomov's first experiment shows one obvious difference. Parkhomov's design kept all of the fuel at an elevated temperature where it appears to be treated uniformly, at least to the first order. He used symetry and plenty of cement toward that purpose. Does anyone understand what happens to any metal vapor, or hot gas that finds it way to the cool end of the inner pipe of the MFMP device? I would guess that the metal vapor would condense immediately and be taken out of the hottest environment. Do we know that the loss of these potentially reactive components is not going to effect the behavior of the device? Is that why the MFMP team witnessed the apparent meltdown? Was a built in spoiler allowed to escape by condensing in the cooler region? Perhaps it would be safer to perform a reproduction that is much closer to the original first and then make desired changes in stages. At this point no one knows what is or is not of great importance to the behavior of a Hotcat. Now is the time that we need plenty of new understanding. Dave -----Original Message----- From: Bob Cook <[email protected]> To: vortex-l <[email protected]> Sent: Thu, Feb 12, 2015 12:47 pm Subject: Re: EXTERNAL: Re: SV: [Vo]:Explosion May Be Out of Control LENR Another idea for the control of the LENR reaction, assuming heat is a driver would be to make a fuel-metal matrix solid instead of the fuel nano powder. This arrangement of a dispersed fuel would allow better control of temperature within any given nano fuel particle. The metal matrix would conduct heat away from the Ni nano fuel particle and allow better control of the fuel temperature as well as the access of the H to the Ni nano particle. Such a fuel--metal matrix (FMM) could be manufactured using powder metallurgy sintering techniques to fuse the metal matrix at a lower melting point than the Ni nano powder, but above the desired LENR reaction temperature. The mixing of the nano Ni and the metal matrix powder could be accomplished in a cryogenic liquid nitrogen mixed to assure a homogenous mix. The nitrogen would boil off after mixing leaving the two powders thoroughly mixed without clumping. 100 micron FMM particles could be created in the sintering to load the reactor. Bob Cook Sent from Windows Mail From: David Roberson Sent: Tuesday, February 10, 2015 10:40 AM To: [email protected] I agree with you Fran that an ideal solution would be to kill the positive feedback gain in some controlled manner. That could likely be done as you are discussing by taking more power from the core than it needs to self sustain. Once this happens the core temperature movement should reverse direction and head lower. The main complication I am concerned about is that there may exist some built in mechanism that allows the present level of core heat generation to continue for a period of time until it resets. I felt that the plateau seen in the Parkhomov report that occurred after the drive coil burned out might fall into that category. Of course if the extraction of excess power were to continue throughout that entire period of time then it should not be such a problem. Dave -----Original Message----- From: Roarty, Francis X <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Feb 10, 2015 6:30 am Subject: RE: EXTERNAL: Re: SV: [Vo]:Explosion May Be Out of Control LENR The best spoiler may be variable heat sinking that takes more energy away as reaction become more robust to throttle it back below the threshold – then perhaps the drive pwm could push it back above on a duty factor basis. IMHO the dynamic thermal loading may become more important than the drive for “growing” the reaction OU once the threshold is breached Fran From: David Roberson [mailto:[email protected]] Sent: Tuesday, February 10, 2015 4:05 AM To: [email protected] Subject: EXTERNAL: Re: SV: [Vo]:Explosion May Be Out of Control LENR That seems like a good quote to add Mats. I have a strong suspicion that you will have several more to add in the next few months as people experiment with these latest devices. There is little doubt that many are going to melt down as the fuel within them is adjusted. It will also be interesting to observe how they behave when additional insulation is added to restrict the heat flowing outwards. There is going to be a great deal of trading off of parameters when people attempt to reduce the input power yet maintain adequate output power and stability. Rossi may have done a lot of the work for us already as he modified his devices to make them marketable. I hope that the fuel can also be adjusted to assist in the process. We need some form of reversible spoiler that applies brakes to the heat generation process once the temperature exceeds a designed set point. Dave -----Original Message----- From: Lewan Mats <[email protected]> To: vortex-l <[email protected]> Sent: Tue, Feb 10, 2015 3:46 am Subject: SV: [Vo]:Explosion May Be Out of Control LENR I could add this quote from my book, describing what Giuseppe Levi told me about experiments with the Hotcat back in 2012, when the device was destroyed by thermal run-away. That’s two and a half years ago. “When they disassembled the reactor they found that the ceramic shield containing the reactor had melted, and it should withstand up to 2,700 degrees Celsius. The steel tube containing the fuel had a large hole in it and Levi saw on the edges of the hole that it had not melted—it must have been so hot that the steel boiled or burned up, indicating a temperature around 3,000 degrees.” (An Impossible Invention, chapter 19). Mats www.animpossibleinvention.com Från: Lewan Mats [mailto:[email protected]] Skickat: den 10 februari 2015 09:25 Till: [email protected] Ämne: SV: [Vo]:Explosion May Be Out of Control LENR David, It’s always interesting to read your analyses of the energetic and thermal dynamics of LENR systems. They deserve more attention. I find your model with three types of systems convincing, and I think it is obvious from what Rossi told me many times about his experiments that the run-away tendency is one of the main issues when trying to achieve and sustain a controlled LENR reaction. I also believe that the amount of time that Rossi has put into trial and error is an indication of the experience you need to gain in order to get the reaction under control, although it seems that Parkhomov has made significant progress. Yet, arriving at sustaining a reaction for days and weeks, with long periods in self-sustained mode, is probably a tough challenge. Mats www.animpossibleinvention.com Från: David Roberson [mailto:[email protected]] Skickat: den 10 februari 2015 02:47 Till: [email protected] Ämne: [Vo]:Explosion May Be Out of Control LENR I just read the latest facebook entry by the MFMP group and suspect that they witnessed an explosion due to a thermal runaway event. The latest Parkhomov experiment appears to indicate the same out of control system problem. We know that the earlier Parkhomov device was stable but appeared to be on the verge of entering a negative resistance type of operation. The slope of power input versus temperature for that original system was very close to zero but slightly positive according to the data he reported. Although I would like to have a much more extensive collection of points defining power input versus temperature, I am having to assume that the curve connecting the three given points is relatively smooth. This is not too much of a stretch since the entire temperature range over which the points are taken is very limited. When Parkhomov increased the insulation surrounding his device for the recent testing, he effectively increased the positive feedback gain by a large amount. With the insulation the amount of input power required to obtain the same temperature readings was substantially reduced. It seems reasonable to assume that the core generates the same amount of heat power when subjected to the same temperature. If this is true then the ratio of internally generated power to input power must become larger at any temperature where internal heat is being generated. Since the original product was very close to becoming unstable, with the increase in gain the latest experiment most likely resulted in a situation where the positive feedback gain exceeded unity. This is just another way of saying that a negative resistance region is now present. Of course, once the input power pushes the temperature into that region the device will self sustain all the way to thermal destruction. This increase in temperature can be extremely rapid since it is of an exponential nature. With this thought under consideration I strongly suspect that the MFMP team observed the same sequence of events. Until they increased the drive level to the threshold of destruction everything would have appeared fairly normal. The main difference I would expect is for the temperature to rise faster than expected had a dummy system been driven in a like manner. Unfortunately, it might be a fine line between a stable input drive power and the initiation of run away. My take on the debris following the explosion is that there is evidence of an extreme heating event having taken place. The spheres of molten metal along with the other indications is pretty strong evidence. I do not believe that the time frame during which the heat is emitted is necessarily very long in duration. An exponential release can occur very quickly and the heat is confined by the structure as the damage is being done. To prevent this from occurring too often, I would recommend that the amount of fuel be reduced significantly for the earlier testing. A curve can then be constructed under stable conditions which will act as a guide to indicate how much fuel can be inserted before the thermal run away condition can begin. Perhaps the fact that MFMP guys and Parkhomov did such a good job of sealing in the hydrogen under a large amount of pressure is the root cause of the issue. There remains many unanswered questions, but the important fact is that we may now be witnessing an excellent example of LENR. Dave
