Posts by can

What about graphite sheet? It should not decompose easily in hydrogen at moderate temperatures.

From this paper https://doi.org/10.1088/1009-0630/10/1/07 on electrolytic glow plasma discharges the authors have these current-voltage graphs:

Regarding Fig.2a they point out that between points B-C current readings fluctuated significantly, and in D-E greater chemical yields than Faraday's law may be observed. From this it might be inferred that in conventional experiments just using a simple variac+bridge rectifier such region might not be reached. A higher electrolyte conductivity shifts the curve to lower voltages. Point B is roughly where breakdown starts occurring.

I think the current instability in the B-C region is associated with intense RF emission. I could observe in my tests this by dropping the cathode further into the electrolyte, which increased load, causing my small HV power supply to limit current by decreasing voltage. The plasma then turned from metal-ion colored (I was using one single 0.25 mm copper filament, which produced a mostly green color) to a weaker yellow color, became unstable and broadband RF noise increased substantially, even at zero gain setting at the RF receiver.

Although it has been sometimes suggested that such "negative resistance" region is important, if greater (or much greater as reported in some cases) than Faradaic efficiency is achieved at higher voltages, would that really be important?

As a side note: the previously discussed "ball-forming" effect is best achieved at low electrolyte concentrations (I was using 0.012M KOH), which has sometimes been described as "atmospheric glow plasma" in the literature. At higher concentrations (e.g. 0.05M KOH), "true" plasma electrolysis becomes easier and bringing in contact the electrode with the water level causes sharp bangs. Higher concentrations (I tried up to 0.25M KOH) make plasma electrolysis more difficult to control at high voltage and cause rapid melting of the cathode material.

Alan Smith

I just ordered some from another vendor, 0.10 mm thickness.

Peter

I should have thought of that a few weeks ago when I replaced a small 12V one at home, although probably the filament was too thin.

I'm starting to suspect that there are other non-intuitive factors involved, in any case. I just tried thin guitar string steel wire; it seems as if copper still heats up faster and cools down slower, especially once it melts. If I add a copper filament to the tip of a thin steel wire, it becomes easier to bring to high temperature, as long as there is copper that can easily melt (and causes a green plasma). High conductivity could be involved, or perhaps there is some effect contributed by the molten metal.

EDIT: perhaps the effect slow cooling of copper observed under these conditions (which are not exactly plasma electrolysis anyway but more like heating with atmospheric glow plasma over a liquid anode) is due to recalescence: https://en.wikipedia.org/wiki/Recalescence

The above ball was made using 2x0.25 mm copper filaments. After more tests I believe that the melting point of copper is significantly exceeded and the glowing ball stays on the wire as a liquid drop, while apparently spinning at the same time. This was earlier on (different thread) likened by Alan Smith to a sort of homopolar motor. I find that as soon as the material melts, it stays hot longer than in solid form, even after power is removed (of course, not indefinitely).

I am considering getting molybdenum (m.p. 2623 °C) or tungsten (m.p. 3422 °C) thin wire for more of the same tests with potentially better materials at higher temperatures, but the latter tends to be very expensive and of the former I have no knowledge about for these applications. Suggestions?

Typically tungsten welding electrodes would be used in these experiments, but even 1.0 mm diameter ones might not perform well in my case due to power supply limitations.

Below is a more extreme case of "ball-forming" reaction using copper, although this is probably not strictly plasma electrolysis anymore. Still, hydrogen is evolved in the process and with a sufficiently powerful power supply the cathode (-760V relative to the anode) could be probably immersed completely in the electrolyte (0.05M KOH in 150ml tap water).

I have already showed this type of reaction in a completely different thread some time ago. The cathode ball heats up quickly and cools slowly, and the reaction can be easily maintained as long as the material is hot. If anything, it quickly 'runs away' and the reaction must be stopped to not make the material further recede from melting.

Here is a detail of the smooth sphere formed after the above reaction:

Curbina

I might have used ambiguous wording. I meant writing that it seemed as if to reproduce natural processes they thought they had to build a small-scale model or reproduction (or "imitation").

I was asking this because on a much smaller scale I think I'm observing that a similar bulbous or spherical shape seems to work better in typical electrolytic glow plasma experiments, if uncontrollable melting does not occur first. The plasma appears to get stable sooner around the sphere, and mostly just the sphere appears to heat up. It could be the lack or sharp corners, or that heat is not carried away from it too quickly, and so on.

Curbina

I see; so that's a kind of philosophical motivation (i.e. "imitating nature"). I was wondering more if from theoretical modeling, calculations or experimental data it might possibly work more efficiently for certain plasmas, or perform better in some aspects, etc.

I think a version of this document about Birkeland's Terrella experiments has been posted in the past on LENR-Forum: http://theu.one/tuo/wp-content…12/Birkeland_Terrella.pdf

Not exactly related with the most recent discussions here, but are there known/disclosed theoretical reasons for using a spherical anode?

EDIT: the focus is on "spherical".

The same reaction does not occur just with clean Al, or at least not as easily (it tends to form spheres as with other low-melting point materials, or slowly oxidize from the heat and fragment into small pieces depending on several variables). My hypothesis was that the oxide would heat up to very high temperatures—possibly in excess of 2000 °C—before the metal starts burning at a fast rate.

EDIT: Here's a photo of one with a melted tip.

I was trying to form a surface oxide layer on an aluminium anode (in a hope to make it perform better as a cathode. Under certain conditions Al2O3 can glow quite intensely bright as a cathode) when I noticed an unusual luminescence effect. At the same time, a large amount of gas or vapor would be evolved from the electrolyte surface.

The electrolyte was 0.12M K2CO3 in 100 ml tap water; open-circuit voltage was 780V, but decreased to very unstable 240-280V under load in the conditions shown in the the video; this is due to power supply limitations.

A plastic separator placed between both electrodes acts as a barrier to increase inter-electrode resistance.

The video below is only 23 seconds long.

EDIT: here's another, 1:17. It's a thick and already partially oxidized Al foil folded multiple times.

EDIT: below is a gif of the effect, here only transiently occurring, when there is an Al2O3 layer on the electrode as the cathode. I'm not sure if it's just helping the Al burning.

A possible major advance in how these experiments can be run.

Following suggestions I've read in some mainstream publications, I tried adding a separator between the anode and the cathode. It only has a small hole on the bottom for ion exchange to continue. This significantly increases inter-electrode resistance and stabilizes the plasma.

As a result I could substantially increase input voltage in plasma electrolysis experiments (up to 750–800V) without annoying explosions and/or loud spark discharges.

On top of this, I tried adding at the cathode a few filaments of stranded tin-plated copper wire. The idea was to have a thinner cathode that would be hopefully more efficient in producing the [glow] plasma discharge.

Copper is an easily melted material. It did melt fairly quickly in the tests, but surprisingly it also formed semi-molten balls in the process.

Plasma electrolysis for some reason appears to occur easily with these balls despite the large surface area, at least on top of the water level. Occasionally the formed copper ball can be observed heating up very quickly.

After finishing the test, the melted copper material appeared to be shiny, meaning that hydrogen had indeed been evolved and the material did not oxidize with intense heat.

I've made a video of the process.

Video index:

• [0:00] Initial test starting with copper filaments
• [2:15] Second long test with the previously melted copper ball

Curbina

For the most part I'm referring to mainstream publications that do not involve novel states of matter or molecular bonding. Significantly greater than Faradaic electrolytic efficiency seems a big deal and I can't wrap my head around how it could easily pass under the radar. Perhaps I'm missing or not understanding something.

While I do get loud bangs under certain conditions from electrode operation immersed in the electrolyte, the large and persistent bubbles themselves did not seem to be readily explosive.

I couldn't make a test with a matchstick, but an unsatisfactory test with a long lighter (unfortunately out of fuel) appeared to show non-explosive combustion of such bubbles.

EDIT: I made another test with an enclosed cathode. I do not get persistent bubbles with it (they do not accumulate in large amounts and quickly burst), but I have similar problems likely caused by the weak power supply which cannot maintain a constant voltage at less than very light loads. In the video I ramp voltage up, then down until the reaction disappears. Above a certain voltage the gas pockets formed around the cathode detonate immediately and make the reaction look apparently more continuous and stronger, but from RF measurements it becomes more intermittent.

A better/stronger power supply for proper testing at high voltages, where supposedly the reaction can become much more efficient than normal electrolysis, would be very useful.

On this buried topic again, recently I found that there are several mainstream publications claiming non-Faradaic hydrogen evolution with cathodic plasma electrolysis. Some cite Mizuno's paper linked above; those references can be seen for example on Google Scholar. They are not generally studies related to LENR, but they should be about "excess hydrogen".

Excess heat in LENR-related (or "LENR-claimed") plasma electrolysis experiments has been often calculated by the amount of water lost as steam after a certain period of operation, but the gases actually evolved by the reaction are most often ignored. If there is truly a large amount of excess H₂(+O₂) evolved in the reaction, it may or may not actually show as true excess heat depending on whether the gases recombine to water (hopefully not in large amounts at once).

Conditions are of course far from being controlled here. Then, OH- is probably not directly involved in the observed reactions as I previously assumed.

Perhaps [at least the explosions] might be something as "simple" as H₂–O₂ from water decomposed by the hot electrode and/or the plasma. Tadahiko Mizuno actually discussed years ago about the anomalous (non-faradaic) decomposition of water from cathodic plasma electrolysis. In some cases it could apparently greatly exceed conventional electrolysis efficiency.

Other authors have observed this effect as well, it turns out after looking on Google Scholar if/when that same paper has been cited.

From the above list from Google Scholar, this paper (and possibly other works from the same authors) could be relevant. It seems that the effect should be able to occur at both the anode and cathode: https://www.researchgate.net/p…faradaic_chemical_effects

Quote

Abstract: Normal electrolysis (NE), at sufficiently high voltages, breaks down and undergoes a transition to a phenomenon called contact glow discharge electrolysis (CGDE) in which a sheath of glow discharge plasma encapsulates one of the electrodes, the anode or the cathode. The chemical effects of CGDE are highly non-faradaic e.g. a mixture of H₂ and H₂O₂ plus O₂ each in excess of the Faraday law value is liberated at the glow discharge plasma electrode from an aqueous electrolyte solution. [...]

Some interesting tables from the paper:

This other one is a quite recent paper (published July 2020) from different authors, even: https://iopscience.iop.org/art…149/1945-7111/aba15c/meta

...etc.

Alan Smith

I misread and thought you wrote "H2O2" instead of "2H20". I now see that you actually meant that H₂O₂ may possibly also be formed (in lieu of 2H₂O), but not in an energetically favorable way. What I tried searching on Wikipedia was if H₂O₂ formation from OH (in any form) is a known reaction.

Alan Smith

It looks like it's not known enough to be on Wikipedia: https://en.wikipedia.org/wiki/Hydrogen_peroxide

I tried looking there first, but did not find much.

EDIT: It looks like I misread your comment

The higher the voltage, the more the loud explosions occurring even under water (and the louder the explosions). Typically I would use about 500V as in the brief video above.

Earlier on I tried igniting those large bubbles with a piezo igniter and with the hot cathodic plasma reaction ("standard" plasma electrolysis), but I couldn't manage to, or at least not to any clear extent. They are strong enough to be collected on a metal support (e.g. screwdriver) without bursting. I can only attempt the matchstick test tomorrow at the earliest.

Earlier on in this thread I have reported that the Mondaini/Mizuno plasma electrolysis experiment with the Bazhutov electrode polarity (thin anode and large cathode / anodic plasma) would require higher voltages and be rather noisy to run (ear protection strongly recommended).

While performing RF emission measurements as reported in a newer thread, I tried enclosing the anode with a small plastic tube. This was possible as with this configuration the electrode does not heat up significantly/melt/burn.

By doing this, operation with the electrode immersed in the solution is doable even with the DC boost converter that I've been using so far, which is not very powerful and cannot maintain high voltages under strong load.

The unexpected part however was that after a relatively short period of operation a large number of close-packed gas bubbles would form on the water surface. I believe they could be due to H₂–O₂ gas: regularly evolved gas at the anode from electrolysis, even at moderately high voltages, does not cause the same bubble formation. This could be the main reason why this mode of operation generates loud noise from repeated explosions when performed at the water level.

As for why this happens, I do not have clear ideas, but OH- anions accumulate in large amounts at the anode. Could it be that at high voltage they decompose to O₂ and H₂ or possibly combine to form H₂O₂ (hydrogen peroxide)?

I made a video of the large persistent bubbles formed in the process. Small explosions can sometimes be seen even with the immersed electrode. Unfortunately the video ended up being vertically oriented.

The bubbles don't seem to be easily ignited, but I haven't made many tests on this regard.

magicsound

I use an RTL2832U-based software-defined radio, and more in detail this one:

https://www.nooelec.com/store/nesdr-smart.html

However, after more tests, it turned out that the power supply was the cause. I noticed that turning it off/on would cause the same signal for a short while. That yesterday I saw something reminiscent of 50 Hz AC inside the same signal was a hint. Here are the spikes I got typically when trying to turn it off:

After I tried using a VRLA 12V battery to power up the boost converter, the only noise of similar frequency that I got in the area was that of its 75 kHz PWM operation.

Just to make sure, I then tried to get again the spectrum of the noise generated by the plasma over the entire frequency range (24–1750 MHz) and I got results similar to those in the opening post. So at least this one does not seem to be PSU-caused. The yellow line is the background signal (for the gain setting used).

The left one was taken with the whip antenna at its minimum length, the right one with the antenna fully extended.

In summary, the 127.5 (or 128) kHz repeating signal at low frequencies was only a coincidence and was due to the power supply. The larger-scale features seem still dependent on (probably) the cable and antenna length. At the next (larger) scale level, there appears to be a real signal, which is apparently mostly broadband noise decreasing in intensity with frequency.

EDIT: I tried a different 12V power supply and the ~127 kHz noise did not appear with it during the plasma reaction. So it does not seem to be something dependent on grounding or similar issues.

I tried measuring it again at 24 MHz (the lowest frequency that I can set with my RF receiver) and not surprisingly—in retrospect—it was sharper and better defined, and other switching-type noise was too. Below a comparison of such signal with one of the previously posted figures from actual papers.

This also allowed better sensitivity to possible nearby disturbances. I couldn't find (yet) other sources of 127.5 kHz noise, but other than the DC boost converter I found that my computer's power supply has a switching frequency of 70 kHz.

Also, previously I used the anode at +125V and the cathode at -125V. Both HV outputs from the DC boost converter have had their capacitor replaced in the past, but they have differing capacitances now (8.2 and 10 µF). I tried changing the setup so that the anode is at ground voltage and the cathode at negative voltage (at -250V) and only one capacitor is used, but no change was observed. The boost converter seems to operate more smoothly when only one output is used, among other things.

Eventually I tried to use a different program to "listen" at a high rate the time variation of one such peaks with 127.5 kHz spacing with amplitude modulation (AM), which can only be done on very narrow bandwidths. I used a program called CubicSDR for this. It turns out that the noise varies on-off at a 100 Hz rate. It looks as if this could possibly be something from 50 Hz AC, but I have no idea if it's the cause or a result of the 127.5 kHz signal observed during the plasma reaction.

I have attached the wav file to the comment.