BTE-Dan: Replication Attempt for This Week

Quote from axil

How can a blue white light be produced in an experiment that uses resistant heat at 350C. Is the reaction producing a laser like effect? The measured heat at 350C and the observation of a 5000K light source does not make sense to me. It is not blackbody or is it?

Jack said he had a hot coil (filament) inside. The coil (filament) may be well above 1000°C. The light from that high temperature coil (filament) is transmitted through the cooler alumina shell, which is at 350°C. Then you end up with a spectrum from the transmitted light from the hot coil (filament) plus the blackbody spectrum emitted by the 350°C alumina shell.

Quote from BobHiggins

Jack said he had a hot coil (filament) inside. The coil (filament) may be well above 1000°C. The light from that high temperature coil (filament) is transmitted through the cooler alumina shell, which is at 350°C. Then you end up with a spectrum from the transmitted light from the hot coil (filament) plus the blackbody spectrum emitted by the 350°C alumina shell.

Shouldn't the reaction temperature be accurately reckoned at 1000C rather that 350C. The place in the alumina tube closest to the filament is receiving heat at 1000C not at a distance where the temperature is cooled to 350C. We are dealing with a very hot spot here. The AVERAGE temperature of the tube might be 350C but where the hot spot is, the temperature is 1000C. You can not state that alumina is translucent at the average temperature of 350C, it may be translucent very near the hot spot where the temperature is 1000C.

Quote from axil

Shouldn't the reaction temperature be accurately reckoned at 1000C rather that 350C. The place in the alumina tube closest to the filament is receiving heat at 1000C not at a distance where the temperature is cooled to 350C. We are dealing with a very hot spot here. The AVERAGE temperature of the tube might be 350C but where the hot spot is, the temperature is 1000C. You can not state that alumina is translucent at the average temperature of 350C, it may be translucent very near the hot spot where the temperature is 1000C.

You cannot deal in averages - it doesn't work. Look at the spectral transmittance of sapphire - alumina will have that transmittance but with wavelength dependent scattering. Do some research, don't just speculate.

Quote from BobHiggins

You cannot deal in averages - it doesn't work. Look at the spectral transmittance of sapphire - alumina will have that transmittance but with wavelength dependent scattering. Do some research, don't just speculate.

If your belief were true, then the entire length of the alumina tube would be lit by the central hot spot as in an incandescent light bulb. But the tube does not glow in a uniformly distributed light. Most of the light generated by the filament passes through the hottest section of the tube only.

This hot spot based reckoning has been verified by Rossi's latest experiment where a hot spot is also present. Blackbody generated light is produced by the hot spot that does not melt the nickel electrodes at the edge of the tube. And yet, subsequent calorimetric measurements back up the initial spectroscopic calculations of energy gain.

Quote

Andrea Rossi
May 20, 2017 at 3:07 PM

Frank Acland:

You know, we too were very sceptical when we found this new order of magnitude of COP and power density, so anytine we make measurements both with Wien and Boltzmann equations after spectrometry and get a certain COP, eventually we make calorimetric measurements and get the same order of magnitude of COP we are very enthusiast, also because now we are arrived at a Sigma rating very high, albeit lower than 5.

Warm Regards,

A.R.

Rossi claims to be running the QuarkX for a year without refueling.

One of the biggest challenges in the QuarkX design is keeping hydrogen contained inside the tube at 2700C for an extended period of time. The containment material must have to be very dense, thermally stable, and impermeable to hydrogen escape at those very high temperatures. Hexagonal Boron nitride is a good candidate for a compound that would minimize hydrogen leakage at those extremely high temperatures.

Other properties that the tube material must possess is derived from being an “electrical insulator”. This is necessary to avoid any electromagnetic interaction from the tube material that might interfere with plasma ions.

The tube material must not interfere with electrostatic and/or magnetic stimulation. An electrical indicator will provide this property.

I can understand why Rossi needs to run this reactor for a very long time (sigma 5) to make sure that the tube material holds up both physically and electromagnetically and that this tube does not leak hydrogen to any significant degree.

And that oxygen corrosion does not affect the structure of the tube over an extended timeframe of a year of operation. As a matter of fact, an oxide coating on the surface of the boron tube will effectively block hydogen penetration through that surface coating.

Boron nitride and lithium get along well together.

http://news.rice.edu/2016/04/1…onents-can-take-the-heat/

It's a bummer that the topic has drifted this much over the past pages - I'm responsible too - but I guess it's still in-topic since it's now about how Rossi could have [seemingly] obtained results.

Here is a random photo of alumina tubes from the internet. They're clearly translucent at room temperature: light from the outside makes the internal walls appear lit. I'm assuming that the opposite (with an internal light source) can easily happen too.

Here's another where the effect is less apparent but still visible:

Alan Smith

Now it would be really interesting to see what an IR camera or even an IR thermometer would measure.

Definitively translucent.

Alan Smith

I guess that was to be expected; still it's quite interesting that it can let so much light pass through, that means you could have a gas discharge phenomenon occurring inside (as Ahlfors appears to be hinting above) with it sort of operating like a lamp.

https://en.wikipedia.org/wiki/Barringer_Hill

The fact that the light can escape without the envelope of the tube being high temperature is a well known design principle for plasma lamps. Take for example the high pressure arc lamps used to pump continuous YAG lasers. The lamp is lit by a high current DC discharge (about 1kW) through the gas in the tube (filled with xenon and argon I think). The fused quartz tube would melt in air, but the elliptical cavity that holds the tube and the YAG rod (at the two focii) are filled with flowing water to cool the tube (and the rod). The fused quartz envelope of the DC discharge plasma lamp is probably held to under 100°C while the core plasma is still hot and emitting light at at a blackbody spectrum >4000°K (with strong lines as well).

In the case of the alumina tubes, there will be loss in transmission and scattering. The light that is scattered will have to pass through more alumina than light not-scattered. Light passing through the individual crystallites is bent (a scattering) by the orientation of the crystallite, but is transmitted with a loss of only a few %. Most of the attenuation in the alumina is from scattering such that on average, to make its way out of the alumina, it has to go through many more of the crystallites than necessary by virtue of its thickness. I have alumina substrates (flat, about 1mm thick). You can apply a laser to one substrate, look at the spot size on the incident side and the spot size on the exit side. Then add additional substrates to the stack and watch the spot diameter grow from the scattering. The laser spot, even expanded in size, makes its way through 5 mm of the alumina substrates with significant intensity remaining.

Quote from Can

Now it would be really interesting to see what an IR camera or even an IR thermometer would measure.

Most IR cameras and IR thermometers measure the IR in the far infrared. When illuminating the interior of an alumina tube with a white light LED, the light is reddened because the blue light is scattered far more effectively than the red light, causing it to go less "straight through" the tube wall and undergo more attenuation. The photon energies have not been changed through this scattering - if there were no far infrared emissions in the LED to start, there will be none coming out - and there were no far infrared emissions from the LED. The IR cameras and IR thermometers have a far infrared optical bandpass filter in their bolometer sensor so that they only respond to far IR. There are a few near IR thermal sensors available, but they have even sharper filters to look at very specific wavelengths. Their optical bandwidth is small enough that they will not respond significantly to broad spectrum light or the product wouldn't be viable. Note that the white LED does not have completely broadband emission. It is a blue LED which excites a translucent phosphor that supplies some red and green from fluorescence.

@BobHiggins 

Yep; I should have added that this would have been enough to deceive the viewer, but not to deceive an IR sensor. An arc discharge or a hot filament would still be needed.

Quote from Alan Smith

The tubes are transparent at room temperature. Can you get transparent boron nitride?

Bigger than this, of course. https://arxiv.org/ftp/arxiv/papers/1405/1405.7179.pdf

Both hexagonal and Cubic Boron nitride are transparent at certain EMF wavelengths and cubic BN has the same structure and properties as diamond. BN can be hot pressed to produce a translucent tube that will allow high energy photons to pass through. Using this stuff, there is a good chance that the SunCell could be miniaturized to produce XUV light with the same characteristics of the SunCell and pass that light through a translucent BN tube. The key to this concept is the manufacture of the tube. BN is hot pressed just like the other ceramic materials that are used in LENR to form tubes. A refractory metal like Tungsten could be used for the heat resistance electrodes and Solar cells could surround the BN tube or an array of BN tubes. In effect using BN, the SunCell could be converted into a solid state device with no moving parts.

Silver could be used as a metal vapor in the same way that occurs in the SunCell. A photonic base down shifting mechanism such as used in a florescent light could be used to convert the XUV light into the visible light range usable by Solar Cells.

Most of the ultraviolet wavelengths are not absorbed.