FAQ - Temperature!...of a fusor...of fusion

If you wonder how/why fusion works, or how/why the Fusor works, look here first.
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Richard Hull
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FAQ - Temperature!...of a fusor...of fusion

Post by Richard Hull » Mon Mar 10, 2014 6:07 pm

There is an atmospheric temperature of the fusor shell and it will rarely reach the boiling point of water. There are localized spot temperature zones where ion and electron streamlines impact the walls. These spots are much warmer as they are the source of spot heating of the shell which is part of the overall atmospheric temperature of the fusor shell. These spot heating points might reach 500 deg C at the impact point inside a fusor which is a very tiny point. In glass bell jars, this is a point of great danger and can lead to flaking of localize glass chips and, if continued, could result in total failure of the jar.

All metal fusors are in no danger of overheating unless the use of very soft soldered or epoxied joints are part of its construction. All joints should be TIG welded or Hard silver soldered (brazed). A fusor can be cooled if desired by winding a coil of copper tubing over the fusor body and pumping water through the tubing to a heat exchanger and recirculated. I think only one or two of our folks have attempted this. Thus, it is not necessary to cool the average fusor.

There are temperatures or more honestly, energies, often quoted in degrees kelvin related to the internal fusing plasmas. The use of the word "Kelvins" is proper, but few folks detail this fact. In these often misleading statements, mostly giving by physicists trying to impress a lay audience, millions of degrees are quoted. They often never add the word kelvins. Why confuse the ingnorant with the proper terminology? Just say it in degrees like the temperature they understand in day to day life. (deliberately misleading)

The fusor's internal, individual "ion" and fusion temperatures in kelvins are in a vast range. From as cool as 165,000 degrees to the ideal fusion ion-ion collisions resulting in fusion of 440 million degrees in a 40 kilovolt fusor (my fusor IV). Most of the ions in a 40kv, (440million degree), fusor are much hotter than 1 million degrees and much cooler than 100 million degrees. I have delivered the foregoing as a fusion physicist would deliver it to the media when talking about how close they are to doing fusion. Again, substitute the word "Kelvins" in every instance where I used degrees and the truth is told.

The fusor fuses in "velocity space" and not in a unifrom neutral plasma as in an idealized thermal fusion machine (tokamak, ITER). This is key to its operation. We are dealing with ion-ion, ion-neutral and neutral-neutral collisions when we fuse in an IECF fusor within velocity space, thus, there is a range of energies within velocity space.

The fusion in a fusor or a tokamak occurs in a hyper-thin atmosphere of deuterium ions and not a feelable solid so a feelable heat in kelvins or degrees is just not there. Temperature, (thermally speaking), is nothing more that the speed of particles/molecules in a solid, liquid or gas and nothing more. The faster those particles move, the higher the temperature in kelvins or degrees of that particle. This is really just another expression of the energy contained in that particular particle and in relation to its mass, its momentum.

In solids, quintillions of particles all colliding with each other, make a "feelable" temperature to our skin. In a vacuum, (low pressure), level gas of deuterium in a fusor, all of the gas particles moving about at a relative temperature of 100 million kelvin degrees would feel incredibly cold.

In deep space the temperature is near absolute zero degrees and zero kelvins. why? There are only a rare few particles moving about per square cm. In space your hand, a solid "water bag", would ultimately freeze ....YET.... the few particles impacting your hand's skin in space each second are at millions of billions of kelvin degrees, (cosmic ray matter particles, etc.)

* note * There is some amount of beam on target collision in the fusor that does not involve velocity space fusion. (explained in another FAQ)

Fusion temperatures are conversions of the energy of the deuterons, neutrons, electrons, and neutral molecules in motion, (kinetic energy), to an equivalent temperature of a particle in motion in a sea of molecules in a solid substance at that temperature. In the fusors or any fusion device, you are in a "near space" vacuum of flying deuterons, electrons, fusion debris - (neutrons Tritons, 3He, protons) and neutrals and not in a solid, so, you can't relate this to a "feelable", "touchable", temperature that our senses are commonly linked to. The normal method of talking among fellow physicists would be to discuss the energies as "electron volts" (ev). The relation of electron volts to kelvins is to multiply the (ev) kinetic energy of the particle by about 11,000. A 1kev particle is said to represent an 11 million kelvins particle. (11 million kelvin degree particle)

The general public would have issues understanding this concept. The fusion physicist absolutely relies on this to befuddle and confound, the public, yet impress enough to obtain continued funding. Don't be a "general public" type! If you are still confused, read up on the physics and Boltzmann's work on thermodynamics.

Absolute zero = no motion of any particle = -273deg C = - 460 deg F = 0 kelvins = 0 eV (electron volts)
Water as a dense liquid freezes at 0 deg C 32 deg F 273 kelvins = .0325eV (corrected - Thanks to Joe Ballantyne)

Richard Hull
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Re: Temperature!...of a fusor...of fusion

Post by Jeroen Vriesman » Wed Mar 12, 2014 10:01 am

Translating the speed of accelerated particles to temperature seems a bit confusing to me.

Temperature is defined for a system in "its own state of internal thermal equilibrium", which usually implies a maxwellian speed distribution.

On the other hand, a beam of high speed particles, where all the particles have the same speed can be called "cold", in the right frame of reference it can have a very low temperature while real temperature does not depend on the frame of reference (I think there are still some mysteries about relativistic transformation of temperatures, but that's another discussion)

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Re: Temperature!...of a fusor...of fusion

Post by Richard Hull » Wed Mar 12, 2014 4:05 pm

........"Temperature is defined for a system in "its own state of internal thermal equilibrium", which usually implies a maxwellian speed distribution"......

This is why the "maxwellian tail", that I have noted before is where most fusion occurs and is, therefore, no place to hang your fusion hopes and dreams.

This FAQ was more of a way to link the concept of temperature claims of the press quoting from a physicist who is boosting his own fusion efforts to the reality of what temperature means in our normal day-to-day sense of temperature. It also sought to define the electron volt concept of particle kinetic energy to Boltzman's thermal particle kinetic motion. Boltzman is the guy to blame for setting up the conversion, but the phsyicist is the one to blame for dealing the lay person the jargon of "hundreds of millions of degrees in a 10kev plasma.

We have a lot of regular folks and younger fusion aspirants showing up here who have not been exposed to the physics of fusion to any great depth, but who have been enthralled by the terms of "hundreds of millions of degrees" needed to do fusion.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
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Re: FAQ - Temperature!...of a fusor...of fusion

Post by JoeBallantyne » Tue Nov 10, 2015 1:28 am

One correction to the FAQ above: Water freezes at 32 deg F = 0 deg C = 273 K = 0.0235 eV.

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Re: FAQ - Temperature!...of a fusor...of fusion

Post by Dan Tibbets » Tue Nov 10, 2015 5:08 am

I don't think expressing temperature in what ever common unit of measure is terribly miss leading. Mildly miss leading perhaps, but close enough for general discussions. 1 million degrees C equals 1,000,273 degrees K. Not much relative difference. Degrees F would be ~ 9/5ths greater, but this is still only 1,800,304 degrees F (if I calculated right). Close enough for most general discussions. Well almost, C is very close, and F may require an appreciation that a factor of almost two may need to be remembered.

As for the temperature of the cosmos. It has little to do with the KE of any very rare particle that may hit and transfer +/- heat to a test object. The average density of particles is just to small to contribute much. The cosmic background radiation temperature refers to the wavelength of light that that would be emmited via theoretical black body radiation. I think it is primarily a consequence of the expansion of the universe acting on the average temperature of the universal gas once it became transparent to radiation. It ties in with the red shift of galaxies that is used to measure distance/ time.

I'm not sure how quickly you would freeze if exposed to the vacuum of deep space. Unless you were undergoing evaporative cooling, the only way of getting heat away from your body would be radiation. There would be no convection or conduction of heat. There is a moderate temperature difference (~ 300 degrees C or K). Compare this to a heat light where the temperature difference may be twice that. Of course exposed surface area and other considerations apply. The cold of deep space does have significant effects, just not as much strength(rapidity) as other methods of heat transfer under common human environments. I suspect your body temperature would drop more rapidly if you fell off of the Titanic into the North Atlantic (at least till you closely approached the temperature of the water). Without a space suit, you would very quickly lose consciousness with death closely following due to suffocation. Your blood may boil- at least in areas close to the surface, things may rupture or become engorged with blood- like the lungs. Freezing would be a more gradual process. This is not to imply that the cold temperature of deep space is completely trivial. Frost/ dew forms in open fields at night faster than under trees due to radiative cooling to deep space. This despite any convection processes that tends to even out the temperatures provided there is little wind (enhanced convection processes).

Dan Tibbets

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Re: FAQ - Temperature!...of a fusor...of fusion

Post by Frank Sanns » Wed Nov 11, 2015 5:43 am

Temperature is the average molecular or atomic or subatomic motion. Temperature is energy of the individual units. It can be expressed in electron volts, Kelvin, joules or any other energy unit for that matter. It says nothing about the total energy of a system, only the individual elements of the system.

In the ionosphere of the earth, temperatures are well in excess of 1,000 Kelvin yet you would freeze to death there (if lack of air did not kill you) as your body would radiate heat away at T^4. The air is so rarified there that even though the ions are ripping along, there are so few of them that no significant amount of heat is transferred.

If you want to prove this to yourself, blow some 140 F air on your hand. Then try to touch a piece of styrofoam at the same temperature, then wood. Lastly, try to hold your hand on a 140F piece of aluminum. It is all about density and above a certain density, heat conductance like in the case of aluminum.

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Re: FAQ - Temperature!...of a fusor...of fusion

Post by Richard Hull » Wed Nov 11, 2015 5:52 am

Thanks Joe for the correction. I have entered the correct value in the original and noted it as corrected. FAQs need to be accurate.

Richard Hull
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Fusion is the energy of the future....and it always will be
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Re: FAQ - Temperature!...of a fusor...of fusion

Post by jancecrdle » Thu Dec 03, 2015 5:43 pm

Hi, could you please explain to me how exactly do you calculate the 11,604 ratio between kelvins and electronvolts? Jan Čečrdle

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Richard Hull
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Re: FAQ - Temperature!...of a fusor...of fusion

Post by Richard Hull » Thu Dec 03, 2015 9:17 pm

I am not one to hound a poster for their questions, but could you not have typed in "electron volt to kelvins" in google and arrived at this fabulously complete discussion in wikipedia.

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

If you can't understand the full derivation and explaination found in the above link, then you must accept as a given, what I posted is a direct and simplified explanation. Temperature, as we perceive it, is little understood at its core level by about 99% of all living entities. Chemists and physicists as well as the few who absorbed and retained it from college classes are among those who might really forever understand what energy of particles coupled with material densities and conductivities mean in relation to what is commonly called temperature.

Just as there is no such thing as a vacuum, except in theory...(There are only varying pressures in the real universe). Temperature is all about energy in a system, solid or particle. There are many expressions of energy depending on how you wish to understand it in relation to the system under study.

My treatment in the FAQ presented here is more to aquaint the younger amateur fusioneer, who is yet ignorant of such things as particle energy, as displayed in plasma physics in relation individual particle temperatures and the effective misrepresentation by fusion physicists to the lay audience and press that they are playing with really big stuff when they really just want more money to continue to play with big stuff.

Real phyicists, when talking to one another about nuclear particles, ions, etc., talk only in electron volts which immediately means something to them in concrete terms. Only at wine and cheese parties with ignorant, but wealthy patrons would they throw out millions and millions of kelvin degree terms related to their work. The real tell is if they say "degrees" instead of the more proper "kelvins" without the degrees.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Re: FAQ - Temperature!...of a fusor...of fusion

Post by Jason C Wells » Fri Dec 04, 2015 6:06 am

The late Admiral Rickover taught us that units should be named: degrees Kelvin, degrees Rankine, degrees Celsius, or degrees Fahrenheit or shorthand: °C, °F, °K, °R. Anything less was unsat. I don't care for units of temperature in place of kinetic energies, so thanks for this article.

Does the distribution of energies in a fusor actually follow a Maxwell-Boltzmann distribution? It seems to me to be very hard to measure this.

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