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Re: tungsten anyone?

Original poster: David Speck <Dave@xxxxxxxxxxxxxxxx>
I suspect that there are two entirely different mechanisms involved with Thorium in electrical discharges. I think that the reason that Thorium is used in vacuum tube filaments and welding rods is because when it is hot, its metallurgical properties make it a very good electron emitter, quite apart from its properties as an alpha particle emitter. Since Thorium has a very long nuclear half life, I don't believe that its radioactive decay alpha particles contribute significantly to initiation or maintenance of a welding arc. You would have to have an extremely radioactive piece of material, like the element on an old Polonium antistatic record brush, before you would start to see facilitation of air ionization. In any event, when Thorium, Radon, or Plutonium end up as airborne particles, they are small enough to become deposited in the alveoli, the tiniest air sacs of the lungs. There they act as permanent personal internal X-ray machines (well, OK, high energy alpha particle emitters), blasting helium ions into the nuclei of adjacent lung cells, breaking up DNA strands, and triggering cancer. Plutonium has a half life of 24,000 years, but I've heard that the atmospheric plutonium particles absorbed from old atmospheric nuke tests by tobacco plants and then inhaled by smokers are a significant if not major part of the carcinogenicity of tobacco smoke. Internal absorption of alpha particles from a microscopic amount of ingested polonium were what killed the Russian in England recently -- he had total body irradiation , just done from the inside out. 
Therefore, I'd still rather use RSG parts without Thorium.

Dave Speck (MD)


Tesla list wrote:

Original poster: Frank <fxrays@xxxxxxxxxx>

Hi All,
I posted earlier about out gassing radioactive vapors for those who are really concerned.
Truth be known, you have more radiation inhaled in the form of radon gas in your basement, for those who have them or in a well sealed house. 
There is far too much paranoia about this stuff than merits the fears.
Most of us have smoke detectors in the house that emits more radiation that what little would ever come out of the electrodes during operation. Now, if you ran the coil 24 hrs a day/ 365 days a year in a small room with little or no air exchange, then there might be some possible concern but the EM and ozone would do a lot more damage!
Like running any coil, just make sure you have adequate ventilation and that is for your ozone concerns!
If it was a danger to use thorium electrodes, they would have been outlawed years ago. 

Thanks, Frank

At 03:40 PM 2/11/2007 -0700, you wrote:

Original poster: Mike <megavolts61@xxxxxxxxx>

Hi All,
I doubt there's really enough Thorium oxide created to cause concern. At 2%(by wt, I presume), and the tiny amount of material oxidized - even over a year's time would not amount to much. 
Welder's go through quite a few of those rods they use per year .
Thorium has a very long halflife, so the specific activity is pretty low. Plutonium's 24000 yr halflife would present a much higher danger. Polonium 210's half life is so short by comparison(138 days) that a gram of it encapsulated in a stainless steel capsule will raise it's own temperature to as much as 500º(I picked that because of that Russian spy who was killed with it). Plutonium in metal form will actually feel warm, but nothing like Polonium. Uranium and Thorium have half lives in the billions of years for the main naturally occuring isotopes (Th 232 and U 238). You could hold a ten lb hunk of either and not notice any temperature. They wouldn't use them in welding if they presented much of a hazard. I'd avoiding breathing any dust or oxides, but you wouldn't want to breathe the tungsten oxide dust either. 
Mike


Hi Anthony,

One has to wonder how much radiation is gased out on a rotary spark
gap...
We are running multiple rods not just one.

Jim Mora