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Re: Thoriated Tungsten vs Pure

Tesla List wrote:
> 
> > Subject:       Re: Thoriated Tungsten vs Pure
> > Subject: Re: Thoriated Tungsten vs Pure
> 
> >From single-at-mail.sat-dot-netSun Sep 29 22:05:23 1996
> Date: Sun, 29 Sep 1996 13:35:55 +0000
> From: Chris Singletary <single-at-mail.sat-dot-net>
> Reply to: single-at-imsday-dot-com
> To: tesla-at-pupman-dot-com
> Subject: Re: Thoriated Tungsten vs Pure
> 
> > Date:          Sat, 28 Sep 1996 22:25:08 -0600
> > From:          Tesla List <tesla-at-poodle.pupman-dot-com>
> > To:            Tesla-list-subscribers-at-poodle.pupman-dot-com
> > Subject:       Re: Thoriated Tungsten vs Pure
> > Reply-to:      tesla-at-pupman-dot-com
> 
> > >From ed-at-alumni.caltech.eduSat Sep 28 21:36:18 1996
> > Date: Sat, 28 Sep 1996 15:21:59 -0700 (PDT)
> > From: "Edward V. Phillips" <ed-at-alumni.caltech.edu>
> > To: Tesla-list-subscribers-at-poodle.pupman-dot-com, tesla-at-pupman-dot-com
> > Subject: Re: Thoriated Tungsten vs Pure
> >
> > Thoriated tungsten is used for tube filaments because it hnas
> > has much higher emission at lower temperatures than pure tungsten,
> > hence lasts much longer.  Effect was discovered accidently in the
> > early 1920's.  Thorium was originally added to light bulb filaments
> > "to make them easier to draw through the wire dies" (per RCA
> > Vaccum Tube Design Manual, circa 1940).
> > Can't prove it, but suspect the radioactivity is barely detectable,
> > and certainly not a health hazard.
> > Ed Phillips
> >
> That is not quit true. Thoriated tungsten such as are used in TIG
> welding do not cause a health hazard except under continous inhaling
> of the vaporized metal for many years. (Welders can get lung cancer
> from long term exposure.) Or... that large quatities of the
> electrodes are not stored in close proximity to a persons body.
> Casual use of the rods pose no health hazards that are known. But it
> is another thing to be exposed to the fumes and or a large quantity
> of the electrodes. A geiger counter will go crazy with full box of
> them. (Just try it!) Welders that do alot of TIG welding should protect
> themselves for the vapors and against carrying boxes of them in their shirt
> pocket (Like so many are prone to do.)
> 
> Chris Singletary
> member - TCBA
> Believe that you CAN accomplish the impossible and you shall.


All, 

Being an old "Rad" guy from way back, and an element collector, I can 
tell you that the thoriated tungsten rods I have measured (up to 1/4" 
diameter)  are just slightly above background at point contact range.  
The stuff is so self absorptive that only what little Rad stuff is on the 
surface counts.  Its the Alpha particles that do the most Bio damage and 
this stuff can't fight its way out of a wet paper bag even at 4-6 million 
electron volt energies. At a range of 2-3 cm even in air, it is all 
played out.

I have lotsa' pure elemental Thorium (100%- actually 99.99)  the rods, 
chunks, and pieces that I have are quite hot.  The largest rod I have 
(1/2" diameter 6" long) of the pure stuff is cookin' away at 50,000 
counts per minute point contact.  It weighs several hundred grams.  I 
have some thorium foil .003" thick, and it weighs only 2grams but boils 
off the Rad spooey at exactly the same rate of the heavy rod.  With 
ultra-dense materials, the radiation is just a function of surface area 
and concentration. especially for alpha and beta particles.  

Gamma is another matter. Actually it's not matter at all.  It is 
electromagnetic wreakage from the atomic nuclei going high order.  Kind 
of a "nuclear RF".  From thorium, the risk from gamma is virtually zero. 
 Most of the gamma emitted in any small nuclear source makes it out to 
the real world, but usually we don't stop much of it either.  It just 
zips on through us.

As has been mentioned already by others, breathing any alpha particle 
source is a real no-no.  A 1 curie alpha only source (like concentrating 
2 million smoke alarms in a block) can be held in the bare hand!  You 
will get a terrible surface burn after just a few hours and maybe after 
20 years develop skin melanomas on that hand, but you will live from what 
would be a lethal dose of any other radiation.  However, breathe a mere 
.0000001 gram of radium and lung cancer is virtually assured over the 
long haul.  You would absorb 100% of all the 4 MEV alpha particle 
radiation from this invisble quantity.  Every atom would destroy 
tissue!!!  .0000001 gram of radium emits about 3700 high speed helium 
nuclei every second!!!  So in a week you would have suffered a minimum of 
2.2 billion ionizing collisions and total absorption of nuclear radiation 
within a limited area of you lung tissue.

Scarey!!!!  You bet guys!

Richard (th' Radman) Hull, TCBOR