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Tuesday, January 27, 2009

The case of the bogus "expert" (guest post)

Commenter Bill #2, who is incredibly knowledgeable about weapons, noticed a news item I translated from the Palestine Today about a British "expert" who determined that Israel used uranium weapons in Gaza based pretty much on watching the explosions on TV. Bill did a little research:
Following your link and doing a bit of research, the 'expert's name is Dai Williams. From where is his expertise? Well, if you read his own introduction at http://www.grassrootspeace.org/ d...iams_oct03.html , you can see where his expertise comes from:

• Is he a biological researcher? No
• Is he ex-military with extensive experience or training in either EOD (Explosives Ordnance Demolition) or BDA (Bomb Damage Assessment)? - No
• Is his background in civil engineering or demolitions? No
• Is he a chemical engineer, especially one studying explosives No

Dai Williams is a Chartered Occupational Psychologist, from his own web page at http://www.eoslifework.co.uk/. So far there is nothing to suggest that he is an expert in the subject matter of identifying explosives type by detonation cloud. He has done work as an environmental consultant in the oil industry for many years.

So far, there has not been definitive proof of the use of depleted uranium (DU) in Lebanon, as far as I understand. A lot of supposition and allegations, but so far no definitive proof. [The UN found that Israel did not use it, but Bill #2 is taking the allegations at face value, for argument's sake. - EoZ] Given that the type of explosions would be the same if DU wasn't used in either case, and possibly the same if DU was used in either or both cases, it is so far just an allegation based on what was seen on television from Gaza. Any deep penetrating explosion is going to have a similar dust and smoke plume, with the debris channeled up into a high dust cloud as it takes the path of least resistance upward. This can include the path that the incoming bomb took, or it can mean the tunnel itself if the explosion happened inside the tunnel, as you would expect with precision-guided munitions. The cloud of hot gases and dust will rise quickly, emphasizing the narrowness of the cloud, and often it will continue to rise to form a miniature mushroom cloud as the dust and gases stop rising as they cool at the top of the plume.

Let's look at some of his other claims (not exhaustive, just some quick ones):
"Some versions of these warheads also use tungsten but tungsten does not burn." http://www.eoslifework.co.uk/ pdf...weapons2006.pdf

Well, that's news to light globe manufacturers who seem to insist on putting inert gas inside glass envelopes with the tungsten filaments for no reason whatsoever. Let's look at a reference, just to be sure: Tungsten Powder "In finely divided form, highly flammable."[3]. Eric Lassiter in his book Tungsten[4] describes how tungsten of 1µm or smaller can be pyrophoric (likely to ignite spontaneously on exposure to air). Finally, United States Patent 3946673 "Pyrophoris penetrator" - 'Alloys of tungsten, zirconium and one or more binder metals are utilized as pyrophoric penetrators.' I think I will agree that bulk tungsten will not burn, but in the presence of the shock waves, temperature, and pressure from high explosives, the metal may be finely dispersed and raised to a temperature that may be causing it to burn, especially if the explosive is oxidizer-rich. I would agree that uranium is more pyrophoric than tungsten, but the claim that tungsten can't be used because it doesn't burn is not convincing.

"Now tungsten will be no good for that because it will burst but is no more than that; while uranium if it fragments, it will turn then into a firebomb." http://www.grassrootspeace.org/ d...iams_oct03.html
Certainly the standard enthalpy of formation is high for U3O8 (-3575 kJ/mol), but it is much lower for the other uranium oxides: UO2 (-1085 kJ/mol) and UO3 (-1224kJ/mol)[1]. This is the energy released by oxidizing (burning) uranium. Compare this to tungsten dioxide (-586 kJ/mol) and aluminum oxide: Al2O3: (-1676 kJ/mol), zirconium dioxide (-1097 kJ/mol), magnesium oxide (-602 kJ/mol) and water (-285 kJ/mol). Note that tritonal, an explosive used in bombs, uses a mixture of TNT and aluminum powder to increase brisance, but if we take the energy released just by TNT, we have a figure of 950kJ/mol[2], but you can't harness the full energy of the standard enthalpy of formation like you can with the TNT since you still need an oxidiser - which may be partly supplied by the TNT itself - and it needs to be finely dispersed enough for the oxidisation to achieve a useful effect. The problem is you may not get much of the higher energy from the U3O8 in a limited oxygen environment than you might if you just added aluminum powder to your primary explosive. You can't just look at the standard enthalpy of formation, and make a prediction without reference to other things such as the stability of the oxides which may affect the oxidation of the underlying metal and the rate of its burning.

"Researcher Dai Williams believes this is a new class of weapons using enriched uranium, not through fission processes but through new physical processes kept secret for at least 20 years." http://www.globalresearch.ca/ind...& articleId=3813
Well, maybe not so much a secret, since enriching uranium through centrifuge methods (i.e. non fission process) has been going on since 1945, and Iran is proud of its ongoing work with uranium hexafluoride gas centrifuges[6]. Wikipedia has a super secret page on these non-fission enrichment processes[9].

Dai actually raises a very interesting point[8], one overlooked by many. Depleted uranium can be used as a shaped charge liner[5] for the type of anti-tank weapons supplied to Hamas and Hezbollah (Self Forging Fragment). Iran has significant deposits of copper[7], so it is unlikely that it would be driven to deploy depleted uranium because of a lack of copper, the traditional shaped charge liner. Note [5] refers to a five times better penetration to that of copper. If there are traces of depleted uranium, they may be due to Iranian, although it is anyone's guess at whether Iran would risk exposure through the deployment of such material. If it has, then that may explain some of the DU material that people are claiming to have found. It is also possible that people may be unwittingly using DU-based weapons.

In conclusion, we just don't know, but I think it's a stretch basing one supposition onto another as proof.

Notes:
[1] http://webbook.nist.gov/cgi/cboo...Units=SI& cTC=on
[2] http://en.wikipedia.org/wiki/ Tri...Trinitrotoluene , http://en.wikipedia.org/wiki/Tritonal (using public sources here)
[3] http://www.ilo.org/public/englis...14/ icsc1404.htm
[4] ISBN 0306450534
[5] http://www.freepatentsonline.com...om/ 4441428.html
[6] Official Iranian web site: http://web-srv.mfa.gov.ir/output...nts/ doc7949.htm
[7] http://www.indexmundi.com/en/ com...copper_t20.html
[8] http://www.eoslifework.co.uk/ pdf...u26leb19oct.pdf , page 25
[9] http://en.wikipedia.org/wiki/ Ele...tope_separation
OK, it was more than a little research!

Bill #2 also wrote a pretty exhaustive treatise on white phosphorus in the comments that I've been meaning to post....