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Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
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<blockquote data-quote="Magnetoman" data-source="post: 130684" data-attributes="member: 2806"><p>I found an article on the use of polonium in spark plugs in a 1940 issue of the Journal of Applied Physics by J.H. Dillon of the Physics Research Division of Firestone. The data show the ionization due to emission of alpha particles significantly lowers the voltage required to initiate a spark.</p><p></p><p>The practical problems are 1) the range of alpha particles is greatly decreased if the Po is covered by carbon, so placing a separate Po wire nearby quickly loses its effect, and 2) coating the electrode with a thin layer Po works, but the layer is quickly eroded during operation. This means the Po has to be alloyed with the electrode material itself, which is expensive and wasteful since only the Po on the surface does any good because of the limited escape depth of the alpha particles.</p><p></p><p>Before mercurycrest starts searching for a set of those plugs for his Lada, the half-life of Po is 136 days. Although the data shows they would have worked great when newly manufactured using Po straight from the reactor, if those plugs were made in 1950, that's ~188 half-lives so the radioactivity has been reduced by a factor of 2.5×10<span style="font-size: 12px">–57</span>.</p></blockquote><p></p>
[QUOTE="Magnetoman, post: 130684, member: 2806"] I found an article on the use of polonium in spark plugs in a 1940 issue of the Journal of Applied Physics by J.H. Dillon of the Physics Research Division of Firestone. The data show the ionization due to emission of alpha particles significantly lowers the voltage required to initiate a spark. The practical problems are 1) the range of alpha particles is greatly decreased if the Po is covered by carbon, so placing a separate Po wire nearby quickly loses its effect, and 2) coating the electrode with a thin layer Po works, but the layer is quickly eroded during operation. This means the Po has to be alloyed with the electrode material itself, which is expensive and wasteful since only the Po on the surface does any good because of the limited escape depth of the alpha particles. Before mercurycrest starts searching for a set of those plugs for his Lada, the half-life of Po is 136 days. Although the data shows they would have worked great when newly manufactured using Po straight from the reactor, if those plugs were made in 1950, that's ~188 half-lives so the radioactivity has been reduced by a factor of 2.5×10[SIZE=3]–57[/SIZE]. [/QUOTE]
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Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
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