Hi Phil,in general, a tungsten/copper alloy should have a longer life then pure tungsten, when used in a spark gap. It also has a better electric conductivity and, what is very important for rotary gaps, it's density is way smaller than pure tungsten. There are 3 mixtures available:
80% W / 20% Cu 75% W / 25% Cu and, what is not used so often: 70% W / 30% CuUsing thoriated tungsten is a very very bad idea! Getting microscopic thorium particles into your lungs or digestive system by breathing in or eating the dust of the vaporized electrodes brings a high risk of lung cancer, because thorium emits alpha radiation, directly into your body.
Regards, Stefan----- Original Message ----- From: "Phil" <pip@xxxxxxxxxxx>
To: <Tesla@xxxxxxxxxx> Sent: Thursday, March 12, 2015 11:24 PM Subject: [TCML] Mouldy RSG electrodes?
Gents, The electrodes of my RSG had quite an odd appearance when viewed up close,after running at a recent teslathon, obviously not really mould, but I havenever seen this occur before: https://www.flickr.com/photos/33962508@N03/16794887172/in/photostream/lightb ox/ (click to enlarge) Ablation was only around 10 thou or so, and the ridges that you see are mainly formed by deposits. The outer two are the stationary pair (3/8 inch Tungsten/copper alloy), while the centre one, is one of the four rotating ones (0.25 inch thoriated tungsten).The other three looked the same. Power was around 7.5 kw Phil _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxhttp://www.pupman.com/mailman/listinfo/tesla
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