Anytime you find yourself writing a sentence like this..."At only 20-30 kV and a few hundred uA in cold-cathode mode the x-ray radiation pours out, making the end-window Geiger counter scream from more than a meter away."
... perhaps some alarm bells should be going off.
Our friend Alan, VK2ZAY, has been busy in the lab, generating X-Rays from old 2X2 rectifier tubes. This reminds me of one of the articles in the wonderful C.L. Strong book, "The Amateur Scientist." Check it out: http://www.vk2zay.net/article/222
Hey Alan, can you make us up some of those X-Ray glasses that they always advertised in the backs of magazines? As a teenager, I somehow always wanted one of those...
Methinks Alan received one too many jolts from his cute 'do.
ReplyDeleteAnd the Honor House Ad......I get that same look after a wild night of rosin snorting :-).
73 from Oxnard, Steve Smith WB6TNL
If you are close to a public or university library, look at the July, 1956 edition of "Scientific American" - page 135.
ReplyDeleteEarly-day radio tubes (1920's) initially used relatively high atomic numbered metallic alloys as "getters". These old tubes will often show a shiny, mirror-like splash on the inside of the glass envelope. And yes, they can generate a copius amount of x-rays with only a modest (10 - 15 KV) high voltage. By the mid-1920's though most tube manufactures had discovered cheaper, and easier to apply getter materials which incidentally had lower atomic numbers such as Barium. By their nature, these tubes don't hold a candle (so to speak) to the earlier tubes for the production of X-rays.
Bruce - KK0S