Re: strength of vacuum

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Bert Hickman <bert.hickman-at-aquila-dot-net> 

Antonio and all,

I've found that some elongated lamps that are intended for scroll lamps do 
indeed have a high vacuum instead of inert gas. The glass fluoresces a 
brilliant yellow-green color, especially if the filament becomes 
incandescent from field emission (with lots of electrons being emitted). An 
old antique light bulb I have does a similar thing, only the glass 
fluoresces a brilliant blue color. In either case, I could easily detect 
the presence of X-rays via a Geiger counter 8 feet away. Remember that 
distance is your friend (inverse square law), keep run times down, or, 
preferably, don't irradiate yourself at all... :^)

Best regards,

-- Bert --
-- 
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Tesla list wrote:

>Original poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
>Tesla list wrote:
>  > Original poster: John <fireba8104-at-yahoo-dot-com>
>  >
>  >   How many people do you think got more
>  >   than the recommended dose of rads in the last year while
>  > experimenting with standard vacuum light bulbs?
>"Normal" lamps don't have high vacuum inside, but are actually filled
>with an inert gas at low pressure. If in the experiments some corona
>or similar light appears inside the bulb, there is no problem. But
>if nothing appears, and worse, the glass fluoresces with a green
>light, this is sign of X-ray generation. Some small lamps are said
>to have high vacuum inside. I am not sure. Vacuum tubes certainly
>have (Humm... VTTCs may be dangerous...).
>Antonio Carlos M. de Queiroz
>
>.