Re: vacuum spark gap

Hi Alfred,

A vacuum spark gap is certainly a real thing, but it must be a "hard"
vacuum, i.e. 10E-7 torr or so. Heat dissipation becomes a real issue, and
so does soft x-ray production depending on voltage. At say, 15KV, then you
will have ~21 KeV x-rays. I think your idea of a "home brew" vacuum gap is
interesting, but will be a great challenge. It is hard to beat the power
handeling capability of a basic air spark gap...


David Trimmell

At 06:45 AM 4/30/00 , you wrote:
>Original Poster: "Alfred C. Erpel" <aerpel-at-pil-dot-net> 
>What I mean is parallel copper (or tungsten) bars in a vacuum (10^-4 torr)
>to be used in the primary tank circuit. From what I have been able to read
>from searches, some people say this won't work and others say it will. I
>believe (not know) that it will work. What I don't know is what is the
>breakdown voltage of a vacuum (volts/mil). Also what danger might there be
>about radiation being generated?
>> Original Poster: "Alfred C. Erpel" <aerpel-at-pil-dot-net>
>> Original Poster: "Lau, Gary" <Gary.Lau-at-compaq-dot-com>
>> I don't believe that a "vacuum spark gap" actually involves a vacuum.
>> Rather it employs a vacuum cleaner motor to suck or blow air across static
>> gaps.  The spark gap must assume a low resistance state in the triggered
>> condition, and this requires plasma - super hot ionized air.  I don't
>> a spark gap would work in a vacuum, and it would work poorly in low
>> air.
>> Gary Lau
>> Waltham, MA USA
>>> Hello,
>>>     I am going to build a vacuum spark gap. I have a vacuum
>>> pump capable of
>>> 10^-4 torr. I have all the machine shop equipment, vacuum
>>> grade grease etc. to
>>> do this properly. It will need to switch less than 500
>>> watts.
>>>     What non-mechanical issues might there be? X-ray
>>> concerns or any other type
>>> of radiation? What percentage of energy might be expected to
>>> be absorbed by the
>>> gap and/or radiated? What is the dielectric strength of a
>>> 10^-4 torr vacuum?
>>> Regards,
>>> Alfred Erpel