Re: Thinking About A Geiger Counter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: robert heidlebaugh <rheidlebaugh@xxxxxxxxxxxxxx>

Just a passing comment. Early geiger counter tubes were made of copper
tubing from 3/8 inch to 2 inch dia stoppered with a cork or phenolic plug
and filled with an inert gas ( NO Oxygen) and a organic such as carbon
tetrachlorid to quench the discharge. The copper tube blocked alpha and beta
particals and only electromagnetic photons like gama ray or Xray could
penetrate them. Only the newer geiger tubes with mica windows or glass
bodies can detect particals. Very thin aluminum tubes can detect beta rays
but not alpha. If your tube is protected with a plastic cover or is mounted
inside a box even the best tube can not detect alpha particals. If you want
to detect particals get a sintalation counter or ion chamber not a geiger
counter.
      Robert   H
--


> From: "Tesla list" <tesla@xxxxxxxxxx>
> Date: Sat, 12 Nov 2005 08:49:53 -0700
> To: tesla@xxxxxxxxxx
> Subject: RE: Thinking About A Geiger Counter
> Resent-From: tesla@xxxxxxxxxx
> Resent-Date: Sat, 12 Nov 2005 08:51:49 -0700 (MST)
>
> Original poster: "Dave Halliday" <dh@xxxxxxxxxxxxxx>
>
> This would work but there are several issues.
>
> The paper is not very sensitive.
>
> There is a time lag between the exposure and developing it -- if your
> Geiger Counter starts going nuts, you hit the power switch or get the
> hell out of the area.
>
> With the paper, you will have the appreciation of knowing that you
> absorbed a significant hit of radiation and can do nothing about it.
>
>> -----Original Message-----
>> From: Tesla list [mailto:tesla@xxxxxxxxxx]
>> Sent: Friday, November 11, 2005 8:07 PM
>> To: tesla@xxxxxxxxxx
>> Subject: Re: Thinking About A Geiger Counter
>>
>>
>> Original poster: Blake Hartley <teslaspud@xxxxxxxxx>
>>
>> "Any thoughts would be great." How about the paper stuff that is used
>> in taking x-rays of people? It would change color in the presence of
>> x-rays, or at least that is what i would think.
>>
>> Blake
>>
>> On 11/7/05, Tesla list
>> <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx> wrote:
>> Original poster: "Bob (R.A.) Jones"
>> <<mailto:a1accounting@xxxxxxxxxxxxx>a1accounting@xxxxxxxxxxxxx>
>>
>> Hi,
>>
>>> Original poster: "Malcolm Watts" <<mailto:m.j.watts@xxxxxxxxxxxx>
>> m.j.watts@xxxxxxxxxxxx>
>> snip.
>>>>
>>>> I very well know that high voltages striking objects is
>> something that
>>>> creates X-RAYS.  My intended meaning is that Geiger
>> counters count
>>>> particles, not x-rays or other radiated energy.
>>>>
>>>> Skip
>>>
>>> Sorry, not true. They detect gamma rays with ease. In fact
>> the clicks
>>> you get from background radiation are mostly if not all,
>> gamma rays.
>>> When I built mine, the first measurements I took were of gamma rays
>>> leaking out of a supposedly radiation proof locker with some Cs-137
>>> samples inside.
>>>
>>> Malcolm
>>>
>> snip
>>
>> More specifically Geiger counters detect ionizing particles/radiation
>> (photons i.e. UV light x-rays gamma rays) that have
>> sufficient penetrating
>> power to get in to the tube and ionize the gas it contains.
>> They can probably detect neutral particles too via nuclear
>> reactions which
>> create ionizing particles/radiation but with a very very  little
>> (negligible) efficiency.
>>
>> As has already been pointed out x-rays are generated when
>> electrons, of
>> sufficient velocity strike not only a solid object but a gas
>> or for that
>> matter a liquid.
>>
>>
>> R A Jones
>>
>>
>>
>>
>>
>>
>>
>
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