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Re: How many x-ray in space ?

William -

Ron presented some very good references.  The Geiger-Muller tube has been
used for
measurement on satellites since Explorer 1, the first US satellite launched
in 1958.


That was the single scientific instrument on Explorer 1 lead by chief
scientist Dr. James Van Allen.  This instrument on follow-up satellites
(both Russian and US) established and confirmed the existence of radiation
belts surrounding the earth, named the "Van Allen" radiation belts.

All of his papers for this work are available

Here is a link on the Explorer 1 and 3 spacecraft.  Explorer 3 carried a
tape recorder than recorded to its limit of 128, the number of counts per



----- Original Message -----
From: "Ron Sparks AG5RS" <rlssat1@attglobal.net>
To: "William Leijenaar" <pe1rah@hotmail.com>; <amsat-bb@AMSAT.Org>
Sent: Monday, May 27, 2002 12:10 PM
Subject: RE: [amsat-bb] How many x-ray in space ?

> William,
> I am no expert, but it seems like you may have some confusion on
>  what you are wanting to measure.  X-rays are not the same as
> Gamma rays.  X-rays are lower in energy and I don't think they
> will penetrate your box.  That is not true of Gamma rays, they
> will get in.
> If you want to measure Gamma rays, I think the normal background
> count will run a few counts per minute.  Unless you have a lot
> of granite near you.  Then it will be about double.  It has been
> MANY years ago, but I seem to remember a "hot" lab source running
> a few counts per second (25?).
> You should go to:
> http://www.rentron.com/geiger.htm or
> http://www.imagesco.com/catalog/geiger/geiger.html or
> http://www.gibsonteched.net/vk2645.html
> I have no affiliation with any of these, but their info should be
> useful.
> One final note, your neon bulb will have different sensitivities
> between light and dark.  The cheapest bulbs have only neon in them
> so the dark trigger voltage is quite a bit higher than the light
> voltage.  That is why some cheap neon panel lights begin to flicker
> at night.  The slightly more expensive bulbs have a bit of Radon
> gas added to prevent this, but that would contaminate your experiment.
> I suggest you measure the firing and quenching voltage on your lamp(s)
> and find one with the biggest difference.  Then keep it dark for all
> your tests.
> BTW, X-rays are hard to design a detector for.  The best x-ray detector
> is the fastest Black & White film you can buy.  Keep one roll on the
> ground and sent one up in a thin, light proof holder.  "Push" develop
> them both to the highest ASA (ISO) you can and then compare them.
> X-rays will fog the film.
> As I said, I will defer to the experts but this is my general
> understanding of things.
> Hope this helps.
> Ron, AG5RS
> ----
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