Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

I'd have guessed that the thorium has been replaced by some other
material these days, but I could be wrong.

--
John

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

Don't know, but do you have an old luminous watch or, best of all, the
standard War Dept prismatic compass? Mine gives about 500 counts per second.
The natural K40 in high potash fertiliser will give you about double the
natural background.

"Newshound" wrote:

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

Don't know, but do you have an old luminous watch or, best of all, the
standard War Dept prismatic compass? Mine gives about 500 counts per second.
The natural K40 in high potash fertiliser will give you about double the
natural background.

Thanks for the suggestion. I've looked on ebay, and WWII luminous
watches are about £20-£30, which is a bit expensive. I didn't know
about the potash fertiliser.

--
John

Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes - the potassium nitrate in them from (a)
tobacco being fertilised and (b) being added to ensure they don't go
out when lit being radioactive enough. I could never find a source for
that story, 'though, despite a lot of searching. It seems unlikely, if
you read the article in the reference URL below.

The natural radioactivity of the normal isotopic mixture of potassium
on Earth is interesting - it being the major source of radioactivity
within the human body.

See
URL:http://www.fas.harvard.edu/~scdiroff/lds/QuantumRelativity/RadioactiveHumanBody/RadioactiveHumanBody.html

Cheers,

Sid

wrote:
Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes - the potassium nitrate in them from (a)
tobacco being fertilised and (b) being added to ensure they don't go
out when lit being radioactive enough. I could never find a source for
that story, 'though, despite a lot of searching. It seems unlikely, if
you read the article in the reference URL below.

The natural radioactivity of the normal isotopic mixture of potassium
on Earth is interesting - it being the major source of radioactivity
within the human body.

See
URL:http://www.fas.harvard.edu/~scdiroff/lds/QuantumRelativity/RadioactiveHumanBody/RadioactiveHumanBody.html

Following up on the above, buy a pack of Lo-Salt, which is about 66%
Potassium Chloride. Its radioactivity (due to the potassium 40) will
be significantly above background levels. See here
URL:http://www.blackcatsystems.com/science/radprod.html

Cheers,

Sid.

In message .com,
writes
Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

--
geoff

On Tue, 20 Jun 2006 21:04:39 GMT, raden wrote:

In message .com,
writes
Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

Do they set it off as well then???

:O

"EricP" wrote :


I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

Do they set it off as well then???


Dunno, but what I want to know is: do cats have eighteen half-lives?

Steve S

EricP wrote:

On Tue, 20 Jun 2006 21:04:39 GMT, raden wrote:

In message .com,
writes

snip

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

Do they set it off as well then???

Only if you've been sitting on boulders in Cornwall...



I'll get me coat...

In message , EricP
writes
On Tue, 20 Jun 2006 21:04:39 GMT, raden wrote:

In message .com,
writes
Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

Do they set it off as well then???

After the therapy, prolly, yes

--
geoff

raden wrote:
In message .com,
writes
Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

--
geoff

Not completely, as far as I can tell. Do a bit of googleing for
cigarettes and polonium 210 for some interesting data on the radiation
dosage to the lungs from smoking cigarettes. However, as polonium-210
is an alpha emitter, it's not detectable by a portal monitor, which
will look for gamma emmissions, and maybe neutrons. However, (again) -
as potassium-40 is a gamma-emitter, it is just about feasible to detect
raised concentrations of potassium in the environment by looking for
the characteristic signature of K-40 emissions, which are at a
particular energy - however, an expensive multi-spectral monitor is
needed. The Americans have tried using just this technique to detect
contraband tobacco & marijuana in freight in 1992 see
URL:http://spiedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PSISDG002276000001000 374000001&idtype=cvips&gifs=yes
so it is possible that a portal monitor - especially the 'pause for 5
seconds while being measured' type would notice elevated K-40 levels.

If a nuclear worker reads this newsgroup, they might be able to say
definitively.

Cheers,

Sid

unopened wrote:
raden wrote:
unopened writes
I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -
Sounds like ******** to me

Not completely, as far as I can tell. Do a bit of googleing for
cigarettes and polonium 210 for some interesting data on the radiation
dosage to the lungs from smoking cigarettes. However, as polonium-210
is an alpha emitter

Interestingly, smokers are less likely to suffer from certain
radiation damage to the lungs, as the mucous coating is thicker
in theirs, due to the reduced functionality of the cilia and
irritant effect of all the gunk inhaled.

In message .com,
writes

raden wrote:
In message .com,
writes
Newshound wrote:


It's actually for testing an old Geiger counter that was a Maplin kit.

The natural K40 in high potash fertiliser will give you about double the
natural background.

I was told that the radiation detectors at Sellafield/Windscale were
sensitive enough to trigger an alarm if somebody went past them
carrying a pack of cigarettes -

Sounds like ******** to me

--
geoff

Not completely, as far as I can tell. Do a bit of googleing for
cigarettes and polonium 210 for some interesting data on the radiation
dosage to the lungs from smoking cigarettes. However, as polonium-210
is an alpha emitter, it's not detectable by a portal monitor, which
will look for gamma emmissions, and maybe neutrons. However, (again) -
as potassium-40 is a gamma-emitter, it is just about feasible to detect
raised concentrations of potassium in the environment by looking for
the characteristic signature of K-40 emissions, which are at a
particular energy - however, an expensive multi-spectral monitor is
needed. The Americans have tried using just this technique to detect
contraband tobacco & marijuana in freight in 1992 see
URL:http://spiedl.aip.org/getabs/servlet...og=normal&id=P
SISDG002276000001000374000001&idtype=cvips&gifs=y es
so it is possible that a portal monitor - especially the 'pause for 5
seconds while being measured' type would notice elevated K-40 levels.

If a nuclear worker reads this newsgroup, they might be able to say
definitively.

Yeah - rambutans ...

such low levels - a bit challenging

--
geoff

On Mon, 19 Jun 2006 20:11:49 GMT, John Nickum wrote:

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

I'd have guessed that the thorium has been replaced by some other
material these days, but I could be wrong.

Try a smoke alarm. The disc is Americium (alpha source)
--
Jim
Tyneside UK
http://www.jimscot.plus.com

The message
from Jim Scott contains these words:

Try a smoke alarm. The disc is Americium (alpha source)

Just remember to crimp it back again afterwards!

--
Skipweasel
Pay no attention to that man behind the curtain.

Jim Scott wrote:

On Mon, 19 Jun 2006 20:11:49 GMT, John Nickum wrote:

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

I'd have guessed that the thorium has been replaced by some other
material these days, but I could be wrong.

Try a smoke alarm. The disc is Americium (alpha source)

Thanks. I've just tried monitoring a smoke alarm, but of course, alpha
particles can't go through its plastic case. At least smoke alarms are
cheap, so I'll try breaking one open tomorrow.

--
John

"John Nickum" wrote

Thanks. I've just tried monitoring a smoke alarm, but of course, alpha
particles can't go through its plastic case. At least smoke alarms are
cheap, so I'll try breaking one open tomorrow.

Careful now, you will have the anti-terrorist squad kicking your door in
(and maybe shooting you) for trying to build an improvised dirty nuclear
device :-)

H

"HLAH" wrote:

"John Nickum" wrote
Thanks. I've just tried monitoring a smoke alarm, but of course, alpha
particles can't go through its plastic case. At least smoke alarms are
cheap, so I'll try breaking one open tomorrow.

Careful now, you will have the anti-terrorist squad kicking your door in
(and maybe shooting you) for trying to build an improvised dirty nuclear
device :-)

Aaagh! ;-)

Anyway, I've broken open the smoke detector and found that it's more
than enough to prove that the Geiger counter is working.

Job done.

If I hold the Geiger counter just 1cm from the source, it really does
thunder, and I have to switch it to its uppermost range, but if I hold
it 5cm away, then it's back to background levels. So it seems that the
smoke detector emits low-energy alpha particles that have low
penetration even through the air, so it's a nice safe test.

--
John

"John Nickum" wrote in message ...
Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

I'd have guessed that the thorium has been replaced by some other
material these days, but I could be wrong.

Most valves (out of a nold Telly etc) have thoriated tungsten cathodes in
'em, which might be enough of a source? I'd guess that the electron gun in a
tube might be a source, too. IIRC, camping gas lamp mantles are thoriated,
TAAW.

I used to work in a big transmitter cabin which had fibre-optics for the
control gear, and wondered why we had to replace them every few years, only
to be told "Oh, the radiation from the TWT [1] makes them go cloudy..." 0

Dave H.
(The engineer formerly known as Homeless)

[1] Travelling Wave Tube, a big (ie several KW) broadband microwave
transmitting amplifier. With a 5KV, 5A power supply. Dangerous. VERY
Dangerous.

"Dave H." wrote:

Most valves (out of a nold Telly etc) have thoriated tungsten cathodes in
'em, which might be enough of a source? I'd guess that the electron gun in a
tube might be a source, too. IIRC, camping gas lamp mantles are thoriated,
TAAW.

Thanks. I guess I could go into the local electonics shack and ask if
they've got anyold valves that they were going to throw away.

I used to work in a big transmitter cabin which had fibre-optics for the
control gear, and wondered why we had to replace them every few years, only
to be told "Oh, the radiation from the TWT [1] makes them go cloudy..." 0

Jeez.

--
John

John Nickum wrote:

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

It's actually for testing an old Geiger counter that was a Maplin kit.

I'd have guessed that the thorium has been replaced by some other
material these days, but I could be wrong.

http://www.mindfully.org/Nucs/Radioa...cout1nov98.htm

;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:

http://www.mindfully.org/Nucs/Radioa...cout1nov98.htm

I'd heard of the story, but not at that level of detail. Really
astonishing and quite frightening.

--
John

On Mon, 19 Jun 2006 20:11:49 GMT, John Nickum
wrote:

|Anybody know if it's still possible to get thorium mantles of the sort
|fitted to tilley lamps from any place there days?
|
|It's actually for testing an old Geiger counter that was a Maplin kit.
|
|I'd have guessed that the thorium has been replaced by some other
|material these days, but I could be wrong.

If you live in a granite area, Cornwall, Scotland etc, the rock is mildly
radioactive. Are you traveling to a granite area sometime soon?
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.

Dave Fawthrop wrote:

If you live in a granite area, Cornwall, Scotland etc, the rock is mildly
radioactive. Are you traveling to a granite area sometime soon?

I'm in the Midlands, so it's a long way to travel either way.

--
John

On Mon, 19 Jun 2006 20:11:49 GMT, John Nickum wrote:

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

Yes. The cheap Chinese mantles contain thorium, expect 500-600 Becquerel.

Anchor and Egret are mantle brands that are radioactive, Luxor and Petromax
aren't.

Just take you Geiger counter into the shop!


Thomas Prufer

Thomas Prufer wrote:

On Mon, 19 Jun 2006 20:11:49 GMT, John Nickum wrote:

Anybody know if it's still possible to get thorium mantles of the sort
fitted to tilley lamps from any place there days?

Yes. The cheap Chinese mantles contain thorium, expect 500-600 Becquerel.

Anchor and Egret are mantle brands that are radioactive, Luxor and Petromax
aren't.

Just take you Geiger counter into the shop!

Thanks for the info. But using the Geiger counter to select a mantle
might not be too clever. ;-)

--
John

On Tue, 20 Jun 2006 07:55:12 GMT, John Nickum wrote:

Thanks for the info. But using the Geiger counter to select a mantle
might not be too clever. ;-)

I had a bunch of my mantles tested at a nuclear lab. Some were radioactive, some
weren't; they documented them, and were very nice about it.

Trouble was walking out through the exit -- the contamination alarm went off,
security guards came out, explaining to do...



Thomas Prufer