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Endimion17
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Radium glow
It is said that radium glows with a bluish tint. I've never seen radium, and there aren't any reasonable quality photos out there, not to mention
videos. This information just keeps on getting copied and copied from one book to another, and it's like a dogma.
I'm a bit skeptical about the glow and think that pure radium in vacuum wouldn't glow.
The glow is described as a special case of luminescence, produced by the release of the energy from the fresh daughter products of its fission. A
truly rare case. It's not radioluminescence, because radioluminescence is luminescence that appears when ionizing radiation strikes different atoms or
ions and they release light, at least that's the definition I know.
But what if this is really radioluminescence from the surface, produced by the trace amounts radium compounds (nitride, hydroxide)?
Radium compounds glow, and it's known that radioactive compounds glow more than the radioactive elements themselves. That's why we get erroneous info
about many radioactive elements, and the story repeats itself when you hear about the Curie couple and their work. They actually saw the radium salts
glowing, not the element.
Actinium is said to glow, too. But its glow is produced by the radioluminescence of the layer of air just next to the metal, being bombarded by
intense radiation and getting ionized in the process. The metal itself supposedly doesn't glow, although that could be tested in a vacuum chamber with
a getter such as metallic caesium.
So what if the same thing happens with radium?
This is a very interesting subject and I hope some of you will be able to help me with it.
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The WiZard is In
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Help? Sure. www.justfuckinggoogleit.com
djh
----
... but even now any rich man
who did not mind possessing a luxury
could furnish a very efficient illumination
for an ordinary sized room which would
be permanent, or, at all events,
would last out his time—at any rate,
some three thousand or four thousand
years—for an expenditure of about 500l.
If he could get the radium.
Sir William Ramsay
Journal of the Society of Chemical Industry
23[14]855
July 31, 1903
PS - The Analogue Guy
found this because he owns
JSCI by the yard.
[Edited on 18-8-2011 by The WiZard is In]
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Endimion17
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What's with the attitude?
I don't really think that a 108 years old posh factoid answers a rather complex question involving radiochemistry, surface chemistry, etc.
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The WiZard is In
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Quote: Originally posted by Endimion17  | What's with the attitude?
I don't really think that a 108 years old posh factoid answers a rather complex question involving radiochemistry, surface chemistry, etc.
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Attitude? Given you have done-did Zero work on your own....
A 108 year old factoid tells me that if this effect has been
know for that long.... there is a SL of info out there ripe for the
picking.
djh — Mea virtute me involvo.
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IrC
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Just so you have a more recent claim by someone still living. Yes the air around it has a blue glow. You have to be in the dark for a while before you
can see it, very pretty and mysterious looking. It was not a glow coming from the metal itself rather a blue glow around it which looks identical to
blue aurora if you have ever lived in Montana or farther north, sort of a soft shifting, shimmering glow. You could carefully look tangent to the
surface and see the air around it glowing. Very eerie and knowing what you are in the presence of quite frightening to think of the radiation levels.
There was a news story years ago about actual casualties in Mexico when some people stripped an old Xray machine and took the metal home to make
ornaments. IIRC Cobalt 60 in that case but my memory could be off as to the actual metal involved. It killed some and made others critically ill. The
survivors said it was the pretty blue glow around the metal which prompted so many to take it home.
"Science is the belief in the ignorance of the experts" Richard Feynman
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Bot0nist
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| Quote: Originally posted by IrC | The survivors said it was the pretty blue glow around the metal which prompted so many to take it home.
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What poor fools.
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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The WiZard is In
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| Quote: Originally posted by IrC | There was a news story years ago about actual casualties in Mexico when some people stripped an old Xray machine and took the metal home to make
ornaments. IIRC Cobalt 60 in that case but my memory could be off as to the actual metal involved. It killed some and made others critically ill. The
survivors said it was the pretty blue glow around the metal which prompted so many to take it home.
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I'll refresh your memory gratis.
These from Wiki-P.
This is la Blue-Glow one
The Goiânia accident was a radioactive contamination [Cesium-137] accident that
occurred on September 13, 1987, at Goiânia, in the Brazilian State
of Goiás after an old radiotherapy source was taken from an
abandoned hospital site in the city. It was subsequently handled by
many people, resulting in four deaths and radioactive
contamination of 245 other people, 20 of whom showed signs of
radiation sickness and required treatment.
This is El Mexico one.
December 6, 1983 – Ciudad Juárez, Mexico, A local resident
salvaged materials from a discarded radiation therapy machine
carrying 6,000 pellets of 60Co. The dismantling and transport of
the material led to severe contamination of his truck; when the
truck was scrapped, it in turn contaminated another 5,000 metric
tonnes of steel with an estimated 300 Ci (11 TBq) of activity. This
material was sold for kitchen or restaurant table legs and building
materials, some of which was sent to the U.S. and Canada; the
incident was discovered when a truck delivering contaminated
building materials months later to the Los Alamos National
Laboratory accidentally drove through a radiation monitoring
station. Contamination was later measured on the roads that were
used to transport the original damaged radiation source. In some
cases pellets were actually found embedded in the roadway. In
the state of Sinaloa, 109 houses were condemned due to
contaminated building material. This incident prompted the Nuclear
Regulatory Commission and Customs Service to install radiation
detection equipment at all major border crossings
There are being a 'hole bunch of such accidents on file.
djh
---
Physiological Action of the Radiation from Radium.
H. Becquerel and P. Curie.
Comptes. Rend. 132 [22], 1289-1291.
In - The Journal of the Society of Chemical Industry, 8 [20] 845. August, 1901.
The action of the radiation from radium on the skin, announced by
Walkoff and by Giesel, has been confirmed by M. and Mme. Curie,
and by Becquerel. Preparations of radium, carried next to the arm
or in the waistcoat pocket for periods of two to six hours, gave rise
to inflammation increasing very gradually, but lasting many
days, and leaving after treatment and recovery, little permanent
scars. The intensity of the physiological action depends on the
activity of the radium and the duration of its application. When
handling radium and its compounds the finger tips become
hard and painful ; the pain often remains long after the
inflammation has disappeared.
One would think two Nobel Prize winners would know better.....!
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watson.fawkes
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It's called Cherenkov radiation. Now you know a search term.
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Endimion17
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1. I have searched the Web and found nothing. As I've said, the same stupid dogma-like info is being copied over and over again. That's why I
asked actual people on an actual ontopic forum.
2. The radiological incident in Goiânia involved a metallic capsule with a small window through a blue glow could be seen. The glow was from a
caesium-137 salt, which is a chemically and physically stable form of caesium (you can do stuff with salts, where the metal melts at room temperature
and has a nasty tendency to catch flames). People that stole the capsule opened it using brute force and dispersed the glowing salt, and it ended
everywhere. The glow is a typical radioluminescence case.
3. Neither the radium nor the glow from Goiânia had nothing to do with Cherenkov radiation. Cherenkov radiation shows up when charged particles
travel through a dielectric medium at the speed greater than the speed of light in that medium. It shows up in water at intense radiation, such as the
one being emitted by the fuel rods in an operating nuclear reactor, or reactor pulsing, or by fresh spent fuel rods that have lots of uranium-235
decay daughter products inside.
For Cherenkov radiation to be emitted in air, the energy of the particle would have to be truly fantastic, cause air is a dielectric of refractive
index almost the same as vacuum, (indeed, in most cases when you do some calculations, you can take air instead of vacuum) and then you couldn't even
distinguish the Cherenkov glow, because the glow of ionization would've been extreme. Ionization glow bursts were actually seen by few people in the
history (see the Demon's core, Slotin) and they mostly died.
So actinium glowing is actually the glow of ionization of the air, and if it's immersed in water (shielded to avoid the chemical reaction), Cherenkov
glow should be visible, too.
Then radium should show the same phenomena. But a freshly cut, degassed piece of metal in vacuum should not glow at all. AFAIK, fission does not
produce visible photons, but gamma rays and heat.
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IrC
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You have me wondering. Could water vapor and possibly dust in the air play a part in the glow? n is 1.0003 for air but 1.33 for any water vapor in the
air. There is always a large number of particles a quarter micron or larger in the air. Having never really looked into the composition of average
dust I wonder if a fluorescence is possible. Not so sure as it would seem this would have a granular appearance like scintillation and the glow I
remember was more continuous in appearance. Having lived for 7 years under the Aurora I can say when blue (rare, usually the blue is hidden by the
overwhelming amount of green glow), the glow was similar in appearance.
I also believe the web is not as thorough in knowledge as you imply. Depending upon what you can find online is severely limiting your knowledge base
in my opinion.
"Science is the belief in the ignorance of the experts" Richard Feynman
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watson.fawkes
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| Quote: Originally posted by Endimion17 | | Neither the radium nor the glow from Goiânia had nothing to do with Cherenkov radiation. Cherenkov radiation shows up when charged particles travel
through a dielectric medium at the speed greater than the speed of light in that medium. |
You do know that
air is exactly such a dielectric medium, right? Admittedly the index is close to 1, about 300 parts per million more, but you'll still get Cherenkov
radiation. Now what's different is that the intensity is going to be much lower, by about seven orders of magnitude. See the Frank-Tamm formula for an
estimate. Nevertheless, that's within the dynamic range of the eye to see. As IrC observed, such a source is pretty dim, at least one that's not
proximately fatal. A source whose Cherenkov glow you can see in daylight is mighty radioactive. If you ever see one with your own eyes, run.
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IrC
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http://www.orau.org/ptp/collection/radioluminescent/radiolum...
From the link above:
RADIUM
Radium-226 is an alpha emitter with a 1600 year half-life. It emits a gamma ray at 186 keV. Radium decays into a number of short lived decay products
that can usually be expected to be present at, or close to, the same activity as the radium. These decay products (Rn-222, Po-218, Pb-214, Bi-214,
Po-214, Pb-210, Bi-210, and Po-210) emit alphas, betas and gamma rays.
A Little History
By itself, radium in high enough concentrations will glow blue, a phenomenon first observed by Marie and Pierre Curie.
Another possible mechanism:
Instead, the blue glow of a criticality accident results from the spectral emission of the excited ionized atoms (or excited molecules) of air (mostly
oxygen and nitrogen) falling back to unexcited states, which happens to produce an abundance of blue light. This is also the reason electrical sparks
in air, including lightning, appear electric blue. It is a coincidence that the color of Cherenkov light and light emitted by ionized air are a very
similar blue despite their very different methods of production. It would be also interesting to remark that the ozone smell was said to be a sign of
high radioactivity field through Chernobyl liquidators.
http://en.wikipedia.org/wiki/Criticality_accident#Blue_glow
[Edited on 8-18-2011 by IrC]
"Science is the belief in the ignorance of the experts" Richard Feynman
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Endimion17
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| Quote: Originally posted by IrC | You have me wondering. Could water vapor and possibly dust in the air play a part in the glow? n is 1.0003 for air but 1.33 for any water vapor in the
air. There is always a large number of particles a quarter micron or larger in the air. Having never really looked into the composition of average
dust I wonder if a fluorescence is possible. Not so sure as it would seem this would have a granular appearance like scintillation and the glow I
remember was more continuous in appearance. Having lived for 7 years under the Aurora I can say when blue (rare, usually the blue is hidden by the
overwhelming amount of green glow), the glow was similar in appearance.
I also believe the web is not as thorough in knowledge as you imply. Depending upon what you can find online is severely limiting your knowledge base
in my opinion.
|
I doubt it. Cherenkov glow requires a dense dielectric.
But I envy you for the stuff you saw. 
| Quote: Originally posted by watson.fawkes | | You do know that air is exactly such a dielectric medium, right? Admittedly the index is close to 1, about 300 parts per million more, but you'll
still get Cherenkov radiation. Now what's different is that the intensity is going to be much lower, by about seven orders of magnitude. See the
Frank-Tamm formula for an estimate. Nevertheless, that's within the dynamic range of the eye to see. As IrC observed, such a source is pretty dim, at
least one that's not proximately fatal. A source whose Cherenkov glow you can see in daylight is mighty radioactive. If you ever see one with your own
eyes, run. |
No, you simply can't see Cherenkov glow in the air because it's completely washed away by the fierce ionization glow. If there was not any ionization,
you could see Cherenkov glow, though. But you just can't exclude the ionization. A source so fiercely radioactive will ionize just about everything
around itself.
Those are two very different phenomena that look similar, though not identical.
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The WiZard is In
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Cherenkov is the glow you see in fuel pool's for spent reactor
rods. Work's not with out the water.
No doubt one could fine a zillion snap's via Google.
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blogfast25
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Photos of radium can't be that hard to find: I have one (B & W) in a very old encyclopedia, claiming the element had been photographed in the
dark, by its own light.
Not long ago I found a photo of a few mg of Curium on a very reputable German science site (not a hobby forum); that tells me that pics of Radium
can't be that hard to get if you just drill down a lot.
Like Wizard I'm a tad skeptical about Cherenkov radiation outside a water bath: the refractive index just seems too low for that...
[Edited on 18-8-2011 by blogfast25]
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pantone159
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| Quote: Originally posted by blogfast25 | Photos of radium can't be that hard to find: I have one (B & W) in a very old encyclopedia, claiming the element had been photographed in the
dark, by its own light.
Not long ago I found a photo of a few mg of Curium on a very reputable German science site (not a hobby forum); that tells me that pics of Radium
can't be that hard to get if you just drill down a lot. |
I have looked some and have not found too many photos. The ones I did find are here: http://gotexassoccer.com/elements/088Ra/Ra.htm
BTW - Re your Cm photo, did you find it at http://www.chemie-master.de/? They have some nice photos of the actinides.
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IrC
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What I saw was blue not green. That vial, is it filled with some gas to prevent oxidation? Or is it the glass itself glowing? I have uranium glass and
it is green. Also since it tarnishes fairly quickly could the glow be from a surface layer of oxide?
"Science is the belief in the ignorance of the experts" Richard Feynman
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Endimion17
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| Quote: Originally posted by pantone159 | | Quote: Originally posted by blogfast25 | Photos of radium can't be that hard to find: I have one (B & W) in a very old encyclopedia, claiming the element had been photographed in the
dark, by its own light.
Not long ago I found a photo of a few mg of Curium on a very reputable German science site (not a hobby forum); that tells me that pics of Radium
can't be that hard to get if you just drill down a lot. |
I have looked some and have not found too many photos. The ones I did find are here: http://gotexassoccer.com/elements/088Ra/Ra.htm
BTW - Re your Cm photo, did you find it at http://www.chemie-master.de/? They have some nice photos of the actinides.
|
I think that photo of "radium" could very well be a computer simulation. I remember that photo coming up few years ago. There are no hi-res versions,
which smells like CGI from the beggining of the 21st century. I don't know how long have you searched the Web, but I've been searching it for radium
photos for the past 7-8 years, and I remember that images come up as fake, but some laymen copy them on their blog or webpage, and as soon as that
happens, google/yahoo/altavista/etc index them and they get false credibility.
The same stuff happened to astatine and francium.
That's how the Web works. It is a storage place for information. It doesn't filter the correct ones.
Before the web, that happened with books and magazines, only at a much slower rate. Today, wrong info becomes truth in a manner of days.
So that's why I find Wizard's sarcastic try laughable. "Teh google" is not omnipotent. Internet is full of incorrect info, and giving an advice to use
it as a manual is totally wrong.
As for my current opinion on the glow, I say it's mainly the glow of air being ionized, with probably some glow from the nitride/hydroxide on the
surface.
Freshly cut, degassed radium in vacuum should not glow.
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IrC
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"Freshly cut, degassed radium in vacuum should not glow."
I agree you have my vote. Also, In air it's blue not green.
"Science is the belief in the ignorance of the experts" Richard Feynman
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blogfast25
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Yes! Thanks for reminding me! Good site...
[Edited on 18-8-2011 by blogfast25]
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pantone159
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| Quote: Originally posted by Endimion17 |
I think that photo of "radium" could very well be a computer simulation. I remember that photo coming up few years ago. There are no hi-res versions,
which smells like CGI from the beggining of the 21st century. I don't know how long have you searched the Web, but I've been searching it for radium
photos for the past 7-8 years, and I remember that images come up as fake, but some laymen copy them on their blog or webpage, and as soon as that
happens, google/yahoo/altavista/etc index them and they get false credibility.
The same stuff happened to astatine and francium. |
You mean the second Ra photo?
I wondered too, although it is from American Institute of Physics, they ought to get such things right but perhaps not. The lower two photos on my
page are Ra/salts mixed with a phosphor, which is why they are green.
I have these 'photos' for Fr which I dont think are fake
 and
but I have not found others, and I have found none for astatine.
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IrC
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It could simply be Radium was a victim of time. Back in the day you could find someone with enough Ra to photograph, color photos with low light
sensitivity were either not prevalent or not in existence (too lazy to search the time line history of color film). Old BW photos might show a glow
but not the color obviously. I have not seen Ra in elemental form since 1975.
"Science is the belief in the ignorance of the experts" Richard Feynman
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Endimion17
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| Quote: Originally posted by pantone159 | You mean the second Ra photo?
I wondered too, although it is from American Institute of Physics, they ought to get such things right but perhaps not. The lower two photos on my
page are Ra/salts mixed with a phosphor, which is why they are green. |
Yeah, that one. It looks way to artificial to me. And if it is the real thing, it's coated in hydroxide, so we're seeing nothing relevant.
Salts glow, of course.
| Quote: | I have these 'photos' for Fr which I dont think are fake
and
but I have not found others, and I have found none for astatine.
|
No, those are the real things. They've managed to collect only a handful of atoms of francium. It's not an actual macroscopic image, but it's valid.
I was thinking about images similar to this one. Pure and utter stupidity.
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blogfast25
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Nah, that first one is a well known star cluster! 
With photos like that who needs the real thing, huh?
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annaandherdad
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Cerenkov radiation in air from radium decay
| Quote: Originally posted by Endimion17 | | Quote: Originally posted by IrC | You have me wondering. Could water vapor and possibly dust in the air play a part in the glow? n is 1.0003 for air but 1.33 for any water vapor in the
air. There is always a large number of particles a quarter micron or larger in the air. Having never really looked into the composition of average
dust I wonder if a fluorescence is possible. Not so sure as it would seem this would have a granular appearance like scintillation and the glow I
remember was more continuous in appearance. Having lived for 7 years under the Aurora I can say when blue (rare, usually the blue is hidden by the
overwhelming amount of green glow), the glow was similar in appearance.
I also believe the web is not as thorough in knowledge as you imply. Depending upon what you can find online is severely limiting your knowledge base
in my opinion.
|
I doubt it. Cherenkov glow requires a dense dielectric.
But I envy you for the stuff you saw.
| Quote: Originally posted by watson.fawkes | | You do know that air is exactly such a dielectric medium, right? Admittedly the index is close to 1, about 300 parts per million more, but you'll
still get Cherenkov radiation. Now what's different is that the intensity is going to be much lower, by about seven orders of magnitude. See the
Frank-Tamm formula for an estimate. Nevertheless, that's within the dynamic range of the eye to see. As IrC observed, such a source is pretty dim, at
least one that's not proximately fatal. A source whose Cherenkov glow you can see in daylight is mighty radioactive. If you ever see one with your own
eyes, run. |
No, you simply can't see Cherenkov glow in the air because it's completely washed away by the fierce ionization glow. If there was not any ionization,
you could see Cherenkov glow, though. But you just can't exclude the ionization. A source so fiercely radioactive will ionize just about everything
around itself.
Those are two very different phenomena that look similar, though not identical. |
I agree with the earlier comments about it not being Cerenkov radiation. The index of refraction of air is about epsilon=3x10^{-4} above unity.
Thus the phase velocity of light in air is about c x (1-epsilon), If gamma is the relativistic factor of time dilation then 1/gamma^2 =
epsilon(1+epsilon) = 2xepsilon = about 5x10^{-4}. Thus gamma^2 = 2000 and gamma = about 45. Thus the energy of an electron (the lightest charged
particle) with this gamma is about 22.5MeV. The energies released in Ra decay (Ra itself and daughter products) are all less than 10MeV.
[Edited on 20-9-2011 by annaandherdad]
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