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Radon Lasers?

alf638

alf638

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Hi, I'm just new to gas lasers an I've been wondering about the possibility of a radon laser.
As i'm sure you know gas lasers use a noble gas or a mixture of them as radon is a noble gas in theory it could be used.
I've searched for them on google with no results.The only reason I can think of that they are not in use is due to the extreme radioactivity of radon.
If anyone has any info or ideas they'd be much appreciated.:yh:
 





hello, alf.
here you can read something like "lasers don't use radiation".
if you search for "Lasers Active Mediums Radon" you will not found so much appealing results. I'm not a physics master but I think because, radon having a short time-life (except ²²²Rn, with 3,824 days) it is not such good for laser diodes, as it turns into Polonium. It may have to do with the ionization energy, you need someone that understand physics to explain here.
hope that helps :p
 
To understand why it won't work, you need to know how a laser actually works.

ruby_laser_e.gif


In this picture, you can see the 3 main components- the mirrors, the gain medium (ruby) and the pump (the flashlamp). To understand how a laser works, you need to understand how these three components come together.

In the simplest form of the laser, a flashlamp is used to pump a gain medium, which causes the atoms in the gain medium to enter a raised energy state. To return to the ground state, these atoms emit radiation in the form of a 694nm photon (visible red light). As more of the atoms enter this higher energy state, a population inversion occurs (where there are more atoms in the raised energy state than in the ground state). Eventually, some atoms will begin to spontaneously release these photons. These photons may collide with other atoms, causing them to release their stored energy as a photon. These waves of photons resonate between the mirrors, eventually escaping through the partially silvered mirror.

In practicality, lasers are much more complex, and that was just a watered-down, back-to-basics explanation that works. It's a common misnomer that lasers use radiation, instead, the radiation being referred to here is actually light radiation, with the whole acronym being Light Amplification by the Stimulated Emission of Radiation.

That aside, let's take a look at an argon laser. In this case, the gain medium is the argon gas, and the pump is the electrical current flowing through the tube.

The reason why argon works as a lasing medium is because it emits, and does so quite easily. You may be able to get other substances (such as water even) into an excited state, but there's no point, as it won't emit photons.

With Radon, it doesn't have a useful emission band, and it can't be made to readily emit at this band, so it'd be pretty useless even if it weren't radioactive. Combined with the fact that it is radioactive only intensifies the problem. Dealing with a laser tube that has an effective life of a few days, and which settles into radioactive components is not fun.

Radon has bands in the 700nm range. There's easier ways to get 700nm or so laser light, without dealing with the short half-life, radioactivity and the difficulty in exciting radon. Ti:Sapphire, for example, is tunable from 690nm up to 1000nm, covering those bands.
 
I suppose you could build one, but as stated above, the emission bands aren't that spectacular, and dealing with a radioactive gas that has a half life of only 3 days makes it completely useless for practical application.

You should also notice that there are no Xenon-ion lasers, although it does have a lasing line. Xenon is used in excimer lasers in the ultraviolet range, but the principe of operation of such lasers is different from the krypton and argon ion lasers.
 
Your simplest form of laser is a pulsed ruby laser, I'd say thats already pretty specific. And light is definately radiation, so it's not a misnomer. It's not alpha or beta radiation from a nuclear decay, but even the gamma radiation from a nuclear decay is a photon just like our lasers give photons.
There exists water lasers, I think they work somewhere in the IR.
As long as you have enough usable energy levels, you can make a laser out of it. 4 level lasers work better than 3 level lasers because you need to get the lower laser level empty.
 
High pressure pulsed xenon lasers does exists, but what utility they have for hobbysts, with a maximum of 1Kw peak for just 0,5 microsecond pulses, it's a different thing ;)


Bluefan said:
As long as you have enough usable energy levels, you can make a laser out of it. 4 level lasers work better than 3 level lasers because you need to get the lower laser level empty.
Click to expand...

Well, Russian scentists made a laser with vodka, in the first experiments, too ..... and, if i recall correctly, USA scentists replied with a laser that was using whisky :p :D
 
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And I've seen people meaking a poor's man dye laser by using laudry detergent. Uranium can also be used to make a laser, flashlamp pumped U:CaF2 can lase at 2.5um.
I'd love to see a very complete overview of all known laser gain media, regardless of their usefullness.
 
Bluefan said:
And I've seen people meaking a poor's man dye laser by using laudry detergent. Uranium can also be used to make a laser, flashlamp pumped U:CaF2 can lase at 2.5um.
I'd love to see a very complete overview of all known laser gain media, regardless of their usefullness.
Click to expand...

Highlighter ink, laundry whitener and even fluorescent food dye can be used as a gain medium in a dye laser when pumped with a N2 laser. The high peak pump power makes up for the crappy media, and dye is an extremely high-gain media anyway.

I chose to explain using the flashlamp pumped ruby laser, because it's as simple as it gets (using a flashlamp pump, no intracavity optics such as an NLO crystal or a Q-Switch), and it isn't very complicated either (ruby being your 'classic' 3-level medium). There's no need for fancy cavity components either, even a partly-silvered mirror (instead of a proper dielectric one) will do.

Nearly anything can be used as a gain medium- if it has an absorption band and is capable of spontaneously emitting some form of radiation in a raised energy state (in the form of a photon, be it UV, IR or even microwave). Whether it's practical or not is another question. There's no point using something that's dangerous, needs special cooling, special storage, or specialised, expensive equipment if a cheaper, more practical alternative is available.

The misnomer is that they emit non-EM radiation (such as alpha or beta particles). Light is radiation, otherwise the acronym wouldn't be as it is.

I think you're thinking of the methanol laser, which operates in the far IR band (2uM or so, tunable).
 
I don't think a complete list will ever be compiled... there are lots of things can can potenially serve as lasing media, but are not very practical or inferior to other existing technology.

As for 3 or 4 state media: 4 states would be preferable with the lasing transition between the middle two states, but 3-state systems are perfectly feasible. While they may be very inefficient and inpractical, they would add a huge number of 'feasible' lasing wavelengths to the list.

For practical application i think diode lasers will be closing the gap before anything new emerges. Wavelengths are creeping down from the bluray/445 end, and will probably hit green in the next few years.

Obviously gas lasers will still be used, but not as 'pretty lights', but in fields where pulse power is desirable, or factors like coherence length play a role.
 
Thanks for all the info guys, its been very usefull. I've been thinking about radon lasers and specificly the products of radon decay. I realised that as the radon decayed it would contaminate the tube, does anyone know how much decay it would take to stop the tube working?:san:
 
Shitloads.. radon decays into mostly solid substances that would just deposit onto the tube. You could add more radon gas as you go until those desposits short out the tube.

One problem would be your laser tube becoming more and more radioactive up to the point it would no longer be safe to handle even for people that have radioisotope work certifications.
 
As I thought, also one of the products just happens to be polonnium, 2500 times more deadly than hydrogen cyanide :crackup:.
Still, despite the overall deadlyness and short life span I think it would still be pretty cool to see. :).
 
Considering the polonium, it would be a once-in-your-lifetime experience :D
 
Well just for more fun...........
Hydrogen cyanide laser:
A gas laser using hydrogen cyanide, which emits infrared radiation at wavelengths of 311 and 337 micrometers.
 
Personally i'd prefer the cyanide laser due to the lack of deadlieness (and radioactivity:yh:)
But the polonium/radon laser coul spell a new age of laser weapons, the reverse laser!!!, you give it to someone in a special "lead lined" (important) gift box, they open it up, they turn it on and before they know it they are dead and full of polonium and radon, how fun!:crackup:
 
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