radioactive material and laser ionization threshold

area denial system? like denial of personnel or what? still sounds sketchy to me

I wonder,if alpha radiation is really better for making plasma than beta.One advantage I see is that it have maximum penetration in air about 2.5cm,so these flying particles hit the air in the focal point and not fly through it mostly like beta.Alpha decay is called ionising radiation,it "shoots" helium ion stripped of all its electrons so I guess ionising is the right word to describe it but I want to point out that while we talk about ionising radiation and ions,and yes plasma is ions,ions are not always plasma.Salt water is full of ions but no plasma.

While americium have intense "ionising" radiation,its really just bukkake of relatively fast moving helium nucleus,its kind of like spraying salt ions into air,I think for airborn laser plasma generation it would not do much.Why? Becose for air laser plasma you need electron avalanche breakdown,just putting helium ions into the area would probably not do anything,since the helium nucleus is without electrons its very small so probabilty of being hit is small,it have no electrons to give to contribute to avalanche breakdown.Only thing it can do is maybe hit some of the gas atoms in air and heat them up but that is minor factor probably.

edit: Nevermind,I found out the Alpha radiation energy of Americium is 5.486 MeV,when that nucleus hits atom in the gas atom in the air,it will knock out the electron out of it thus providing many free electrons in the area.Seul was right,Alpha really is the best!

I'm telling you the only way to get the result you want is to either heat up the area with infrared or microwaves. Get the ambient energy close to ionization of your gas and then shoot a laser in it to put it over the activation energy.

I will research it but I will ask anyway,how it exactly works that when gas is in normal state laser fly through it no problem,but the moment we turn it into plasma,it starts absorbing the laser beam.Why the wavelenght absorbion property changes?

Fonograph said:

I will research it but I will ask anyway,how it exactly works that when gas is in normal state laser fly through it no problem,but the moment we turn it into plasma,it starts absorbing the laser beam.Why the wavelenght absorbion property changes?

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Is there any specific point, practical aspect, reason, or goal to your questions so that people on the forum have a chance of addressing same? Laser induced air plasmas have been extensively studied and written about of since 1963.

Maybe these papers will help you understand a little bit: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.600.242&rep=rep1&type=pdf

and http://aries.ucsd.edu/LIB/REPORT/JOURNAL/MISC/BindhuAS04.pdf

Encap Thanks for link,I am going to read them all.

I would like to ask all the smart members here to give me some good/interesting/information rich studies about this subject,also if you know some book that is about this air plasma phenomenon,then name it.I found so far "Applications of Laser-Plasma Interactions" and "Laser-Plasma Interactions" but if there is another good book about it that missed then please tell me.

Fonograph said:

Encap Thanks for link,I am going to read them all.

I would like to ask all the smart members here to give me some good/interesting/information rich studies about this subject,also if you know some book that is about this air plasma phenomenon,then name it.I found so far "Applications of Laser-Plasma Interactions" and "Laser-Plasma Interactions" but if there is another good book about it that missed then please tell me.

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lots of research papers online including that paper link I posted.
btw none of the papers talk about radioisotopes assisting air breakdown with lasers.

Seoul_lasers said:

lots of research papers online including that paper link I posted.
btw none of the papers talk about radioisotopes assisting air breakdown with lasers.

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Exactly Seoul_lasers thousands of papers and hundreds of books.

That radioisotope contribution to formation of a plasma is not discussed in any of them points to that isotopes make little if any difference in formtion of an air plasma. As a practical matter even if radioistopes did make a difference small or large--the cost getting the Nuclear Regulatory Commission license to be able obtain and handle a 1cm cube, per his question, of any radioactive material very expensive and requiring specialized facilities and personnel with knowledge of nuclear material material safety handling and reporting and so on.

Fonograph in his first thread his 1st post says : " I want to build laser,focus the beam and turn air into plasma." why---who knows but he indicates he has little if any knowledge of plasma generation or how to do that so what he really needs is some knowledge of how that can be done. As everyone indicated he could maybe make a plasma with the correct equipment butit is not going to be a low cost thing that can be done easily without knowledge of what he is doing and why.

Laser induced air breakdown and plasma generation has been known and explored for more than 50 years by dedicated scientists from many standpoints and is very clearly understood . He needs to study what has been done, what "is" in the real world, and what the cost of doing is which requires some serious education and comprehension of the process to get beyond imaginary and daydream aspects and solutions.

Encap said:

Exactly Seoul_lasers thousands of papers and hundreds of books.

That radioisotope contribution to formation of a plasma is not discussed in any of them points to that isotopes make little if any difference in formtion of an air plasma. As a practical matter even if radioistopes did make a difference small or large--the cost getting the Nuclear Regulatory Commission license to be able obtain and handle a 1cm of any radioactive material very expensive and requiring specialized facilities and personnel with knowledge of nuclear material material safety handling and reporting and so on.

Fonograph from his first post says : " I want to build laser,focus the beam and turn air into plasma." why---who knows but he indicates he has little if any knowledge of plasma generation or how to do that so what he really needs is some knowledge of how that can be done. As everyone indicated he could maybe make a plasma with the correct equipment butit is not going to be a low cost thing that can be done easily without knowledge of what he is doing and why.

Laser induced air breakdown and plasma generation has been known and explored for more than 50 years by dedicated scientists from many standpoints and is very clearly understood . He needs to study what has been done, what "is" in the real world, and what the cost of doing is which requires some serious education and comprehension of the process to get beyond imaginary and daydream aspects and solutions.

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Fonograph also makes it quite clear he knows nothing about Radioactivity either. His posting style is quite downputting to members here ... using terms like Bukkake (Japanese **** term), "smart members"... ending posts with "get it?" as though we're the stupid ones for not understanding incoherent/rambling postings .. this is what prompted me to neg rep him at the beginning.

Now,if we place a radioactive material,lets say Uranium 238/Thorium232/Radium cube with 1cm width 1 centimeter away from the focal point of laser beam where the plasma is created,it will cause alpha,beta and x-ray/gamma radiation in the area of focal point.

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Here he talks explicitly about creating xrays/ gamma alpha and Beta in the area of the focal point. His response to me...

You purposfully quoted only half of the sentence to really make it seem like my post was badly written.From wikipedia "Quoting out of context (sometimes referred to as contextomy or quote mining) is an informal fallacy and a type of false attribution in which a passage is removed from its surrounding matter in such a way as to distort its intended meaning"

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He clearly has no idea what he writes, nor does any research on his own.
Arguing after posting this drivel doesn't help much either when more experienced members try and correct or figure out what is being posted.
:yabbmad: Makes me quite angry!

Seoul_lasers said:

Good luck on getting your hands on a tank of Fluorine!

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And more good luck not getting yourself killed while messing with it.

There are very few substances that scare experienced chemists. Two of them are hydrogen fluoride and fluorine gas.

These things are pretty dangerous do dea with really as they are hard to confine and can cause severe bodily harm. As a chemist by education i'd happily work with something like hydrogen cyanide in a fume hood, since that provides adequate protection in combination with gloves and such.

Fluorine is most dangerous to life when it's in an ionic state, but the downside is that is oinizes basically anything it can touch, so the danger is always there. Being a tiny diatomic element as it is things like gloves don't protect you from it all that well either.

Benm said:

And more good luck not getting yourself killed while messing with it.

There are very few substances that scare experienced chemists. Two of them are hydrogen fluoride and fluorine gas.

These things are pretty dangerous do dea with really as they are hard to confine and can cause severe bodily harm. As a chemist by education i'd happily work with something like hydrogen cyanide in a fume hood, since that provides adequate protection in combination with gloves and such.

Fluorine is most dangerous to life when it's in an ionic state, but the downside is that is oinizes basically anything it can touch, so the danger is always there. Being a tiny diatomic element as it is things like gloves don't protect you from it all that well either.

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indeed. Fluorine requires very special labware to handle. Tanks used to store Fluorine also are required to be Nickel (Ni). Nickel reacts with F to form a Nickel fluoride layer which protects the tank from being eaten apart further. F2 can then be stored in the tank without fear of a rupture. Despite this
even a small leak can prove lethal.

As an aside, While I worked for LG Display in 2012, we had one highly publicized anhydrous HF release that managed to escape from a poorly maintained storage facility owned by Hube Global in Gumi, Gyeongsanbuk-do. The company was associated with LG Display and Samsung and supplied the HF for glass etching at both plants. 5 workers died from exposure to the HF instantly and some 30,000 people were put on evacuation notice. The Gas leak killed just about everything within 2Km radius from the plant
and 3000 people were treated for exposure to HF fumes about 10Km down wind. 18 people including emergency personnel were seriously burned/injured responding to the incident.

The below video is CCTV footage of the actual leak. Note the lack of protective gear worn by the workers (they do not have respirators nor full body suites). This is a quite commonplace practice as safety rules are often seen as being optional.
If it is inconvenient just ignore it attitude is pervasive in many parts of Asia.



Below showing the damage done to crops ~5Km from the plant in greenhouses.

Benm said:

And more good luck not getting yourself killed while messing with it.

There are very few substances that scare experienced chemists. Two of them are hydrogen fluoride and fluorine gas.

These things are pretty dangerous do dea with really as they are hard to confine and can cause severe bodily harm. As a chemist by education i'd happily work with something like hydrogen cyanide in a fume hood, since that provides adequate protection in combination with gloves and such.

Fluorine is most dangerous to life when it's in an ionic state, but the downside is that is oinizes basically anything it can touch, so the danger is always there. Being a tiny diatomic element as it is things like gloves don't protect you from it all that well either.

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There's a chemist that does a sort of blog on chemicals he'd never work with, interesting reads. The one on FOOF (Dioxygen Difluoride) is good. There's lots more though.

Things I Won?t Work With: Dioxygen Difluoride | In the Pipeline

Seoul_lasers said:

Fonograph also makes it quite clear he knows nothing about Radioactivity either. His posting style is quite downputting to members here ... using terms like Bukkake (Japanese **** term), "smart members"... ending posts with "get it?" as though we're the stupid ones for not understanding incoherent/rambling postings .. this is what prompted me to neg rep him at the beginning.

Here he talks explicitly about creating xrays/ gamma alpha and Beta in the area of the focal point. His response to me...
He clearly has no idea what he writes, nor does any research on his own.
Arguing after posting this drivel doesn't help much either when more experienced members try and correct or figure out what is being posted.
:yabbmad: Makes me quite angry!

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Good points---he probably doesn't understand there are no answers to his questions because they are not really questions based on knowledge, experience or an understanding of what he is writing about.

Maybe he is working on some realistic science fiction story and wants detail--who knows;
Here is a site that gives detail for science fiction work which gives a lot of real world considerations --- How to Build a Laser Death Ray for science fiction setiings: http://panoptesv.com/SciFi/LaserDeathRay/DeathRay.html

diachi said:

There's a chemist that does a sort of blog on chemicals he'd never work with, interesting reads. The one on FOOF (Dioxygen Difluoride) is good. There's lots more though.

Things I Won?t Work With: Dioxygen Difluoride | In the Pipeline

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O2F2 article was very enjoyable! I had no idea that O2F2 was even stable enough to be a compound.
I don't think I'll want to synthesize any. I've had my go at synthesizing some pretty nasty chemicals ( esp. middle school ~23 years ago) and managed to survive.

Or you know just stay away from NFPA diamond ratings of 4. Leave the handling of fluoride gasses and solutions to experienced doctors of chemistry. The common hobbyist should never need to handle PHMs like UF6 or the sort

HydroSean said:

Or you know just stay away from NFPA diamond ratings of 4. Leave the handling of fluoride gasses and solutions to experienced doctors of chemistry. The common hobbyist should never need to handle PHMs like UF6 or the sort

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What could be possibly more more enjoyable than having a highly toxic, highly reactive, Radioactive compound to melt your face off with. :angel: