Talk:Induced gamma emission

Ok, looking good.

The move is done, and I've tracked down and fixed anyone linking to ballotechnics that actually meant IGE (not easy!). I think I may have killed one redir in the process though, but IIRC it was unused anyway (still looking for it).

I have also started the cleanup, changing refs IN the article from ballotechnics to IGE. I am about 1/4 done, but I have to go so feel free to jump in. I have removed a small snippet from the intro for now:

and was originally concerned with ballotechnic nuclear reactions. The term 'ballotechnics' is attributed to Samuel Cohen, an early proponent. The concept is that there are nuclear reaction that produce gamma rays, and no alpha or beta particles. And it is proposed that this is the result of a high-energy nuclear isomer changing into a low-energy nuclear isomer, (i.e. with no change of mass number). Such high-energy isomers would include both spin isomers and shape isomers.

Maury 17:00, 30 August 2006 (UTC)

The "what links here" toolbox item is handy for tracking down links to "ballotechnics". A brief look showed cases that were ambiguous (mostly these just look like they just need wording tweaks to clarify that the term was being mis-applied). Thanks for taking the effort to do all of this! --Christopher Thomas 19:52, 30 August 2006 (UTC)

Trim50 (talk) 06:01, 14 December 2013 (UTC) An interesting patent published last month. "HAFNIUM TURBINE ENGINE AND METHOD OF OPERATION" http://www.freepatentsonline.com/20130300120.pdf

Wow

Well I don't know about you guys, but after basically adding an intro and moving stuff around I think the article actually seems pretty amazingly good now! Maury 17:56, 30 August 2006 (UTC)

I've also re-written the Ballotechnics article. See what you think. Maury 18:22, 30 August 2006 (UTC)

Inconvenient Truth

Absolutely splendid job handling the mechanics and titling of the page. Unfortunately you got the physics completely wrong. Please try to keep an open mind about this for a bit because it has nothing to do with Science politics, just established concepts in the laser field in which I published probably about 100 reviewed articles by now.

There is a tremendous difference between the production of photons by: stimulated emission, fluorescent emission, and Raman emission. The most convenient insight is given at Raman scattering down that page at the subheading "Distinction with fluorescence." Someone did a very good job in that section. "Stimulated emission" insists upon coherence between input and output photons. Gamma rays are photons and you are not going to get coherence at the gamma level of energies in this century. That would require a gamma ray laser with an unthinkable coherence length. However, the term "Gamma ray laser" has been useful but the thinking there is for a superradiant device for which the coherence length is so short that the device would be an intense directional source of gamma rays with little coherence between photons.

Induced gamma emission covers all of these analogs of laser-like processes for the gamma ray region of wavelengths. So please, give me a little time to try to correct the physics to be reasonable correct at the lay level of quantum electronics, ie laser physics.

--Drac2000 20:58, 30 August 2006 (UTC)

exoergic. (n.d.). WordNet® 2.0. Retrieved August 30, 2006, from Dictionary.com website: http://dictionary.reference.com/search?q=exoergic&x=23&y=14 Uncommon but legitimate terms, endoergic and exoergic.

--Drac2000 21:45, 30 August 2006 (UTC)

Pausing for now to see to what extent the big amount of work documenting and referencing material in the new first paragraph is treated constructively. Again, congratulations to you two, Maury and Christopher for all of the dedicated effort on the other aspects of rectifying the old Ballotechnics mess !

--Drac2000 23:03, 30 August 2006 (UTC)

Most of the experiment citations should frankly be moved to the "experiments" section, if they aren't already covered. The introduction also completely fails to mention with the Collins citations that the results are disputed.

Christopher, it seems that you have some sort of serious bias. You are asking for a disclaimer on work that was published and settled for 18 years simply on the basis of the name of one of the authors. It certainly seems you are implying that if Collins does an experiment in 2000 that remains controversial for 6 years (not unusual for an important experiment) then you want to have disclaimers stuck on everything he ever did. That is not the way science works. Try to think about NPOV.

--Drac2000 00:48, 31 August 2006 (UTC)

Also, are you sure your description of the effect is accurate?

Yes, you seem to have preconceived ideas that IGE is narrowly constrained to the "Collins effect" or somesuch. You would understand better if you approached with a more open mind. I guess you might accept that there are still things for you to learn. There is a lot of information in the references, links and further references contained within. I hope that you would enjoy taking a look to learn more.

--Drac2000 00:48, 31 August 2006 (UTC)

Fluoresence, as I realize you're aware, involves exciting from the ground state to a state that decays to a metastable state. Decays from the metastable state give the (relatively)

Relative to what, typical atomic or nuclear transition rates?

--Drac2000 00:48, 31 August 2006 (UTC)

long-lived light emission. My understanding was that the process discussed

Discussed where, why? Before the move from Ballotechnics to Induced gamma emission, I explained that IGE was a field, Isomers were an example, and the controversial part was the application using Hf-178m2. Say again IGE => Exoergic IGE => Hf178m2 triggering, still controversial. There is also IGE => Endoergic IGE => In115, settled 18 years ago. Also IGE => Exoergic IGE => Ta180m, useless but independently confirmed for 8 years.

--Drac2000 00:48, 31 August 2006 (UTC)

was more or less the inverse of this: a long-lived metastable nuclear isomer is perturbed into a shorter-lived state with comparable energy, which promptly decays (as it's either not metastable or has a much shorter lifetime). The reason you get net energy release out for the "gamma ray laser" application was that you already had a population inversion,

population inversion has nothing to do with anything with which we have been concerned so far. If you are interested in learning as opposed to "spinning" the topic, that is probably IGE => endoergic IGE => lifetime inversion in three levels, so far unexplored.

--Drac2000 00:48, 31 August 2006 (UTC)

not that something particularly special was going on. Regarding Prof. Collins' claims, I am uncertain as to where the "resonance" mentioned in the introductory text comes into play. My impression is that Collins claims to accomplish the perturbation using x-rays of an energy much lower than the actual perturbation transition energy, but the actual mechanism proposed doesn't seem to be explained anywhere in this article. --Christopher Thomas 23:29, 30 August 2006 (UTC)

Best to get the field defined first and explain some things to help lay people.

--Drac2000 00:48, 31 August 2006 (UTC)

Both the beauty and the challenge of the Wikipedia is the democracy that allows those who do not know what they do not know to override expertise. So if you want to spin this topic against Prof. Collins more than you want to develop clarity and insight into the topic, you can do it. My further efforts, if any, are going to be motivated by what happens next. I have no problem if you produce a page on Induced gamma emission that will be perceived as ridiculous in the laser community, but together we could do something that would be a credit to Wikipedia. Your move, Christopher.

--Drac2000 00:48, 31 August 2006 (UTC)

Afterthought ! You realize that I have looked only at the first paragraph on this page of Induced gamma emission. There is much more work to be done on the rest of the page, if you want to join me in producing a quality article throughout.

--Drac2000 00:59, 31 August 2006 (UTC)

What a mess!

We agree completely, but as explained six lines up, I only tried to improve the first introductory paragraph to see if it were possible. Please look at what I started with yesterday. Contrary to promises, after I helped in dividing up the abominable "Ballotechnics" page I found that the part that was moved over here and was supposed to be preserved as it was instead had been completely rewritten by someone knowing absolutely nothing about quantum electronics or nuclear physics - and without any discussion.

--Drac2000 15:37, 31 August 2006 (UTC)

OK, I have a PhD in theoretical nuclear physics

Perfectly wonderful news. I have over 100 published articles in laser physics topics. We should be able to do something together, if personalities permit.

--Drac2000 15:37, 31 August 2006 (UTC)

, and I am having trouble understanding this article:

• What the heck is exoergic and endoergic? The article on flourescence fails to even mention "exoergic flourescence" or "endoergic flourescence".

Fluorescence starts with fluor... not flour....I am hoping it was a minor typo. The terms were defined with links about 18 lines down from the start of the subsection "Inconvenient truth."

--Drac2000 15:37, 31 August 2006 (UTC)

• The article on flourescence is a mess, and could use a lot of love and care.

Want to try it together, the "together" being the important part?

--Drac2000 15:37, 31 August 2006 (UTC)

• What the heck is a "resonant process"?

A "resonant transition" is one that jumps directly between an excited state and the ground state: a "nonresonant transition is one which occurs between an excited state and another [lower] excited state (which is of course not the ground state).Delphwhite (talk) 00:37, 15 December 2013 (UTC)

• The intro says "its like flourescnece". The first section says "its like lasing". So which is it?

That's part of the mess that I have not even tried to touch yet.

Drac2000 15:37, 31 August 2006 (UTC)

• The first section states: and then coaxed to release this energy as gamma photons through the application of an external light source: Oh really? I'm gonna apply a few 1eV photons to induce a nucleus to emit multi KeV or MeV gammas? I don't think so ...
• ...sequence of papers that raised concerns...' Huh? why would this "raise a concern?" OK, so I read a bit further in, and I see why, but its clear that these concerns should therefore be mentioned in the intro, which is currently a word-salad of jargon.

Guhh. Please clean this up. linas 04:00, 31 August 2006 (UTC)

Maybe, if you will help as opposed to criticise about issues you did not take the time and effort to look 6 lines up to solve. It is hard work and no appreciation.

--Drac2000 15:37, 31 August 2006 (UTC)

Yeah, Drac, too much detail in the intro! I welcome the changes to make the intro factually correct (my bad for not being ready in the first place), but remember, it's the intro, and needs to be short, sweet, and simple. If IGE is a fluoresence-like process, the intro should simply state that and move on.

But now I have to stop and think about what's going on. Fluoresence generally involves a downshifting of wavelength (right?), so how is this process similar, when it is creating gammas from x-rays? That doesn't sound like fluoresence to me.

Why not? Any nuclear database will show many cases of gammas emitted with energies smaller than the characteristic x-rays from the same material.

--Drac2000 15:37, 31 August 2006 (UTC)

I'm not questioning the physics (yet), but if there is a proposed mechanism here, as others have pointed out, it desperately needs to be added. Just don't put it in the intro!

And could you lay off the "open mind" comments? Do you have any idea how insulting they are? Maury 13:58, 31 August 2006 (UTC)

In spades, I had just been dealing with Christopher as you see above.

--Drac2000 15:37, 31 August 2006 (UTC)

Do we go forward?

Do we? --Drac2000 15:37, 31 August 2006 (UTC)

Only the intro paragraph has been worked upon. Length and treatment of references conform to those of the page Ballotechnics from which this page was split under the agreement that both daughter pages would preserve consensus reached before the split. --Drac2000 17:12, 31 August 2006 (UTC)

Absolutely. The remaining problems are my using the laser as a metaphor, which I guess is just "wrong" and should be removed outright, and the lengthy intro which is simply too detailed. Split that up, separate it out, and I think it's in good shape. Maury 18:39, 31 August 2006 (UTC)

Maury, Appreciate your continued interest and glad you expressed an understandable human concern about how we should realize how insulting our statements can sound. Thanks for asserting that very needed comment. Now, I ask for your reconsideration of a modestly different point of view, namely mine.

• So far I do not see the difference (but remain willing to try to see it) between the size, complexity and reference with structure between the intro of Induced gamma emission and the intro of Ballotechnics.
• We are also challenged with 71.133.205.75 who continues to change statements without one word of participation in these discussions here. He has some sort of distinction because he is on some kind of "Special page" that has been around only a month. Do you know the significance of such an arrangement. If he is taking over, we are wasting our time seeking consensus. Can you suggest or recommend something? I would have no problem working with anyone interested, but such heavy-handed exercise of "privilege" is another insulting aspect of this page.
• As I see it, the challenge is that IGE is an interdisciplinary effort between nuclear physics and quantum electronics. It is lightly treated formally in nuclear and discussed in these terms of quantum electronics that need more explaining. It started in 1939 as references show and that surprises most people and since there were no lasers then, it would have been "sensitized fluorescence." That's passe now, but what is relevant is that there is and was no controversy until recently when the weapons gurus tried to hijack it for war or peace, as those partisans divided up. The positive approach that I am recommending is in the next bullet.
• Please could we finish an introduction that lays the foundation for understanding of all of the non-controversial parts. When we reach consensus that it tells the story of what the field is about then we could usefully consider how to trim it down or split it or whatever, but doing so from an informed point upon which we have arrived at consensus?
• I am willing to try a little more while ignoring 71.133.205.75 to see if we can reach an informed consensus upon the non-controversial part of the science, if you will help.

--Drac2000 20:22, 31 August 2006 (UTC)

My mistake. I have a "Special page" just like Superman71.133.205.75. He's nothing special, just does not know how to work with people in a collegial fashion. Can be dealt with later if we can just get the field defined.

--Drac2000 20:38, 31 August 2006 (UTC)

Sometimes (rarely) I get optimistic. Let's cool it a bit and see if I can come up with a visual that would help with the non-controversial part. I think there is an opportunity to connect with nuclear reactions as well.

--Drac2000 20:54, 31 August 2006 (UTC)

"# So far I do not see the difference (but remain willing to try to see it) between the size, complexity and reference with structure between the intro of Induced gamma emission and the intro of Ballotechnics."

Well for one, the intro to ballotechnics is 50 words, while the intro to this article is 212. A good intro should include a definition of the term, where the term is used, and perhaps a comparison to similar topics. Things not to include in the intro are, well, pretty much everything else. Certainly a list of experiments does not belong, while at the same time the intro still fails to clearly describe what the topic is - which is the whole point. It also uses terminology that no one here has ever heard of, so that's pretty much a great definition of something that shouldn't be there. Here, try this on for size:

In physics, induced gamma emission (IGE) refers to the process of fluorescent emission of gamma rays from excited nuclei, or nuclear isomers. It is an analog of conventional fluorescence, which is defined in terms of photons of light and excited states of atoms or molecules. In the case of IGE, nuclear isomers can store significant amounts of excitation energy for times long enough for it to serve as "nuclear fluorescent" material.

THAT is an intro.

Maury 21:59, 31 August 2006 (UTC)

And an excellent one, at that. English was never one of my strong subjects. Also the clean-up on the article is very helpful.

--Drac2000 22:15, 31 August 2006 (UTC)

Wow - once again

Maury, Splendid improvement I think. If you feel the example of the 5 fluorescent isomers should come later, please change it as you judge best. I got used to those concrete examples being right up front and thought it made the concepts more comfortably tangible. --Drac2000 22:37, 31 August 2006 (UTC)

Tough job, but none of the history up to 1999 as written should be controversial. Maury, I am very interested in your judgement and upgrading of this History part. --Drac2000 00:40, 1 September 2006 (UTC)

This work helped tremendously! I think even I am starting to understand it now (no mean feat, let me assure you). Maury 12:37, 1 September 2006 (UTC)

Yes, intro currently looks good. Sorry for being overly critical above, got off on a bad start. But perhaps its easier if I play role of critic for a little longer. So:

• Intro lists five isomers, but the history section promptly mentions a sixth (indium).

Made small addition and believe problem fixed. However cost is word count increase to 118 in Intro. Problem? Not for me, anyway. --Drac2000 17:57, 1 September 2006 (UTC)

• History should explicitly state that In is indium (I had to guess).

Done --Drac2000 17:57, 1 September 2006 (UTC)

• The commentary about "usually overlooked" raises an eyebrow: what's the point of raising questions in the readers mind?

Anyone taking the link to Nuclear reaction will not find gamma-gamma' reactions.--Drac2000 17:57, 1 September 2006 (UTC)

• Don't use the condensed notation. Use A+B arrow C+D, this will aid in understanding when non-experts read this.

Let's save for later, I copied this below under "Pending"

• Indicate energy of gamma-prime and gamma, so we don't have arguments about whether gamma's are x-rays or not. I assume the reaction that reaction is prompt; I presume the incoming gamma is an MeV or so, the outgoing gamma is 100KeV or so.

Hope figure fixes it?

• Not quite clear what Pontecorvo and Lazard did: Is the news that they created an isomer? That they created the isomer using only gammas? That they discovered something with a half-life of hours?

Hope figure fixes it?

• Indicate that there are two reactions: one to create the isomer, and the second being the decay of the isomer. The second is the actual "fluorescence".

Hope figure fixes it?

• According to the indium article, the isomer decays by beta to tin, and not by gamma, as the fluorescence label suggests ... so this is confusing.

Link in 3rd line of intro shows an IT (isomeric transition) from isomer as indicated in schematic drawing of that data.

• Need a better link to resonant process than resonance. I still have no clue what a "resonant process" is. OK, I'm guessing spectral line? As in, a sharp emission line/absorption line? This would explain the funny talk about energy/momentum conservation that currently seems to confuse things.
• The paragraph that starts with "There is little conceptual difference..." finally made the light bulb go off in my head. If I understand this correctly, the reaction that is actually of interest is the time-reversed reaction: taking the indium isomer, shining a low-energy x-ray on it, thus popping it into an excited state where it promptly decays to a ground state by emission of a high-energy x-ray. Right? That's the point of this, right? If so, this somehow needs to made clearer, earlier, cause I had to concentrate before that lightbulb went off.

Hope figure fixes it?

Bold inline comments this section added by --Drac2000 20:40, 1 September 2006 (UTC)

Maybe this time, I was more helpful? linas 04:19, 1 September 2006 (UTC)

Absolutely, Yes. ! I find such truly constructive criticisms to be extremely helpful. Also, it shows that we will have a lot more discussions to do (exciting in my opinion) and still being inexperienced with the technicalities of Wikipedia processes, I am worried about warnings I keep getting that this page is too long. I am going to start by trying to delete a lot of the discussion and contention about the Ballotechnics part that applied to what was left on that page when we moved over here. If anyone feels we lost something in doing so, please put back those parts and do something else to cope with the length warnings on this talk page.

--Drac2000 15:02, 1 September 2006 (UTC)

Completed process by archiving using

• Wikipedia:How to archive a talk page

Have to stop and contribute to earning a living for a bit. I did change the title of the history section to bracket the major period of study and conceptualization over which there was no lingering controversy. I am hoping it might help deal with the upset over later events that began (conveniently) in the 61st year, 2000. Welcome your critiques on that idea. More work here later today.

--Drac2000 15:47, 1 September 2006 (UTC)

Suggesting framework; lasing.

OK, the below is my guess, emphasize "guess", as to what the main points are, in describing IGE.

1) Nuclear isomers exist.

2) Certain nuclear isomers can be created with the following process:

N + g --> M + x

where N is a nucleaus in the ground state,

g is a gamma ray, say a 1MeV gamma ray

M is the excited nucleus aka isomer

x is another gamma-ray (aka x-ray), say about 100KeV

3) The above reaction is "instantaneous", in that x is emitted within picoseconds after absorption of g.

3a) the state M is metastable, i.e. will decay but is long-lived

4) This reaction is "resonant" in that it involves only photons, and thus kind-of resembles normal emmission/absorption-line type atomic physics with photons.

In short, one takes a nucleus, pumped some energy into it, and the resulting isomer is stable over relatively long periods of time. It will eventually decay, by alpha, beta or gamma radiation: in this sense, anything that is radioactive is "kind of like" fluorescence. By restricting the analogy to nuclear isomers only, and nuclear isomers that decay only by gamma emission, it is even more "kind of like" fluorescence. I think the analogy stands.

OK next step:

5) All quantum processes are time-reversible.

6) Thus, we can consider the reaction:

M + x --> N + g

We take an isomer, shine a 100KeV photon on it, and, whammo: a very energetic 1MeV photon pops out. Yes, this looks like upconversion.

7) Some lasers, e.g. dye lasers, made with fluorescent dyes, use a similar process (???), with eV scales insteade of MeV scales, and orbital electrons instead of nuclei. That is, you set up a population of M, pump it with low-frequency x, and whammo, you lase out a bunch of high-energy g, finishing with a completely depleted, ground state dye N that remains. But I know just about nothing about lasers, so this is speculation. I do know that some lasers, e.g nitrogen lasers, have such a short lasing length that no mirrors are needed. I have no clue what sort of density one needs to get the population inversion.

I suggest the above, if correct, should provide the technical expository framework for explaining this stuff in understandable terms. linas 17:39, 1 September 2006 (UTC)

Close, and terrific approach, but needs some "tuning". Our considerations crossed in Wiki-space. Please see inline changes I made that are found above in bold, just to help them be found. Short break, then back to concentrated effort. Many thanks.

--Drac2000 17:49, 1 September 2006 (UTC)

Illustration

Added picture, hopefully worth 1000 words, as the saying goes. It is an excellent point attempting to contrast time-reversed processes as recommended above, but this illustration shows the complications that must be addressed. I am hoping the illustration, drawn just for this article will make the job easier. Let's see.... --Drac2000 20:20, 1 September 2006 (UTC)

Pending concerns

• Don't use the condensed notation. Use A+B arrow C+D, this will aid in understanding when non-experts read this.

Only needs to be done once, to introduce the shorter notation.

The graphic looks great, its exactly what was needed.

The intro still lists five elements, and indium is not one of them. A sentence should be added to explain why indium is not one of the five. The intro should also include mention of the applications, singling out the high-energy density battery, and the gamma ray laser. The intro should also mention the controversy. This probably means that the technical content in the current intro gets moved to a section called "technical overview". linas 22:00, 2 September 2006 (UTC)

Non-controversial version

The version of this time and date contains what I offer as being the non-controversial aspects of Induced gamma emission. As recommended somewhere in the Wikipedia protocols I saw where we were asked to concentrate upon non-controversial "cores" of a subject first and then consider linking to another subpage of "status" and "contrast of perceptions." I really think this will be the only way to get something credible. Please let's make this version into concensus without adding here any of the old "fighting statements." In my view anything beyond what is in the article at this time is "research", unsettled and supposed to be excluded from Wikipedia. In any case I strongly recommend that we get this pre-2000 work into consensus if you feel it is not acceptable as is, before enlarging the scope to catch more trouble. --Drac2000 23:39, 1 September 2006 (UTC)

Some clean-up added. --Drac2000 13:26, 2 September 2006 (UTC)

Looks to be in fine shape now. Good job! As a controversial topic, I suppose someone will show up next month or next year and insist on something; all you can do now is wait to see what happens. linas 21:48, 2 September 2006 (UTC)

Linas, many thanks again for for essential and constructive work. Having reflected upon matters some more and looked at WP:SP I think they make a good point. Indeed, the page here still needs the touches you wisely recommended that are still pending, but I think to protect what we have already, we need to put the "lightening rod" up somewhere else to try to develop a subpage that deals with IGE after 1999 when thing became so impassioned. A Google search on "Imaginary weapons" will show just how unfortunate things have become. Though opinions seem to be smoothing somewhat, unspent passions need an outlet and have to be considered as we try to write something about the last 6 years of IGE. Perceptions remain very time-dependent and so the last 6 years will be best treated as a subpage.

--Drac2000 13:21, 3 September 2006 (UTC)

Gamma ray laser

So .. out of idle curiosity ... how well are the cross-sections known? Has anyone done the calculations for ASE, is it known what sort of densities are required? How feasible is this? I mean, aside from the obvious risks of a criticality accident or outright explosion of the thing, it seems like a theoretically straightforward thing to do, once the various cross-sections, etc. are known. Right? What's the blocker? linas 22:11, 2 September 2006 (UTC)

Great point. Currently studying the excited states involved in the IGE cascades looking for lifetime inversion.

--Drac2000 13:21, 3 September 2006 (UTC)

Hafnium-178m2 triggering: controversy after 1999

A 6 year controversy has raged over the results of using Hafnium-178m2 in IGE experiments. Attempting to conform to WP:SP while developing a second page reporting the last 6 years of IGE, the prototype of that second page and its discussion have been moved. Please take the link User:Drac2000/Induced gamma emission: Hafnium-178m2 and participate in the development of the second page of IGE. (Emphasis added --Drac2000 20:18, 13 September 2006 (UTC))

--Drac2000 13:34, 3 September 2006 (UTC)

Woo hoo! I see now why its controversial! Anyway, I think that the above should be moved into the main article namespace, under the title of IGE controversy or Hafnium controversy or Hafnium bomb, and just let the general public have at it. You may want to personally invite some of the previous participants in these discussions (e.g Chris Thomas) to review. linas 14:12, 6 September 2006 (UTC)

Please see reply and talk continuation at User_talk:Drac2000/Induced_gamma_emission:_Hafnium-178m2. Everyone is invited.

--Drac2000 16:40, 6 September 2006 (UTC)

NPOV tag

It's obvious from the talk page that this has been a controversial article. The present state of the article is ridiculously credulous.--76.81.160.198 (talk) 06:22, 21 December 2007 (UTC)

Unsubstantiated use of the perjorative ridiculously credible because of unspecified obvious attributes constitutes vandalism, not collegial improvement.

Drac2000 (talk) 14:26, 19 February 2008 (UTC)

false picture

Info: this image: Image:HafniumMetalUSGOV.jpg isn't hafnium. It look similar to germanium. I think it was a confusion from the author. --Alchemist-hp (talk) 21:56, 20 June 2009 (UTC)

The hafnium image now on the main page is an exceptionally well photographed piece of a Van Arkel crystal bar - my compliments! The previous image Image:HafniumMetalUSGOV.jpg is of a small piece broken off a hafnium Van Arkel bar that is poorly illuminated and out of focus (doesn't really look like hafnium). -- Delphwhite (talk) 19:24, 21 September 2011 (UTC)

Platinum-186m does not exist...

This isomer of platinum is not listed in the element's article, nor could I find any credible source for it. Isomers of platinum are 193m, 185m and 197m. Please check... —Preceding unsigned comment added by Rnbc (talk • contribs) 13:42, 6 August 2010 (UTC)

I agree--there is no Pt186m. That was my comment as well. Charlie Moquin 24May2011 —Preceding unsigned comment added by 68.236.71.92 (talk) 22:03, 24 May 2011 (UTC)

Long living isomers:

Halbwertszeiten der stabilsten Isomere
Isomer	180m1Ta	210mBi	186mRe	166mHo	108mAg	192mIr	242mAm	121mSn	178mHf
Kernspin und Parität (Jπ)	−9	−9	+8	−7	+6	+4	−5	−11/2	+16
Energie über Grundzustand (keV)	77,1	271,3	149	5,9	109,4	56,7	48,6	6,3	2446,1
Halbwertszeit	stabil	3·106 a	200·103 a	1200 a	418 a	241 a	141 a	43,9 a	31 a
rel. zum Grundzustand	stabil	210·106×	2·106×	0,4·106×	9,3·106×	1.200×	77.000×	14.000×	instabil
Die dazu gehörenden Grundzustände
Grundzustand	180Ta	210Bi	186Re	166Ho	108Ag	192Ir	242Am	121Sn	178Hf
Kernspin und Parität (Jπ)	+1	−1	−3	±0	+1	−1	−1	+3/2	±0
Halbwertszeit	8,15 h	5 d	3,72 d	1,12 d	2,37 min	73,8 d	16 h	27 h	stabil