Was Helium ever found in fusion reactors?

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Discussion Overview

The discussion revolves around the detection of helium in fusion reactors, particularly in tokamaks, and whether its presence is necessary to confirm that fusion reactions are occurring. Participants explore the implications of neutron radiation detected in these devices and the potential sources of such neutrons, including photonuclear reactions and relativistic collisions.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Exploratory

Main Points Raised

  • Some participants suggest that the detection of neutron radiation in fusion reactors could be attributed to photonuclear reactions, which are not directly related to fusion, raising the question of whether helium has ever been found in these reactors as definitive proof of fusion.
  • Others argue that the amount of neutrons detected is significantly higher than what could be produced by photodisintegration, implying that fusion is indeed occurring, but the challenge lies in achieving efficient fusion.
  • Concerns are raised about the reliability of data regarding neutron production and the lack of widely known reports on helium detection in tokamaks, with some participants questioning the transparency of such findings.
  • Technical inquiries are made regarding the energy thresholds for photodisintegration and the sources of gamma energy required for such reactions.
  • Some participants assert that helium, specifically alpha particles, has been detected in fusion experiments, referencing reports from facilities like JET.
  • There is a repeated emphasis on the need for clear evidence of helium detection to validate the occurrence of fusion reactions, with skepticism expressed about the absence of such reports.

Areas of Agreement / Disagreement

Participants express disagreement regarding the necessity of helium detection as proof of fusion, with some asserting it is essential while others claim that neutron detection alone is sufficient evidence of fusion processes. The discussion remains unresolved, with multiple competing views presented.

Contextual Notes

Participants highlight potential limitations in the data regarding neutron production and the conditions under which helium detection might be reported. The discussion also reflects varying levels of familiarity with the subject matter among participants.

Stanley514
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Some scientists have reported up to date success with such devices as tokamaks and Z-pinch
devices by reporting neutron radiation that they registered inside such reactors.It gives them hope to build such a devices as ITER for following fusion researches.
Meanwhile there have been overlooked such a fact that neutron radiation inside of reactors could be produced due to photonuclear reactions which are not exothermic and
not directly related to fusion.I think that only finding Helium in reactors could be a proof that nuclear syntesis is really going on there.
Do you know if any scientist EVER reported that Helium was found inside of experimental fusion reactors?
 
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The amount of neutrons being detected from fusion devices is VASTLY more than what could possibly be produced by photodisintegration. The issue isn't whether fusion is being performed, its getting it to be performed efficiently.
 
The amount of neutrons being detected from fusion devices is VASTLY more than what could possibly be produced by photodisintegration.
From what sorces do you know it exactly?I could belive, but think such data could be easy to manipulate.Try to define number of photoreaction neutrons which could be or may not be...
Does not it seems strange to you that there is no widely know reports on finding Helium inside of tokamaks which could be the only UNDENIABLE proof of fusion reactions...
 
Photodisintegration of what - deuterons?

What is the threshold energy for photodisintegration of a deutron or a photoneutron from any other source?

What would be the source of such gamma energy?
 
Nueutrons also could form as result of collisions of relativistic electrons and ions.
 
Stanley514 said:
Neutrons also could form as result of collisions of relativistic electrons and ions.
Thetypical ion or electron energy is on the order of 10 keV (108 K). The ions coming from fusion have energies on the order to MeV, but quickly lose that energy to cooler ions. 1 to 10 MeV does not make for relativistic ions, and 10 or even 100 keV does not make for a relativistic electron.

So what would the source of MeV gammas required for photoneutron reactions, and what is the binding energy of neutrons in the various nuclei one might find in a fusion plasma?
 
If Helium was never found inside of TOKAMAKS there can`t be a fusion reactions.
If it was found why not to report it?
 
Of course the alphas are there, and they have been looked for and seen. Why would you think otherwise? See for example the attached reports from JET.
 

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Stanley514 said:
From what sorces do you know it exactly?I could belive, but think such data could be easy to manipulate.Try to define number of photoreaction neutrons which could be or may not be...
Does not it seems strange to you that there is no widely know reports on finding Helium inside of tokamaks which could be the only UNDENIABLE proof of fusion reactions...

Widely known? To whom? The only people it will be widely known to are people that work in the industry, have an active part in it, or people that follow all of it closely for whatever reason they want. Unless you are one of those people then I doubt it would ever be widely known to you.
 

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