Binding energy or Kinetic energy?

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SUMMARY

The discussion centers on the relationship between binding energy and kinetic energy in nuclear fusion, specifically the Deuterium-Tritium fusion process. It is established that the fusion of deuterium and tritium results in helium-4 and a neutron, releasing 17.6 MeV of energy. This energy is derived from the mass defect, which corresponds to the difference in binding energies before and after the reaction. The confusion arises from the interpretation of mass defect and binding energy, which are intricately linked through the equation E = Δmc².

PREREQUISITES
  • Understanding of nuclear fusion processes, specifically Deuterium-Tritium fusion.
  • Familiarity with concepts of binding energy and mass defect.
  • Knowledge of the equation E = Δmc² and its implications in nuclear reactions.
  • Basic grasp of nuclear physics terminology, including terms like nucleons and isotopes.
NEXT STEPS
  • Research the binding energy changes in Boiling Water Reactors (BWR) and their implications for energy production.
  • Explore the concept of mass defect in various nuclear reactions beyond fusion.
  • Study the differences between kinetic energy and potential energy in nuclear processes.
  • Investigate the role of binding energy in other nuclear reactions, such as fission and alpha decay.
USEFUL FOR

Nuclear physicists, students of nuclear engineering, and anyone interested in understanding the principles of energy release in nuclear fusion and the relationship between binding energy and mass defect.

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Summary: I always confuse Binding Energy with Released Energy in such processes. Which one comes from mass defect?
For example in a Deuterium-Tritium fusion two nuclei with lower binding energy converse to He-4 with much higher binding energy (and a neutron). The released energy is 17.6 MeV.
What exactly happens to mass defect?
Is it conversed to the higher binding energy of ∝-particle
or the released kinetic energy of the products?

Anyone could help me with this problem?

1565138815307.png
Fusion of deuterium with tritium creating helium-4, freeing a neutron, and releasing 17.59 MeV as kinetic energy of the products while a corresponding amount of mass disappears, in agreement with kinetic E = Δmc2, where Δm is the decrease in the total rest mass of particles....This difference in mass arises due to the difference in atomic "binding energy" between the atomic nuclei before and after the reaction.

Isn't it a contrast?!:confused:
https://en.wikipedia.org/wiki/Nuclear_fusion
 
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Concrete has high chemical binding energy. Uranium has low binding energy, it's actually negative. When an atom bomb explodes above a city, the end result is that the uranium has gained more binding energy while the concrete has lost binding energy. The concrete gained mass, the bomb lost mass.

An asteroid can do the same thing as an atom bomb, because it has lot of kinetic energy.

What can we conclude now? Well, it seems that kinetic energy is negative binding energy. Or those two things are the same thing.

(Maybe I made a little bit too strong claim there, negative binding energy is potential energy, kinetic energy and potential energy are both energy, but different types of energy. )
For uranium: nuclear binding energy + electrostatic binding energy < 0

For concrete: total binding energy < 0 , but chemical binding energy is the only binding energy that changes in this particular scenario.

Questions:

A) What binding energy changes are occurring inside a BWR nuclear power plant? BWR = Boiling Water Reactor.

B) What binding energy changes are occurring inside a dedicated district heating reactor?
 
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A M said:
What exactly happens to mass defect?
Is it conversed to the higher binding energy of ∝-particle
or the released kinetic energy of the products?
You're confused because you're double counting. It's not that mass defect is spent on changing the binding energy - it is the difference in binding energy. More tightly bound means less massive. That difference is then emitted as kinetic energy or radiation.

So, let's say we have the reaction shown in the picture:
##m_d, m_t, m_h, m_p, m_n## - rest masses of deuterium, tritium, helium, isolated proton, and isolated neutron respectively.
##E## - released energy
##B## - binding energy

now:
##m_d=m_p+m_n-B_d##
##m_t=m_p+2m_n-B_t##
##m_h=2m_p+2m_n-B_h##

and the fusion reaction is:
##m_d+m_t=m_h+m_n+E##

here we could write:
##m_d+m_t-m_h-m_n=E##
##\Delta m=E## (*using natural units)
and conclude that all the energy comes from the difference in initial and final masses (mass defect),

or write:
##(m_p+m_n-B_d)+(m_p+2m_n-B_t)=(2m_p+2m_n-B_h)+m_n+E##
cancelling out all the rest masses of isolated nucleons we get
##-B_d-B_t=-B_h+E##
##-B_d-B_t+B_h=E##
##\Delta B=E##

So we can see that all the released energy comes from the difference between initial and final binding energies. It's the same thing, just more deeply understood.
 
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Bandersnatch said:
You're confused because you're double counting. It's not that mass defect is spent on changing the binding energy - it is the difference in binding energy. More tightly bound means less massive. That difference is then emitted as kinetic energy or radiation.

So, let's say we have the reaction shown in the picture:
##m_d, m_t, m_h, m_p, m_n## - rest masses of deuterium, tritium, helium, isolated proton, and isolated neutron respectively.
##E## - released energy
##B## - binding energy

now:
##m_d=m_p+m_n-B_d##
##m_t=m_p+2m_n-B_t##
##m_h=2m_p+2m_n-B_h##

and the fusion reaction is:
##m_d+m_t=m_h+m_n+E##

here we could write:
##m_d+m_t-m_h-m_n=E##
##\Delta m=E## (*using natural units)
and conclude that all the energy comes from the difference in initial and final masses (mass defect),

or write:
##(m_p+m_n-B_d)+(m_p+2m_n-B_t)=(2m_p+2m_n-B_h)+m_n+E##
cancelling out all the rest masses of isolated nucleons we get
##-B_d-B_t=-B_h+E##
##-B_d-B_t+B_h=E##
##\Delta B=E##

So we can see that all the released energy comes from the difference between initial and final binding energies. It's the same thing, just more deeply understood.
Thank you very much!
 

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