Neutron Temp: Does It Apply to Subatomic Particles?

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    Neutron Temperature
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Discussion Overview

The discussion centers on whether temperature applies to subatomic particles, specifically neutrons. Participants explore the relationship between temperature and kinetic energy, the implications of absolute zero, and the nature of energy absorption in atoms versus subatomic particles.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that temperature can be defined for subatomic particles like neutrons based on their kinetic energy, suggesting that slower neutrons correspond to lower temperatures.
  • Others argue that temperature is a measure of the average kinetic energy of an ensemble of particles, including neutrons, and reference the concept of "electron gas" in conductors as an analogy.
  • A participant mentions that for non-relativistic free neutrons, temperature can be related to kinetic energy through a specific equation, highlighting practical applications in neutron scattering experiments.
  • One participant expresses confusion about the concept of temperature in relation to subatomic particles, questioning how particles that do not absorb photons can have a temperature.
  • Another participant challenges the idea that temperature increases solely through photon absorption, noting that energy input can also affect potential energy and not just kinetic energy.
  • Concerns about the clarity of previous teachings on atomic and subatomic behavior are raised, with a participant reflecting on their learning journey and the evolution of scientific understanding over time.
  • There is a suggestion that neutrons may not have an "internal" temperature analogous to the "external" temperature of atoms, particularly in relation to energy absorption and electron behavior.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of temperature to neutrons and subatomic particles, with no consensus reached on the nature of temperature in this context. The discussion remains unresolved regarding the definitions and implications of temperature at the subatomic level.

Contextual Notes

Participants highlight limitations in understanding related to the definitions of temperature and energy absorption, as well as the challenges of applying macroscopic concepts to subatomic phenomena.

coolul007
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Does temperature apply to subatomic particles, in particular the neutron? The question is prompted by the definition of absolute zero, being specific to atomic movement.
 
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coolul007 said:
Does temperature apply to subatomic particles, in particular the neutron?
I am not sure if a get question properly but, in general, particles temperature can be defined with its kinetic energy
slow neutrons are colder, hot neutrons are faster..

as analogue of classical temperature, where $$ T \sim <E_k> $$
 
coolul007 said:
Does temperature apply to subatomic particles, in particular the neutron? The question is prompted by the definition of absolute zero, being specific to atomic movement.

I don't think you understand the definition of temperature. It is a measure of the average kinetic energy of an ensemble of ANY particles, neutrons included.

If you do a search, you can even find, especially in a solid state text or webpage, the temperature of the "electron gas" in a conductor at room temperature.

Zz.
 
Yes neutrons have a temperature. For non-relativistic free neutrons (eg: moderated neutrons radiating from a nuclear reactor) the equations are trivial ##E = \frac{3}{2}k_{B}T## where ##E## is the kinetic energy ##E = \frac{1}{2}mv^{2}##. Indeed, at neutron scattering facilities dedicated to using neutrons as a probe of condensed matter, the different instruments are typically classified as cold, thermal, or hot. Which is a direct reference to the neutron temperatures used in the scattering experiments.
 
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I was thinking of temperature in the classic sense of atom versus subatomic particle. I have been lied to about atoms my whole life, so if I am way off base here I apologize. My understanding is the atoms increase "temperature" by absorbing photons. Therefore a rock that does not have kinetic energy can have "stored heat". Therefore, my thoughts went to particles that don't seem to absorb a photon and are at "rest" in the nucleus of an atom. That is what spurred my question.
 
coolul007 said:
I have been lied to
That's a bit harsh. I probably got the same stories but don't share the feeling; learning is a gradual process that has to start somewhere. And what you can absorb in one step is limited (as well as what you can absorb in a whole lifetime :cry: :confused: ).
 
coolul007 said:
My understanding is the atoms increase "temperature" by absorbing photons.
I wouldn't say that is a meaningful statement. It's trying to extend a macroscopic, statistical idea into the behaviour of a single entity. Absorbing Energy doesn't imply a pro-rata increase in temperature, even in a real gas because input energy can result in an increase in Potential Energy as well as KE. Van der Vaal forces beween gas molecules stop them behaving ideally.
I would say that you haven't been "lied to" as much as taken an inappropriate message from a not-to-good presentation of the situation.
 
BvU said:
That's a bit harsh. I probably got the same stories but don't share the feeling; learning is a gradual process that has to start somewhere. And what you can absorb in one step is limited (as well as what you can absorb in a whole lifetime :cry: :confused: ).
I didn't mean to be harsh, the implication is that, as understanding increases the previous teachings are invalidated. I'm 72 1/2 years old, so you can imagine the world, as well as the subatomic world has changed for me. I ask this question in relation to absolute zero, being the lack of "static" energy in an atom. I was just pondering if there is a subatomic equivalence. No condemnation of physicists on my part. Thank you for your replies.
 
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coolul007 said:
I didn't mean to be harsh, the implication is that, as understanding increases the previous teachings are invalidated. I'm 72 1/2 years old, so you can imagine the world, as well as the subatomic world has changed for me. I ask this question in relation to absolute zero, being the lack of "static" energy in an atom. I was just pondering if there is a subatomic equivalence. No condemnation of physicists on my part. Thank you for your replies.
I think you're asking if neutrons have "internal" temperature as well as "external" temperature that SpinFlop described. Atoms can receive energy which pushes electrons into "higher orbits". I don't believe there is an equivalent in neutrons.
 

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