Can Five Neutrons Form a Neutroium Nucleus?

  • Context: Graduate 
  • Thread starter Thread starter Forestman
  • Start date Start date
  • Tags Tags
    Neutron
Click For Summary

Discussion Overview

The discussion centers around the possibility of forming a stable nucleus composed solely of neutrons, specifically considering the hypothetical "neutroium" nucleus made of five neutrons. Participants explore the conditions under which neutrons can be packed together, referencing neutron stars and the forces involved in nucleon interactions.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants propose that while neutrons can be densely packed in neutron stars due to strong gravitational forces, this does not translate to the formation of a stable neutroium nucleus due to the limitations of the strong force.
  • It is suggested that the only stable nucleon-nucleon bound state is deuterium, indicating that a significant number of neutrons would be required to achieve any form of stability.
  • One participant mentions that a purely neutronic nucleus is unstable and decays faster than a free neutron, highlighting the challenges in forming such a nucleus.
  • Another viewpoint discusses the possibility of trapping slow neutrons in a box, where their fermionic nature would manifest, but this does not lead to a bound state.
  • Historical experiments from the late 1960s are referenced, which investigated di-neutron states, suggesting that there has been prior interest in neutron clustering.
  • Recent experimental work is mentioned regarding tetra-neutron states, indicating ongoing research into the behavior of neutron clusters and their implications for understanding atomic nuclei.

Areas of Agreement / Disagreement

Participants generally agree that a stable nucleus composed solely of neutrons is unlikely, but multiple competing views remain regarding the conditions under which neutrons might interact or cluster. The discussion remains unresolved regarding the potential existence and stability of neutron clusters.

Contextual Notes

Limitations include the dependence on the definitions of stability and bound states, as well as the unresolved nature of neutron interactions in various experimental contexts.

Forestman
Messages
212
Reaction score
2
I meant to title it "Neutrons packed together"

Since neutrons can be packed together in a neutron star, would it be possible to take say five neutrons and pack them together and make a neutroium nucleus. And if not, how come?
 
Physics news on Phys.org
Gravity in a neutron star is strong enough to overcome the repulsion between neutrons. The strong force is not.
 
The strong force is not enough to form bound state of neutrons, the only bound nucleon-nucleon state is deuterium. So you need A LOT of neutrons to form a bound state, a state which is bound by gravity, as Vanadium suggested
 
A purely neutronic nucleus is not stable - is decays even faster than a free neutron itself.

But you can take several very slow neutrons and put them in a trap with the reflecting walls (a box). Such neutrons are "large" - their De Broglie wave length is big. If the trap size is small enough, you can obtain "overlapping" neutrons in a box. They do not form a bound state but rather manifest their fermionic nature (filling the "box" states is specific here).

Bob.
 
malawi_glenn said:
The strong force is not enough to form bound state of neutrons, the only bound nucleon-nucleon state is deuterium. So you need A LOT of neutrons to form a bound state, a state which is bound by gravity, as Vanadium suggested
There were experiments done in the late 1960s (by Abashian, Booth, and Crowe, or ABC) looking for di neutron states in scattering protons off of deuterium at low energies. Search web "abashian booth crowe ABC experiment"
 
Neutron clusters have been under consideration in some experimental work, see for instance
PHYSICAL REVIEW C, VOLUME 65, 044006, F. M. Marques et al.
where tetra-neutron states are considered in the breakup from 14Be.
If they exist they will be very short-lived, one would rather see traces of it when it dissolves instead of a bound neutron cluster. But it is of interest in order to better understand clustering effects within atomic nuclei.
 

Similar threads

Undergrad Can proton/neutron decay be avoided in some conditions?
  • · Replies 3 ·
Replies
3
Views
4K
Undergrad Can Neutron-X Fusion Reactions Overcome the Repulsion Problem in Fusion Energy?
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad Separation energy of nucleons and Coulomb barrier
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Question about gluons and nucleon binding
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Kerma from neutron irradiation
  • · Replies 5 ·
Replies
5
Views
2K
High School Can alpha radiation make other materials radioactive?
  • · Replies 9 ·
Replies
9
Views
4K
Undergrad Negative Q-value for 7Li(alpha,n) reaction
  • · Replies 18 ·
Replies
18
Views
5K
High School Can a hydrogen atom become a neutron?
  • · Replies 5 ·
Replies
5
Views
3K
High School Why does the nucleus become unstable as the number of nucleons increases?
  • · Replies 12 ·
Replies
12
Views
5K
Undergrad Nucleus energy levels, neutron energy
  • · Replies 15 ·
Replies
15
Views
4K