Hi,

The neutron is believed to have some sort of internal structure. I'm
not up on current quark theory. The free neutron decays with a half
life of ~15 min according to:

n -> p + e + 1.29 MeV, (ignore neutrinos)

That's a lot of energy per unit mass. Fortunately the relatively long
decay time provides some kind of "get away from danger grace time".

However, in the event of a relatively high energy inelastic nuclear
collision, internal resonance states of the neutron might be excited
that might enhance the rate of decay. That would make high kinetic
energy neutrons more dangerous than might be expected from the value
of the kinetic energy alone. I'm thinking of processes that might take
place in less than a millisecond.

My questionis to any quark experts out there: Are internal resonance
states of the neutron known that might effectively 'catalyze' more
rapid release of neutron energy?

What does that mean?

High energy neutrons decay with *longer* externally observed
half-lives - Special Relativity.

My questionis to any quark experts out there: Are internal resonance
states of the neutron known that might effectively 'catalyze' more
rapid release of neutron energy?

H-bomb secondaries propagate without any exotic corrections for fast
(2.45 MeV for D+D, 14.1 Mev for D+T) neutron decay.

On Apr 28, 6:11 pm, Uncle Al <Uncle...@hate.spam.net> wrote:

What does that mean?

Metaphorical language.


High energy neutrons decay with *longer* externally observed
half-lives - Special Relativity.

My questionis to any quark experts out there: Are internal resonance
states of the neutron known that might effectively 'catalyze' more
rapid release of neutron energy?

H-bomb secondaries propagate without any exotic corrections for fast
(2.45 MeV for D+D, 14.1 Mev for D+T) neutron decay.

We know all that. But you haven't answered the question

Let's use the device of metaphor to illuminate the question better.
Let's say you have a chemical substance that is unstable and decays
with a half life of 15 minutes at a specific temperature. At that
temperature, energy is distributed among internal degrees of freedom
and Boltzman statistics and kinetic factors controls the rate at which
molecules surmount the energy barrier and decay to product(s). When
you raise the temperature, there is a greater amount of energy
distributed amoung the internal degrees of freedom and molecules
surmount the kinetic energy barrier at a faster rate.

Now the neutron is said to have internal structure and weak force
mediated beta decay. I don't know all the details. My question is
whether it is known whether internal degrees of freedom can be excited
within the neutron by inelastic collision and increase the rate of
beta decay. This is unrelated to relativistic effects. Is there a
known quantum mechanical energy level diagram for the neutron? If so
then Boltzman statistics and kinetic theory would allow prediction of
enhanced decay rate. The nucleus is held together by the strong force
and it does have higher energy states. These higher energy states can
be accessed by inelastic collision with neutrons or charged particles,
by neutron absorbtion, by high energy EM excitation all to enhance the
rate of nuclear reactions, typically fission energy release.

Do I make myself clear? The neutron is said to have internal
structure. If so then there ought to be some expectations about its
behavior. BTW this may be controversial but there are plenty of
nuclear rate processes whose rate changes at temperatures near
ambient. There are isotopes whose rate of beta decay or electron
capture decay depend on crystal field (chemical) effects. To put my
question in the most simple terms, is the rate of neutron beta decay
temperature dependent?

H-bomb secondaries propagate without any exotic corrections for fast
(2.45 MeV for D+D, 14.1 Mev for D+T) neutron decay.

To put my
question in the most simple terms, is the rate of neutron beta decay
temperature dependent?

Do I make myself clear? The neutron is said to have internal
structure. If so then there ought to be some expectations about its
behavior. BTW this may be controversial but there are plenty of
nuclear rate processes whose rate changes at temperatures near
ambient. There are isotopes whose rate of beta decay or electron
capture decay depend on crystal field (chemical) effects.

To put my
question in the most simple terms, is the rate of neutron beta decay
temperature dependent?

H-bomb secondaries propagate without any exotic corrections for fast
(2.45 MeV for D+D, 14.1 Mev for D+T) neutron decay.

H-bomb secondaries undergo disassembly within nanoseconds so any
second order correction for neutron decay rate is insignificant (at
that time scale).

On Apr 29, 4:06=A0pm, d....@hotmail.com wrote:

To put my
question in the most simple terms, is the rate of neutron beta decay
temperature dependent?

I don't seem to be making any progress in probing the minds of quark
experts so I'll use the metaphorical device again to rephrase the
question.

The neutron is a spin 1/2 particle and so neutron magnetic resonance
spectroscopy exists and at a field strength of 14.7 Tesla the
resonance frequency of the neutron is around 30 MHz, (IIRC). It is
known that at very low temperatures, the neutron undergoes total
reflection from the walls of many materials. So, it is possible to do
long time neutron magnetic resonance studies, except for the
complication that the neutron decays. I have no knowledge of the
magnetic resonance of unstable nuclei (it is too dangerous) so I
cannot use that for constructing another metaphor. But I do have
knowledge of electron spin resonance. In ESR one selects an electron
spin label that is long lived and one generally studies spin labeled
molecules that are long lived. However, if one's molecule or one's
spin label decays in a time of about 15 minutes then one would expect
that decay to be reflected in ESR line shape or in the time dependent
signal decay. If only one decay mechanism pertains then one would see
only monoexponential decay. If more than one decay mechanism pertains
then one would expect to observe biexponential or multiexponential
signal decay. Now the mathematical analysis of noisy multiexponential
decay is almost intractable so such analysis is almost on the
forefront of mathematics, AFAIK.

Kinetics is exponential with temp via the Arrhenius equation

k = Ae^[-E_a/RT]

Boosting the absolute temp by a factor of 98 million (0.025 eV to 2.45
MeV) will decrease the half-life by a factor of e^(98 million) or
10^(42,560,859). Tell Uncle Al how nanoseconds are large compared
with

That is 47 orders of magnitude smaller than nanoseconds. H-bombs and
nuclear reactors (1 MeV fission neutrons must travel to repeatedly
bounce off moderator atoms) would not work by a huge margin if neutron
half-life were inversely temperature dependent. The Original Poster
is a simpleton.

d.... at (no spam) hotmail.com wrote:

H-bomb secondaries propagate without any exotic corrections for fast
(2.45 MeV for D+D, 14.1 Mev for D+T) neutron decay.

H-bomb secondaries undergo disassembly within nanoseconds so any
second order correction for neutron decay rate is insignificant (at
that time scale).

Room temp is 0.025 eV; neutron half-life is 613.9 sec at 4 kelvins
(3.45x10^(-4) eV).  Assume it is unchanged at room temp.  What follows
is therefore *very* conservative.

http://www.ornl.gov/info/ornlreview/v37_1_04/article_17.shtml

Kinetics is exponential with temp via the Arrhenius equation

k = Ae^[-E_a/RT]

In article <481B397F.4D4CA39B at (no spam) hate.spam.net>, UncleAl0 at (no spam) hate.spam.net
says...

Kinetics is exponential with temp via the Arrhenius equation

k = Ae^[-E_a/RT]

Boosting the absolute temp by a factor of 98 million (0.025 eV to 2.45
MeV) will decrease the half-life by a factor of e^(98 million) or
10^(42,560,859). Tell Uncle Al how nanoseconds are large compared
with

Does this argument apply also to the decay of, say, Uranium or Radium?
Their nuclei, after all, are certainly capable of entering high energy
vibrational states. If not, perhaps you would care to explain why it
must apply to the decay of the neutron.

That is 47 orders of magnitude smaller than nanoseconds. H-bombs and
nuclear reactors (1 MeV fission neutrons must travel to repeatedly
bounce off moderator atoms) would not work by a huge margin if neutron
half-life were inversely temperature dependent. The Original Poster
is a simpleton.

The OP never asserted that the decay rate would be inversely dependent
on temperature - he peoposed, rather, that resonant states might be
thermally induced, and would result in an increased decay rate. I agree
that his speculation of a millisecond decay rate is implausible - even
if neutrons have accessible low energy vibrational states, which seems a
bit implausible. But you say nothing here that eliminates the
possibility of some such effect.

- Gerry Quinn

Now the neutron is said to have internal structure and weak force
mediated beta decay. I don't know all the details.

My question is
whether it is known whether internal degrees of freedom can be excited
within the neutron by inelastic collision and increase the rate of
beta decay. This is unrelated to relativistic effects. Is there a
known quantum mechanical energy level diagram for the neutron?

If so
then Boltzman statistics and kinetic theory would allow prediction of
enhanced decay rate.

d.086 at (no spam) hotmail.com skrev:

[some text snipped]

Now the neutron is said to have internal structure and weak force
mediated beta decay. I don't know all the details.

The neutron consists of one up-quark (u) and two down-quarks (d).

My question is
whether it is known whether internal degrees of freedom can be excited
within the neutron by inelastic collision and increase the rate of
beta decay. This is unrelated to relativistic effects. Is there a
known quantum mechanical energy level diagram for the neutron?

There is a partially known diagram of the energies of the different
states that udd can exist in. Each one of these levels are usually
considered to be their own kind of elementary particle or resonance. The
energy differences between these different levels are typically 100s of
GeV. For instance the neutron, which is a spin 1/2 particle, has a mass
of 940 GeV, and the spin 3/2 udd particle is Delta-0, which has an
energy of 1232 GeV. The lifetime of Delta-0 is 1e-23 s.

[ Mod. note: That would be MeV instead of GeV. -ik ]

If so
then Boltzman statistics and kinetic theory would allow prediction of
enhanced decay rate.

In theory yes, but the energy gaps between the different particles are
so huge that there will not be any effect at any temperature that can be
achieved in the laboratory.

Ulf Torkelsson

nuclear temperature ~ h * 1E23/boltzmann = 5E12 K
It is remarkable that these extreme [temperatures]
reside (and do not normally express themselves) in our 310 K bodies.