| Topic: |
Science > Physics |
| User: |
"" |
| Date: |
18 Feb 2005 05:23:51 PM |
| Object: |
Jar of neutrons |
Hi
What would happen if you collected a jar full of neutrons at room
temperature/atmospheric pressure?
What would they look like? Gas? Liquid? Solid? Colour?
How much would the jarful weigh?
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| User: "Uncle Al" |
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| Title: Re: Jar of neutrons |
18 Feb 2005 06:10:29 PM |
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wrote:
Hi
What would happen if you collected a jar full of neutrons at room
temperature/atmospheric pressure?
What would they look like? Gas? Liquid? Solid? Colour?
How much would the jarful weigh?
Unbound elementary particles cannot be colored, for obvious reasons.
Neutrons are fermions. A "jar full" wouldn't have many neutrons at
all - and you can't squeeze 'em in, either. You cannot trap neutrons
inside walls except at deeply milli-kelvin temps when their long de
Broglie wavelengths allow reflection from perdeuterated polyethyelene
or a frozen layer of Krytox or Fomblin (rough surface) upon it. Given
a much bigger budget, one can be much more clever about it.
<http://www.iucf.indiana.edu/~cyliu/doc/UCN/UCN.html>
<http://www.doylegroup.harvard.edu/neutron/overview/overview.html>
http://www.physics.tulane.edu/fw_r.htm
http://arXiv.org/abs/nucl-th/0409055
http://arXiv.org/abs/nucl-ex/0408010
http://www.edpsciences.org/articles/epjb/pdf/1999/05/b8465.pdf
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
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| User: "edddy" |
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| Title: Re: Jar of neutrons |
19 Feb 2005 07:27:24 PM |
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wrote:
Hi
What would happen if you collected a jar full of neutrons at room
temperature/atmospheric pressure?
What would they look like? Gas? Liquid? Solid? Colour?
How much would the jarful weigh?
A nuke almost ready to explode has a bunch of free
neutrons in a material type container.
At the correct density they interact with the requisite
number of atoms to fission them funny like. Funny
because the adjacent atom skews the normal fission
nuclide distribution.
A bunch of neutrons in the reactor core can do little
unless they interact. And neutron-neutron interaction
is boring scattering only. They stick alittle maybe also
if slightly charged.
A soup of neutrons is a kind of material soup. It can be
made using more coorporative material.
A real neet experiment is to take the single neutron
and find the spacing of two atoms for the single
atom to fission. And this is a special critical density
where the work done squashing the two atoms is
requisitlyey rewarded with an energy return.
It is called, single neutron interaction. A crosssection
is found to increase nicely to the critical spacing.
Any two atoms can be made to fission, btw. With some
returning more or less energy than break even.
Spallation is another term for "any atom" fission.
The magic spacing for hydrogen is one. One atom's
wideth defined by the scatterring of the 1 Mev
alpha particle. Infer the diameter of the atom
like Mr Ruthurford. And It looks like a little
nucleaus compared to electron scatterring.
So one small 1X10-10 cm spacing can cause the fission
to occur with a single neutron.
And here the rather large spacing is the meaning of the
degree of alteration of spacing necessary to cause the
standard diameter measuring method to change by One.
The last sentence is funny on purpose.
1x10-10 cm overlap is the intention. Over lap two
nucleus' by 10000000% And here the diameter is found
to always exist in relation to the measuring alpha
scattering standard.
Make the overlap cause the size of the two nuclei
to be 1x10-10 cm is the simple explaination.
A one MeV hydrogen scattering interaction shows this
degree of nucleus size. Mechanically replicating
1 Mev scattering is hard work be doable.
Measure the two trainsiently interacting nuclei!
Measure by scattering the alpha theoretically!
Anyways explosive compression of One Mev is hard
work. A small sample to be overlapped and fissioned
can be used to trigger the larger hydrogen bomb.
That is right inverted fission is fusion.
So the outcome is neutrons and two stuck together
nuclei.
SO take the single neutron trigger. And trigger
the hydrogen bomb!!! Hurra. A direct fission
trigger free hydrogen bomb.
And the only hard part is the ultra high pressure of
the trigger sample. A diamond press is the kind of
pressure required. And the 1x1010 pounds is the 10
gigapound level required.
And expolsive compression to 10 gigapounds is hard
work.
A small ten gram hydrogen sample to test the theory
is already in experiment. And Compress to explosives
and sample together with the diamond press and then
explode.
So special high pressure explosives are needed.
A rather funny chemistry.
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| User: "edddy" |
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| Title: Re: Jar of neutrons |
19 Feb 2005 07:36:41 PM |
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So high pressure explosives allow the
trigger to reach 10 gigapounds.
And the tengram hydrogen sample
will vaporize the nearby press and trigger
another larger conventionally compressed
h-bomb.
THe critical measure is the allowable separation
of the trigger and the new interaction site.
And here the number of neutrons liberated
must be 1e-22 neuttrons/cm cubed.
So ten grams fusions to this number
not.
All this works and the energy balance of this
trigger is found failing.
A spacing of two inchs is required!! And the press
system is always greater than two inches.
That is unless I design a special ultrahigh
pressure press with the right likable window.
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| User: "" |
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| Title: Re: Jar of neutrons |
19 Feb 2005 05:30:10 AM |
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wrote:
Hi
What would happen if you collected a jar full of neutrons at room
temperature/atmospheric pressure?
What would they look like? Gas? Liquid? Solid? Colour?
How much would the jarful weigh?
Thanks for the replies everyone. You guys at sci.physics really know
your stuff!
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| User: "Uncle Al" |
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| Title: Re: Jar of neutrons |
19 Feb 2005 11:42:19 AM |
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wrote:
wrote:
Hi
What would happen if you collected a jar full of neutrons at room
temperature/atmospheric pressure?
What would they look like? Gas? Liquid? Solid? Colour?
How much would the jarful weigh?
Thanks for the replies everyone. You guys at sci.physics really know
your stuff!
You go to Google, you look around, you learn how to ask a good
question, you ask it, you find out. You don't need us. The Liberal
tenet is that everybody is a cirpple needing centrally-administered
aid. You poke a finger in Uncle Al's chest, you pull back a bloody
stump where your hand formerly resided. Strong is better - as the
ruling classes know full well.
Uncle Al says, "Government cannot award people what it first has not
stolen from them. What one man receives without effort is confiscated
from another who labors."
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
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| User: "Gregory L. Hansen" |
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| Title: Re: Jar of neutrons |
18 Feb 2005 07:50:45 PM |
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In article <1108769031.877429.202750@g14g2000cwa.googlegroups.com>,
<matt271829-news@yahoo.co.uk> wrote:
Hi
What would happen if you collected a jar full of neutrons at room
temperature/atmospheric pressure?
What would they look like? Gas? Liquid? Solid? Colour?
How much would the jarful weigh?
As has been mentioned, nobody has collected many neutrons in a jar at room
temperature. But it wasn't really emphasized that one of the main
experimental techniques of measuring the neutron lifetime is to collect
ultracold neutrons in a bottle, wait some time, and then empty it and
count them.
That aside, they'd be a gas with the same color as air, except with a much
lower index of refraction. A jarful would weigh the same as a jar full of
an equal number of hydrogen atoms.
Anecdote: On a neutron beam line at NIST, the group I was with were
counting neutrons in detectors that were shielded from all sources, and
so shouldn't have been counting neutrons. One of the group, Wietfeld,
suggested what came to be known (very) locally as the "Wietfeld gas"-- the
neutrons were bouncing around in the air and can scatter multiple times,
turning corners and defeating collimation and shielding. They have a
limited lifetime since they'll eventually be absorbed, but they can still
travel quite some distance.
--
"Not that there's anything wrong with just lying around on your back. In
its way, rotting is interesing too... It's just that there are other ways
to spend your time as a cadaver." -- Mary Roach, "Stiff", 2003.
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| User: "Sbharris[atsign]ix.netcom.com" |
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| Title: Re: Jar of neutrons |
18 Feb 2005 06:10:19 PM |
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You couldn't do it. Neutrons are 10^-5 the size of atoms, and they just
slip right through walls made of atoms like buckshot through a
sculpture of chickenwire.
If you could somehow contain the neutrons in some magical container of
thin neutronium, I suppose they'd behave pretty much like any ideal
gas. Should be a gas, because the neutron-neutron interaction would not
keep them together, so they'd bounce off each other at mach 7.6 on
average.They would be pretty much like a jar of hydrogen, except with
half the density of H2, of course (roughly 1/22.4 gram per liter at
STP, or half that of H2 at STP). Transparent, since no light interacts.
Cool them enough and eventually you'd probably get some kind of liquid,
like liquid helium-3 at very very close to absolute zero. A Bose
condensate of neutron-pairs, as in He-3. But with the density of
neutronium, which is roughly that of atomic nuclei. On the order of
10^14 kg per liter (the cube of the 10^-5 factor in size difference,
for obvious reasons). Maybe it would be a solid-- I don't know. But
ought to still be transparent, I would think, since there are no
charges in neutronium to interact with light.
SBH
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| User: "Keith F. Lynch" |
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| Title: Re: Jar of neutrons |
22 Feb 2005 09:45:06 PM |
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Sbharris[atsign]ix.netcom.com <sbharris@ix.netcom.com> wrote:
You couldn't do it. Neutrons are 10^-5 the size of atoms, and they
just slip right through walls made of atoms like buckshot through a
sculpture of chickenwire.
Their size depends on their wavelength. An extremely cold neutron gas
can be, and has been, contained.
Maybe it would be a solid-- I don't know. But ought to still be
transparent, I would think, since there are no charges in neutronium
to interact with light.
Neutrons do have magnetic moments, so they should interact with light.
--
Keith F. Lynch - http://keithlynch.net/
Please see http://keithlynch.net/email.html before emailing me.
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| User: "Uncle Al" |
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| Title: Re: Jar of neutrons |
23 Feb 2005 10:09:06 AM |
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"Keith F. Lynch" wrote:
Sbharris[atsign]ix.netcom.com <sbharris@ix.netcom.com> wrote:
You couldn't do it. Neutrons are 10^-5 the size of atoms, and they
just slip right through walls made of atoms like buckshot through a
sculpture of chickenwire.
Their size depends on their wavelength. An extremely cold neutron gas
can be, and has been, contained.
Maybe it would be a solid-- I don't know. But ought to still be
transparent, I would think, since there are no charges in neutronium
to interact with light.
Neutrons do have magnetic moments, so they should interact with light.
Tell us of the energy spectrum for optical excitation of an isolated
elementary particle.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
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| User: "Androcles Androcles@ MyPlace.org" |
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| Title: Re: Jar of neutrons |
23 Feb 2005 01:33:04 PM |
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The royal fuckwit "Uncle Al" <UncleAl0@hate.spam.net> wrote in message
news:421CA8D5.202258D0@hate.spam.net...
Why are you having so much trouble with basic algebra?
Let L_1 = distance light travels in going from Sam to Joe, as
measured in the stationary frame.
1) L_1 = cL/(c-v)
What a right royal stooopid *****.
See the peeing puppy moortel, he'll not be glad to add
you to his list of truly IMMORTAL fumbles. I will, though.
Androcles
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| User: "Sbharris[atsign]ix.netcom.com" |
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| Title: Re: Jar of neutrons |
26 Feb 2005 04:28:02 PM |
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Their size depends on their wavelength. An extremely cold neutron
gas
can be, and has been, contained<<
I suppose so, though use of the word "size" in this fashion bothers me
a bit. What does it mean when the wavelength of an object with manefest
structure and radius, like a hadron or even an entire atom, is much
larger than the size of the thing itself? I mean, nobody really
believes that cold atoms or neutrons blow up like balloons, their
quarks get farther apart, and all that. So how to picture this? It
doesn't seem to bother us as much mentally with electrons, because
they're structureless anyway, and have no definite size. So large is as
good as small. But big dichotomy between hadron size and wavelength
just really pushes the quantum weirdness button. Maybe there is no good
way to think about this. Or maybe the best way is Bohm's after all: the
neutron stays the same size, but its "pilot wave" (a separate thingie,
in Bohm's view) expands, and that controls its behavior.
Yeah, I know there's no physical consequence to considering a separate
pilot wave to exist and be something totally different from the
physical particle which has structure and (more or less) fixed radius.
But it doesn't help with the mental imagery alot. Without it, the whole
thing is totally bananas.
True, neutrons have a magnetic moment. But the effect of that on light
will be on polarization only, if anything. They'll still be
transparent.
SBH
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| User: "Keith F. Lynch" |
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| Title: Re: Jar of neutrons |
01 Mar 2005 10:56:40 PM |
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Sbharris[atsign]ix.netcom.com <sbharris@ix.netcom.com> wrote:
"Keith F. Lynch" <kfl@KeithLynch.net> wrote:
Their size depends on their wavelength. An extremely cold neutron
gas can be, and has been, contained
I suppose so, though use of the word "size" in this fashion bothers
me a bit. What does it mean when the wavelength of an object with
manefest structure and radius, like a hadron or even an entire atom,
is much larger than the size of the thing itself?
This sort of thing happens all the time. Cold atoms often have
wavelengths -- and uncertainties in position -- much larger than
the distance from the proton and electron within the atom.
I mean, nobody really believes that cold atoms or neutrons blow up
like balloons, their quarks get farther apart, and all that. So how
to picture this?
Multiple Worlds? Relative states?
But big dichotomy between hadron size and wavelength just really
pushes the quantum weirdness button.
Yep.
In principle, *people* have wavelengths. You could do the two slit
experiment with a person, and get interference patterns. Of course
he'd have to be cryopreserved at the time. So you couldn't ask him
which slit he remembered going through. (Well, you could, but he'd
have no useful answer.)
True, neutrons have a magnetic moment. But the effect of that on
light will be on polarization only, if anything. They'll still be
transparent.
I don't see how that follows. Ordinary matter is electrically neutral
on the scale of the wavelength of light, but is often reflective.
A photon can cause a neutron to rotate. A rotating neutron can emit a
photon. Ergo, reflection.
--
Keith F. Lynch - http://keithlynch.net/
Please see http://keithlynch.net/email.html before emailing me.
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| User: "Ben Rudiak-Gould" |
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| Title: Re: Jar of neutrons |
02 Mar 2005 11:17:09 AM |
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Keith F. Lynch wrote:
In principle, *people* have wavelengths. You could do the two slit
experiment with a person, and get interference patterns. Of course
he'd have to be cryopreserved at the time. So you couldn't ask him
which slit he remembered going through. (Well, you could, but he'd
have no useful answer.)
If he did remember, you wouldn't get the interference patterns. The
interference is between different ways of arriving at the *same* final
state; if going through different slits leaves the person's memory in
different states, there will be no interference.
And since it's the state of the whole system that matters, not just the
person, you'd better make sure he doesn't emit or absorb any photons over
the course of the experiment (so he'd better be very cold indeed). The whole
thing will need to take place in a hard vacuum. And watch out for slight
positional variations in his gravitational field too.
Other than that, the experiment should work as you describe. :-)
-- Ben
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