Neutron Microscope

[Carrot44]

Saw on Enterprise tonight a mention of a neutron microscope. Being bored and skimming the web and looked it up. Low and behold there is such a thing. Is this anything like the electron microscope? Could not find much info.
Anybody out there got more info on it and how they work.

Ken

 

[zephyrprime]

Well I guess the neutrons would have a shorter wavelength so they could conceivably attain higher resolution.

 

[f95toli]

Neutron microscopes are very similar to electron microscopes. There are three problems:

1) You need a neurton beam-source. The only way to get that is to use a particle accelerator and those are really big and expensive.

2) You need lenses, this is quite tricky but there has been some progress.

3) You need a detector, this is can be a problem; at least if you want an imaging microscope (which is what most people think of when they hear the word "microscope") since you need a imaging matrix.

In the papers I've seen the resolution is really bad and the magnification is only about x40, what is missing is a good lens- technology.

 

[Jeff7]

Yeah, I would've expected a more futurish name...maybe a quark microscope? Or quantum microscope - everyone likes to use the word "quantum" in something to make it sound better.
But I did also wonder that a neutron microscope would have a lower resolution than an electron microscope; neutrons are larger particles.

 

[exp]

Never heard of a neutron microscope before, but I would guess that even with a lower resolution it could be still be useful in situations where the negative charge of electrons is a problem.

 

[f95toli]

Originally posted by: Jeff7
Yeah, I would've expected a more futurish name...maybe a quark microscope? Or quantum microscope - everyone likes to use the word "quantum" in something to make it sound better. But I did also wonder that a neutron microscope would have a lower resolution than an electron microscope; neutrons are larger particles.

The size of the neutron is not relevant. The fact fact that the neutron is about 1000 as heavy means that it should be possible to magnify x1000 better than any electron microscope, the resolution is of the order of the wavelength and the wavelength of a neutron is h/mv (h beeing Planck's constant). If the speed of the neutron is lets say 90% of the speed of light (which is entirely possible) we would get 6e-34/(0.9*3e8*1e-27)=2e-15 m=2 fm which is very small....
The limited resolution is due to problems with lenses and detectors, not the neutron itself.

 

[unclebabar]

wouldn't it be funny if <your favorite trek character> fired enough of these neutrons at a material to cause a nuclear reaction and blew up the lab?

 

[MadRat]

Originally posted by: f95toli
size of the neutron is not relevant. The fact fact that the neutron is about 1000 as heavy means that it should be possible to magnify x1000 better than any electron microscope, the resolution is of the order of the wavelength and the wavelength of a neutron is h/mv (h beeing Planck's constant). If the speed of the neutron is lets say 90% of the speed of light (which is entirely possible) we would get 6e-34/(0.9*3e8*1e-27)=2e-15 m=2 fm which is very small....
The limited resolution is due to problems with lenses and detectors, not the neutron itself.

Denser, at the subatomic level, does tend to be smaller.

 

[Carrot44]

Well the only research I can find says the Neutron source is how do you say it HUGE......... Ya can't slip it into your pocket

I am wondering what they do use for optics? One would think that straight lenses would not work. Would have to use magnets or something of that sort.

 

[Shalmanese]

How exactly do you lens neutrons? gravitational lens? I dont think so, rely on them to bounce off atom nuclei? That sounds really inefficient.

 

[MadRat]

You use a one-shot super high speed film that has extremely fussy trace elements in it sitting on the end of your atomic smasher. Your target is destroyed in the process and you only catch the splash of the atomic particles as they fly apart. It collects everything from evidence of electrons to protons to neutrons. And then you endlessly debate the results since it looks pretty inconclusive...

 

[Shalmanese]

which leads to the question, why would you use neutrons if they suck so much.

 

[f95toli]

Originally posted by: MadRat
You use a one-shot super high speed film that has extremely fussy trace elements in it sitting on the end of your atomic smasher. Your target is destroyed in the process and you only catch the splash of the atomic particles as they fly apart. It collects everything from evidence of electrons to protons to neutrons. And then you endlessly debate the results since it looks pretty inconclusive...

That is not a microscope, that is a particle collider. Neutron microscopes USE particle accelerators to generate the neutrons but you do not need to smash anything. I think that what Carrot39 meant was a something similar to a electron microscope, but with neutrons.

I found a paper describing a simple neutron microscope. The authors have used the particle accelerator in Grenoble as a source, the lens was a stack of biconcave aluminium discs, the magnification is x35. In the paper there are a couple of images taken with this microscope. If anyone is interested (and have access to online-journals) here is the reference:

Beguiristan H.R: et al, Applied Physics Letters, v. 81, n. 22, 4290-2

 

[MadRat]

Awww, but that takes all the fun out of it if nothing gets smashed.