Question about a MRI research report
26 Aug '13 11:573 editshttp://phys.org/news/2013-08-real-time-nuclear-noise.html
“...However, for very small objects (i.e. smaller than a single cell) containing a small number of nuclei, the natural fluctuations of the nuclear spin polarization actually become larger than the polarization produced by a large magnetic field. These deviations are known as "spin noise". The fact that spin noise is so dominant at small scales is one of the reasons why measuring NMR and MRI in very small objects is so difficult.
….
The team …. has now demonstrated …. a method for creating polarization order from such random fluctuations. By monitoring, controlling, and capturing statistical spin fluctuations, the team produced polarizations that were much larger than what can be created by applying a magnetic field.
...”
My question is;
How is it possible to create polarization order from such random fluctuations WITHOUT an external magnetic field applied DESPITE those fluctuations being RANDOM?
-The article doesn't seem to really explain this at all and only says above it is done by “ monitoring, controlling, and capturing statistical spin fluctuations” which seems to be a rather vague statement and don't know what exactly that is supposed to mean! -”controlling” how so? And how do you “capture” statistical spin fluctuations? -are they talking here about some sort of physical 'capture' and, if so, in what sense can you physically 'capture' something that is both 'statistical' and a 'spin fluctuation'? or are they merely talking here about just “capturing” statistical information for analysis?
I hope someone here can shed some sort of light on what they mean.
“...However, for very small objects (i.e. smaller than a single cell) containing a small number of nuclei, the natural fluctuations of the nuclear spin polarization actually become larger than the polarization produced by a large magnetic field. These deviations are known as "spin noise". The fact that spin noise is so dominant at small scales is one of the reasons why measuring NMR and MRI in very small objects is so difficult.
….
The team …. has now demonstrated …. a method for creating polarization order from such random fluctuations. By monitoring, controlling, and capturing statistical spin fluctuations, the team produced polarizations that were much larger than what can be created by applying a magnetic field.
...”
My question is;
How is it possible to create polarization order from such random fluctuations WITHOUT an external magnetic field applied DESPITE those fluctuations being RANDOM?
-The article doesn't seem to really explain this at all and only says above it is done by “ monitoring, controlling, and capturing statistical spin fluctuations” which seems to be a rather vague statement and don't know what exactly that is supposed to mean! -”controlling” how so? And how do you “capture” statistical spin fluctuations? -are they talking here about some sort of physical 'capture' and, if so, in what sense can you physically 'capture' something that is both 'statistical' and a 'spin fluctuation'? or are they merely talking here about just “capturing” statistical information for analysis?
I hope someone here can shed some sort of light on what they mean.
