Magnetic Effects

"Uncle Al" Schwartz UncleAl0 at ix.netcom.com
Sat Mar 1 11:27:10 EST 1997


Adam Reed wrote:
> 
> I am sorry for the confusion.  I did not mean to imply that MRI "gave off"
> gamma radiation.  The information that I have collected in my research
> shows that when the magnetic field is applied to the body it will cause the
> water molecules in the body to reach an excited state.  This excited state
> will cause the water molecules to all face the same direction.  The
> positive and negative poles of the water molecule will align themselves
> with the magnetic field of the MRI.  When the magnetic field is turned off,
> the water molecules will return to the relaxed state, resulting in the
> production of gamma radiation.  The body is the source of the gamma
> radiation.

The foregoing is the product of unspeakable ignorance.  It is painful to
read.  
Are you burdened with ANY technical education?

Gamma radiation is the energy "evaporated" from nuclear transitions.  It
is in the range of around 100 KeV to multiple 1000s of KeV.  X-rays are
commonly generated from atomic elecronic transitions and
bremsstrahlung.  X-rays are in the energy range of 10s or 100s of KeV. 
Chemistry is 3 ev and below.  That's electron volts, not kiloelectron
volts.  Magnetic resonance imaging is on the order of FM radio, 60-200
MHz tops.  Work it out.  It's a small fraction of an eV - barely above
the thermal background.  Does your car radio emit gamma radiation? 
Idiot.

The fraction of protons net aligned (population inverted) is of the
close order of ten per million.  The great Achilles Heel of magnetic
resonance techniques is their insensitivity to the bulk of the sample. 
Idiot.

The spontaneous disordering of magnetically ordered nuclei upon field
removal is ENDOTHERMIC.  It ABSORBS free energy (/_\G = /_\H - T/_\S). 
It is the basis of extreme cryogenic refrigeration, as in the adiabatic
demagnetization of paramagnetic salts to reach milli-degrees kelvin
temperatures.  Idiot.

Idiot.  Idiot, idiot, idiot.

-- 
Alan "Uncle Al" Schwartz
UncleAl0 at ix.netcom.com ("zero" before @)
http://www.ultra.net.au/~wisby/uncleal.htm
 (Toxic URL! Unsafe for children, Democrats, and most mammals)
"Quis custodiet ipsos custodes?"  The Net!



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