Talk:Reducing relaxation losses

what't the proper term - spin relaxation, coherence relaxation? Evgeny Fadeev 12:57, 23 April 2008 (MDT)

I think spin relaxation would be more general, if it's appropriate. Because you have both population, and coherence relaxation. ( on google spin relaxation, seem to be used frequently in the NMR field ,coherence relaxation much less ) but I have some doubts about it's validity. Coherence relaxation is much less frequent, because, most of the time, what experimentalist want, and compare are T1 and T2.

RF inhomogeniety and relaxation
does RF pulse field inhomogeniety enhance relaxation? Evgeny Fadeev 12:57, 23 April 2008 (MDT)

=> It depend on what you label as relaxation, but if you consider field inhomogenities to be a factor of relaxation, you have also to considered RF field inhomogenities as a relaxation factor.

Of course tuned field inhomogenities, as also tuned static field inhomogenities, could be used to measure diffusion, for the first one you could read paper from Daniel Canet.

Sorry I didn't log in

I was thinking that losses due to inhomogeniety are not really relaxation but rather imperfections in the pulses. Relaxation sounds like a spontaneous phenomenon, so maybe relaxation due to diffusion in non-homogenous field could be dubbed as mechanism of relaxation, since diffusion is a spontaneous process too... don't know. Somwhere there must be a line in the terminology - maybe we'll figure out later. By the way, you can sign your posts by ~ (four tilde symbols in the row) Evgeny Fadeev 14:41, 24 April 2008 (MDT)

I was thinking that losses due to inhomogeniety are not really relaxation but rather imperfections in the pulses. Relaxation sounds like a spontaneous phenomenon, so maybe relaxation due to diffusion in non-homogenous field, since diffusion is a spontaneous process too... don't know. Somwhere there must be a line in the terminology. By the way, you can sign your posts by ~ (four tilde symbols in the row) Evgeny Fadeev 14:41, 24 April 2008 (MDT)

Ok it's more an experimental issue, so on experimentalist point of view it's relaxation, but for RF and static field it'll be the same. I agree that it's not relaxation in the same sens than the relaxation that occur at a molecular point of view.

I fact I was putting RF inhomogenities more on thinking about pulse imperfection, and this one you are right, it's not really relaxation, but static field inhomogenities, was really a challenge at the beginning of the NMR. don't forget, we are close to 1 Ghz, and measure during 1 second, we keep the relative phase, during the whole setting of the experiment, I think that's really a feat, no ?

The best solution to avoid relaxation is to shut down the field, so you don't have to worry any more about relaxation ( you might have seen the long lasting fid on stan blog, no ? to have this for biomolecular NMR would be very nice ( but a little bit long to measure, and we'd still accumulate the noise during the signal acquisition ) ). So we should also add that the magnetic field influences the relaxation, because depending on the strength of this field, that relaxation will be fast or slow.