Talk:Nuclear magnetic resonance

message: The diagram that demonstates the splitting of the electon spin energies is wrong with the lowest energy being negative. This is not the case, in NMR the lowest energy of the split angular momentum is positive in value. Would be great to see this changed if any one still has the original .jpeg. EPR is the spectroscopy that has a negative value for the lowest split energy value125.238.142.222 (talk) 10:02, 28 May 2008 (UTC)
thread_title: Diagram needs changing

message: In the history section, it would be nice to add a couple of sentences on the discovery of chemical shift and how Bloch commented that if this were "some nasty chemical phenomenon" it could "terribly impede" the measurment of nuclear magnetic moments. Detials of the story can be found at http://www.ebyte.it/library/hist/ProctorWG_Reminiscences.html
Roy Hoffman 11:20, 26 March 2006 (UTC)
thread_title:  Discovery of chemical shift 

message: Concerning the sentence:
"When radio power is sent to the antenna, it generates an oscillating magnetic field H1 (not to be confused with the external magnetic field). "
should this not be "..generates an oscillating electromagnetic field"?
Foppe Brolsma, brolsma_produkties (at) hotmail.com
:No, the current text is correct. To call it an oscillating electromagnetic field would imply it were electromagnetic radiation, which it isn't. -- Tim Starling 00:45, Mar 19, 2004 (UTC)
::The fact that it is a radio antenna which generates the field implies that it is electromagnetic radiation. Moreover, the text mentions left-handed and right-handed circularly-polarized photons, which also implies it is radiation. What you might mean is that
::1. we are dealing with the near field (i.e. less than a wavelength from the radiation source), which means that E and B are not necessarily perpendicular. However, NMR would work just as well in the far field (e.g. at higher radio frequencies that have a shorter wavelength) so that is not the issue here.
::2. It is the magnetic component that interacts with the nuclei. However, in the description of quantum-mechanical transitions in atoms in an electromagnetic field, it is mainly the electrical component that acts on the atoms, but that is not a reason to call it "transitions involving an oscillating electric field" instead of "radiative transitions".
:::Yeah OK, that could be right, sorry. When I was taught this initially, we used the semi-classical treatment which talks entirely in terms of a rotating or oscillating magnetic field. Chapter 3 of this random web site, which I found using this google search, uses terminology very similar to what I'm used to:
::::A coil of wire placed around the X axis will provide a magnetic field along the X axis when a direct current is passed through the coil.  An alternating current will produce a magnetic field which alternates in direction.
::::In a frame of reference rotating about the Z axis at a frequency equal to that of the alternating current, the magnetic field along the X' axis will be constant, just as in the direct current case in the laboratory frame.   
::::This is the same as moving the coil about the rotating frame coordinate system at the Larmor Frequency. In magnetic resonance, the magnetic field created by the coil passing an alternating current at the Larmor frequency is called the B1 magnetic field. When the alternating current through the coil is turned on and off, it creates a pulsed B1 magnetic field along the X' axis. 
:::I'm happy to go with common usage, whatever that may be. Do you have any references calling it an electromagnetic field? -- Tim Starling 15:08, Mar 19, 2004 (UTC)
::::Well, no, I was merely countering the statement that "it is NOT E-M radiation". :) I'd say the current article text is fine. I certainly would not agree with the moving-coil description above since a correct transformation to a rotating coordinate system would be much more involved than is suggested. The rotating-wave approximation which lies behind this is purely quantum-mechanical, and after this approximation, it turns out that you can describe the precession of the spins in a rotating frame as if there were no B0 field. However, I strongly oppose to "deriving" the approximation from a macroscopic and incorrect metaphor.  -- Hankwang 16:52, 19 Mar 2004 (UTC)
thread_title: Magnetic or electromagnetic?

message: RE: "Nuclear spins do not emit radio waves...":
Although this general comment is `true' for both liquids and solids NMR absorption, it is certainly not quite so for the emission of both radio waves and microwaves by resonating protons (Yes, H-1 (+) ions) in oscillating plasmas placed in static magnetic fields, also coupled to electrons in such plasmas,  that have been demonstrated repeatedly both experimentally and theoretically to emit both radio waves and microwaves in addition to light!!!
This does not mean, however--as you said and cited-- that one should confuse NMR **absorption** of resonant RF with the above cited phenomenon in oscillating plasmas that involves RF and microwave emission by proton plasma resonances in static magnetic fields. Should you require the relevant references for the above observed emission phenomenon in proton containing plasmas, I will be glad to oblige.
Bci2
Consensus?
Currently the beginning of this article reads:
(NMR) is a property that magnetic nuclei have in a magnetic field and applied electromagnetic (EM) pulse or pulses, which cause the nuclei to absorb energy from the EM pulse and radiate this energy back out. The energy radiated back out is at a specific resonance frequency which depends on the strength of the magnetic field and other factors. This allows the observation of specific quantum mechanical magnetic properties...
Later however, it seems to be suggested that data is generated in NMR spectroscopy by the formation of an electrical current, which, in turn is generated by oscillation in the net direction and instensity of the local magnetization.  So whether or not RF-irradiated nuclei absorb and then later give-off radiation (of any-which frequency) is fact or not, it is unclear from this article what is being measured.  It seems to me that "the energy radiated back out" from an irradiated nucleus may not directly affect the Free Induction Decay (FID) which is what the spectrometer records.  Is this true?  Please modify.  —Preceding unsigned comment added by 24.3.17.121 (talk) 03:54, 15 February 2010 (UTC)
thread_title: Comment: This is not quite "true"

message: The COSY section should be removed/sidelined until it can be explained better. It reads scattily, as if pulled directly from a textbook, and there are many technical aspects unexplained (double Fourier-transformation, Pulses, how the 2nd dimension arises) and many aspects are poorly written (Example of ethanone). I feel this doesn't make it an asset to this entry.
Any feeling/input on this would be appreciated because its a very major edit! Unless anyone objects I'll be removing it  when I edit the theory of this section. (And hopefully have time to put something meaningful in its place). Let me know --Lee-Jon
The COSY section deals with other aspects of 2D NMR as well and should be part of a separate entry entitled 2D NMR or Two dimensional NMR Roy Hoffman 13:20, 27 December 2005 (UTC)
thread_title: Cosy section

message: The How NMR Works section has been renamed to Theory... and consigned to the latter part of the article so not to frighten undergraduates etc. It has been expanded so (hopefully) every concept makes sense and has some theoretical background presented. 
Sections I (or you!) want to add are on spin-spin coupling, Pulse NMR & Fourier-transformation, and possibly a brief talk on the nuclear Overhauser effect relevant to NMR. I think that covers almost everything to give some detail on NMR without it being too technical. 
--Lee-Jon 21:52, 9 Mar 2005 (UTC)
thread_title:  How NMR Works - major edit 

message: I am an organic chemist and I would describe myself as an experienced user of NMR spectroscopy. I can not claim to be an NMR expert, I could never write my own pulse sequences etc.  I also teach introductory organic chemistry, covering the basics of 1D proton and C-13 NMR in the first semester, then students get to run a COSY and a DEPT experiment in their second semester.  I am therefore very familiar with explaining the basics of the NMR spectroscopy.  It seems clear to me that there are two different topics covered on this page currently
# Nuclear magnetic resonance- the physical phenomenon, and
# NMR spectroscopy- the analytical technique.
For example MRI (as I understand it) uses the phenomenon of NMR, but is clearly distinct as a technique from NMR spectroscopy. 
This difference between physical phenomenon and analytical method has already resulted in there being separate pages for Infrared and Infrared spectroscopy, also Ultraviolet and UV/VIS spectroscopy. See :Category:Spectroscopy for other page titles.
NMR spectroscopy is the most widely-used technique in modern organic chemistry and it surely deserves its own page.  The spectroscopy page should have less discussion on the theory and physics, and much more on how the technique can be used to analyse molecular structure- things like equivalence, chemical shift, integration, multiplicity, diastereotopic protons in chiral molecules, which nuclei lend themselves well to analysis and which don't, etc.  Some of this information is already on this page, much is not. My undergraduate students would currently find almost nothing on this page of value to them. We need this separate NMR spectroscopy page. The COSY section could be part of this new page or could be big enough for its own page. What do others think? Walkerma 07:14, 14 May 2005 (UTC)
thread_title:  Splitting the NMR page in two- NMR and NMR spectroscopy 

message: I agree, however NMR Spectroscopy extends far beyond Organic chemistry so maybe the page could be written from a few angles:
# Sample preparation
# organic structure (typical stuff)
# biological structure (structure/function etc)
# dynamic NMR (reactions/thermo etc)
# Solid state NMR
# multinuclear NMR (13C 15N 17O etc)
# Techniques (multidimensional etc)
# Fourier transformation and computational methods
Unlike UV/VIS and similar techniques, modern NMR Spectroscopy is a very large and very complex area. And as I'm sure you're aware, an end-user approach to NMR is very difficult to discuss without having to delve into some nuclear physics. Any section on NMR Spectroscopy should continually reference a theory section to keep it accurate. 
The page has been created here and I'll try and finish a good first build throughout this month! 
Lee-Jon 09:11, 17 May 2005 (UTC)
thread_title: Good idea

message: I think the article could use a nice diagram of the innards of an NMR machine and an explanation of how the larmor frequency relates to the naming of individual machines (field strength correlation etc.) though, I am not the one to do it. I can't find a good PD diagram of an NMR device so.....any takers?--Deglr6328 20:11, 18 Jun 2005 (UTC)
thread_title: needed

message: The main reason for my failing this is the fact that the article tends to blur the difference between NMR the physical phenomenon (the subject of this article) and NMR spectroscopy (the application of said phenomenon, covered mainly in the NMR spectroscopy article).  This is understandable because (a) both topics used to be covered on this page and (b) chemists tend to talk about "an NMR" when they mean an NMR spectrum.  The applications of NMR in spectroscopy and MRI are important and deserve coverage, but they should not be in place of NMR as a phenomenon.  The History section (after the first four paragraphs) reads more like a history of NMR spectroscopy rather than of the study of the phenomenon itself (ironically, the spectroscopy page doesn't include any of this same history!).  This is a bit like reading the article on microwaves and finding the history of the development of microwave ovens described, simply because "microwave" in the vernacular refers to the ovens.  To someone unfamiliar with the topic, this must be very confusing.
The theory section seems fine - sure, it's technical, but then again this is a pretty technical subject.  Terms are explained as they should be.  
The "Uses" section really needs a single person to rewrite it into a coherent section.  It reads like 50 different people have thrown in bits of information - the content is there, but it needs organising and rewriting in places (e.g. the  C60 paragraph).  I would like to see subsections of Uses
*Magnetic Resonance Imaging starting with  then an overview of MRI.
*NMR Spectroscopy starting with  then describing the main uses of NMR spectroscopy.
*Other uses as described.
I also suspect there may be some things missing from here, and moving inappropriate spectroscopy stuff elsewhere would create the space for this.  I'd like to see listed some of the elements that are most active in NMR.  The Nuclear spin and magnets section explains which will be active, but some examples like why 12C is inactive but 13C is active. I'd like to see discussion (in simple terms, perhaps purely qualitative) of the sensitivity of the nucleus - why 1H is easy to see, but 15N is not.  Could it include how quadrupolar relaxation can smear out a signal and make it harder to observe with a nucleus like 51V?  I'm not knowledgable enough to write this material, but I suspect this article could have a lot more useful content. Walkerma 03:27, 17 June 2006 (UTC)
thread_title:  Failed Good Article candidate 

message: There is no explanation or Wikilink of what T2 is.  It's just dropped in. --Scottandrewhutchins 22:16, 19 January 2007 (UTC)
replies: text: It's explained on the MRI page, but it needs to be explained here. --Scottandrewhutchins 19:36, 24 January 2007 (UTC)
thread_title: T2

message: The problem of poor noise-to-signal ratio is mentioned under the CONTINUOUS WAVE SPECTROSCOPY section, and the subsequent need therefore for signal averaging.
As I understand it however, poor noise-to-signal ratio is a problem inherent to the NMR process itself, not just CW Spectroscopy but also FOURIER SPECTROSCOPY. No signal-to-noise aspects are discussed under the FOURIER SPECTROSCOPY section of the article however.
Perhaps the issue of signal-to-noise needs it's own heading and section, separate from CONTINUOUS WAVE SPECTROSCOPY to make things a little more clear.
Pookie69 11:51, 2 April 2007 (UTC)
thread_title:  Noise-to-Signal Ratio 

message: I cannot find a reference to EFNMR in wikipedia, though there are good web pages about it.
I suggest adding a reference to it, and developing an article.
GilesW 12:00, 13 April 2007 (UTC)
replies: text: Links to (updated) Magnetometer article and an EFNMR web site added to article. Stub page for EFNMR needed. Editor, please help. GilesW 09:09, 20 May 2007 (UTC)
replies: text: I have drafted an EFNMR page, some time ago now, help welcome, GilesW 13:06, 20 September 2007 (UTC)
thread_title:  Earth's Field NMR - EFNMR 

message: I suggest adding a link from the NMR article to the Magnetometer article, which discusses PPM and Overhauser magnetometers.
I notice that the Magnetometer article does not mention that these are EFNMR effects. Perhaps this should be remedied, once the EFNMR references are in place.
GilesW 12:08, 13 April 2007 (UTC)
replies: text: Done, GilesW 14:04, 30 May 2007 (UTC)
thread_title:  Proton Precession Magnetometers etc 

message: article reads:"NMR studies magnetic nuclei by aligning them..."
Should it not read:"NMR studies magnetized nuclei by aligning them...". Correct or elaborate please, in a strong enough magnetic field all nuclei can be influenced, essentially the flow of energy is directly influenced to produce statistically strong/weak results, albeit lamonistic. anon 203.59.189.244 19:15, 15 June 2007 (UTC)
thread_title:  Gah an edit! 

message: Help with Zero Field NMR, Earth's field NMR, and Electric field NMR articles needed, please. 
Plus a mention in the text of the main article. Earth's field NMR is a poor relation, but significant (bore hole logging, magnetometers etc).
Any thoughts about sorting the 'See Also' list into alphabetical order? GilesW 16:29, 16 June 2007 (UTC)
replies: text: Done GilesW 10:44, 22 September 2007 (UTC)
thread_title:  Help needed with ZNMR and EFNMR 

message: The wording of the introduction is orientated towards NMR spectroscopy in high-field laborotory environments, and is not applicable to some other applications of NMR. Furthermore it is rather abstract. I propose that the intro be generalised to make it applicable to Earth's field NMR etc.
See above for various references and questions re EFNMR etc.
The following quote is helpful and could be used with attribution or paraphrased:
"... the [stimulating] frequency necessary to cause nuclear transitions is different for each element or isotope. The resonance frequency is found to vary in direct proportion to the applied field (for all magnetic nuclei); thus the larger the magnetic field the larger the frequency necessary to achieve resonance." Kemp, W. NMR in Chemistry : a multinuclear introduction Macmillan Ist Ed 1986 p6.
In addition, may I suggest something like:
In the laborotory, NMR studies magnetic nuclei by aligning them with a very powerful external magnetic field and perturbing this alignment using a high frequency magnetic field. The resulting high frequency magnetic field generated by the sample in response to the external perturbing magnetic field is the phenomenon that is exploited in NMR spectroscopy and magnetic resonance imaging.
In the Earth's magnetic field, NMR frequencies are in the audio frequency range, and are typically stimulated by applying a strong dc magnetic field pulse to the sample and analysing the resulting low frequency alternating magnetic field. This effect is exploited in some types of magnetometer and on-location EFNMR spectroscopy.
NOTE: The perturbing fields are generated by inductors, so have no electric component. Electromagnets do not generate electromagnetic fields!
GilesW 21:45, 23 June 2007 (UTC)
replies: text: Edits now incorporated broadly iaw the above. GilesW 11:28, 24 September 2007 (UTC)
thread_title:  Edits to Introduction 

message: Something is missing in this article: Bloch equations. TomyDuby 22:52, 3 July 2007 (UTC)
replies: text: Not only that: I cannot find in Wikipedia an article on Bloch equations. Am I missing something? TomyDuby (talk) 18:25, 10 September 2008 (UTC)

text: Dear Dirac66: Thanks! I will add a chapter on Bloch equations to Relaxation (NMR). It is a good place to start. This may take a couple of days to accomplish... TomyDuby (talk) 05:26, 11 September 2008 (UTC)
thread_title:  Bloch Equations 

message: A while ago the following paragraph was added (by an unregistered user) to the article on the Rabi frequency:
:"In the context of a nuclear magnetic resonance experiment, the Rabi frequency is the nutation frequency of a sample's net nuclear magnetization vector about a radiofrequency field. (Note that this is distinct from the Larmor frequency, which characterizes the precession of a transverse nuclear magnetization about a static magnetic field.)"
I am only familiar with the Rabi frequency in the context of atomic physics.  I've done a quick google search and it is regularly mentioned on pages concerning NMR.  I feel that these are two distinct (although possibly analogous) concepts that probably merit separate articles.  Does anyone have any thoughts on this?--DJIndica 19:43, 23 October 2007 (UTC)
replies: text: Rabi oszillation is what actually happens during the pulse in NMR. Spins oscillate between their alpha and beta state in the rf field. --Maxus96 (talk) 21:44, 22 November 2012 (UTC)
thread_title:  Nuclear [[Rabi frequency]]? 

message: This article definitely lacks information on the phenomenon of resonance.  I personally do not understand this subject fully, especially in the resonance section, where I was hoping to learn about it.  In this section, all that is said is the conditions under which "resonance absorption" will occur, leaving many ambiguities.  Is the resonance here refering to the emitted photon or the precession of the nuclei?  Is the absorption dealing with that of the external electric circuit due to this photon?  Is the "correct frequency" something which the experimenter controls or is one that is naturally occurring as a result of precession?  
I would really appreciate it if someone took the time to answer these questions in the article.
--Wakod2002 (talk) 08:43, 28 November 2007 (UTC)
thread_title:  NMR Phenomenon? 

message: I would like to question the deletion by Cubbi (04:56 12 Jan 2009) with edit summary "rv clathrate spam. Keep it to flow assurance and gas hydrate if you must." The word "spam" normally describes advertising material, but that was not the case here. In fact the deletion consists of 2 sentences about the application of NMR to hydrates, and 3 references in the form of external links to scientific journals published by the ACS (American Chemical Society). This seems to me perfectly valid and on-topic material properly referenced. Please explain why it was deleted. If there is no valid reason I think it should be restored.  Dirac66 (talk) 01:59, 13 January 2009 (UTC)
replies: text: Presumably because it was referring to a specific application of NMR in an article discussing the physical basis of NMR and NMR spectroscopy.  The applications of NMR are so diverse that the article would be a mess if they were all discussed in this way. Spam was a bit harsh, but the deletion from this article was reasonable.  84.92.241.186 (talk) 19:17, 24 January 2009 (UTC)
replies: text: That material was added by a single-purpose account to a number of wikipedia pages. And yes, it has no sensible place in this article. --Cubbi (talk) 22:49, 24 January 2009 (UTC)
thread_title:  Why was clathrate material labelled as spam? 

message: Could someone please explain somewhere in this article the difference between the apparently small population difference between different nuclear spin states for hydrogen nuclei in an NMR machine and the large difference which is frequently said to exist in so called ortho and para hydrogen at room temperature? This is explained at http://en.wikipedia.org/wiki/Spin_isomers_of_hydrogen. As a chemist I find these facts contradictory.82.231.41.137 (talk) 07:40, 20 June 2009 (UTC)
replies: text: When you react a mixture of ortho and para isomers (hydrogen at thermal equilibrium) you get a population difference based on the Boltzmann distribution. The population difference is increased when you react only parahydrogen. The technology is reasonably new and not widely used yet so may not be worth including on the main Wikipedia article, but it should be better explained on the Spin isomers of hydrogen article. You can see the diagrams that explain the effect here: http://www.york.ac.uk/res/sbd/parahydrogen/para_nmr.html 78.105.195.232 (talk) 15:15, 14 September 2009 (UTC)

text: ortho and para only refer to the relative orientation of the spins, not the orientation in an external field. The large (~3:1) population difference of o/p Hydrogen at room temperature is due to the three-fold degeneracy of the ortho state. Four equipopulated (that an english word ;-) ?) states, three of them degenerate, give a 3:1 ratio. --Maxus96 (talk) 22:00, 22 November 2012 (UTC)
thread_title: Ortho and para hydrogen populations and the NMR phenomenon

message: Is there an NMR analog of fluorescence polarization ? That is, if you have some nmr active molecule(s), with a diameter of, say ~ 1nanometer, in a solvent, the molecules will rotate at a rate that is roughly proportional to their size (neglecting second order effects). If the molecule sticks (binds) to something much larger - say a bacterial cell with a diameter of ~ 1 micron - then the nmr active molecule will now rotate with the bacteria, and this rotatation rate is much slower then the rate for the free molecule.
Is there an nmr process which is senstivie to this change in rotation rate ?
65.220.64.105 (talk) 16:06, 18 August 2009 (UTC)
thread_title: analog of fluorescence polarization

message: 14N is listed as an element that can be monitored by NMR spectroscopy. Is this correct? 14N is not listed in my resource. Akita86 (talk) 22:06, 28 October 2009 (UTC)
replies: text: Thanks. Removed (it is not listed because it has spin zero and is thus undetectable by nuclear or spin resonances).Materialscientist (talk) 00:07, 29 October 2009 (UTC)
replies: text: Sorry but 14N has spin 1, due to its odd number of protons and also of neutrons. One of many references for spin 1 is the table in Atkins and de Paula, Physical Chemistry 8th edn p.1014. As stated in the article, NMR of 14N is possible for simple or symmetric molecules, but difficult otherwise because of the nuclear quadrupole associated with spin 1 which broadens the lines. So it is less useful than many spin 1/2 nuclei, which is why it is not listed in all resources.  Dirac66 (talk) 01:43, 29 October 2009 (UTC)
replies: text: Oh dear.. I was still asleep - I myself daily measured hf from 14N in ESR. Idiot. Thanks for comments on broadening. Materialscientist (talk) 01:49, 29 October 2009 (UTC)
thread_title: 14N

message: After the above discussion JWB pointed out in an edit summary (16:09, 29 October 2009) that "There are a few unstable nuclides with odd proton and/or neutron number and zero spin." I have now searched the isotope table in my (1979-80) Handbook of Chem and Physics and found one example which is 206Tl with 81 p and 135 n. Dirac66 (talk) 23:45, 8 November 2009 (UTC)
thread_title: Spin 0 nuclei

message: In the last paragraph of the "Nuclear Shielding" section (2.2.3) there appears to be a distinction made between "isotropic" chemical shift and "average" chemical shift.  I think this is misleading, since the molecular tumbling in solution state NMR is usually isotropic (I can't think of any situations where this would not be the case) and hence the anisotropic contributions are all averaged to the isotropic chemical shift.  The same is the case in MAS solid state NMR (neglecting sidebands).  Any reference to "average" chemical shift I could find was referring to the average isotropic chemical shift of a certain type of structure (alpha helix for example).  I didn't do a very thorough search, so maybe I am just used to a different nomenclature.  Also, I don't see any reason for average chemical shift to be an article worth creating.  If anything I think there should just be a link to chemical shift. And4e (talk) 21:24, 21 January 2010 (UTC)
thread_title:  "Average" vs "isotropic" chemical shift 

message: A picture of a small (say, 60MHz) box-like NMR would be a good addition. Too many research-grade behemoths already illustrated in the article. Rmhermen (talk) 20:21, 19 March 2010 (UTC)
thread_title: Needs image

message: I've just registered to wikipedia, so if I'm doing something wrong, sorry.
http://en.wikipedia.org/wiki/NMR#Discovery
It says here that: "Nuclear magnetic resonance was first described and measured in molecular beams by Isidor Rabi in 1938."
But it does not mention that he got the Nobel Prize in Physics for that in 1944.
After that it says that: "Felix Bloch and Edward Mills Purcell refined the technique for use on liquids and solids, for which they shared the Nobel Prize in physics in 1952"
If they are mentioned to have won the Nobel prize, I think Rabi should too. I have 2 wikipedia sorces (is it ok to cite from another wikipedia page?)
http://en.wikipedia.org/wiki/List_of_Nobel_Laureates_in_Physics
http://en.wikipedia.org/wiki/Isidor_Rabi#Career
Protosss (talk) 16:07, 5 June 2010 (UTC)
replies: text: The article itself is open to being edited directly by you. Feel free to add or improve it as you see fit. DMacks (talk) 19:20, 5 June 2010 (UTC)

text: Best to cite an outside source but it would be nice if you linked their names to the other wikipedia articles. 137.149.98.24 (talk) 00:24, 14 July 2011 (UTC)
thread_title:  Nobel Prize in Physics 1944. 

message: Shouldn't we put in a section that explains how the very high magnetic fields are actually created? 
with at least alink to superconduction, superconducting coils, saturation etc.?
194.53.253.51 (talk) 08:23, 2 November 2010 (UTC)
thread_title:  machine architecture 

message: At the top, it says that NMR redirects here. That's no longer true; when I type NMR into the search bar it takes me straight to the disambiguation page. I don't know how to remove that little notice.
Jojojlj (talk) 17:27, 2 May 2011 (UTC)
replies: text: NMR still does redirect here (click that bluelink to see). But :Nmr does not. You didn't type all-caps, so you wound up somewhere else. One could make an argument that the acronym really should also go to the disambiguation page also, but one could also argue that as an acronym (i.e., all-caps), this page here is the substantially most likely intended one. DMacks (talk) 17:50, 2 May 2011 (UTC)
thread_title:  The redirect no longer exists 

message: This article talks the physics but not parts of the machine.  I am curious of the scanner of radio waves  and can't find info.--Ericg33 (talk) 23:01, 23 August 2011 (UTC)
thread_title:  Mri diagram of components needed 

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thread_title: File:Nuclear Magnetic Resonance Spectrometer.jpg Nominated for speedy Deletion

message: It's really hard to cover such a huge subject at a sensible level in an encyclopedia; I admire those who've tried.
The theory section "Nuclear spins and magnets" tells us that protons pair, and neutrons pair, but proton spins do not pair with neutron spins. Since protons and neutrons both have spin 1/2, we have a nice model for all isotopes with odd-proton having 1/2 spin, odd-neutron having 1/2 spin, and odd-both having 1 spin (both even = spin zero). The model is illustrated by isotopes of hydrogen. But then there is a throw-away comment that 27Al has a spin of 2.5, without explanation. There is also some mention of radioactivity, implying that radioactive isotopes don't follow the normal rules, but no explanation of why/how they differ. Is it worth enlarging on either of these? 149.155.96.5 (talk) 12:09, 20 February 2012 (UTC)
thread_title:  No explanation of how a nucleus can have spin > 1 

message: *Optical Nuclear Magnetic Resonance via Google Scholar
*Optical NMR via Google Scholar
*Laser NMR via Google Scholar
Thom5738 (talk) 05:53, 26 February 2012 (UTC)
thread_title:  optical and laser nuclear magnetic resonance 

message: Dear All,
The T2 animation is really good. There is however a problem, as I believe the spin should realign with the opposite movement after the 180 degree pulse. I.e. they should come together at the right side, just as they were after the 90 degree pulse.
Best regards,
Rune S Jacobsen  — Preceding unsigned comment added by 88.151.179.18 (talk) 05:06, 2 October 2012 (UTC)
replies: text: The animation is correct if the 90 and 180 pulses have the same phase. The spins will re-phase to the starting start if the 180 pulses is 90 degree out of phase to the excitation. The animation could be improved though by using different shades / colours to distinguish the spins by their precession rate. 129.234.252.65 (talk) 17:32, 22 November 2012 (UTC)
replies: text: Tell it like it is! -2601:1C2:102:645A:856C:BD4E:612C:355E (talk) 05:44, 2 March 2016 (UTC)
thread_title:  T2 animation 

message: In the second section of the article (Theory of nuclear magnetic resonance) the symbol "S" is used to denote the intrinsic nuclear spin. While it is true that S is used for the spin quantum number of an electron, or other elementary particle for that matter, "I" is typically used to denote the nuclear spin angular momentum, and I will edit the article to that effect in the near future. I have in front of me two seminal textbooks on NMR: Abragam (1973 edition), and Corio (1967 first edition). On page one, Abragam writes: "Many atomic nuclei in their ground state have a non-zero spin angular momentum Iħ (integer or half integer in units of ħ and a dipolar magnetic moment μ = γħI collinear with it." On page 13, Corio gives a more detailed explanation for this use of I for spin angular momentum rather than S, because atomic nuclei are composite particles... As with this page: . Anyway, if there are any objections, raise them, because otherwise S is going away and getting replaced with I. Cheers -137.53.91.235 (talk) 21:36, 2 March 2016 (UTC)
replies: text: Agree, I for nuclear spin (vs particle spin) is what I have usually seen. Our :nuclear spin is a redirect to :Spin (physics), which only seems to talk about individual particles for use of S (I think? That article is pretty deep in the physics and applied-math analysis). DMacks (talk) 22:03, 2 March 2016 (UTC)
thread_title:  Nuclear spin symbol I, rather than S 

message: Substituted at 01:35, 30 April 2016 (UTC)
thread_title: Assessment comment

message: Hello, I have ran across this article two times and each time I find the sentence with the term "spin−1/2" confusing as it appears to be stating that the spin for the proton and the neutron are negative.  I suppose it would be nice to link to the wiki article on spin-1/2 and maybe reword the sentence so that it is clear that the reference to spin-1/2 means particles that have a net spin of 1/2.  I appreciate the reference to fermions, which should make it more clear that the reference is not to negative 1/2, but not everyone is going to realize that the fermion reference will clarify the ambiguity that is present.  As such, I think that
:(1) link to the Wikipedia Article on "spin–1/2"
:(2) clarify the section notation and add sources.
PinkAppleFlower (talk) 21:10, 26 January 2017 (UTC)
thread_title: Nuclear Spin and Magnets Sub-Section

message: The article presently has the sentence in the History section:  Yevgeny Zavoisky likely observed nuclear magnetic resonance in 1941, well before Felix Bloch and Edward Mills Purcell, but dismissed the results as not reproducible.  I do not understand the point of this sentence in this article.  I offer no assessment or challenge to its authenticity, it just seems to me to serve no point to the article.  The issue is in that gray area in writing, which is choice of material.  Or, if you like, the statement does not seem "notable" to me.  It has the sense, now cliché, of statements that Russians did it all first.  In short, delete? Bdushaw (talk) 01:56, 5 September 2022 (UTC)
replies: text: It appears that Zavoisky made more important contributions to electron paramagnetic resonance (EPR or ESR). See the articles Yevgeny Zavoisky and also Electron paramagnetic resonance. Dirac66 (talk) 02:12, 26 November 2022 (UTC)
thread_title:  Zavoisky?