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Friday, December 7, 2007

Shaped Pulses for Selective Excitation

Short rectangular pulses have broad excitation profiles (see BLOG entry for November 20, 2007) and are used for non-selective uniform excitation. These are often called "hard" pulses. Longer low power shaped pulses are used to excite specific spectral regions for selective excitation. An example of this is shown below.These are often called "soft" pulses.

8 comments:

Anonymous said...

how do you invert only a peak in your spectrum with a selective pulse while leaving the other peaks unperturbed?

Glenn Facey said...

Anonymous,

See this post of January 20, 2011

http://u-of-o-nmr-facility.blogspot.ca/2011/01/excitation-profiles-for-shaped-pulses.html

which describes the excitation profiles of shaped pulses.

Glenn

chanti said...

Please clarify selective and non-selective relaxation. While measuring selective T1 only proton singlets are only should be inverted? What about multiplets?

Phani Kumar

Glenn Facey said...

Dear Phani Kumar,

I don't know what you mean by "selective relaxation".

Glenn

chanti said...

selective and non-selective spin-lattice relaxation in terms of self and cross relaxation.

chanti said...

I would like to know selective and non-selective spin-lattice relaxation times and their correlation with self and cross relaxation times. For measuring selective T1 only proton singlets (in 1H nmr) are used? For multiplets how to measure selective T1

chanti said...

Selective inversion recovery to measure T1

Glenn Facey said...

Phani,

I don't know the answers to your questions.

Glenn