Go to eNMR
1D Stimulated Echo experiment

PRELIMINARY SET-UP
  • Insert the sample.
  • Choose the solvent deuterium signal with the lock command.
  • Tune and match the probehead.
  • Optimize the shim procedure (read a shim file with the command rsh if required).
  • Record a conventional 1H spectrum.
  • PARAMETER SET
    Create a new dataset with edc or, alternatively, increment the experiment number with the iexpno command from the reference 1H spectrum and change the pulse program to stegp1s1d (it can be displayed with the command edcpul).  

    Set the following gradient parameters:

    Gradient ratios: gpz6 1-100(variable) and gpz7 -17.13.
    Gradient Lengths: p30 1 ms and p19 1.1 ms.
    Recovery delay: d16 100u.
    The diffusion time is d20. A standard value can be set to 100-200 ms.
    MODIFY SPECIFIC PARAMETERS
    Set the number of scans as a function of the sample concentration (fos instance, ns 8 and ds 16).

    Repeat the experiment increasing the gradient strength (gpz6) (the gradient length (p30) can be also varied). The diffusion time value (d20) can also be modified to obtain other series of 1D spectra.

    ACQUISITION
    Start the first acquisition by rga and zg (the expected experimental time is observed with the expt command). All other acquisitions will use the same rg value.
    PROCESSING
    Process the first recorded data with ef (lb=1) and phase to pure absorption. The same phase correction is applied for will be applied in all remaining spectra.
    PLOT
     Use XWINPLOT.
    OBSERVATIONS
    It is advisable to store acquisition and processing parameters (for instance, with the command wpar ste1d all) to be used later.

    Alternatively, you can perform the acquisition and processing steps of this experiment using predefined automated AU programs (See 2D DOSY for more information) and defining the pulse program to stegp1s (it can be displayed with the command edcpul).  

    OTHER RELATED VERSIONS
    A list of other related experiments can be found in Tutorials: Diffusion Experiments.
    3("/guide/tutorials/menu_e.html");