zulf_abrupt.m

Zero-field NMR experiment with an abrupt field drop that propagates the initial condition through an exponential drop in the external magnetic field and then detects at zero field.

Syntax

    fid=zulf_abrupt(spin_system,parameters,H,R,K)

Parameters

   parameters.drop_field   - the magnetic field that the sample should 
                             be dropped to, starting from the field spe-
                             cified in sys.magnet, Tesla

   parameters.drop_time    - drop time, seconds

   parameters.drop_npoints - number of discretisation points in the drop

   parameters.drop_rate    - field drop rate, Hz

   parameters.sweep        - sweep width during acquisition

   parameters.npoints      - number of points during acquisition

   parameters.detection    - 'uniaxial' to emulate common ZULF
                             hardware, 'quadrature' for proper
                             frequency sign discrimination

   parameters.flip_angle   - pulse flip angle in radians for
                             protons; for other nuclei, this
                             will be scaled by the gamma ratio

Outputs

     fid          - the free induction decay detected on the
                   internally generated gamma-weighted state

Notes

This function ignores the offset parameter and makes its own Hamiltonian.

Examples

See zero_field_acetonitrile.m file in examples/nmr_zerofield directory.

See also

zerofield.m, fieldscan_enlev.m, fieldscan_magn.m

Version 2.1, authors: Ilya Kuprov