# Bloch Decay Spectrum method¶

mrsimulator.methods.BlochDecaySpectrum(spectral_dimensions=[{}], **kwargs)

A one-dimensional Bloch decay spectrum method.

Parameters
• name (str (optional)) – The value is the name or id of the method. The default value is None.

• label (str (optional)) – The value is a label for the method. The default value is None.

• description (str (optional)) – The value is a description of the method. The default value is None.

• experiment (CSDM or ndarray (optional)) – An object holding the experimental measurement for the given method, if available. The default value is None.

• channels (list (optional)) – The value is a list of isotope symbols over which the given method applies. An isotope symbol is given as a string with the atomic number followed by its atomic symbol, for example, ‘1H’, ‘13C’, and ‘33S’. The default is an empty list. The number of isotopes in a channel depends on the method. For example, a BlochDecaySpectrum method is a single channel method, in which case, the value of this attribute is a list with a single isotope symbol, [‘13C’].

• spectral_dimensions (List of SpectralDimension or dict objects (optional).) – The number of spectral dimensions depends on the given method. For example, a BlochDecaySpectrum method is a one-dimensional method and thus requires a single spectral dimension. The default is a single default SpectralDimension object.

• magetic_flux_density (float (optional)) – A global value for the macroscopic magnetic flux density, $$H_0$$, of the applied external magnetic field in units of T. The default is 9.4.

• rotor_angle (float (optional)) – A global value for the angle between the sample rotation axis and the applied external magnetic field, $$\theta$$, in units of rad. The default value is 0.9553166, i.e. the magic angle.

• rotor_frequency (float (optional)) – A global value for the sample spinning frequency, $$\nu_r$$, in units of Hz. The default value is 0.

Returns

Return type

A Method instance.

Example

>>> from mrsimulator.methods import BlochDecaySpectrum
>>> Bloch_method = BlochDecaySpectrum(
...     channels=["1H"],
...     rotor_frequency=5000,  # in Hz
...     magnetic_flux_density=9.4,  # in T
...     spectral_dimensions=[
...         dict(count=1024, spectral_width=50000, reference_offset=-8000)
...     ],
... )


Bloch decay method is a special case of Method1D, given as

>>> from mrsimulator.methods import Method1D
>>> Blochdecay = Method1D(
...     channels=["1H"],
...     rotor_frequency=5000,  # in Hz