EventOperators

class torchsim.model.EventOperators(excitation=<function Excitation>, refocusing=<function Refocusing>, inversion=<function Inversion>, saturation=<function Saturation>, readout=<function Readout>, delay=<function Delay>)

Bases: object

Which operator plays each kind of event.

Each field is an operator factory, called with the parameters the protocol has for that event. Assigning one is how a sequence says that its readouts wind the states on, or that its excitation is a shaped pulse rather than an ideal rotation.

These are roles a sequence is written in terms of, not the tags the events end up carrying: a factory here decides which RfUse and which EventAction its events are emitted with.

Methods

delay	Return time passing, and whatever the sequence plays across it.
excitation	Return a pulse that tips magnetization into the transverse plane.
inversion	Return an ideal inversion, scaled by the tissue's inversion efficiency.
readout	Return one sample of the transverse magnetization, demodulated by a phase.
refocusing	Return a pulse the sequence sits between crushers, unless told otherwise.
saturation	Return an off-resonance pulse that deposits power in a semisolid pool.

excitation(phase_rad=0.0, *, duration_s=0.0, definition_id=0, frequency_hz=0.0, shim_id=0, action=EventAction.NONE)

What a pulse that tips magnetization into the transverse plane plays.

refocusing(phase_rad=0.0, *, crushed=True, duration_s=0.0, definition_id=0, frequency_hz=0.0, shim_id=0)

What a refocusing pulse plays, including the gradients it sits between.

inversion(*, flip_rad=torch.pi, phase_rad=0.0, definition_id=0)

What an inversion plays, and the recovery it holds the timeline for.

saturation(flip_rad, *, offset_hz=0.0, phase_rad=0.0, duration_s=0.0, shim_id=0)

What a saturation pulse plays.

readout(*, role=AdcRole.SINGLE, is_echo=True, duration_s=0.0, action=EventAction.NONE)

What a sample and the rest of its repetition play – which is where a sequence says whether it winds the states on, spoils them, or rewinds them.

delay(*, action=EventAction.NONE)

What a wait plays, which is nothing but time.