gradient pulse simulation

[Mengjia He]

Dear Prof. Kuprov,

I'm including a gradient field in my simulation, the gradient pulse shape is flexible, such as square, sinc and so on.

When I add the gradient term to the Hamiltonian, I need to deal with a time-dependent Hamiltonian.

could the Spinach handle the evolution under time-dependent Hamiltonian, or consider shaped gradient pulse like RF pulse?

Best regards,
Mengjia

[kuprov]

Of course it can. Use the imaging() context (see imaging examples for how to use it); it returns gradients as operators. At that point, gradient operators may be used in exactly the same way as pulse operators, including in shaped pulse functions, such as shaped_pulse_xy(), including simultaneously with RF shapes. So yes, the current public version supports simultaneous shaped pulses and shaped gradients.

Good starting points are examples/imaging/dpfgse*.m files and their associated dpfgse_select and dpfgse_suppress pulse sequences. There are also many examples in nmr_spen folder that contains spatially encoded NMR experiments.