Shimming

This sequence sweeps the offset on the gradient to determine the optimal shimming by evaluating the spectrum amplitude and Full Width at Half Maximum (FWHM).

Parameters:

• nPoints: Number of points to be acquired in each acquisition window.
• Larmor frequency offset (kHz): Frequency offset in kHz relative to the calibrated Larmor frequency found in larmorFreq in configs/hw_config.py.
• Excitation flip angle (º): RF excitation pulse flip angle in degrees.
• Refocusing flip angle (º): RF refocusing pulse flip angle in degrees.
• RF excitation time (us): RF excitation pulse duration in microseconds.
• RF refocusing time (us): RF refocusing pulse duration in microseconds.
• Echo time (ms): Time from the excitation to the echo in milliseconds.
• Repetition time (ms): Time between excitations in milliseconds.
• Acquisition time (ms): Duration of the acquisition window.
• Dummy pulses: Number of dummy pulses.
• Shimming: Center values for the shimming sweep.
• n Shimming steps: Number of shimming values to sweep per channel.
• Shimming step: Step values for the sweep.

After running the sequence, the optimal shimming values are displayed in the console and applied to all subsequent sequences.