Test B1

[samadams8]

Confirm that B1 waveforms work as intended. Specific test items

• [x] Flip angle is correct: magnetization change matches the area under the B1 waveform
• [ ] Phase angle works correctly: Purely real B1 rotates around +x-axis, purely imaginary B1 rotates around +y-axis, etc. for arbitrary phase angles
• [ ] Off resonance excitation test? Need to confirm that off resonance is simulated correctly first. Then modulate the excitation envelope with off resonance frequency and confirm that we can simulate frequency selective pulses

[samadams8]

Also test B1map

• [x] B1 map scaling: Flip angle at some point in space varies proportional to B1 map. For example, if FA=15° for a pulse and B1map varies from 0.7-1.5, the actual flip angle varies from 10.5-22.5°