Fig. 5.

Pulse sequences used in the experiments. (A) A π pulse used to invert the spins for measuring the flow profile. The pulse duration is 116 μs. The detection timing of the magnetometer is relative to the π pulse. (B) Phase-encoding pulse sequence for magnetic resonance imaging. The pulse duration is 58 μs for the π/2 pulses and 1.2 ms for the phase-encoding gradient pulses (G^PE). The gradient step sizes were 0.3, 0.22, and 0.1 G/cm, for axes x, y, and z (flow direction), respectively. The number of steps are 10, 14, and 10 for x, y, and z, respectively.