Fig. 1. Principle of excitation dynamics of magnetic resonance sounding: (a) Traditional type; (b) adiabatic type.

Fig. 2. Excitation process of the adiabatic pulses: (a) The sequence diagram of the transmitting current (red) and FID signal (blue); (b) the relationship of the excitation magnetic field (dark red arrow) and magnetization (blue line).

Fig. 3. The relationship of transverse magnetization and exciting magnetic based on hyperbolic tangent AHP pulse: (a) The waveform of transmitting current amplitude; (b) its frequency vs. time; (c) magnetization x-component, y-component and real value.

Fig. 4. The real kernel function of adiabatic half-passage pulses for the same excitation current (1–600 A) corresponding to different τ, with quality factor Q = 30: (a) τ = 20 ms; (b) τ = 40 ms; (c) τ = 60 ms; (d) τ = 80 ms; (e) τ = 100 ms; (f) τ = 120 ms; (g) τ = 140 ms; (h) τ = 160 ms.

Fig. 5. The imaginary kernel function of adiabatic half-passage pulses for the same excitation current (1–600 A) corresponding to different τ, with quality factor Q = 30: (a) τ = 20 ms; (b) τ = 40 ms; (c) τ = 60 ms; (d) τ = 80 ms; (e) τ = 100 ms; (f) τ = 120 ms; (g) τ = 140 ms; (h) τ = 160 ms.

Fig. 6. The real kernel function of adiabatic half-passage pulses for the same pulse moment corresponding to different τ, with quality factor Q = 30: (a) τ = 20 ms with maximum current 600 A; (b) τ = 40 ms with maximum current 300 A; (c) τ = 60 ms with maximum current 200 A; (d) τ = 80 ms with maximum current 150 A; (e) τ = 100 ms with maximum current 120 A; (f) τ = 120 ms with maximum current 100 A; (g) τ = 140 ms with maximum current 85.7 A; (h) τ = 160 ms with maximum current 75 A.

Fig. 7. The imaginary kernel function of adiabatic half-passage pulses for the same pulse moment corresponding to different τ, with quality factor Q = 30: (a) τ = 20 ms with maximum current 600 A; (b) τ = 40 ms with maximum current 300 A; (c) τ = 60 ms with maximum current 200 A; (d) τ = 80 ms with maximum current 150 A; (e) τ = 100 ms with maximum current 120 A; (f) τ = 120 ms with maximum current 100 A; (g) τ = 140 ms with maximum current 85.7 A; (h) τ = 160 ms with maximum current 75 A.

Fig. 8. The forward modeling of adiabatic half-passage pulse for the same pulse moment (0.01–7.3 A·s) with different τ and current. The modeling assume a homogeneous aquifer subsurface with 10% water content, the quality factor Q = 30.

Fig. 9. The (a), (b), (c), (d) real and (e), (f), (g), (h) imaginary part of the kernel function of adiabatic half-passage pulses for different quality factor Q with τ = 80 ms: (a), (e) Q = 10; (b), (f) Q = 20; (c), (g) Q = 30; (d), (h) Q = 40.

Fig. 10. The forward modeling of adiabatic half-passage pulse for the same pulse current (1–600 A) with different quality factor Q (The gray dotted line is the initial amplitude of traditional nuclear magnetic resonance responses). The modeling assume a homogeneous aquifer subsurface with 10% water content with τ = 80 ms.