Figure 3.

CLEANEX-PM pulse sequence (18). Shaped pulses are selective for water. The CLEANEX-PM windowless pulse train consists of: 135° (x) 120° (−x), 110° (x), 110° (−x), 120° (x), 135° (−x). Shaped pulses are 180° pulses selective for water. The phases of the pulses are cycled as follows: φ₁ = x; φ₂ = x, y, −x, −y; φ₃ and rec. = x, −x, x, −x. A selective 90° water flip-back pulse (19) enables a higher repetition rate for the pulse sequence, and any residual water is suppressed by the WATERGATE (20) water-suppression scheme. The long, low-power (≈0.1 Gauss/cm) gradient applied during the spin lock prevents radiation damping (21) during this period.