A broad effort is underway to improve the sensitivity of NMR through the use of dynamic nuclear polarization. Nitrogen vacancy (NV) centers in diamond offer an appealing platform because these paramagnetic defects can be optically polarized efficiently at room temperature. However, work thus far has been mainly limited to single crystals, because most polarization transfer protocols are sensitive to misalignment between the NV and magnetic field axes. Here we study the spin dynamics of NV−13C pairs in the simultaneous presence of optical excitation and microwave frequency sweeps at low magnetic fields. We show that a subtle interplay between illumination intensity, frequency sweep rate, and hyperfine coupling strength leads to efficient, sweep-direction-dependent 13C spin polarization over a broad range of orientations of the magnetic field. In particular, our results strongly suggest that finely tuned, moderately coupled nuclear spins are key to the hyperpolarization process, which makes this mechanism distinct from other known dynamic polarization channels. These findings pave the route to applications where powders are intrinsically advantageous, including the hyperpolarization of target fluids in contact with the diamond surface or the use of hyperpolarized particles as contrast agents for in vivo imaging.
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机译：用等离子体约束实现重力场的动态控制热核聚变（TLTS）方法，通过热辐射等离子体绝缘的壁反应堆防止中子辐射并节省磁场和等离子体的混合，使用旋转磁场的异步磁惯性约束反应堆（AMITYAR和HFM）为实施该方法，在该反应器中点燃热核反应的方法，爆炸式等离子发生器（VIP）的实施方法，以及具有HFM的特立普安瓿，以实现D + T反应和具有超高温热度的HFM D +3НЕ和1Н+11В的高温反应
