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arXiv · 2604.02365

Adiabatic Fast Passage Spin Manipulation Measurements in Solid Polarized Targets

M. F. Hossain·K. Nakano·N. G. Vismith·D. Keller
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Abstract

Adiabatic fast passage (AFP) is a rapid method for reversing nuclear polarization and manipulating spin populations in polarized solid targets, avoiding the long repolarization times associated with dynamic nuclear polarization (DNP). We report AFP measurements in a 5~T, 1~K polarized-target system for irradiated $^{15}$NH$_3$, irradiated $^{14}$ND$_3$, and butanol-based materials prepared either with TEMPO doping or by irradiation. We also present a joint manipulated-lineshape analysis for spin-1 targets and demonstrate that vector and tensor polarizations can be extracted from AFP-manipulated deuteron NMR spectra even when the populations are not described by a single Boltzmann spin temperature. Finally, we report a reproducible polarization- and direction-dependent AFP response in a large irradiated $^{15}$NH$_3$ sample. These ammonia results are presented as empirical observations under the specific sample-coil conditions of the experiment, with possible circuit-mediated mechanisms such as radiation damping or superradiant behavior discussed but not assigned as a definitive cause.

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M. F. Hossain, K. Nakano, N. G. Vismith, D. Keller. 2026-03-23. Adiabatic Fast Passage Spin Manipulation Measurements in Solid Polarized Targets. https://doi.org/10.1016/j.nima.2026.171770

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