Modeling alignment enhancement for solid polarized targets

TL;DR

This paper develops a model for optimizing the dynamic orientation of spin-1 systems in solid polarized targets using RF irradiation, enhancing tensor polarization for nuclear and particle physics experiments.

Contribution

It introduces a new model for spin-1 alignment enhancement with optimized RF irradiation, applicable to tensor-polarized solid targets.

Findings

Numerical solutions for steady-state alignment conditions.

Identification of optimal RF parameters for maximum tensor polarization.

Analysis of NMR lineshape for alignment optimization.

Abstract

A model of dynamic orientation using optimized radiofrequency (RF) irradiation produced perpendicular to the holding field is developed for the spin-1 system required for tensor-polarized fixed-target experiments. The derivation applies to RF produced close to the Larmor frequency of the nucleus and requires the electron spin-resonance linewidth to be much smaller than the nuclear magnetic resonance frequency. The rate equations are solved numerically to study a semi-saturated steady-state resulting from the two sources of irradiation: microwave from the DNP process and the additional RF used to manipulate the tensor polarization. The steady-state condition and continuous-wave NMR lineshape are found that optimize the spin-1 alignment in the polycrystalline materials used as solid polarized targets in charged-beam nuclear and particle physics experiments.