Calculation of Polarized Neutron Scattering Cross Sections from Prototypical Spin-Manipulated Hyperpolarized Molecules in Solution*

We present preliminary results for calculated angular cross sections of polarized thermal neutrons scattered from prototypical molecules that are hyperpolarized and spin-manipulated (via NMR techniques) in solution.  Such molecules include, for example, pyridine or methyl nicotinate, for which it has already been proven that high degrees of nuclear spin hyperpolarization are achievable at room temperature through polarization transfer from para-hydrogen (1).  We investigate these cross sections, and on an absolute scale, for both neutron spin-flip and no-spin-flip cases since we have already predicted (2) that experiments combining these two scenarios can yield partial structure factors that would be useful for determining distances between user-selected nuclei.  We demonstrate some calculated cross sections and resulting partial structure factors for representative molecules with varying degrees of initial hyperpolarization.  Preliminary calculations that incorporate the effects of T₁ spin relaxation on the scattering signal will also be discussed.

 

(1) See, for example, P.J. Rayner, et al., PNAS 114 (2017) E3188

(2) M. Kotlarchyk and G.M. Thurston, J. Chem. Phys. 145 (2016) 244201