Polarization transfer in a spin-exchange optical-pumping experiment
|Author:||Rantaharju, Jyrki1,2; Hanni, Matti1,3; Vaara, Juha1|
1NMR Research Unit, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
2Present address: School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom
3Present address: Medical Research Center and Research Unit for Medical Imaging, Physics and Technology, P.O. Box 8000, FI-90014 University of Oulu, Finland; Dept. of Diagnostic Radiology, Oulu University Hospital, P.O. Box 50, FI-90029 Oulu, Finland
|Online Access:||PDF Full Text (PDF, 2.6 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2020092275526
American Physical Society,
|Publish Date:|| 2020-09-22
Spin-exchange optical pumping (SEOP) enables hyperpolarization of magnetic noble gas nuclei and allows enormously enhanced signal in nuclear magnetic resonance studies in materials, biosciences, and medicine. We model the dynamics of the SEOP process taking place in a Rb−129Xe gas mixture and shed light on how the different microscopic processes influence the macroscopic polarization transfer. For each Rb-Xe collision taking place in simulated molecular dynamics trajectory, we sample a time series of quantum-chemically preparametrized Hamiltonians. Combined electron and nuclear spin dynamics of each event is propagated by solving the corresponding Liouville–von Neumann equation. The rarely occurring, long-lived van der Waals molecules are seen to give the most significant contribution to polarization transfer under the simulated conditions (T=300 K, p=2.4 bar), in agreement with earlier findings. Besides the lifetime of the collision complex, the average and minimum Rb-Xe interatomic distances characterize the efficiency of the polarization transfer events. We obtain insight into magnetization transfer in both individual binary collisions and van der Waals complexes and demonstrate a stepwise buildup of 129Xe spin polarization upon bond-length oscillations in the latter.
Physical review. A
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
114 Physical sciences
116 Chemical sciences
Financial support has been obtained from the University of Oulu (Exactus doctoral program, Kvantum Institute) and the Academy of Finland (Project No. 296292).
|Academy of Finland Grant Number:||
296292 (Academy of Finland Funding decision)
© 2020 American Physical Society. The final authenticated version is available online at https://doi.org/10.1103/physreva.102.032813.