A magnetic tunnel to shelter hyperpolarized fluids

Abstract

Theory of long-lived nuclear spin states in methyl groups and quantum-rotor induced polarisation

Construction and 13C hyperpolarization efficiency of a 180 GHz dissolution dynamic nuclear polarization system

“…It has been discussed by Milani et al that, in addition to the detrimental extremely low fields that the hyperpolarized liquids are exposed, non-adiabatic changes in the field experienced by the hyperpolarized liquid, especially when the hyperpolarized liquid exits the polarizer or enters a high field magnet for NMR detection, can lead to a significant loss of polarization. [40] Speeding up the dissolution transfer would almost certainly reduce the hyperpolarization loss due to T 1 decay observed with our dissolution DNP system. In the commercial HyperSense (Oxford Instruments, UK) polarizer where the dissolution process is semi-automated, the dissolution transfer time is around 8 s. [16] Our DNP system takes about twice this time to complete the dissolution mainly because the dissolution process is done manually including the injection of solvent, opening of the valves to eject the hyperpolarized liquid, transfer of liquid into 5 mm NMR tube, then finally insertion of the NMR tube in the high-resolution NMR magnet for detection.…”

Optimizing dissolution dynamic nuclear polarization

“…Indeed, apart from the dual center magnet approach from Kockenberger [59] or the in-situ rapid melt approach from van Bentum [60], the hyperpolarized solution usually needs to be transferred to another magnet during which time it is exposed to very low magnetic fields (mT range). The exact magnetic field pattern experienced by the hyperpolarized fluid in our laboratory was mapped systematically with a triple-axis Hall probe [61]. The hyperpolarized solution effectively travels through a relatively low field, below B 0 = 1 mT, with regions close to zero-field, where the magnetic field gets inverted.…”

“…The hyperpolarized solution effectively travels through a relatively low field, below B 0 = 1 mT, with regions close to zero-field, where the magnetic field gets inverted. In order to protect hyperpolarized solutions from such low field environment and from the associated exacerbated paramagnetic relaxation, we have designed a modular magnetic tunnel to interface our polarizer either to an unshielded 300 MHz or to an ultra-shielded 500 MHz NMR spectrometer [61]. It consists of an assembly of permanent neodymium boron magnets securely maintained by several home built aluminum structures.…”

Hyperpolarized Water to Study Protein–Ligand Interactions

“…25 The hyperpolarized sample is then quickly dissolved using superheated D 2 O and transferred to an NMR magnet through a magnetic tunnel, 26 where it is rapidly injected into an equilibrated protein−ligand solution ( Figure 1). The excitation of hyperpolarized water can lead to massive radiation damping (RD) and demagnetizing distant dipolar field effects.…”