title: A nuclear magnetic resonance spectrometer concept for hermetically sealed magic angle spinning investigations on highly toxic, radiotoxic, or air sensitive materials.
abstract: A concept to integrate a commercial high-resolution, magic angle spinning nuclear magnetic resonance (MAS-NMR) probe capable of very rapid rotation rates (70 kHz) in a hermetically sealed enclosure for the study of highly radiotoxic materials has been developed and successfully demonstrated. The concept centres on a conventional wide bore (89 mm) solid-state NMR magnet operating with industry standard 54 mm diameter probes designed for narrow bore magnets. Rotor insertion and probe tuning take place within a hermetically enclosed glovebox, which extends into the bore of the magnet, in the space between the probe and the magnet shim system. Oxygen-17 MAS-NMR measurements demonstrate the possibility of obtaining high quality spectra from small sample masses (~10 mg) of highly radiotoxic material and the need for high spinning speeds to improve the spectral resolution when working with actinides. The large paramagnetic susceptibility arising from actinide paramagnetism in (Th(1-x)U(x))O2 solid solutions gives rise to extensive spinning sidebands and poor resolution at 15 kHz, which is dramatically improved at 55 kHz. The first (17)O MAS-NMR measurements on NpO(2+x) samples spinning at 55 kHz are also reported. The glovebox approach developed here for radiotoxic materials can be easily adapted to work with other hazardous or even air sensitive materials.
authors.affiliation: Joint Research Centre, Institute for Transuranium Elements, Postfach 2340, D76125 Karlsruhe, Germany. lpm.martel@gmail.com
authors.forename: L
authors.initials: L
authors.lastname: Martel
authors.forename: J
authors.initials: J
authors.lastname: Somers
authors.forename: C
authors.initials: C
authors.lastname: Berkmann
authors.forename: F
authors.initials: F
authors.lastname: Koepp
authors.forename: A
authors.initials: A
authors.lastname: Rothermel
authors.forename: O
authors.initials: O
authors.lastname: Pauvert
authors.forename: C
authors.initials: C
authors.lastname: Selfslag
authors.forename: I
authors.initials: I
authors.lastname: Farnan