Optimization of THz wave coupling into samples in DNP/NMR spectroscopy

Author

Nanni, Emilio A. ; Barnes, Alexander B. ; Matsuki, Yoh ; Woskov, Paul P. ; Corzilius, Björn ; Griffin, Robert G. ; Temkin, Richard J.

Author_Institution

Plasma Sci. & Fusion Center, MIT, Cambridge, MA, USA

fYear

2010

fDate

5-10 Sept. 2010

Firstpage

1

Lastpage

3

Abstract

High power millimeter wave and terahertz sources are used in DNP/NMR spectroscopy to greatly enhance the NMR signal. A key issue is the efficient coupling of the source power to the sample. We present HFSS calculations showing that the MIT 250 GHz DNP/NMR system provides a B₁ value of 13 μT/W^1/2. The simulation shows the importance of the diffraction of radiation passing through the RF coil, leading to non-uniform illumination of the sample. A simple single pass model yields insight into the origin of the observed B₁ value. Methods of optimizing the B₁ value are described.

Keywords

coils; dynamic nuclear polarisation; millimetre wave couplers; nuclear magnetic resonance; optimisation; DNP/NMR spectroscopy; HFSS calculations; MIT DNP/NMR system; NMR signal; THz wave coupling; dynamic nuclear polarization; frequency 250 GHz; high power millimeter wave source; nonuniform illumination; nuclear magnetic resonance; optimization; radiation diffraction; radiofrequency coil; terahertz source; Cavity resonators; Coils; Couplings; Millimeter wave technology; Probes; Radio frequency; Rotors;

fLanguage

English

Publisher

ieee

Conference_Titel

Infrared Millimeter and Terahertz Waves (IRMMW-THz), 2010 35th International Conference on

Conference_Location

Rome

Print_ISBN

978-1-4244-6655-9

Type

conf

DOI

10.1109/ICIMW.2010.5612956

Filename

5612956