Jawla, Sudheer K., Robert G. Griffin, Ivan A. Mastovsky, Michael A. Shapiro, and Richard J. Temkin. “Second Harmonic 527-GHz Gyrotron for DNP-NMR: Design and Experimental Results.” IEEE Transactions on Electron Devices 67, no. 1 (January 2020): 328–34.
We report the design and experimental demonstration of a frequency tunable terahertz gyrotron at 527 GHz built for an 800-MHz dynamic nuclear polarization enhanced nuclear magnetic resonance (DNP-NMR) spectrometer. The gyrotron is designed at the second harmonic (? = 2?c) of the electron cyclotron frequency. It produces up to 9.3-W continuous microwave (CW) power at 527.2-GHz frequency using a diode type electron gun operating at V = 16.65 kV, Ib = 110 mA in a TE11,2,1 mode, corresponding to an efficiency of ~0.5%. The gyrotron is tunable within ~0.4 GHz by combining voltage and magnetic field tuning. The gyrotron has an internal mode converter that produces a Gaussian-like beam that couples to the HE11 mode of an internal 12-mm i.d. corrugated waveguide periscope assembly leading up to the output window. An external corrugated waveguide transmission line system is built including a corrugated taper from 12- to 16-mm i.d. waveguide followed by 3 m of the 16-mm i.d. waveguide The microwave beam profile is measured using a pyroelectric camera showing ~84% HE11 mode content.
Experimental quantification of electron spectral-diffusion under static DNP conditions #DNPNMR
From The DNP-NMR Blog:
Experimental quantification of electron spectral-diffusion under static DNP conditions #DNPNMR
Kundu, Krishnendu, Marie Ramirez Cohen, Akiva Feintuch, Daniella Goldfarb, and Shimon Vega. “Experimental Quantification of Electron Spectral-Diffusion under Static DNP Conditions.” Physical Chemistry Chemical Physics 21, no. 1 (2019): 478–89.
https://doi.org/10.1039/C8CP05930F.
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03-24-2019 10:41 PM
Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization #DNPNMR
From The DNP-NMR Blog:
Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization #DNPNMR
Scott, F.J., et al., Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization. J Magn Reson, 2018. 289: p. 45-54.
https://www.ncbi.nlm.nih.gov/pubmed/29471275
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04-27-2018 10:26 PM
In Silico Design of DNP Polarizing Agents: Can Current Dinitroxides Be Improved? #DNPNMR
From The DNP-NMR Blog:
In Silico Design of DNP Polarizing Agents: Can Current Dinitroxides Be Improved? #DNPNMR
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Perras, F.A., A. Sadow, and M. Pruski, In Silico Design of DNP Polarizing Agents: Can Current Dinitroxides Be Improved? ChemPhysChem, 2017. 18(16): p. 2279-2287.
https://www.ncbi.nlm.nih.gov/pubmed/28599086
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11-09-2017 08:55 AM
A ferromagnetic shim insert for NMR magnets – Towards an integrated gyrotron for DNP-NMR spectroscopy #DNPNMR
From The DNP-NMR Blog:
A ferromagnetic shim insert for NMR magnets – Towards an integrated gyrotron for DNP-NMR spectroscopy #DNPNMR
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Bridge12 is currently developing an integrated THz system for NMR-DNP spectroscopy. The basic idea is to operate the gyrotron inside the NMR magnet, just above the NMR probe head, effectively eliminating the need of a second superconducting magnet. This article is about a ferroshim insert that we had to develop for this purpose.
Ryan, H., J. van Bentum, and T....
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03-10-2017 04:23 PM
500-fold enhancement of in situ (13)C liquid state NMR using gyrotron-driven temperature-jump DNP #DNPNMR
From The DNP-NMR Blog:
500-fold enhancement of in situ (13)C liquid state NMR using gyrotron-driven temperature-jump DNP #DNPNMR
Yoon, D., et al., 500-fold enhancement of in situ (13)C liquid state NMR using gyrotron-driven temperature-jump DNP. J Magn Reson, 2016. 270: p. 142-6.
http://www.ncbi.nlm.nih.gov/pubmed/27490302
Liquid state DNP at high magnetic fields: Instrumentation, experimental results and atomistic modelling by molecular dynamics simulations
From The DNP-NMR Blog:
Liquid state DNP at high magnetic fields: Instrumentation, experimental results and atomistic modelling by molecular dynamics simulations
Prisner, T., V. Denysenkov, and D. Sezer, Liquid state DNP at high magnetic fields: Instrumentation, experimental results and atomistic modelling by molecular dynamics simulations. J Magn Reson, 2016. 264: p. 68-77.
http://www.ncbi.nlm.nih.gov/pubmed/26920832
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05-05-2016 03:15 AM
Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various media
From The DNP-NMR Blog:
Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various media
Glyavin, M.Y., et al., Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various media. Review of Scientific Instruments, 2015. 86(5): p. 054705.
doi:http://dx.doi.org/10.1063/1.4921322
Second Harmonic 527-GHz Gyrotron for DNP-NMR: Design and Experimental Results #DNPNMR
Linear Mode
