Generic placeholder image

Current Physics

Author(s): Vladimir Evgen'evich Zapevalov and Andrey Sergeevich Zuev*

DOI: 10.2174/0127723348284884240330042150

DownloadDownload PDF Flyer Cite As
Advanced Gyrotron Concepts for Spectroscopic Applications

Article ID: e160424228964 Pages: 11

  • * (Excluding Mailing and Handling)

Explore Articles
About Journal
For Authors
For Editors
For Reviewers

Abstract

Background: Currently, some modern spectroscopic applications require sub-terahertz and terahertz continuous-wave electromagnetic radiation sources with power levels from 0.1 to 100 W. Gyrotron, a powerful high-frequency vacuum electronics device, is considered one of the promising sources for these aims.

Methods: Modification of the gyrotron design promotes the widespread use of these devices for DNP/NMR spectroscopy.

Results: Promising non-canonical concepts are presented, the features of which compare favorably with the classical gyrotron scheme.

Conclusion: The gyrotron concepts we considered allow us to master the terahertz range and develop a unique gyrotron installation for each scientific group, considering the specifics of their scientific research.

Keywords: NMR, DNP, spectroscopy, terahertz radiation, gyrotron, cyclotron frequency harmonics, cryomagnet, electron beams.

[1]
Zapevalov, V.E. Evolution of the gyrotrons. Radiophys. Quantum Electron., 2012, 54(8-9), 507-518.
[http://dx.doi.org/10.1007/s11141-012-9326-8]
[2]
Nusinovich, G.S.; Thumm, M.K.A.; Petelin, M.I. The gyrotron at 50: Historical overview. J. Infrared Millim. Terahertz Waves, 2014, 35(4), 325-381.
[http://dx.doi.org/10.1007/s10762-014-0050-7]
[3]
Glyavin, M.Y.; Idehara, T.; Sabchevski, S.P. Development of THz gyrotrons at IAP RAS and FIR UF and their applications in physical research and high-power THz technologies. IEEE Trans. Terahertz Sci. Technol., 2015, 5(5), 788-797.
[http://dx.doi.org/10.1109/TTHZ.2015.2442836]
[4]
Kumar, N.; Singh, U.; Bera, A.; Sinha, A.K. A review on the sub-THz/THz gyrotrons. Infrared Phys. Technol., 2016, 76, 38-51.
[http://dx.doi.org/10.1016/j.infrared.2016.01.015]
[5]
Temkin, R.J. Development of terahertz gyrotrons for spectroscopy at MIT. Terahertz Science and Technology, 2014, 7(1), 1-9.
[6]
Idehara, T.; Sabchevski, S.P. Development and application of gyrotrons at fir uf. IEEE Trans. Plasma Sci., 2018, 46(7), 2452-2459.
[http://dx.doi.org/10.1109/TPS.2017.2775678]
[7]
Lewis, R.A. A review of terahertz sources. J. Phys. D Appl. Phys., 2014, 47(37), 374001.
[http://dx.doi.org/10.1088/0022-3727/47/37/374001]
[8]
Grekhov, G.A.V.; Granatstein, V.L. Applications of high-power microwaves; Artech House: Boston, London, 1994.
[9]
Glyavin, M.Y.; Denisov, G.G.; Zapevalov, V.E.; Koshelev, M.A.; Tretyakov, M.Y.; Tsvetkov, A.I. High power terahertz sources for spectroscopy and material diagnostics. Phys. Uspekhi, 2016, 59(6), 595-604.
[http://dx.doi.org/10.3367/UFNe.2016.02.037801]
[10]
Sabchevski, S.; Glyavin, M. Development and application of thz gyrotrons for advanced spectroscopic methods. Photonics, 2023, 10(2), 189-219.
[http://dx.doi.org/10.3390/photonics10020189]
[11]
Rosay, M.; Tometich, L.; Pawsey, S.; Bader, R.; Schauwecker, R.; Blank, M.; Borchard, P.M.; Cauffman, S.R.; Felch, K.L.; Weber, R.T.; Temkin, R.J.; Griffin, R.G.; Maas, W.E. Solid-state dynamic nuclear polarization at 263 GHz: Spectrometer design and experimental results. Phys. Chem. Chem. Phys., 2010, 12(22), 5850-5860.
[http://dx.doi.org/10.1039/c003685b] [PMID: 20449524]
[12]
Polenova, T.; Budinger, T.F. Ultrahigh field NMR and MRI: Science at a crossroads. Report on a jointly-funded NSF, NIH and DOE workshop, held on November 12-13, 2015 in Bethesda, Maryland, USA. J. Magn. Reson., 2016, 266, 81-86.
[13]
Griffin, R.G.; Swager, T.M.; Temkin, R.J. High frequency dynamic nuclear polarization: New directions for the 21st century. J. Magn. Reson., 2019, 306, 128-133.
[http://dx.doi.org/10.1016/j.jmr.2019.07.019] [PMID: 31327537]
[14]
Denysenkov, V.; Prandolini, M.J.; Gafurov, M.; Sezer, D.; Endeward, B.; Prisner, T.F. Liquid state DNP using a 260 GHz high power gyrotron. Phys. Chem. Chem. Phys., 2010, 12(22), 5786-5790.
[http://dx.doi.org/10.1039/c003697h] [PMID: 20461255]
[15]
Blank, M.; Felch, K. L. Millimeter-wave sources for DNP-NMR. eMagRes, 2018, 7, 155-166.
[16]
Bratman, V.L.; Kalynov, Y.K.; Makhalov, P.B.; Fedotov, A.E. New versions of terahertz radiation sources for dynamic nuclear polarization in nuclear magnetic resonance spectroscopy. Radiophys. Quantum Electron., 2014, 56(8-9), 532-541.
[http://dx.doi.org/10.1007/s11141-014-9456-2]
[17]
Zapevalov, V.E. Non-canonical gyrotrons.Radiophys. Quantum Electron; Copenhagen, Denmark, 2018, 61(4), pp. 272-280.
[http://dx.doi.org/10.1007/s11141-018-9888-1]
[18]
Sabchevski, S.P.; Glyavin, M.Y.; Nusinovich, G.S. The progress in the studies of mode interaction in gyrotrons. J. Infrared Millim. Terahertz Waves, 2022, 43(1-2), 1-47.
[http://dx.doi.org/10.1007/s10762-022-00845-7]
[19]
Nusinovich, G.S. Introduction to the physics of Gyrotrons; The Johns Hopkins University Press: Baltimore, Maryland, 2001.
[20]
Tsimring, Sh.E. Electron beams and microwave vacuum electronics; John Wiley and Sons, Inc.: Hoboken, New Jersey, 2007.
[21]
Torrezan, A.C.; Shapiro, M.A.; Sirigiri, J.R.; Temkin, R.J.; Griffin, R.G. Operation of a continuously frequency-tunable second-harmonic cw 330-ghz gyrotron for dynamic nuclear polarization. IEEE Trans. Electron Dev., 2011, 58(8), 2777-2783.
[http://dx.doi.org/10.1109/TED.2011.2148721]
[22]
Qi, X.B.; Du, C.H.; Liu, P.K. Broadband continuous frequency tuning in a terahertz gyrotron with tapered cavity. IEEE Trans. Electron Dev., 2015, 62(12), 4278-4284.
[http://dx.doi.org/10.1109/TED.2015.2493563]
[23]
Sabchevski, S.P.; Idehara, T. A numerical study on finite-bandwidth resonances of high-order axial modes (HOAN) in gyrotron cavity. J. Infrared Millim. Terahertz Waves, 2015, 36(7), 628-653.
[http://dx.doi.org/10.1007/s10762-015-0161-9]
[24]
Fedotov, A.E.; Rozental, R.M.; Zotova, I.V.; Ginzburg, N.S.; Sergeev, A.S.; Tarakanov, V.P.; Glyavin, M.Y.; Idehara, T. Frequency tunable sub-THz gyrotron for direct measurements of positronium hyperfine structure. J. Infrared Millim. Terahertz Waves, 2018, 39(10), 975-983.
[http://dx.doi.org/10.1007/s10762-018-0522-2]
[25]
Idehara, T.; Ogawa, I.; Mitsudo, S.; Pereyaslavets, M.; Nishida, N.; Yoshida, K. Development of frequency tunable, medium power gyrotrons (Gyrotron FU series) as submillimeter wave radiation sources. IEEE Trans. Plasma Sci., 1999, 27(2), 340-354.
[http://dx.doi.org/10.1109/27.772260]
[26]
Zavolsky, N.A.; Zapevalov, V.E.; Zuev, A.S.; Plankin, O.P.; Sedov, A.S.; Semenov, E.S. Analysis of the methods of discrete and smooth frequency tuning in gyrotrons for spectroscopy, on the example of a generator operated in the 0.20–0.27 THz frequency range. Radiophys. Quantum Electron., 2018, 61(6), 436-444.
[http://dx.doi.org/10.1007/s11141-018-9905-4]
[27]
Ananichev, A.A.; Sedov, A.S.; Tsvetkov, A.I.; Chekmarev, N.V. The use of simultaneous tuning of several control parameters to stabilize the radiation power of a subterahertz gyrotron when tuning the generation frequency. Instrum. Exp. Tech., 2022, 65(2), 262-266.
[http://dx.doi.org/10.1134/S0020441222020099]
[28]
Fokin, A.P.; Tsvetkov, A.I.; Manuilov, V.N.; Sedov, A.S.; Bozhkov, V.G.; Genneberg, V.A.; Movshevich, B.Z.; Glyavin, M.Y. Control of sub-terahertz gyrotron frequency by modulation-anode voltage: Comparison of theoretical and experimental results. Rev. Sci. Instrum., 2019, 90(12), 124705.
[http://dx.doi.org/10.1063/1.5132831] [PMID: 31893824]
[29]
Fokin, A.; Glyavin, M.; Golubiatnikov, G.; Lubyako, L.; Morozkin, M.; Movschevich, B.; Tsvetkov, A.; Denisov, G. High-power sub-terahertz source with a record frequency stability at up to 1 Hz. Sci. Rep., 2018, 8(1), 4317.
[http://dx.doi.org/10.1038/s41598-018-22772-1] [PMID: 29531359]
[30]
Golubyatnikov, G.Y.; Koshelev, M.A.; Tsvetkov, A.I.; Fokin, A.P.; Ananichev, A.A.; Glyavin, M.Y.; Tret’yakov, M.Y. Application of gyrotrons for molecular gas spectroscopy. Radiophys. Quantum Electron., 2022, 65(3), 157-169.
[http://dx.doi.org/10.1007/s11141-023-10202-w]
[31]
La, A.; Idehara, T.; Mori, H.; Saito, T.; Ogawa, I.; Mitsudo, S. Detailed design of a CW 1 THz gyrotron (gyrotron FU CW III) using a 20 T superconducting magnet. Int. J. Infrared Millim. Waves, 2007, 28(5), 315-328.
[http://dx.doi.org/10.1007/s10762-007-9215-y]
[32]
Idehara, T.; Tsuchiya, H.; Watanabe, O. Agusu La, Mitsudo S. The first experiment of a THz gyrotron with pulse magnet. Int. J. Infrared Millim. Waves, 2006, 27(3), 319-331.
[http://dx.doi.org/10.1007/s10762-006-9084-9]
[33]
Zapevalov, V.E.; Zuev, A.S.; Parshin, V.V.; Semenov, E.S.; Serov, E.A. Reduction of ohmic losses in the cavities of low-power terahertz gyrotrons. Radiophys. Quantum Electron., 2021, 64(4), 240-250.
[http://dx.doi.org/10.52452/00213462_2021_64_04_265]
[34]
Venediktov, N.P.; Dubrov, V.V.; Zapevalov, V.E.; Kornishin, S.Y.; Kotov, A.V.; Kuftin, A.N.; Malygin, O.V.; Sedov, A.S.; Fiks, A.S.; Tsalolikhin, V.I. Experimental study of a continuous-wave high-stability second-harmonic gyrotron for spectroscopy of dynamically polarized nuclei. Radiophys. Quantum Electron., 2010, 53(4), 237-243.
[http://dx.doi.org/10.1007/s11141-010-9222-z]
[35]
Glyavin, M.Y.; Chirkov, A.V.; Denisov, G.G.; Fokin, A.P.; Kholoptsev, V.V.; Kuftin, A.N.; Luchinin, A.G.; Golubyatnikov, G.Y.; Malygin, V.I.; Morozkin, M.V.; Manuilov, V.N.; Proyavin, M.D.; Sedov, A.S.; Sokolov, E.V.; Tai, E.M.; Tsvetkov, A.I.; Zapevalov, V.E. Experimental tests of a 263 GHz gyrotron for spectroscopic applications and diagnostics of various media. Rev. Sci. Instrum., 2015, 86(5), 054705.
[http://dx.doi.org/10.1063/1.4921322] [PMID: 26026544]
[36]
Glyavin, M.Y.; Kuftin, A.N.; Morozkin, M.V.; Proyavin, M.D.; Fokin, A.P.; Chirkov, A.V.; Manuilov, V.N.; Sedov, A.S.; Soluyanova, E.A.; Sobolev, D.I.; Tai, E.M.; Tsvetkov, A.I.; Luchinin, A.G.; Kornishin, S.Y.; Denisov, G.G. A 250-watts, 0.5-thz continuous-wave second-harmonic gyrotron. IEEE Electron Device Lett., 2021, 42(11), 1666-1669.
[http://dx.doi.org/10.1109/LED.2021.3113022]
[37]
Vlasov, S.N.; Zavolsky, N.A.; Zapevalov, V.E.; Koposova, E.V.; Moiseev, M.A. Axisymmetric multistage cavity resonators. Radiophys. Quantum Electron., 2009, 52(9), 642-654.
[http://dx.doi.org/10.1007/s11141-010-9173-4]
[38]
Melnikova, M.M.; Rozhnev, A.G.; Ryskin, N.M.; Tatematsu, Y.; Fukunari, M.; Yamaguchi, Y.; Saito, T. Electromagnetic modeling of a complex-cavity resonator for the 0.4-THz second-harmonic frequency-tunable gyrotron. IEEE Trans. Electron Dev., 2017, 64(12), 5141-5146.
[http://dx.doi.org/10.1109/TED.2017.2764874]
[39]
Vlasov, S.N.; Koposova, E.V.; Pavel’ev, A.B.; Khizhnyak, V.I. Gyrotrons with echelette resonators. Radiophys. Quantum Electron., 1996, 39(6), 458-462.
[http://dx.doi.org/10.1007/BF02122392]
[40]
Belousov, V.I.; Vlasov, S.N.; Zavolsky, N.A.; Zapevalov, V.E.; Koposova, E.V.; Kornishin, S.Y.; Kuftin, A.N.; Moiseev, M.A.; Khizhnyak, V.I. Studies of a gyrotron with the echelette cavity. Radiophys. Quantum Electron., 2014, 57(6), 446-454.
[http://dx.doi.org/10.1007/s11141-014-9527-4]
[41]
Dumbrajs, O.; Nusinovich, G.S. Coaxial gyrotrons: Past, present, and future. IEEE Trans. Plasma Sci., 2004, 32(3), 934-946.
[http://dx.doi.org/10.1109/TPS.2004.829976]
[42]
Shcherbinin, V.I.; Moskvitina, Y.K.; Avramidis, K.A.; Jelonnek, J. Improved mode selection in coaxial cavities for subterahertz second-harmonic gyrotron. IEEE Trans. Electron Dev., 2020, 67(7), 2933-2939.
[http://dx.doi.org/10.1109/TED.2020.2996179]
[43]
Bandurkin, I.V.; Kalynov, Y.K.; Makhalov, P.B.; Osharin, I.V.; Savilov, A.V.; Zheleznov, I.V. Simulations of sectioned cavity for high-harmonic gyrotron. IEEE Trans. Electron Dev., 2017, 64(1), 300-305.
[http://dx.doi.org/10.1109/TED.2016.2629029]
[44]
Bandurkin, I.V.; Fokin, A.P.; Glyavin, M.Y.; Luchinin, A.G.; Osharin, I.V.; Savilov, A.V. Demonstration of a selective oversized cavity in a terahertz second-harmonic gyrotron. IEEE Electron Device Lett., 2020, 41(9), 1412-1415.
[http://dx.doi.org/10.1109/LED.2020.3010445]
[45]
Sprangle, P.; Vomvoridis, J.L.; Manheimer, W.M. A classical electron cyclotron quasioptical maser. Appl. Phys. Lett., 1981, 38(5), 310-313.
[http://dx.doi.org/10.1063/1.92369]
[46]
Fliflet, A.W.; Hargreaves, T.A.; Fischer, R.P.; Manheimer, W.M.; Sprangle, P. Review of quasi-optical gyrotron development. J. Fusion Energy, 1990, 9(1), 31-58.
[http://dx.doi.org/10.1007/BF01057321]
[47]
Nusinovich, G.S. To the theory of gyrotrons with confocal resonators. Phys. Plasmas, 2019, 26(5), 053107.
[http://dx.doi.org/10.1063/1.5099909]
[48]
Bandurkin, I.V.; Kalynova, G.I.; Kalynov, Y.K.; Osharin, I.V.; Savilov, A.V.; Shchegolkov, D.Y. Mode selective azimuthally asymmetric cavity for terahertz gyrotrons. IEEE Trans. Electron Dev., 2021, 68(1), 347-352.
[http://dx.doi.org/10.1109/TED.2020.3039209]
[49]
Samsonov, S.V.; Denisov, G.G.; Bogdashov, A.A.; Gachev, I.G. Cyclotron resonance maser with zigzag quasi-optical transmission line: Concept and modeling. IEEE Trans. Electron Dev., 2021, 68(11), 5846-5850.
[http://dx.doi.org/10.1109/TED.2021.3114141]
[50]
Jory, H.R.; Trivelpiece, A.W. Charged‐particle motion in large‐amplitude electromagnetic fields. J. Appl. Phys., 1968, 39(7), 3053-3060.
[http://dx.doi.org/10.1063/1.1656732]
[51]
Harriet, S.B.; McDermott, D.B.; Gallagher, D.A.; Luhmann, N.C. Cusp gun TE/sub 21/second-harmonic ka-band gyro-twt amplifier. IEEE Trans. Plasma Sci., 2002, 30(3), 909-914.
[http://dx.doi.org/10.1109/TPS.2002.802151]
[52]
Idehara, T.; Ogawa, I.; Mitsudo, S.; Iwata, Y.; Watanabe, S.; Itakura, Y.; Ohashi, K.; Kobayashi, H.; Yokoyama, T.; Zapevalov, V.; Glyavin, M.; Kuftin, A.; Malygin, O.; Sabchevski, S. Development of a high harmonic gyrotron with an axis-encircling electron beam and a permanent magnet. Vacuum, 2005, 77(4), 539-546.
[http://dx.doi.org/10.1016/j.vacuum.2004.09.022]
[53]
Bratman, V.L.; Idehara, T.; Kalynov, Y.K.; Manuilov, V.N.; Samsonov, S.V.; Zavolsky, N.A. Design of a powerful and compact THz oscillator. Int. J. Infrared Millim. Waves, 2006, 27(8), 1063-1071.
[http://dx.doi.org/10.1007/s10762-006-9094-7]
[54]
Bratman, V.L.; Kalynov, Y.K.; Manuilov, V.N. Large-orbit subterahertz and terahertz gyrotrons. Radiophys. Quantum Electron., 2009, 52(7), 472-481.
[http://dx.doi.org/10.1007/s11141-009-9157-4]
[55]
Bratman, V.L.; Kalynov, Y.K.; Manuilov, V.N. Large-orbit gyrotron operation in the terahertz frequency range. Phys. Rev. Lett., 2009, 102(24), 245101.
[http://dx.doi.org/10.1103/PhysRevLett.102.245101] [PMID: 19659020]
[56]
Kalynov, Yu.K.; Manuilov, V.N.; Fiks, A.Sh.; Zavolskiy, N.A. Powerful continuous-wave sub-terahertz electron maser operating at the 3rd cyclotron harmonic. Appl. Phys. Lett., 2019, 114(21), 213502.
[http://dx.doi.org/10.1063/1.5094875]
[57]
Zapevalov, V.E.; Tsimring, S.E. Multibeam gyrotrons. Radiophys. Quantum Electron., 1990, 33(11), 954-960.
[http://dx.doi.org/10.1007/BF01039240]
[58]
Zapevalov, V.E.; Manuilov, V.N.; Malygin, O.V.; Tsimring, S.E. High-power twin-beam gyrotrons operating at the second gyrofrequency harmonic. Radiophys. Quantum Electron., 1994, 37(3), 237-240.
[http://dx.doi.org/10.1007/BF01054034]
[59]
Idehara, T.; Glyavin, M.; Kuleshov, A.; Sabchevski, S.; Manuilov, V.; Zaslavsky, V.; Zotova, I.; Sedov, A. A novel THz-band double-beam gyrotron for high-field DNP-NMR spectroscopy. Rev. Sci. Instrum., 2017, 88(9), 094708.
[http://dx.doi.org/10.1063/1.4997994] [PMID: 28964246]
[60]
Jerby, E.; Kesar, A.; Korol, M.; Lei, L.; Dikhtyar, V. Cyclotron-resonance-maser arrays. IEEE Trans. Plasma Sci., 1999, 27(2), 445-455.
[http://dx.doi.org/10.1109/27.772272]
[61]
Zapevalov, V.E.; Zuev, A.S.; Plankin, O.P.; Semenov, E.S. New gyrotron concept: Multi-barrel gyrotron. Photonics & Electromagnetics Research Symposium (PIERS), 2021.
[62]
Zapevalov, V.E.; Zuev, A.S.; Kuftin, A.N. Multibarrel gyrotrons. Radiophys. Quantum Electron., 2020, 63(2), 97-105.
[http://dx.doi.org/10.1007/s11141-020-10038-8]
[63]
Zapevalov, V.E.; Zuev, A.S.; Plankin, O.P.; Semenov, E.S. Multi-barrel gyrotron for DNP/NMR spectroscopy. Radiophys. Quantum Electron., 2023, 66(1), 1-18.
[http://dx.doi.org/10.52452/00213462_2023_66_01_1]
[64]
Samsonov, S.V.; Leshcheva, K.A.; Manuilov, V.N. Multitube helical-waveguide gyrotron traveling-wave amplifier: Device concept and electron-optical system modeling. IEEE Trans. Electron Dev., 2020, 67(8), 3385-3390.
[http://dx.doi.org/10.1109/TED.2020.3001491]
[65]
Gelvich, E.A.; Borisov, L.M.; Zhary, Y.V.; Zakurdayev, A.D.; Pobedonostsev, A.S.; Poognin, V.I. The new generation of high-power multiple-beam klystrons. IEEE Trans. Microw. Theory Tech., 1993, 41(1), 15-19.
[http://dx.doi.org/10.1109/22.210224]
[66]
Palmer, R.B.; Fernow, R.C.; Fischer, J.; Gallardo, J.C.; Kirk, H.G.; Ulc, S.; Wang, H.; Zhao, Y.; Eppley, K.; Herrmannsfeldt, W.; Miller, R.; Yu, D. The cluster klystron demonstration experiment. Nucl. Instrum. Methods Phys. Res. A, 1995, 366(1), 1-16. https://api.semanticscholar.org/CorpusID:120503579
[http://dx.doi.org/10.1016/0168-9002(95)00609-5]
[67]
Korolyov, A.N.; Gelvich, E.A.; Zhary, Y.V.; Zakurdayev, A.D.; Poognin, V.I. Multiple-beam klystron amplifiers: Performance parameters and development trends. IEEE Trans. Plasma Sci., 2004, 32(3), 1109-1118.
[http://dx.doi.org/10.1109/TPS.2004.828807]
[68]
Conway, G.D. Report on the eighth international reflectometry workshop (IRW8) (St Petersburg, Russia, 2–4 May 2007). Nucl. Fusion, 2007, 47(12), 1710-1714.
[http://dx.doi.org/10.1088/0029-5515/47/12/009]
[69]
Skvortsova, N.N.; Batanov, G.M.; Kolik, L.V.; Malakhov, D.V. Opportunities for plasma diagnostics in fusion devices by means of terahertz sources., 2009.
[70]
Sakamoto, K.; Tsuneoka, M.; Kasugai, A.; Imai, T.; Kariya, T.; Hayashi, K.; Mitsunaka, Y. Major Improvement of Gyrotron Efficiency with Beam Energy Recovery. Phys. Rev. Lett., 1994, 73(26), 3532-3535.
[http://dx.doi.org/10.1103/PhysRevLett.73.3532]
[71]
Manuilov, V.N.; Morozkin, M.V.; Luksha, O.I.; Glyavin, M.Yu. Gyrotron collector systems: Types and capabilities. Infrared Physics & Technology, 2018, 91, 46-54.
[http://dx.doi.org/10.1016/j.infrared.2018.03.024]
[72]
Sirigiri, J.R.; Maly, T. Integrated high-frequency generator system utilizing the magnetic field of the target application. US8786284B2, 2011.
[73]
Bratman, V.L.; Fedotov, A.E.; Kalynov, Y.K.; Makhalov, P.B.; Osharin, I.V. Numerical study of a low-voltage gyrotron (“gyrotrino”) for dnp/nmr spectroscopy. IEEE Trans. Plasma Sci., 2017, 45(4), 644-648.
[http://dx.doi.org/10.1109/TPS.2017.2673550]
[74]
Bratman, V.L.; Kalynov, Y.K.; Kulagin, O.P.; Leontyev, A.N.; Makhalov, P.B.; Manuilov, V.N.; Osharin, I.V.; Savilov, A.V.; Fedotov, A.E.; Fokin, A.P.; Chirkov, A.V. A compact thz source for enhancing the sensitivity of nuclear magnetic resonance spectroscopy with dynamic nuclear polarization. Bull. Russ. Acad. Sci., Physics, 2018, 82(12), 1592-1595.
[http://dx.doi.org/10.3103/S1062873818120274]
[75]
Zavolsky, N.A.; Zapevalov, V.E.; Moiseev, M.A.; Sedov, A.S. Study of subterahertz gyrotrons for dnp spectroscopy at the institute of applied physics ras. News from universities. Applied nonlinear dynamics., 2012, 20(3), 70-80.
[http://dx.doi.org/10.18500/0869-6632-2012-20-3-70-80]