Olgerts DUMBRAJS

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Olgerts DUMBRAJS
Ph.D. in Physics
Full member (academician) of  Latvian Academy of Sciences
Institute of Solid State Physics,
University of Latvia,
8 Kengaraga Str., LV-1063 RIGA, Latvia

Phone: 371-7187-480 (office), 371-26359386 (mobile)
Fax: +371-713-2778, +371-2-225039
E-mail: olgerts.dumbrajs@lu.lv

Born: February 16, 1942, Riga, Latvia

Main Research interests:

Education

Academic and Professional Experience

Honours and Awards

Scientific Visits

International expertise

Fellowships

Patents

  1. O. Dumbrajs and A. Möbius. "Verfahren zur Erhöhung und/oder Sicherstellung des Wirkungsgrades eines Gyrotrons und Gyrotron zur Durchführung des Verfahrens."
    Patentanmeldung 4236149.4, Anmeldetag: 27.10.92. Deutsches Patentamt, München, 27. Oktober 1995.
  2. O. Dumbrajs, A. Möbius, and M. Mühleisen . “Ein in der Frequenz einstellbares Gyrotron.”
    Patentanmeldung 19532785, Anmeldetag: 06.09.95. Deutsches Patentamt, München, 17. April 1997.
  3. Dumbrajs. “Innenleiter eines koaxialen Gyrotrons mit um den Umfang gleichverteilten axialen Korrugationen.”
    Patentanmeldung 10040320.4, Anmeldetag: 17.08.2000. Deutsches Patentamt, München, 28. Mai 2001.

Teaching Experience

PUBLICATIONS

Books:

O. Dumbrajs "Review of the mode competition in gyrotrons developed in Russia."
Chapter in "Gyrotron Oscillators: Their Principles and Practice.”
Editor C.J. Edgcombe, 1993, Taylor&Francis.

Review articles:

Papers: more than 190 refereed papers and more than 110 reports in proceedings of international scientific conferences.

Main (recent) papers

  1. O. Dumbrajs, V. Igochine, D. Constantinescu, H. Zohm, and ASDEX Upgrade team. „Stochastization as a possible cause of fast reconnection in the frequently interrupted regime of neoclassical tearing modes.“ Phys. Plasmas 12, 110704 (2005).
  2. V. Igochine, O. Dumbrajs, D. Constantinescu, H. Zohm, G. Zvejnieks. “Stochastization as a possible cause for fast reconnection during MHD mode activity in the ASDEX Upgrade tokamak.” Nuclear Fusion 46, 741 (2006).
  3. O. Dumbrajs, V. Igochine, and H. Zohm. "Diffusion in a stochastic magnetic field in ASDEX Upgrade." Nucl. Fusion 48, 024011 (2008).
  4. D. Constantinescu, O. Dumbrajs, V. Igochine, and B. Weyssow. "On the accuracy of some mapping techniques used to study the magnetic field dynamics in tokamaks." Nucl. Fusion 48, 024017 (2008).
  5. O. Dumbrajs and T. Idehara. "Hysteresis in mode competition in high power 170 GHz gyrotron for ITER." Int. J. Infrared Millimeter Waves 29, 232 (2008).
  6. O. Dumbrajs, Y. Kominis and G.S. Nusinovich.“Electron dynamics in the process of mode switching in gyrotrons.” Physics of Plasmas 16, 013102 (2009).
  7. O. Dumbrajs, V. Igochine, A. Gude, M. Maraschek, and H. Zohm. “Temporal evolution of neoclassical tearing modes in the frequently interrupted regime.” Physics of Plasmas 17, 053104 (2010).
  8. O. Dumbrajs and G.S. Nusinovich. „To the theory of high-power gyrotrons with uptapered resonators.” Phys. Plasmas 17, 053104 (2010).
  9. O. Dumbrajs.„Influence of possible reflections on the operation of European ITER gyrotrons”J. Infrared Milli.Terahz. Waves 31, 892 (2010).
  10. O. Dumbrajs, T. Idehara, and S.Sabchevski.“Design of an optimized resonant cavity for a compact sub-Terahertz gyrotron” J.Infrared Milli. Terahz. Waves 31, 1115 (2010.
  11. O. Dumbrajs, and T. Idehara.“Frequency tunable gyrotron FU CW VA for measuring hyperfine split of positronium” J.Infrared Milli. Terahz. Waves 31,1265 (2010).
  12. V. Igochine, J. Boom, I. Classen, O.Dumbrajs, K. Lackner, G. Pereverzev, H.Zohm and ASDEX-U team.“Structure and dynamics of sawteeth crashes in ASDEX Upgrade” Phys. Plasmas 17, 122506 (2010).
  13. D. Constantinescu, O. Dumbrajs, V. Igochine, K. Lackner, R. Meyer-Spasche and H. Zohm.“ A low-dimensional model system for quasi-periodic plasma perturbations”Phys. Plasmas 18, 062307 (2011).
  14. Erzhong Li, Liqun Hu, V. Igochine, O. Dumbrajs, and Kaiyun Chen.“Understanding complex magnetohydrodynamic activities associated with a relaxation in HT-7 tokamak”Plasma Phys. Control.Fusion 53,085019 (2011).

 

Citations: more than 1900

Hirsh-index: 19

Journal IF2006 Number of papers
Acta Phys. Pol. B 0.882 3
Ann. Phys. 3.019 1
Czech. J. Phys. 0.568 1
Fortschr. der Physik 2.007 3
Fusion Engin. Design 0.598 1
IEEE Tr. Electron Devices 2.052 1
IEEE Tr. Plasma Science 1.144 23
Int. J. Electronics 0.459 14
Int. J. Infrared Mill. Waves 0.755 12
J. Appl. Phys. 2.316 1
J. Comm. Tech. Electronics 0.102 2
J. Exp. Theor. Phys. 0.937 4
J. Part. Nucl. 0.393 1
J. Phys. B 2.024 2
J. Phys. G 1.781 5
Nuovo Cimento B 0.351 6
Nuclear Fusion 3.278 8
Nuclear Physics A 2.155 5
Nuclear Physics B 5.199 15
Phys. Lett. B 5.043 4
Phys. Plasmas 2.258 17
Physics Reports 10.438 1
Phys. Rev. A 3.047 2
Phys. Rev. C 3.327 5
Phys. Rev. D 4.896 1
Phys. Rev. E 2.438 1
Phys. Scripta 1.161 1
Plasma Phys. Control. Fusion 2.820 4
Rev. Scien. Instr. 1.541 2
Teor. Mat. Fiz. 0.626 2
Z. Naturforschung A 0.904 9


Last update 8.06.2012