We are proud to announce that our MSc student Ivan Traparić defended his MSc Thesis entitled “VUV spektroskopija Lymanove serije jonizovanog atoma helijuma” (“VUV Spectroscopy of the Lyman Series of the Singly Charged Helium Atom”) on 29th September 2020 at the Faculty of Physics, University of Belgrade. Thesis advisor was dr Milivoje Ivković, while the Defense Committee members were dr Milivoje Ivković, prof. dr Bratislav Obradović and prof. dr Milorad Kuraica.
Ivke, Biljana and our MSc student Ivan Traparić participated in this year’s jubilee 30th Symposium of Physics of Ionized Gases (SPIG 2020). Because of the bad situation in Serbia due to Coronavirus pandemic, SPIG 2020 was organized completely in online format. The honor to give the introductory talk had Acad. Prof. dr Zoran Petrović. Ivke was member of the Scientific Committee for the forth consecutive time. Also, Ivke chaired the Thursday’s mourning Plenary Session.
At the poster presentation part of the conference, Biljana presented the poster entitled “Appearance of Be II 436.1 nm line with forbidden component in LIBS plasma”, while Ivan presented the poster entitled “VUV Spectroscopy of the He II – Lyman Series for electron density estimation”.
We are also proud to announce that we invited five lecturers. First, Tony Donne, the Programme Manager of EUROfusion and head of the Fusion Physics Division at the Dutch Institute for Fundamental Energy Research (DIFFER) gave the plenary talk “Challenges and Progress on the Path Towards Fusion Electricity”. Second, Sibylle Günter, Scientific Director of IPP (Max Planck Institute for Plasma Physics) gave the plenary lecture “The Two Conceps of Magnetic Confinement: Tokamak and Stellerator”. Third invited lecturer was Dimitri Batani from University of Bordeaux, who was invited to held the lecture at 1st BegFust (Belgrade Fusion Science and Technology Workshop), which was unfortunately postponed. Nevertheless, prof. Batani held the plenary lecture entitled “Current Status of the Laser Fusion Research and the Shock Ignition Approach”. Fourth invited lecturer was Sebastian Brezinsek from Forschungszentrum Jülich, Institute of Energy and Climate Research, who gave the topical invited lecture “Plasma-Wall interactions in Wendelstein 7-X Operating with Graphite Divertor”. Fifth invited lecturer was Daiji Kato from NIFS (National Institute for Fusion Science) Japan, who gave the topical invited lecture entitled “Compact Electron Beam Ion Trap for Spectroscopy of Multiple Charged Ions“.
We are proud to announce that Biljana defended her PhD Thesis entitled “Istraživanja kompleksnih oblika spektralnih linija berilijuma u prisustvu berilijumske prašine” (“Investigation of Complex Shapes of Beryllium Spectral Lines in the Presence of Beryllium Dust”) on 3rd August 2020 at the Faculty of Natural Sciences, University of Novi Sad. Thesis advisors were dr Milivoje Ivković and dr Igor Savić, the PhD Defense Committee president was dr Stevica Đurović while the Committee members were dr Lazar Gavanski and dr Bratislav Obradović.
Because of the current situation due to Coronavirus pandemic in Serbia, none of the laboratory members were allowed to be present at the public part of PhD defense.
Milica visit to ENEA has payed off. The article “Quantification of heavy metals in oils with µL volume by laser induced breakdown spectroscopy and minimazing of the matrix effect” has been published in Spectrochimica Acta Part B: Atomic Spectroscopy.
From 27th October to 4th November 2019 Ivke visited NIFS (National Institute for Fusion Science) in Toki, Japan, as a member of University of Belgrade delegation headed by rector Ivanka Popović, who signed an Agreement of collaboration between NIFS and University of Belgrade.
Ivke, Bratislav Obradović (Faculty of Physics), Milan Rajković (Institute of Nuclear Sciences Vinca) and Milica Ilić (Faculty of Mechanical Engineering) had a fruitful discussions with Japanese colleagues and made plans for future common projects.
On 23rd October 2019, our Laboratory member Marko Cvejić held an open lecture at the Institute of Physics Belgrade. The lecture was “Challenges in the investigation of compression of magnetized plasma“, where he presented his results obtained at the Weizmann Institute of Science.
The seminar will refer to a compression of magnetic flux that is initially embedded in a plasma that undergoes an implosion. The plasma is produced in a Z-pinch configuration in which a gas puff load is ionized and implodes under the J×B forces resulting from a 1-μs long, 300 kA, current pulse.
The subject of compression of magnetic flux and magnetized plasma is a fundamental problem manifested in a variety of conducting fluid phenomena in laboratory plasmas and astrophysics. Recently, this subject has gained particular interest due to the advances in producing plasmas of high temperature and density for fusion purposes, based on the approach of magnetized plasma compression.
We report the first-time development and employment of spectroscopic methods, based on the Zeeman effect and polarization techniques, to measure both the compressed (axial) and the compressing (azimuthal) magnetic fields throughout the implosion and stagnation processes.
Time and space resolved spectroscopic measurements showed that the application of a relatively weak axial magnetic field (Bz0) has a dramatic effect on the implosion dynamics affecting significantly the current distribution in the plasma . It was found that in the presence of Bz a large part of the current does not flow in the imploding plasma, rather it flows through a slow-imploding low-density plasma (LDP) residing at large radii. Furthermore, it is observed that the fraction of total current that flows in the LDP increases with Bz0.
We suggest an explanation of the phenomena, based on the development of a force-free current configuration. Previously unpredicted observations in high-power magnetized-plasma experiments, including recent unexplained structures observed in the Magnetized Liner Inertial Fusion experiment, may be connected to the present discovery.
 Mikitchuk, D., Cvejić, M., Doron, R., Kroupp, E., Stollberg, C.,
Maron, Y., Velikovich, A. L., Ouart, N. D., Giuliani, J. L., Mehlhorn,
T. A., Yu, E. P., and Fruchtman, A. “Effects of a preembedded axial
magnetic field on the current distribution in a Z-pinch implosion”,
Phys. Rev. Lett. 122, 045001 (2019).
On 9th September 2019 Ivke and Miloš held a seminar in the Library “Dr. Dragan Popović” at the Institute of Physics in Belgrade. Ivke had spoken about the topic “Lasers, Laser Produced Plasmas and Optical Emission Spectroscopy”. Shortly after Ivke, Miloš gave the lecture “VUV Spectroscopy of Fusion Plasmas”.
- ELI attosecond in Szeged (HU);
- High voltage laboratory in Brno (CZ), where they work with 120 kA currents and 2 MV voltages;
- Helmholtz‐Zentrum Dresden‐Rossendorf in Dresden (D) seeing Ion Beam Facility and Radiation Source ELBE;
- ELI beams and Institute of Plasma Physics in Prague (CZ), latter one showed him COMPASS tokamak and PALS ion laser.
Miloš‘ previous work during the PhD research has payed off. The article on “Runaway electron beam stability and decay in COMPASS” has been published in Nuclear Fusion journal.