Journal of Modern Physics, 2014, 5, 82-88 Published Online January 2014 (http://www.scirp.org/journal/jmp ) http://dx.doi.org/10.4236/jmp.2014.52013 Plasma Focus Studies in Serbia Vladimir Udovičić 1 , Nikola Veselinović 1 , Dušan Joksimović 2 , Radomir Banjanac 1 , Dimitrije Maletić 1 , Dejan Joković 1 , Dragan Lukić 1 1 Institute of Physics, University of Belgrade, Belgrade, Serbia 2 Faculty of Business Studies, Megatrend University, Belgrade, Serbia Email: udovicic@ipb.ac.rs Received October 18, 2013; revised November 16, 2013; accepted December 15, 2013 Copyright © 2014 Vladimir Udovičić et al. This is an open access article distributed under the Creative Commons Attribution Li- cense, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In accordance of the Creative Commons Attribution License all Copyrights © 2014 are reserved for SCIRP and the owner of the intel- lectual property Vladimir Udovičić et al. All Copyright © 2014 are guarded by law and by SCIRP as a guardian. ABSTRACT The plasma focus experiment in Belgrade, Serbia started in the late eighties of the last century. The historical overview of the research activity on the Belgrade plasma focus device (BPFD) will be presented in this work. The special attention has been made to the present status and the future plans for the fundamental and applied re- search as a part of the project of the studies of rare nuclear and particle processes in nature. BPFD is intended to operate as optimized neutron source or hard X-ray source. Using Lee model code as a reference, several up- grades of BPFD must be made: better shielding against EMI pulse, rearrangement of capacitors bank so that higher repetition rate can be achieved and also faster digital acquisition system. BPFD can be used for neutron activation or production of short-living radioisotopes. These radioisotopes will have very low activity which can be analyzed in the underground Low-Background Laboratory for Nuclear Physics, Zemun. Also, we compared the obtained experimental data (neutron yield, total current waveform, working gas pressure) with the numeri- cal simulation code (The Lee model code) to test our plasma focus machine. Comparison between neutron yield from our experimental data and neutron scaling laws and neutron yields derived from computation using the Lee Model code shows good matching, but for better verification of the code, more experimental data are needed. KEYWORDS Plasma Focus; The Lee Model Code 1. Introduction Controlled thermonuclear fusion is in the last sixty years, a major challenge for researchers. The main goal, also the main problem, is how to achieve conditions for plasma ignition and the related construction of economical and environmentally friendly reactor. Parameter which cha- racterizes the ignition condition is the product R = nτ E T i (plasma reactivity), where n is the plasma ion concentra- tions, confinement time τ E and T i ions in the plasma temperature, and the value must be greater than 3 × 10 21 m −3 ∙s keV. Over time they have developed various devices for magnetic plasma confinement based on two different approaches [1]. The first group devices are pulse-current electrical discharge accompanied by pinch-effects in dif- ferent geometries (linear z-pinch, toroidal pinch, the- ta-pinch, plasma focus). The second group of devices is based on the use of a variety of magnetic traps, where the magnetic fields needed to achieve plasma confinement with the external currents (device with a minimum-B, stelarator, tokamak). The topic of this paper is the devices that generate fusion plasma in a pulsed electric discharge, a dense plasma focus device. Plasma focus device was invented in the early 1960s by J.W. Mather [2], and independently, by N.V. Filippov [3]. It should be noted that the Filippov’s type plasma focus device differs from Mather’s type in absence of axial phase, so the plasma column is already formed imme- diately after the discharge. An important characteristic of the dense plasma focus is energy density of the focused plasma which is practically a constant over the whole range of machines, from sub-kilojoule machines to me- gajoule machines. Currently, perhaps the best guide to the future of plasma focus is given in [4]. In this paper, the open ques- OPEN ACCESS JMP