Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol.7, No.5, 2016 61 Design and Implementation of 8 - Stage Marx Generator Used for Gas Lasers Dr. Naseer Mahdi Hadi Ministry of Science & Technology, Laser & Electro-Optics Research Center, Baghdad, Iraq. Dr. Kadhim Abid Hubeatir University of Technology, Laser & Optoelectronics Department, Baghdad, Iraq Ghaidaa Hamza Khudair (M.Sc laser engineer) Ministry of Science & Technology, Laser & Electro-Optics Research Center, Baghdad, Iraq. Sarmad Fawzi Hamza University of Technology, Laser & Optoelectronics Department, Baghdad, Iraq. The research is financed by Ministry Of Science & Technology, Baghdad, Iraq. Abstract Marx generators have been designed, built and tested. A Marx generator with eight stages, which can be deliver 64 kV maximum output, is charged up to 2 kV and the high voltage output was 12 kV with pulse rise time of 666 ns, decay time 4 µs, inductance 11 µH and efficiency of 75%. Energy stored in Marx 75.2 mJ and erected capacitance 5.875*10 -10 F, the Charging current is 1 mA. A Xenon flash lamp trigger circuit with high voltage output pulse (4.5 kV) and pulse width of 2µs, was used for triggering the Marx generator. 1. Marx Generator Power Supply: 1.1 Marx Generator A Marx Generator is a clever way of charging a number of capacitors in parallel through resistance, then discharging them in series through spark caps. Originally it was described by Erwin Marx in 1924 [Young J. C.]. Marx generators offer a common way of generating high voltage impulses that are higher than the available supply charging voltage, as shown in figure (1). Fig. (1) Marx Generator (A) Charging (B) Discharging [Kuffel E. and Abdullah M.]. A typical circuit presented in figure (2) which shows the connections for a five-stage generator. The stage capacitors C charged in parallel through high-value charging resistors R. At the end of the charging period, the points A,B,…,E will be at the positive potential of the D.C sources, with respect to earth, and the points F,G,…,M will remain at the earth potential. The discharge of the generator initiated by the breakdown in the spark gap G1, which followed by simultaneous breakdown of all the remaining gaps. When the gap G1 breaks down, the potential on the point A changes from +V to zero and that on point G swings from zero to -V owing to the charge on the condenser C. If for the time being the stray capacitance C` is neglected, the potential on B remains +V during the interval of the gap G1 sparks over. A voltage 2V, therefore, appears across the gap G2 that immediately leads to its breakdown. This breakdown creates a potential difference of 3V across G3 the breakdown process, therefore, continues and finally the potential on M attains a value of -5V [Kuffel E. and Abdullah M.] . In effect, the low voltage plates of the stage capacitors are successively raised to -V, -2V…,-NV, if there are N stages. This arrangement gives an output with polarity opposite to that of the charging voltage.