Measurement of vircator single-shot high power EM pulse Miloslav Steinbauer, Pavel Fiala, Petr Drexler Brno University of Technology Faculty of Electrotechnical Engineering and Communication Department of Theoretical and Experimental Electrical Engineering Kolejni 2906/4 612 00 Brno Czech Republic Abstract - In connection with the events of the last few years and with the increased number of terrorist activities, the problem of identification /=50m Versionl and measurement of electromagnetic weapons or Measuringdevice other systems impact occurred. Among these are Bi(t) r u1(t) also microwave sources, which can reach extensive t Backward u2(t), B2(t) peak power of up to Pmax = 250 MW. Solitary, in correction some cases several times repeated, impulses lasting Version 11 from tp E <1, 60> ns, cause the destruction of Converter Measuring device semiconductor junctions. The analysis of the U/f possible measuring methods, convenient for the B1(t) * u1(t) u2(t), B2(t) identification and measurement of the ultra-short Version III solitary electromagnetic (EM) pulses is presented Converter Measuring device in this paper; some of the methods were chosen AID converter D/A and used for practical measurement. Version IV METHODS 0 Measuring device- Bi(t) * A, (B) optic fibre X Method based on Faraday's induction law A2(B),Bit) One group of methods is based on the Faraday's Fig. 1. Principles of the methods based on Faraday's induction law application, where the impulse is induction law and magneto-optic effect located by sensor (coil with N, = 1÷-50 turns). Signal induced in the coil is led to the recording device, generally an oscilloscope. Due to safety requirements, Method based on Faraday's magneto-optic effect the distance between the sensor and the oscilloscope is / = 50 m. This parameter introduces a quality Version IV in Fig. 1. is based on Faraday's decrease of the recorded information in the way of the magneto-optic effect [4]. Connection between the signal amplitude reduction, change of the signal phase sensor and the measuring device is implemented in and the impulse prolongation. the optical wavelength. Elimination of this limitation is in Version I The possible active sensors are ofhthree basictypes. depicted in Fig. 1., made by backward correction The first type is garnet with high Verdet constant, the exploiting the Laplace transform. Impulses up to limit second is optic fibre, and the third is based on pulse length Tmax= 1 ns were measured by this magneto-optic properties of ferromagnetic method and magnetic flux b was evaluated [6]. mono/multi thin film. Next types of the Version IV Version II exploits the possibility of principal sensors are based on the magneto-optic Kerr's effects elimination of the influence of the transmitting line (MOKE), or surface MOKE (SMOKE) effect. By an between the sensor and the measuring device by an available measuring devices application we can analogue U/f. converter. Available measuring devices measure impulses with the limit length Tmax =0.1 ns. can achieve measured impulses with the limit length The named methods indicate electromagnetic parts Tmax = 5ns. of the wave - electric or magnetic. They don't express The solution in Version III is similar to Version II the power conditions of the electromagnetic wave. the difference is in the digital converter applied. By For some of the measurement it is essential to an available measuring devices application and evaluate power flow through the defined area. fulfilled sampling theorem we can measure impulses with the limit length Tmax= 20 ns.