A Rogowski coil has been used for the measurement of a pulsed discharge current. The frequency response of the coil is discussed, and a method which extends this response to higher frequencies (100 Mc/s) is described. It has been found that the noise signals associated with the measurement of a pulsed discharge current are due principally to the electromagnetic radiation from the spark gap switches which are required in such a circuit. The radiation depends upon the breakdown mechanism of the spark gap, and its effect upon the measuring circuit can be minimized by making use of damping, resistors in series with the triggering sparks, shielded cables in the measuring circuit, and careful grounding of the discharge circuit. The noise signal on the current wave form can be completely eliminated by altering the spark gap geometry of the open air spark gap switch. / Science, Faculty of / Physics and Astronomy, Department of / Graduate