Development of the Pulse Transformer for Nlc Klystron Pulse Modulator

We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and a pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests are also presented. Presented at the IEEE Particle Accelerator Conference (PAC 97) Vancouver, B.C., Canada May 12-16, 1997 * Work supported by Department of Energy contract DE–AC03–76SF00515. † Visiting from KEK, permanent address: 1-1 Oho, Tsukuba-shi, Ibaraki-ken 305 Japan. DEVELOPMENT OF THE PULSE TRANSFORMER FOR NLC KLYSTRON PULSE MODULATOR M. Akemoto, S. Gold, A. Krasnykh and R. Koontz Stanford Linear Accelerator Center, Stanford University, Stanford, CA 94309, USA *Work supported by the Department of Energy contract DE-AC03-76SF00515. † Visiting from KEK, permanent address: 1-1 Oho, Tsukuba-shi, Ibaraki-ken 305 Japan. Abstract We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and a pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests are also presented.