Conference

Dark Currents

H. Matsumoto, M. Akemoto, H. Hayano, T. Naito, S. Takeda, S. Yamaguchi and M. Yoshioka

KEK, Tsukuba, Japan

T. Nakanishi, S. Okumi, C. Suzuki, M. Tawada and K. Togawa

Nagoya University, Nagoya, Japan

H. Akiyama

Hitachi Ltd., Hitachi Laboratory, Hitachi, Japan

K. Nishitani

ATC Co., Hachioji, Japan

Abstract

Further reducing the dark current and increasing the operating electrical field strengths for a dc-gun and rf-structures will be necessary to realize future linear collider accelerator machines. We conducted studies primarily targeted to clarify the casual relationships between internally generated field emission currents and breakdown of the electrical field in high-gradient structures. From these studies we conclude that the magnitude of the field emission currents depends on the cleanliness of the structures and the maximum electrical field strength is determined by the shape (or geometry) of the structures.

This paper describes the experimental results establishing the relationship between the dark current and breakdown at high electrical field strengths for dc-gun and rf-structures.

sln 14 March 1996