High-power test results of a 3 GHz single-cell cavity

TL;DR

This paper reports the high-power testing of a 3 GHz single-cell cavity, demonstrating its operational limits for potential use in compact, high-gradient accelerators for medical applications.

Contribution

It provides the first high-power test results of a 3 GHz single-cell cavity, informing design limits for high-gradient accelerator structures.

Findings

Maximum BDR threshold of 3 x 10^-6 bpp/m at 170 MV/m

RF pulse duration of 2.5 microseconds

Operational limit data for high-gradient structures at 3 GHz

Abstract

Compact, reliable and little consuming accelerators are required for the treatment of tumours with ions. TERA proposes the "cyclinac", composed of a high-frequency, fast-cycling linac which boosts the energy of the particles previously accelerated in a cyclotron. The dimensions of the linac can be reduced if high gradients are used. TERA initiated a high-gradient test program to understand the operational limit of such structures. The program foresees the design, prototyping and high-power test of several high-gradient structures operating at 3 and 5.7 GHz. The high-power tests of the 3 GHz single-cell cavity were completed in Winter 2012. The maximum BDR threshold measured for Emax of 170 MV/m and RF pulses of 2.5 \mu s was 3 x 10-6 bpp/m.