WEB4IO01
SLAC, Menlo Park, California, USA
Recent advances in rf structure design, material choices and power distribution technology promise to enable high gradient (100s MV/m), highly efficient compact accelerator implementations for a variety of applications.
UCLA, Los Angeles, California, USA
SLAC, Menlo Park, California, USA
Recent SLAC experiments with cryogenically cooled 11.4 GHz standing wave copper accelerating cavities have shown evidence of 250 MV/m accelerating gradients with low breakdown rates. The gradient depends on the circuit parameters of the accelerating cavity, such as the intrinsic and external quality factors (Q0, QE). In our studies we see evidence that Q0 decreases during rf pulse at 7-70 K. This paper discusses experiments that are directed towards understanding the change of Q0 at high power.
UCLA, Los Angeles, California, USA
SLAC, Menlo Park, California, USA
Operating accelerating gradient in normal conducting accelerating structures is often limited by rf breakdowns. The limit depends on multiple parameters, including input rf power, rf circuit, cavity shape, cavity temperature, and material. Experimental and theoretical study of the effects of these parameters on the breakdown physics is ongoing at SLAC. As of now, most of the data has been obtained at 11.4 GHz. We are extending this research to S-band. We have designed a single cell accelerating structure, based on the extensively tested X-band cavities. The setup uses matched TM01 mode launcher to feed rf power into the test cavity. Our ongoing study of the physics of rf breakdown in cryogenically X-band accelerating cavities shows improved breakdown performance. Therefore, this S-band experiment is designed to cool the cavity to cryogenic temperatures. We use operating frequencies near 2.856 GHz. We present the rf design and discuss the experimental setup.