Klystrons capable of 75 MW output power at 11.4 GHz have been under development at SLAC for the last decade. The work has been part of the program to realize all the components necessary for the construction of the Next Linear Collider (NLC). The effort has produced a family of solenoid-focused 50 MW klystrons, which are currently powering a 0.5 GeV test accelerator at SLAC and several test sta...

The low-level RF system for PEP-II is a modular design housed in a VXI environment and supported by EPICS. All signal processing and control is done at baseband using in-phase and quadrature (IQ) techniques. Remotely configurable RF feedback loops are used to control coupled-bunch instabilities driven by the accelerating mode of the RF cavities. A programmable DSP based feedback loop is impleme...

The storage-ring FEL at DELTA has been successfully operated with different filling patterns and temporal structures following the installation of new mirror chambers three years ago. The modulation depth of the opticalklystron spectrum was used to measure the electron energy spread. The measured FEL output power at high beam currents strongly exceeded the predictions of the low-gain model. Thi...

A high-power low-loss mode transducer design has been proposed to adapt the output of the X-Band klystron, WR.90 rectangular waveguide, to the input of the pulse compression system, SLED II, which utilizes overmoded circular waveguides operating in the low-loss TEol mode. This device is much more compact than the conventional Marie’ type mode converters. The device splits the incoming klystron ...

A new klystron based X-band rf power source operating at 11.994 GHz has been installed and started to be commissioned at CERN in collaboration with CEA Saclay and SLAC for CLIC accelerating structure tests. The system comprises a solid state high voltage modulator, an XL5 klystron developed by SLAC, a cavity based SLED type pulse compressor, the necessary low level rf system including rf diagno...

The 6 GeV CEBAF accelerator at Jefferson Lab is arranged in a five-pass racetrack configuration, with two superconducting radio frequency (SRF) linacs joined by independent magnet transport arcs. It is planned to increase the accelerator energy to eventually support 12 GeV operations. To achieve this, a new 7-cell superconducting cavity is being built to operate at an average accelerating gradi...

I am going to t6.lk about RF power murcea for accelerator applications. My approach will be with particular c+omus in mind. That customers are high energy phy6icirtr who w accelerator6 66 experimental tool6 in the rtudy of the nucleus of the atom, and rpchrotron light sourea derived from electron or po6itron storage ring6. I will genually confine my6elf to electron-positron linear accelerator6 ...

The 125 kW CW klystrons to be described in the first part of this paper were specifically designed for energy upgrading of the electron-positron storage ring, SPEAR II, at SLAC. Four tubes are required with an efficiency greater than 50 percent. The operating frequency is 358.54 MHz. The gain is approximately 50 dB, the operating voltage is 41 kV and the microperveance is 0.7. The klystron must...

Electron beam halo formation is studied as a potential mechanism for electron beam losses in highpower periodic permanent magnet focusing klystron amplifiers. In particular, a two-dimensional selfconsistent electrostatic model is used to analyze equilibrium beam transport in a periodic magnetic focusing field in the absence of radio-frequency signal, and the behavior of a high-intensity electro...

The fluctuation of the beam current and energy had been investigated from ’98 to ’99. As a result, readjustment of klystron modulators and temperature stabilization were made so as for the RF system to obtain the phase and amplitude stability. Finally, the beam energy fluctuation of ±0.03% (1σ) was achieved and good reappearance of the injection current was obtained. A beam chicane and an accel...