Ramped Electron Bunch Experiment

X-Band RF System

To produce the low-level RF for the Gun and Linac at the Neptune laboratory, the 38.08 MHz RF signal from the cathode drive laser oscillator is frequency multiplied by 75 times to produce a 2.856 GHz RF signal, which is then pulsed and amplified by an S-Band klystron. To produce the desired X-Band frequency for powering the Transverse Deflecting Mode Cavity, the same 38.08 MHz base signal used to produce RF for the Accelerator will be split off and frequency multiplied by a PLDRO (Phase Locked Dielectric Resonating Oscillator) to a frequency of 9.59616 GHz. This setup ensures that the RF which feeds both the Gun, Linac, and Deflecting Cavity are in phase with each other as well as in phase with the trigger for the cathode laser. A manual phase shifter will be used to adjust the phase of the RF in the deflecting cavity. A schematic is shown below.

(Click image to enlarge.)

The RF signal shown as going to the "Deflector" in the schematic above, will actually undergo a series of attenuations and amplifications before reaching the X-Band klystron where it will be amplified to 50kW of peak power contained in a 1 microsecond pulse. More detailed schematics of the X-Band RF system can be viewed by clicking the links below.

Full Block Diagram of the Proposed X-Band RF System (Download PDF)

Block Diagram of the Minimal System for RF Testing of the Klystron (Download PDF)