FEL CENTER USER DIAGNOSTICS AND CONTROL

In the past year, the Stanford Picosecond FEL Center has produced more than two thousand hours of beam time dedicated to user experiments. To assure reliable beam delivery and to maximize productivity of our users we have developed a sophisticated system of diagnostics and control. An integrated display is now available in all experimental areas which provides continuously updated measurements of beam spectrum, micropulse duration, power, position, and pointing all of which may be saved to document beam conditions during an experiment. The beam is actively wavelength and amplitude stabilized to better than 0.01% and 2%, respectively. Direct wavelength control is available to users in every experimental area, allowing changes of wavelength as large as a few percent. Larger wavelength shifts, and adjustments in macropulse or micropulse width or timing, are readily available with operator assistance.