Timing jitter measurements at the SLC electron source

The SLC (Stanford Linear Collider) thermionic gun and electron source provide a beam of up to 15×10¹⁰ e^- in a single S-band bunch. A 170-keV, 2-ns FWHM (full width at half maximum) pulse out of the gun is compressed by means of two subharmonic buncher cavities followed by an S-band buncher and a standard SLAC (Stanford Linear Accelerator Center) accelerating section. Ceramic gaps in the beam pipe at the output of the gun allow measurement of the beam intensity and timing. A measurement at these gaps of the timing jitter, with a resolution of <10 ps, is described. The timing jitter of the SLC beam at the electron source has a measured upper limit of σ⩽8.4 ps at the gun output. The timing stability falls well within the stability requirements for injection into the SLC emittance-damping ring