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Polarized electrons from GaAs photocathodes have been key to some of the highest-impact results of the Jefferson Lab science program over the past 30 years. During this time, various studies have given insight into improving the operational lifetime of these photocathodes in DC high-voltage photo-guns while using lasers with spatial Gaussian profiles of typically 0.5 mm to 1 mm FWHM, cathode voltages of 100 kV to 130 kV, and a wide range of beam currents up to multiple mA. In this contribution, we show recent experimental data from a 100 kV to 180 kV setup and describe our progress at predicting the lifetime based on the calculable dynamics of ionized gas molecules inside the gun. These new experimental studies at Jefferson Lab are specifically aimed at exploring the ion damage of higher-voltage guns being built for injectors., Proceedings of the 5th North American Particle Accelerator Conference, NAPAC2022, Albuquerque, NM, USA

Nuclear physics experiments performed in the Contin-uous Electron Beam Accelerator Facility (CEBAF) at Jefferson Laboratory (JLab) require spin manipulation of electron beams. Two Wien spin rotators in the injector keV region are essential at CEBAF to establish longitudinal polarization at the end station target, and to flip the polarization direction by π rad to rule out false asymmetries. In a Wien filter, the homogeneous and independent electric and magnetic fields, along with the velocity vectors of the electrons that traverse it, form a mutually orthogonal system. The magnitude of the electrostatic field, established by biasing two highly-polished elec-trodes, defines the desired spin angle at the target yet deviates the beam trajectory due to the Lorentz force. The beam trajectory in the Wien is then re-established by adjusting the magnetic field, induced by an electromag-net encasing the device vacuum chamber. This contribu-tion describes the evolution design and high voltage testing of Wien filters for spin manipulation at increased beam energies in the keV injector region, required by high precision parity violation experiments like MOLLER., Proceedings of the 5th North American Particle Accelerator Conference, NAPAC2022, Albuquerque, NM, USA

A 125kV DC gridded thermionic gun has been de-signed and constructed through a collaboration between Jefferson Lab and Xelera Research LLC. The gun has been recently installed at the Gun Test Stand diagnostic line at Jefferson Lab where transverse and longitudinal parameter space will be experimentally explored. The status and results characterizing the commissioning and trouble-shooting the thermionic gun are presented., Proceedings of the North American Particle Accelerator Conference, NAPAC2019, Lansing, MI, USA