UITF Operational Review UITF Laser and Gun High Voltage John Hansknecht UITF Operational Review March 18, 2016

UITF Laser System Functionally identical to CEBAF laser system, except we will only use one laser. Repetition rate 750Mhz or lower Wavelength 780nm Power set to minimum necessary to achieve current delivery goals

Laser will reside in Class 4 laser cleanroom adjacent to UITF control room. Light delivered to gun laser table via armored fiber

Gun laser table in cave Aluminum enclosure with interlocked cover

Integrated Laser safety Armored fiber light delivery Controlled access cleanroom and interlocked laser table in cave (Opening cover in cave will shutter laser in cleanroom) Class 3R safe laser source can be injected into fiber for alignment of optical components Class 1 laser enclosure means UITF cave will not need to be designated as a laser hazard area except during rare cases.

UITF Laser System plan Laser Table in room 1126B Cleanroom 1560nm to 780nm conversion Fiber 5W amp attenuator, tune mode generator Seed Laser Safety Shutter Pre-Amp 750MHz rf input Fiber Launch Laser Table in room 1126B Cleanroom Armored Fiber to test cave laser table Enclosure cover interlock Fiber Launch PSS Shutters Light delivery Diagnostics and controls (Power meter, X-Y stage, etc.) Fully enclosed launch into vacuum Beamline toward photocathode Laser Table in cave at electron gun

UITF gun high voltage system Glassman 450KV 3mA supply Fully enclosed in SF6 with shielded cable delivery to gun SF6 system simplified to minimum required components for leak free integrity Voltage and max current controlled by EPICS Interlocked to PSS by two independent methods

Cockroft-Walton generator in SF6 tank High voltage socket for cable connection to electron gun

SF6 handling A commercial SF6 recovery cart is used for filling and evacuating the pressure vessel. Gas transfer is zero loss and maintains purity of SF6* Gas is re-liquefied for storage in bottles when removed from Glassman tank. * Residual gas remaining in Glassman depends on vacuum achieved during transfer. This gas is lost when tank is opened. Typically less than 1lb.

Pressure vessel approved and relief set to 75psig Vessel leak checked for four weeks with nitrogen to prove no loss before being filled with SF6. 45lbs of SF6 pressurized the vessel to 60psig. Not an ODH concern. Monitored weekly for losses. No loss since filling Feb 12, 2016 System presently has no internal connection between Cockroft-Walton multiplier and output socket, so it can be energized for testing without additional safety requirements.