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

2. 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

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

4. Gun laser table in cave
Aluminum enclosure with interlocked cover

5. 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.

6. 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

7. 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

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

10. 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.

11. 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.