In preparation for HWSY investigations for Tuesdays and potential commissioning windows during O3 and post-O3, I did the following with remote help from TJ and Ed.

See D1400241 for table layout.

• Signed (for Ed's sake) and posted TSOP M1900163 for HWSY laser, which was extended for 3 months starting today with an approval of Ed, on the VEA entrance door at EY station.
• Transitioned EY to laser hazard.
• Placed the laser on ISCTEY in front of HWS head and connected it to the input spigot of the fiber splitter (which was left on the table). Laser is low enough this is OK.
• Connected the laser power supply temporarily to the laser head and turned on the laser (1st attachment).
• The beam looked clipped after HWS-L2 lens (2nd attachment, the beam is hitting the paper from the front). The clipping appears to be mostly on the right edge of HWS-M2 (1-inch mirror downstream of HWS-M3) viewed from the enclosure door.
• Upstream of HWS-M3 (2-inch steering mirror) it wasn't terrible (3rd attachment, the beam is hitting the paper from the back).
• I didn't have time to make adjustments, so I turned the power off, left the power key on the laser head in "off" position but removed the power supply from the table (4th attachment). Power cable on the laser head is coiled and put around a post.
• I placed the power supply in a black box for the laser head, put a sticky saying "HWSY power supply" and left it at the back of the VEA (5th attachment).
• Transitioned EY to laser safe.

On Tuesdays or in dedicated commissioning windows, one has to transition EY to laser hazard before opening ISCTEY to operate HWSY laser.

The HWSY laser power supply needs to be removed from ISCTEY and disconnected from the mains before we can go back into observation.