[Aidan, Camilla, TJ]

We inspected the ETMX HWS layout this morning. We're going to review:

• Beam propagation (how close do we match the design?)
• Alignment (how well is our system aligned and have we blocked ITM return beam?)
• Imaging (how close is our HWS to the conjugate plane of the ETM)

However, first we looked at the frame rate for the ETM HWS. The return beam without the Hartmann plate had hundreds of saturated pixels at 5Hz. At 10Hz this went to zero. The return beam was very splotchy (medium to high spatial frequencies. Even with ITMY misaligned we saw some spatial shimmering in the intensity, indicative of, perhaps, Transmon or ETMY drifting about).

When we introduced the Hartmann plate, we increased the frame rate to 20Hz and saw about 6 saturated pixels (due to Fresnel diffraction from Hartmann plate holes increasing local intensity). A frame rate of 25Hz produced no saturated pixels so we opted for this.

At 11:25AM we started the HWS code and turned on the ETMY RH to 4W total output from 0.88W. At 12:42PM I turned the RH back to 0.88W total. ITMY was misaligned for this test.