Katsuki, Marc

This morning we checked again the pump beam profile to make sure the earthquake did not affect its properties.

It was fine so we checked the surface calibration (R = 16.64 at z = 35 mm and z_IU = 68mm) and bulk calibration (R_bulk = 0.6909 cm/W).

We inspected the sample with the strong green light and cleaned it with the ion gun.

We checked the centering and got X_center = 326.99mm and Y_center = 122.709 mm.

We increased the laser power to about 7.5 W and did a long z scan from which we got the 2 surfaces at z = 41.34 mm and 76.02mm making Z_center = 58.68 mm.

We could also estimate the absorption to be about 70 ppm/cm (roughly same as previous measurement).

We started a XY absorption measurement at Z_center with 0.25 mm step size, 0.5s waiting time and 10 order average/median filters that will last for about 16 h 30.