Katsuki, Marc

We installed the new ion gun and used it to clean shinkosha7 surfaces.

We removed the first steering mirror after the lens and realigned the pump beam path.

We got R_surf = 18.47 /W and R_bulk = 0.7647 cm/W with Z_IU = 66 mm and Z_crossing ~42 mm.

We resinstalled shinkosha 7 and used the DC signal to find the mirror center as X = 399.08 mm and Y = 122.175 mm.

We started long z scan (between 25 and 110 mm) to find the 2 surfaces z positions with P_t ~ 6.4 W.

The first surface is clearly visible at z = 34.5 mm but not so much the second one.

In any case because we plan to take several XY absorption measurements for comparison with birefringence measurement we started the first map at z = 50 mm and Pin = 8.61W, Pt = 7.37 W.

This map just finished and we can recognize the usual star pattern.

We will take measurement every few centimeters during this entire week at least.