KAGRA MIR (Absorption)
MarcEisenmann - 12:17, Wednesday 10 November 2021 (2732)
absorption measurement of shinkosha evaluation plates 10 , 11 , 14

Katsuki, Marc

 

We measured first the surface calibration R_surf = 17.13 /W with z = 42.75 mm, Ziu = 66 mm and Pin = 24.2mW.

Then we measured bulk calibration R_bulk = 0.7474 cm/W with z = 41.85 mm, zIU = 65.68 mm, Pin = 23 mW and Pt = 11.8 mW.

We installed the evaluation plate 14 and found X_center = 397.5 mm, Y_center = 112.469 mm.

We increased the power to ~1W and could clearly see the 2 surfaces from Z_scan which gave Z_center = 53.875 mm.

We measured evaluation plate 14 absorption with Pin = 1.153W and Pt = 0.985W (fig 1).

The map is 70 mm radius and 1mm step size and lasted ~5h30.

We installed the evaluation plate 11 and confirmed the same Z_center position with a Z scan. Absorption measurement (fig 2) was performed with Pin = 1.169W and Pt = 1.004W.

Finally we installed the evaluation plate 10, confirmed the same Z_center and measured absorption (fig 3) with Pin = 1.153W and Pt = 0.989 W.

 

All evaluation plate were installed with marking of ingot position on the right side (looking from the injection) so that the top side of the ingot faces the injection.

 

All plates show quite high absorption with the usual star pattern.

Images attached to this report
2732_20211116081603_absorption14.png 2732_20211116081608_absorption11.png 2732_20211116081614_absorption10.png