KAGRA MIR (Absorption)
MarcEisenmann - 22:30, Monday 19 April 2021 (2457)
ir realigned & surface reference sample measurement

Abe, Aritomi, Marc

As reported in entry 2446, we could recover the expected ir beam parameter.

Today, we placed the surface reference sample on the translation stage.

After maximizing DC and AC, first calibration gave R_surf~15.

Then we moved back the imaging unit from 74mm to 70 mm and got R_surf~17.3 (AC_surfref = 0.3512,DC_surfref = 3.942,P_in = 23.37mW)

The results are presented in figure 1.

The new crossing point seems to be at z=39.25 mm. Also, the 2 lateral peaks are still slightly unbalanced...

I think tomorrow we can try to do few measurements of the surface reference while varying the imaging unit positions and then try to measure the bulk reference.

Images attached to this report
2457_20210419152941_bestalign.jpg