[Yokozawa, Yuzu]

As an irregular maintenance of TCam for ETMX, we performed the visual inspection this morning. From our inspections, the TCam of ETMX was no problem, except for the small dust.

• During O4a and the commissioning period, the TCam for ETMX showed no troubles. The purpose was to see the TCam in good condition for comparison with the TCam for ETMY in the afternoon.
• We opened the one wall of the TCam (Fig1) and checked the surface of the objective lens. A little dust seemed to be on the surface (Fig2) (Fig3). Next time, we will try to clean it by using an air duster.
• We checked the mirror in the EXA chamber, which reflects the incident light from the ETMX to the telescope (Fig4). The photo shows a cloudy mirror, but this is due to poor camera performance... Eye inspection did not reveal any problems.