Ligo Heat Dissipation: How Do They Protect Mirrors?

[kelly0303]

Hello! I am not sure I understand how the heat from the lasers get dissipated in LIGO, at the mirrors. Given the high power of the lasers, the mirrors heat up, but the setup is in vacuum, so it is difficult to get rid of that heat. How do they make sure that the mirrors don't get too much damage because of the heat? Thank you!

 

[phyzguy]

Here's an interesting paper on this if you are interested. The laser cavity power is 100 kW, but the refectivity of the mirrors is very high (1.0 - 1ppm), so the power absorbed by the mirror is only 0.1W. This is dissipated by radiation to the surroundings, and the mirrors stay at about 17C.

<Moderator's note: attachment deleted>

 

[DrClaude]

Unfortunately, that article is copyrighted and cannot be posted here.

Instead, see the link:
Thermal modelling of Advanced LIGO test masses - https://doi.org/10.1088/1361-6382/aa6e60

 

[vanhees71]

Or you use the good old arXiv :-)):

https://arxiv.org/abs/1612.02866