Not necessarily. It might just have performed at this peak capacity in ideal lab conditions.
This would need to be reproduced, but like you pointed out ASML and Zeiss most likely tested this configuration out at some point in the last 25 years.
That said, the English is very off on this paper - I did a re-read and it looks like they're proposing that they were able to cut the power down to 20W from 200W
Their reference numbered [1] is a more recent book from 2020.
In this book it is said even if EUV mirrors have typically very poor reflectance at high incidence angles, it has become possible to make mirrors with a 60% to 70% reflectance even for high incidence angles (without specifying how high).
They have computed their power advantage using the 65% value which is a middle value between those from the book, so it is OK.
However they have used the same value for the ASML mirrors, which use low incidence angles, so they may have a higher reflectance.
So according to the book, their system should be feasible nowadays, but the actual improvement in light losses is unknown, because the losses in each mirror depend heavily on both the mirror construction and the light incidence angle, which are not taken into consideration in the paper.
Not necessarily. It might just have performed at this peak capacity in ideal lab conditions.
This would need to be reproduced, but like you pointed out ASML and Zeiss most likely tested this configuration out at some point in the last 25 years.
That said, the English is very off on this paper - I did a re-read and it looks like they're proposing that they were able to cut the power down to 20W from 200W