Wednesday, July 18, 2007
Beam delivering mirrors were damaged again
After replacing the Ti:sapphire crystal of the first amplifier, we tested the CPA part 1 and part 2 this week. The output energies measured from test points were perfectly achieved what we expected. The crystal was not burned anymore after running 3 days, the output energy after first amplifier kept very stable from morning to the end of the work day. Unfortunately we found the surface of the beam delivering mirrors M18 and M19 was burned several dots. It's better to find what caused this damage before we change the mirrors. So we try to send the beam to the CCD camera to check the beam profile next week.