LIGO Seminar

All test masses of aLIGO have been delivered and most of the optics have

been measured and characterized. In this talk, some issues related to test

masses are discussed. First is the large angle scattering and loss. So far,

only half of the losses in the aLIGO arms, 100ppm / arm, can be accounted

for by the mirror quality. How to relate measurements of mirrors to the

total arm loss is discussed. Second is the excess PSD in the short wave

length region, ~1mm, which is observed for ETMs with the latest LMA

coatings. Noise contributions by this structure is discussed. Third is the

mode structure induced by ETMs. ETM surfaces have unique structures and the

mode contents in the arm cavity, in the bright port and in the dark port are

different. Quantitative estimation of these effects are done using current

ETMs and new ETMs with the latest coating.

We plan to broadcast these talks using TeamSpeak. Use a sub-channel of

LIGO Lab called "LIGO Seminar", which is not password protected.

NOTE: These and all other scheduled LIGO seminars are listed on the LIGO

Laboratory seminar calendar for convenient reference:

http://arcturus.ligo.caltech.edu/cgi-bin/calendar/Calcium40.pl?Op=

ShowIt&CalendarName=LIGO_Seminars

OR on LIGO Website: Click on LIGO CIT, under Calendars, see LIGO Seminar