A third vibration-sensitive site: HAM2

 

Katie and I have shaken most chambers with shakers on cross beams (focusing on coupling through the isolation rather than scattering from the chamber walls). The figure shows that, in addition to the PSL and HAM6, HAM2 is also close to limiting DARM. Shaking by a factor of about 30 over background, measured by the GS13s in the 800-860 portion of the ISI suspension band, produces features over an order of magnitude tall in DARM.

 

Thus it may be useful to damp higher modes of the blade springs and flexures in HAM2 as well as HAM6.

Katie and I have shaken most chambers with shakers on cross beams (focusing on coupling through the isolation rather than scattering from the chamber walls). The figure shows that, in addition to the vibration senstitive PSL and HAM6, vibration at HAM2 is also close to limiting DARM. Shaking by a factor of about 30 over background, measured by the GS13s in the 800-860 portion of the ISI suspension band, produces features over an order of magnitude tall in DARM.

Thus it may be useful to damp higher modes of the blade springs and flexures in HAM2 as well as HAM6.

Katie Banowetz, Robert Schofield