Dual-Cylinder Laser Reference Cavities for LISA

"Summary: The Laser Interferometer Space Antenna (LISA) mission is under consideration by NASA and ESA as a joint mission to study gravitational wave signals from a number of types of astrophysical sources at frequencies below 1 Hertz. These include mergers of massive black hole binaries out to redshifts of 10 or more and inspirals of stellar mass black holes into galactic center black holes at redshifts out to about 1. Extremely sensitive tests of the predictions of general relativity will be tested under highly relativistic conditions by the measurements. Two dual-cylinder resonant cavities for laser stabilization which are suitable for hard-mounting in spacecraft have been designed and constructed under previous NASA support. Evaluation and testing of these cavities now is being started under NASA Award NNX09AD11G. The cavities have been designed to have substantially reduced sensitivity to vibrations and to temperature variations at frequencies above 1 millihertz. The relative frequencies for the two cavities in their separate small vacuum chambers will tested under a range of different conditions. In addition, a search will be made for occasional small glitches in the phase of lasers locked to the two cavities, which could cause temporary disturbances in the LISA measurements if they occurred too frequently. It now has become clear that the desired range of measurements on the cavities can't be completed by the end of the present funding period. Thus funding is requested under this proposal for two additional semesters of support for a graduate student in order to complete the desired measurements. The category under which this proposal is being submitted is Supporting Technology." More »