High Resolution Seismometer Insensitive to Magnetic Fields for the Linear Collider Program

75225-The elevated level of vibrations complicates the achievement of sub-nanometer stability for the final focusing lenses in the Next Linear Collider. Ultimately, providing stability will require that the vibration of the final lenses be measured to nanometer accuracy. These measurements could be done by seismometers, but they would have to be insensitive to the magnetic field of the particle detector (up to 6T) and very compact to fit into a tight space. No ¿traditional¿ seismometer can satisfy these conditions. Because electrochemical motion transducers are inherently insensitive to magnetic fields, this project will use these transducers to develop a highly sensitive seismometer that will satisfy the lens stabilization requirements of the Next Linear Collider. Phase I will: (1) fabricate and test modified electrochemical transducers for incorporation into the seismometer at SLAC, (2) develop a complete mathematical model of the seismometer system, and (3) build and test prototype seismometers with required resolution, dimensions, and insensitivity to strong magnetic fields. Commercial Applications and Other Benefits as described by the awardee: A high performance sensor, capable of operation in very strong magnetic fields, should provide an inexpensive means of generating the nano-precision signals necessary to stabilize the focusing lenses of the Next Linear Collider. Such an instrument could be incorporated into beam-stabilization systems in many existing and future particle accelerators. A modified instrument also should find application in monitoring nuclear power stations, dams, etc., that are located in seismically active areas.