This work discusses the theory and design of multi -mode bar detectors of gravitational waves and our construction and test of a five-mode system. The theory includes the calculation of the energy absorbed from a pulse of gravitational radiation, the calculation of the energy transfer from the bar antenna to the electromechanical transducer, the detector noise analysis and an algorithm for the design of the optimum filter for gravitational signal retrieval. Design and construction efforts have been focused on a five-mode system. We describe the use of finite element methods (FEM), computer-aided design (CAD) and results from tests on a 10g niobium resonator in the design of multi-mode systems and in our construction of a specific five-mode system. The results of tests of that five-mode system carried at room temperature are given. The energy transfer from the bar to the fifth resonator is determined to be high (67%) and completed within 4.6 ms, which leads to an effective detector bandwidth of ~500 Hz.
- Pub Date:
- January 1990
- Physics: General, Physics: Astronomy and Astrophysics, Physics: Radiation