APT/LEDA tunnel floor random vibration measurements

Mechanical vibration spectra have been measured periodically on the tunnel floor below the APT/LEDA RFQ since installation in May of 1998. Facility vibration levels are of concern because if excessive, they will degrade the performance of vibration sensitive components and thus overall accelerator performance. The measured spectra accurately quantify the accelerator's mechanical vibration environment, permitting reasonably accurate finite element calculations of the hardware dynamic response. Identification of the various vibration sources, as well as detection of anomalous vibration sources, is also readily performed. The vibratory environment is largely due to nearby operating mechanical equipment such as coolant pumps, vacuum pumps, compressors and blowers. Input from external natural sources such as wind and flowing water as well as man-made sources such as traffic are also present.