HEAT COUPLING IN MULTI-WIRE VIBRATING WIRE MONITOR

Due to the extreme sensitivity of vibrating wire monitors (VWMs), it is possible to place these devices outside of an accelerator vacuum chamber in air to detect only very hard x-rays that penetrate the chamber. The VWM response time in air vs. vacuum is reduced substantially due to convective cooling. In this paper, the thermal coupling between the wires of a multi-wire VWM is described. Experiments in which x-ray sources were modeled by DC currents were performed to find the heat coupling coefficients between the wires. Using the assumption that the unknown beam transversal distribution is stable during the scan, a statistical data treatment allows the recovery of source profile from measured wire overheating.