Analysis of the wire sag in the pulsed taut-wire technique

Background: The metal wire used in pulsed taut-wire technique would sag for gravity, so the wire may not just at the geometrical axis of the solenoid, this would result in error. Purpose: This paper studies the wire sag and finds some methods to minimize this error. Methods: From theoretical analysis, we find an expression (Catenary) to describe the wire sag, and this has been verified by experiment. Based on the catenary and wave equation, a taut wire vibration model is established and wire's vibration waveform is calculated. Results: The waveform shows that wire sag may lead to -0.964 mm offset and -0.162 mrad tilt measurement error. Conclusion: There are three ways which can reduce this error, i.e. (1) numerical correction, (2) the increasing of the tension on the wire, and (3) the building of a vertical experiment roof. (authors)