SRF2013 - List of Authors (Magne, C.)

Paper	Title	Page
TUP111	Experimental Investigations of the Quench Phenomena for the Quench Localization by the Second Sound Wave Method	739
	J. Plouin, J.-P. Charrier, C. Magne, J. Novo CEA/DSM/IRFU, France L. Maurice CEA/IRFU, Gif-sur-Yvette, France
	The quench localization by the second sound method is now widely used in many laboratories. This method avoids the complicated implementation of temperature arrays around the surface cavities. Instead, specific sensors are placed around the cavity and the time of arrival of the second sound wave generated by the quench is measured on each sensor; then the distance from sensors to quench is deducted from the theoretical second sound wave velocity. In principle, the quench position can be localized with a triangulation by a limited number of sensors. However, many measurements have shown that the time of arrival of the wave was not corresponding to the theoretical second sound wave velocity: the “measured” velocity is often 50% higher than the theory. At CEA-Saclay we performed several measurements on single cell cavities to investigate these phenomena. Several hypotheses are studied: large quench spot, heat propagation by another phenomenon than the second sound near to the cavity where the heat power density is very high. These results and the discussions on these hypotheses will be presented.

Paper

Title

Page

Experimental Investigations of the Quench Phenomena for the Quench Localization by the Second Sound Wave Method

739

J. Plouin, J.-P. Charrier, C. Magne, J. Novo
CEA/DSM/IRFU, France
L. Maurice
CEA/IRFU, Gif-sur-Yvette, France

The quench localization by the second sound method is now widely used in many laboratories. This method avoids the complicated implementation of temperature arrays around the surface cavities. Instead, specific sensors are placed around the cavity and the time of arrival of the second sound wave generated by the quench is measured on each sensor; then the distance from sensors to quench is deducted from the theoretical second sound wave velocity. In principle, the quench position can be localized with a triangulation by a limited number of sensors. However, many measurements have shown that the time of arrival of the wave was not corresponding to the theoretical second sound wave velocity: the “measured” velocity is often 50% higher than the theory. At CEA-Saclay we performed several measurements on single cell cavities to investigate these phenomena. Several hypotheses are studied: large quench spot, heat propagation by another phenomenon than the second sound near to the cavity where the heat power density is very high. These results and the discussions on these hypotheses will be presented.