Magnetic linear birefringence measurements using pulsed fields

Abstract

In this paper we present the realization of further steps toward the measurement of the magnetic birefringence of a vacuum using pulsed fields. After describing our experiment, we report the calibration of our apparatus using nitrogen gas and discuss the precision of our measurement giving a detailed error budget. Our best present vacuum upper limit is $\ensuremath{\Delta}n\phantom{\rule{0.16em}{0ex}}\ensuremath{\leqslant}\phantom{\rule{0.16em}{0ex}}5.0\phantom{\rule{0.16em}{0ex}}\ifmmode\times\else\texttimes\fi{}\phantom{\rule{0.16em}{0ex}}{10}^{\ensuremath{-}20}$ T${}^{\ensuremath{-}2}$ per 4 ms acquisition time. We finally discuss the improvements necessary to reach our final goal.