50 V.m −150 \text { V.m }{ }^{-1}50 V.m −1
100 V.m −1100 \text { V.m }{ }^{-1}100 V.m −1
400 V.m −1400 \text { V.m }{ }^{-1}400 V.m −1
1600 V.m −11600 \text { V.m }{ }^{-1}1600 V.m −1
