We present a novel susceptometer with a particularly small spatial footprint and no moving
parts. The susceptometer is suitable for use in systems with limited space where magnetic
measurements may not have been previously possible, such as in pressure cells and
rotators, as well as in extremely high pulsed fields. The susceptometer is based on the
proximity detector oscillator, which has a broad dynamic resonant frequency range and has
so far been used predominantly for transport measurements. We show that for insulating …