An apparatus (100) for quenching at least part (110) of a superconductor in a superconducting state in reply to a quench signal to initiate a transition from the superconducting state into a normal-conducting state comprises: means (120) for providing an alternating (AC) current of a predetermined strength and/or predetermined frequency to the at least part (110) of the superconductor, wherein the means (120) for providing the AC current comprises a control terminal (130) configured to receive the quench signal. The means (120) for providing the AC current is configured to be activated in response of receiving the quench signal at the control terminal (130) so that the AC current flows through the at least part (110) of the superconductor, wherein the predetermined strength and/or the predetermined frequency is selected such that the transition from the superconducting state into a normal- conducting state is triggered.