Research Article

Impact of shock waves on the conductive properties and structure of MgB₂ tapes

¹ A.A. Baikov Institute of Metallurgy and Materials Sciences of the RAS, Moscow 119991, Russia
² P.N. Lebedev Physical Institute of the RAS, Moscow 119991, Russia
³ National Research Nuclear University MEPhI, Moscow 115409, Russia

^* e-mail: vnik@sci.lebedev.ru

Received: 4 April 2017
Accepted: 16 August 2017
Published online: 25 October 2017

Abstract

This article presents data on shock waves effect on the structure and the critical current of superconducting MgB₂ tapes. To generate shock waves, a plasma focus installation (PF) was used. The conductive characteristics of the superconducting tapes dependence on the intensity of the impact and the number of shock pulses were studied. A distinct pattern of change in critical currents in transversal and longitudinal magnetic fields in the range of 2–9 T is studied at a temperature of 4.2 K. The microstructure of the superconducting tape and chemical composition of its layer are studied in the original state and after the shock wave effect. Changes were found in a microstructure of layers of MgB₂ (granulation, subdivision of grains and consolidation), which arose due to the shock-wave impact (SWI), are found. The possibility of increasing the critical current of tapes on 50–80 A in a transversal magnetic field of 2–3 T by means of SWI has been established. In a parallel magnetic field, the impact of the shock effect was essential in magnetic fields lower than 4 T.