Rev Sci Instrum 2019 Apr;90(4):043502
Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, D-17491 Greifswald, GermanyDepartment of Nuclear and Quantum Engineering, KAIST, Daejeon 34141, South KoreaDepartment of Astronomy and Astrophysics TUB, Hardenbergstr. 36, D-10623 Berlin, Germany.