REFRACTION OF DIRECTED SHOCK ELECTRONS AT PLANAR SOLID SURFACES H. ROTHARD, K. KRONEBERGER, M. BURKHARD, C. BIEDERMANN, J. KEMMLER, O. HEIL et K.O. GROENEVELD J. Phys. Colloques, 50 C2 (1989) C2-105-C2-110 DOI: 10.1051/jphyscol:1989219