HOW FAST α PARTICLES ARE EMITTED IN "MASSIVE TRANSFER" REACTIONS ? C. Gerschel, N. Perrin, L. Valentin, H. Tricoire, B. Ader and D. Paya J. Phys. Colloques, 41 C10 (1980) C10-239-C10-242 DOI: 10.1051/jphyscol:19801025