2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142300The construction of an ion pulse ionization chamber aimed at measuring ultra-low levels of surface alpha-activity of different samples is described. The results of measurement carried out with alpha-source and copper samples and light-reflecting film VM2000 are presented.6 pages, 7 postscript figures, talk at the XIV-th Int. School "Particles and Cosmology"Instrumentation and Detectorstext