Wojciech Polak1, Janusz Lekki1, Joanna Gryboś1, Roman Hajduk1, Marian Cholewa2, Oleg Kukharenko3, Zbigniew Stachura1
1 The Henryk Niewodniczanski Institute of Nuclear Physics, 152 Radzikowskiego Str., 31-342 Kraków, Poland
2 Gesselschaft fuer Schwerionenforschung, 1 Planck Str., D64291 Darmstadt, Germany
3 Institute of Applied Physics, 58 Petropavlovskaya Str., Sumy, Ukraine
Testing Si3N4 membrane windows is a preliminary research for the single-ion - single-cell irradiating programme prepared at the Cracow nuclear microprobe facility. The present investigation is concerned with finding a method to register every single particle of the microprobe beam when passing through a membrane to the atmosphere. The 200 nm thick membranes covered with different layers were investigated. The alpha particles, after passing the membrane window, were registered by a particle detector. Secondary electrons ejected from the membrane by alpha particles were registered by a channeltron. The channeltron signals were collected in coincidence with the silicon detector signals. The detection efficiency is the ratio of the fast coincident channeltron signal number to the total number of the silicon detector signals. The results of investigation of the membranes with different coverages are reported in the present work.