1. Institute of Optoelectronics, M.U.T., Kaliski 2, 01-489 Warsaw, Poland
2. Soltan Institute of Nuclear Studies, 05-400 Świerk, Poland
3. Institute of Electronic Materials Technology, Wolczyńska 133, 01-919 Warsaw, Poland
4. Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw, Poland