[1] NASB, Inst Phys, Minsk 220072, BELARUS
[2] Univ Fed Alagoas, Inst Fis, BR-57072970 Maceio, AL, Brazil
[3] Inmetro, BR-25250020 Duque De Caxias, RJ, Brazil
[4] Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio de Janeiro, Brazil
[5] Univ Estadual Campinas, Inst Fis, BR-13083970 Campinas, SP, Brazil