... Kingdon, Penning and Paul ion traps invented correspondingly in 1923, 1936 and 1956 have played essential role in 20th century physics- test of the validity of quantum electrodynamics, tests of symmetry properties of fundamental laws-particle-antiparticle (electron-positron), the electric dipole moment of the neutron, ion spectroscopy, hyromagnetic ratio, comparison of masses m(p+/m(e-) m(CO+)/m(N2+) frequency and time standards, dusty plasma and so on. ... 2007 Biophysics dep., ...