The 1993 atomic mass tables and beyond

With a Penning trap technique applied to even short lived (few s) radioactive nuclides, masses of many isotopes of half a dozen elements have been determined with a precision of about 10 keV or better, which is sufficient for nuclear physics purposes. With time of flight methods applied to undecelerated particles (in the region below mass number 80) from bombarded targets, but also with more classical methods, masses of many nuclides far from beta stability have been improved, or measured for the first time. It is expected that extension of these methods will lead to further extensions and improvements. Information is given on the way in which the mass values in the tables have been derived from many thousands of measurements of masses and of nuclear reaction and decay energies.<>