A THEORETICAL-STUDY OF SOME NEGATIVE-IONS OF INTEREST TO ACCELERATOR MASS-SPECTROMETRY

Accelerator mass spectrometry (AMS) exploits the properties of negativ e ions to measure the abundances of certain rare radioactive atoms. In cases such as C-14, Al-26 and I-129, the complete instability of the negative ion of the abundant isobar makes the mass spectrometry relati vely easy. Clearly a systematic understanding of the properties of neg ative ions is of value to AMS and the development of methods of isobar separation that involve the manipulation of negative ions by atomic c ollisions, electric fields and lasers, The purpose of the present work is to attempt to understand the stability or instability of some of t he negative ions which are important to AMS and to point out that the periodic table of the negative ions has many differences from that of the neutral atoms.