Historically, the technique of accelerator mass spectrometry has required that samples be processed into solid form prior to analysis. The processing is time and labor intensive and limits the technique due to contamination. There has been recent interest to develop an ion source that would allow direct injection of gaseous samples, thus eliminating the processing. Previous attempts to build such an ion source have been limited by low mass usage efficiency and severe memory effects. This presentation will describe the development of a plasma driven negative ion source that allows direct injection of gaseous material. This ion source was able to produce a negative C-12 ion beam of approximately 4.5 microamps from carbon dioxide with a mass efficiency of 0.15%. This design was also free from significant memory effects. There are many improvements to the design of this ion source that would further enhance its performance. These results are promising and show that this type of ion source could be used effectively in an accelerator mass spectrometry system.
See more of Ion Sourcery (optics, modeling, performance, etc)
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)