Feasibility Study on a Cf Plasma Desorption Imaging Mass Detector (IMD)

The DoD is seeking the development of analytical methodology and instrumentation with graphic imaging capabilities to determine the quantity and speciation of metals found in contaminated soils. In this SBIR Phase I submission we are proposing to develop an Imaging Mass Detector (IMD) which acquires both mass and energy dispersive spectra from locations on the sample and generates images based on molecular weight and elemental determinations. Combined with a database of standard mass spectra, compounds would be identified and mapped. The heart of this instrument is a low level (252) Cf (californium) source, which desorbs and ionizes sample molecules via fission fragments. Californium fragments cause rapid, high energy desorption and ionization which generate simple mass spectrum patterns. Imaging will be achieved through a new and innovative technique which takes advantage of the recoil fragments produced by Cf at each fission event. The trajectories of the recoil fragments will be used to extrapolate to the hit positions of the forward fragment on the sample. Applications of this instrument would be far reaching, including mapping and identification of nuclide, inorganic, and organic compounds in the mass range through 3000 amu.