Setup

Below shows a sketch of GemTOF setup as in operation at SSEF. A 193nm wavelength laser beam from ArF excimer laser (a) is focused on gemstones (b) sealed in a sample chamber (c). The LA chamber is flushed by helium flow (d) which transports the ablated particles into the ICP torch (e). Plasma (f) dissociates, atomizes and ionizes the particles into preferably singly charged ions (g), which are sampled by interface (h) from atmospheric pressure to high vacuum region. The stream of ions is extracted through a series of ion lenses (i) and neutrals are separated from ions after angular deflection lens (j). Collision/reaction cell (k) can be used to reduce interferences. Entering the TOF-MS, a notch filter (l) first rejects the selected dominant ions (e.g. Ar+) from the ion stream, then the extractor (m) pushes ions orthogonally at a high frequency into the field-free time-of-flight region (n). Ions are mirrored by a reflectron (o) and finally registered at a detector (p).

Scheme GemTOF Website.png