Computer Interface and Instrumentation for a Scanning Atomic Absorption Spectrometry Flux Monitor (2024)

Undergraduate: Alexander Mayers

Faculty Advisor: Frank Tsui
Department: Physics and Astronomy

---

Molecular Beam Epitaxy (MBE) is a ultrahigh vacuum based synthesis technique to grow novel thin films and heterostructures one atomic layer at a time, which is controlled in real-time by atomic absorption spectroscopy (AAS). This work involves computer interface and testing of a motorized scanning AAS system, which allows a single monochromator/detector to monitor and control multiple elements during MBE deposition. Computer software/code was created and tested for controlling the AAS system. Using this computer code, the emission spectra in the near ultraviolet of five element specific hollow cathode lamps (HCLs) were measured under various conditions and with different fiberoptic cables. Various operating procedures and combinations of HCLs were examined and evaluated for future optimization. Different HCLs were compared across a range of wavelength for the future integration of the AAS system. Effects of mechanical hysteresis introduced by the motorized monochromator and the optoelectronic relaxation of the detector were measured and potential solutions of these were explored.

Link to Abstract