Design of a low-cost Photon Height Analyzer for a Mössbauer spectrometer

Mössbauer spectroscopy is a technique that allows to investigate with high accuracy the changes in the energy levels of an atomic nucleus due to the surrounding environment. The technique consists in measuring the energy dependence of the resonant absorption of Mössbauer gamma rays by nuclei. To obtain these gamma rays a radioactive source is needed. In the laboratory, the isotope 57Co is used, which spontaneously captures an electron to reach a metastable state of 57Fe, which in turns decays in a more stable state (ground state) by a gamma ray cascade that includes the 14.4 keV Mössbauer gamma ray. To work just in this energy range, the spectrometer has an energy window, which should be centred at 14.4 keV. The objective of the present work is to design and build a low-cost analyzer of the photon energy emitted by the radioactive source, in order to be able to check easier, faster and automatically where the energy window is located and, if necessary, to know how its position should be modified. The steps necessary to perform this work are the following. a) Characterization of the main properties of the emission's peaks (time duration and amplitude) that are going to be analyzed. These features are needed to know the characteristics of the data acquisition system (i.e, sampling rate, bit number and price). b) Signal analysis in order to differentiate properly all the emission peaks from peaks due to noise or overlap. c) Creation of a software to automate all the steps to do and prepare a graphical user interface easy to understand. Finally, the performance of the designed system will be evaluated and compared with an analogous commercial equipment