Compositional Analysis by a Superconductor-Based Energy Dispersive Spectrometer

Energy dispersive spectrometers (EDS) are widely used in material science to provide elemental identification by analyzing the energy of characteristics fluorescence X-rays of an excited specimen. We present compositional analysis of materials of interest in various contexts (from electronics to cultural heritage). They were obtained by a superconductor/based - energy dispersive spectrometers (S-EDS) mounted on a scanning electron microscope. The superconducting detector is a Au/Mo/Pd transition edge sensor (TES) with a Au absorber and a SQUID read-out. The achieved energy resolution is 10 eV at an energy of 1.486 keV (one order of magnitude better than semiconductor based EDS). The working temperature is T = 110 mK and is obtained with a cryostat which uses a combination of a pulse tube cooler and a two-stage adiabatic demagnetization refrigerator. In this way there is no need of liquid coolant during the cool down operation. The complete system allows high performances morphological and compositional analysis representing a successful example of an electronics application of superconductivity.