Cryogenic setup for electron counting experiments

This technical report describes the electrical and mechanical configuration of a system devoted to the mise en pratique of the DC electrical current in the range 100 fA - 100 pA. A commercial dilution refrigerator (Leiden Cryogenics B.V. MicroKelvin-50), installed in the Cryogenic Laboratory (b302b @ INRiM), represents the starting point of the measurement setup. The instrument allows the achievement of a base temperature near 30 mK, this latter being necessary for the implementation of a single-electron-transistors- device-based current source. The entire measurement set up has been designed to fulfill the strict low-noise ambient requirements reaching a state-of-the-art configuration in the field of quantum metrology of low currents. The problem of the transport of the electrical signals from room temperature electronics (isolated voltage sources, low-noise current amplifier..) to the devices located in the coldest region of the refrigerator has been faced with a multi-stage modular approach. In this view several custom components have been designed and developed, keeping in mind the metrological scope of the whole experiment.