Linus Leo Stöckli

We present our newly developed laboratory setup, called COCoNuT (Characteristic Observation of Cometary Nuclei using THz-spectroscopy), consisting of a THz spectro-goniometer in a vacuum chamber along with a cryo-cooler intended for cooling down samples rich in ices expected in cometary environments. This setup allows the use of THz time domain spectroscopy on analogs including refractory materials in the spectral range from 0.1 to 5.5 THz with a spectral resolution of up to 0.005 THz. Since the optical setup is mounted on a precision controlled x/y-stage, imaging or spatial averaging can be performed. In this work, we present the design decisions and selection of components. Furthermore, the commissioning of the setup is described and the capabilities are shown. The system can reach pressures of 10−7 mbar and temperatures of 50 K. For 2D scanning, a spatial resolution of 0.3 line-pair per mm is obtained.

Cryogenic experiments strongly depend on accurate temperature measurements. Many of the sensors used for these purposes are glued to the object to be measured to achieve adequate thermal contact. This calls for a more flexible, long lasting and robust bolt-mounted solution. Therefore, we present a low-cost (\textless5$), compact, PCB (printed circuit board) based sensor mount for RTDs (resistance temperature detector) and diodes showing reliable results at temperatures from 50 K to 400 K with possible modifications for an extended range down below 20 K. We anticipate that the robustness and low cost of the reported sensor mount design will strongly enhance the accessibility of reliable temperature measurements at a wide range of temperatures in laboratory applications.