Biblio

This work examines volatile memory modules as ephemeral key storage for security applications in the context of low temperatures. In particular, we note that such memories exhibit a rising level of data remanence as the temperature decreases, especially for temperatures below 280 Kelvin. Therefore, these memories cannot be used to protect the superconducting modules found in high-speed Magnetic Levitation (MagLev) trains, as such modules most often require extremely low temperatures in order to provide superconducting applications. Thus, a novel secure storage solution is required in this case, especially within the oncoming framework concept of the internet of railway things, which is partially based on the increasing utilisation of commercial off-the-shelf components and potential economies of scale, in order to achieve cost efficiency and, thus, widespread adoption. Nevertheless, we do note that volatile memory modules can be utilised as intrinsic temperature sensors, especially at low temperatures, as the data remanence they exhibit at low temperatures is highly dependent on the ambient temperature, and can, therefore, be used to distinguish between different temperature levels.

The precise measurement of temperature is very important to the security and stability of the operation for a superconducting magnet. A slight fluctuation in the operating temperature may cause a superconducting magnet unstable. This paper presents a low-temperature measurement system based on C8051 Micro Controller Unit and Platinum resistance thermometer. In the process of data acquisition, a modified weighted average algorithm is applied to the digital filter program of the micro controller unit. The noise can be effectively reduced and can measure temperature of three different location points simultaneously, and there is no the interference among the three channels. The designed system could measure the temperature from 400 K to 4.0 K with a resolution of 1 mK. This system will be applied in a conduction cooling Nb3Al superconducting magnet. In order to certify the feasibility of the system, tests are performed in a small NbTi non-insulation superconducting magnet model. The results show that the measurement system is reliable and the measured temperature is accurate.