Low temperature scanning probe microscope system based on pulsatron refrigeration technology

Abstract

The invention relates to a low temperature scanning probe microscope system based on pulse tube refrigeration technology. Aimed at vibration source and characteristics, a multistage active / passive damping device, including a sylphon bellowss, a piezoelectric ceramic tube and a spring are adopted. The sylphon bellowss is used for connecting a main system cavity and a refrigeration head of the pulse tube to realize vibration isolation of the whole system. As for low frequency vibration unique to a pulse tube refrigerator, an active damping device with a piezoelectric ceramic tube and a digital signal processor as the core is adopted. A beryllium copper spring and a damping magnet form a first stage passive damping device to isolate vibration. The system eliminates the vibration from the pulse tube refrigerator and the refrigeration head to the scanning probe, applies to other vibration sensitive occasions that require low temperature, saves a large amount of liquid helium refrigerant, simplifies equipment operation and maintenance, and significantly prolongs the retention time at low temperature.

Description

technical field [0001] The present invention relates to a novel cryogenic scanning probe microscope (SPM) system. By combining pulse tube refrigeration technology, the system can reach a temperature below 4K without using liquid helium refrigerant, and has obvious advantages in low temperature maintenance time compared with traditional liquid helium refrigeration methods. Background technique [0002] Scanning probe microscopy is currently the most widely used powerful tool for studying various physicochemical phenomena and effects at the nanoscale. In order to reduce electronic noise, realize atomic / molecular manipulation, and resolve splitting of fine energy levels, scanning probe microscope systems usually work in the liquid helium temperature region or lower. The traditional refrigeration method not only has a limited time for keeping low temperature, but also consumes a large amount of expensive liquid helium refrigerant, which makes the operation and maintenance costs...

AI Technical Summary

Problems solved by technology

However, the micron-scale vibration generated by the moving airflow in the refrigerator limits the application of pulse tube refrigeration technology in vibration-sensitive fields.

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