Low-cost modular liquid nitrogen low-temperature multi-nuclear magnetic resonance probe

A low-cost modular liquid nitrogen low-temperature multi-nuclear magnetic resonance probe, comprising a Dewar, a pluggable coil and a front-end gain amplifier, wherein the Dewar comprises a cylindrical sandwich chamber, a center of the cylindrical sandwich chamber constitutes a room-temperature chamber, a sandwich of the cylindrical sandwich chamber is divided into a vacuum chamber and a liquid nitrogen chamber by a liquid nitrogen vessel wall, and the vacuum chamber is located between the room-temperature chamber and the liquid nitrogen chamber;

• the pluggable coil and the front-end gain amplifier are provided in the vacuum chamber, the pluggable coil comprises a coil portion and a pluggable base, the coil portion is in pluggable connection with the pluggable base, and the pluggable coil is connected with the front-end gain amplifier;
• the pluggable base of the pluggable coil and the front-end gain amplifier are connected to the liquid nitrogen vessel wall by means of low-temperature glue;
• the vacuum chamber is connected with a gas gate provided on an end face of the cylindrical sandwich chamber, the liquid nitrogen chamber is respectively connected to a detachable connection port and an exhaust port provided on the end face of the cylindrical sandwich chamber, and the front-end gain amplifier is respectively connected to a coaxial cable interface and a direct-current power supply interface provided on the end face of the cylindrical sandwich chamber;
• a tuning rod interface is provided on the end face of the cylindrical sandwich chamber, a tuning rod is connected with the tuning rod interface via a thread, and the tuning rod extends into the vacuum chamber near the coil portion of the pluggable coil;
• the room temperature chamber is provided with a thermocouple, the vacuum chamber is internally provided with a thermocouple in a vicinity of the coil portion of the pluggable coil, the vacuum chamber is internally provided with a thermocouple in a vicinity of the front-end gain amplifier, the end face of the cylindrical sandwich chamber is provided with a thermocouple interface, and each thermocouple is connected with the thermocouple interface;
• the cylindrical sandwich chamber is made of glass fiber reinforced plastic, and the liquid nitrogen vessel wall is made of ceramic;
• the vacuum chamber is internally provided with activated carbon and sodium aluminosilicate;
• a side wall of the liquid nitrogen vessel wall in the vacuum chamber is provided with a polyimide thermal insulation layer at a position except for a position corresponding to the pluggable coil;
• and
• the pluggable base is made of copper.