A fast response, low heat generating activation method for LHe level sensors.

Area of Science:

• Cryogenics
• Superconducting devices
• Level sensing technologies

Background:

• Accurate liquid helium (LHe) level monitoring is critical for cryogenic applications.
• Conventional sensors can introduce significant heat load into LHe cryostats.
• Understanding thermal characteristics in helium gas versus liquid is key for sensor design.

Purpose of the Study:

• To fabricate and characterize a superconducting LHe level sensor.
• To evaluate a new level measurement technique for reduced heat load and improved performance.
• To analyze the dynamic thermal and timing response of the sensor.

Main Methods:

• Fabrication of a 300 mm superconducting sensor using a 38 μm multifilament wire.
• Comprehensive thermo-electrical characterization in a dedicated setup.
• Dynamic thermal response analysis at various LHe levels and excitation currents.

Main Results:

• The sensor demonstrated effective level detection based on differential heat transfer.
• A new measurement technique was evaluated, showing potential for reduced heat load.
• Dynamic response studies provided insights into timing characteristics for faster detection.

Conclusions:

• The developed superconducting sensor and novel measurement technique offer a promising solution for LHe level monitoring.
• The technique minimizes heat input to the liquid helium, crucial for sensitive experiments.
• Faster and more accurate LHe level detection is achievable with this advanced sensor technology.