Research on temperature measurement technology for graphite-cone-absorption-cavity absolute calorimeter

Area of Science:

• Optics and Photonics
• Materials Science
• Metrology

Background:

• High-energy laser calorimeters face measurement errors due to nonlinear material effects and steep temperature gradients.
• Traditional integral temperature sensors are insufficient for accurate measurements in these conditions.

Purpose of the Study:

• To develop a novel measurement method for high-energy laser calorimeters to enhance accuracy.
• To address the limitations of traditional sensors in measuring temperature rise in absorbers.

Main Methods:

• Dividing the absorption cavity into multiple sections with discrete thermocouple sensors.
• Theoretical analysis, numerical simulation, and experimental verification of temperature distribution.
• Optimizing thermocouple layout and correcting for factors like specific heat and sensor responsivity.

Main Results:

• A high-accuracy calorimeter was developed using the proposed discrete sensor method.
• Calibration against a standard energy meter yielded a correction coefficient of 1.027.
• The relative standard deviation of the correction coefficient was as low as 0.8%.

Conclusions:

• The proposed method significantly improves measurement accuracy in high-energy laser calorimeters.
• Discrete temperature sensing effectively overcomes errors caused by nonlinear effects and gradients.
• The developed calorimeter demonstrates reliable and precise energy measurement capabilities.