An Interferometric Multi-Sensor Absolute Distance Measurement System for Use in Harsh Environments.

Area of Science:

• Optical Metrology
• Interferometry
• Particle Accelerator Technology

Background:

• Harsh environments in particle accelerators pose significant challenges for remote measurement and monitoring systems.
• Traditional metrology systems struggle with electromagnetic interference, radiation, and cryogenic temperatures.
• Precise alignment of accelerator components is critical for High-Luminosity Large Hadron Collider (HL-LHC) operations.

Purpose of the Study:

• To review challenges in remote measurement systems for harsh environments.
• To detail the development and validation of an FT-FSI-based measurement system.
• To highlight the system's role in achieving micrometric alignment accuracy.

Main Methods:

• Fourier transform-based frequency sweeping interferometry (FT-FSI) for absolute distance measurement.
• Integration of FT-FSI into a full remote alignment system (FRAS) for accelerator components.
• Utilizing specialized interferometers and sensors (inclinometers, distance, leveling sensors).

Main Results:

• FT-FSI enables robust, simultaneous distance measurements to multiple targets.
• The technique maintains accuracy despite variations in optical signal intensity and low reflectance.
• The FRAS system, employing FT-FSI, demonstrated critical role in enabling micrometric alignment accuracy.

Conclusions:

• FT-FSI is a highly accurate and robust interferometric technique suitable for demanding metrology.
• The developed FT-FSI-based system effectively addresses challenges in harsh accelerator environments.
• Findings are transferable to other metrology applications requiring high precision in adverse conditions.