Metrology for optical components of Taiwan Photon Source beamlines

Area of Science:

• Optics and Photonics
• Metrology
• Synchrotron Radiation Technology

Background:

• Beamline optical component metrology is crucial for achieving theoretical optical simulations and high performance.
• The Taiwan Photon Source requires precise metrology for its beamline optical components.

Purpose of the Study:

• To describe the design and performance of a long-trace profiler (LTP) for beamline metrology.
• To demonstrate the application of LTP in optimizing and correcting optical components.
• To address and mitigate vibrations in the double-crystal monochromator (DCM).

Main Methods:

• Utilized a long-trace profiler (LTP) with a moving optical head for metrology.
• Employed LTP measurements for optimizing water-cooled mirror surface profiles to a slope error of 0.1 µrad (rms).
• Applied screw adjustment guided by LTP measurements to correct bendable cooling mirrors.
• Investigated vibrational spectra of the double-crystal monochromator (DCM) using an autocollimator before and after stiffening bellows hoses.

Main Results:

• Achieved optimization of water-cooled mirror surface profiles to a slope error of 0.1 µrad (rms) with adequate thermal conductance.
• Successfully corrected sagittal slope errors in bendable cooling mirrors using LTP-guided adjustments.
• Demonstrated that stiffening bellows hoses partially inside the vacuum chamber effectively suppresses flow-induced vibrations in the DCM.

Conclusions:

• The long-trace profiler (LTP) is an effective metrological tool for the assembly and correction of beamline optical components.
• The proposed method for stiffening bellows hoses is an effective solution for suppressing flow-induced vibrations in double-crystal monochromators (DCMs).
• Precise metrology and component correction are essential for realizing high-performance synchrotron radiation beamlines.