Sub-microradian Surface Slope Metrology with the ALS Developmental Long Trace Profiler

Conference · Mon Jun 15 04:00:00 EDT 2009

OSTI ID:962723

Yashchuk, Valeriy V; Barber, Samuel; Domning, Edward E; Kirschman, Jonathan L; Morrison, Gregory Y; Smith, Brian V; Siewert, Frank; Zeschke, Thomas; Geckeler, Ralf; Just, Andreas

Development of X-ray optics for 3rd and 4th generation X-ray light sources with a level of surface slope precision of 0.1-0.2 {micro}rad requires the development of adequate fabrication technologies and dedicated metrology instrumentation and methods. Currently, the best performance of surface slope measurement has been achieved with the NOM (Nanometer Optical Component Measuring Machine) slope profiler at BESSY (Germany) [1] and the ESAD (Extended Shear Angle Difference) profiler at the PTB (Germany) [2]. Both instruments are based on electronic autocollimators (AC) precisely calibrated for the specific application [3] with small apertures of 2.5-5 mm in diameter. In the present work, we describe the design, initial alignment and calibration procedures, the instrumental control and data acquisition system, as well as the measurement performance of the Developmental Long Trace Profiler (DLTP) slope measuring instrument recently brought into operation at the Advanced Light Source (ALS) Optical Metrology Laboratory (OML). Similar to the NOM and ESAD, the DLTP is based on a precisely calibrated autocollimator. However, this is a reasonably low budget instrument used at the ALS OML for the development and testing of new measuring techniques and methods. Some of the developed methods have been implemented into the ALS LTP-II (slope measuring long trace profiler [4]) which was recently upgraded and has demonstrated a capability for 0.25 {micro}rad surface metrology [5]. Performance of the DLTP was verified via a number of measurements with high quality reference mirrors. A comparison with the corresponding results obtained with the world's best slope measuring instrument, the BESSY NOM, proves the accuracy of the DLTP measurements on the level of 0.1-0.2 {micro}rad depending on the curvature of a surface under test. The directions of future work to develop a surface slope measuring profiler with nano-radian performance are also discussed.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Advanced Light Source Division; Engineering Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 962723
• Report Number(s): LBNL-2046E
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
ACCURACY
ADVANCED LIGHT SOURCE
ALIGNMENT
APERTURES
CALIBRATION
DATA ACQUISITION SYSTEMS
DESIGN
FABRICATION
LIGHT SOURCES
MEASURING INSTRUMENTS
MIRRORS
OPTICS
PERFORMANCE
SHEAR
TESTING
long trace profiler LTP metrology surface slope metrology x-ray optics