  Residual stress is an important factor governing evaluating and controlling
the quality of metal materials in industrial products. X-ray measurements
provide one of the most effective means of evaluating residual stress without
destruction. In such measurements, the effects of residual stress on the
crystal structure can be observed through the Debye ring deformation.
  In previous studies, we developed a residual stress measurement system based
on the $cos \alpha$ method, using a two-dimensional (2D) silicon-on-insulator
pixel (SOIPIX) detector known as INTPIX4. In a typical laboratory setup, this
system requires only 1 second to measure a specified point. This is drastically
faster than the conventional system based on the $sin^{2} \psi$ method, which
requires more than 10 min, and the $cos \alpha$-based system using an imaging
plate, which requires 1 min. Compared to other systems, it can evaluate the 2D
distribution of residual stress faster and provide more detailed information
for evaluating materials. We first attempted to measure the 2D distribution in
a laboratory setup with a Cr X-ray tube (Cr K$\alpha$ 5.4 keV) and obtained
satisfactory results. We subsequently took measurements using synchrotron
monochromatic X-rays to determine the fine accuracy and fine sampling pitch
distribution. In this paper, we report the results of the initial synchrotron
experiment, including the residual stress distribution of the standard specimen
obtained by the first prototype setup. Furthermore, we compare the synchrotron
measurements with those from the laboratory.
