Precise measurement of 3D-position of SiPMs in the liquid xenon gamma-ray detector for the MEGII experiment.

We developed two complementary ways to measure the position of SiPMs inside liquid xenon detector for MEG II experiment; one uses laser tools and the other uses an X-ray beam. We measured the position of all SiPMs to an accuracy of 320 μ m. • Precise alignment of SiPMs in liquid xenon detector with X-ray and laser. • The SiPM array is scanned with X-ray beam that makes a local energy deposit. • Reconstructed 3D SiPM array from an image taken by a laser scanner. • Reasonable thermal contraction was observed from the comparison. • Consistent shape of the SiPM array measured by two measurements. [ABSTRACT FROM AUTHOR]