Investigation of the in-pixel response of the Mupix11 monolithic pixel sensor using a microfocus X-ray beam at Diamond Light Source

A. S. Rotelli; H. Augustin; D. Bortoletto; A. Brooks; M. Grimes; A. J. A. Knight; M. S. Köppel; A. E. McDougall; R. Plackett; D M S Sultan; L. Vigani; S. Wood

arXiv · 2604.24367

Investigation of the in-pixel response of the Mupix11 monolithic pixel sensor using a microfocus X-ray beam at Diamond Light Source

A. S. Rotelli·H. Augustin·D. Bortoletto·A. Brooks·M. Grimes·A. J. A. Knight·M. S. Köppel·A. E. McDougall·R. Plackett·D M S Sultan·L. Vigani·S. Wood

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Abstract

MuPix11 is a High-Voltage Monolithic Active Pixel Sensor (HV-MAPS) developed for the tracking system of the Mu3e experiment. The in-pixel photon response of a MuPix11 sensor thinned to 70 {\mu}m was measured using an 8 keV X-ray beam with a 3 {\mu}m spot size at the B16 beamline at Diamond Light Source, emulating the passage of a minimum ionising particle (MIP). At nominal operating voltage and threshold, high-resolution scans across the pixel matrix show the detector response to be uniform. In the absence of reverse bias (0 V), the relative sub-pixel response is location-dependent as a reduced detection rate is observed at pixel boundaries.

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A. S. Rotelli, H. Augustin, D. Bortoletto, A. Brooks, M. Grimes, A. J. A. Knight, M. S. Köppel, A. E. McDougall, R. Plackett, D M S Sultan, L. Vigani, S. Wood. 2026-04-27. Investigation of the in-pixel response of the Mupix11 monolithic pixel sensor using a microfocus X-ray beam at Diamond Light Source. https://arxiv.org/abs/2604.24367

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