Jun 25 – 29, 2023
Ole-Johan Dahls Hus
Europe/Oslo timezone

Balancing gain and dynamic range in a 25 μm pitch hybrid pixel detector

Jun 28, 2023, 2:20 PM
Simula Auditorium (Ole-Johan Dahls Hus)

Simula Auditorium

Ole-Johan Dahls Hus

Oslo Science Park Gaustadalléen 23B, 0373 Oslo
Oral Frond-end Electronics and Readout Front-end Electronics and Readout


Dr Julian Heymes (Paul Scherrer Institut)


MÖNCH is a hybrid pixel detector featuring 25 μm pixel pitch and analogue readout for X-ray imaging at synchrotron radiation (SR) facilities. Sub-pixel spatial resolution has been demonstrated using charge sharing and interpolation algorithms [1]. The current prototype version, MÖNCH0.4, features 19 different pixel architectures to assess the design choices and components for an optimised architecture to be used at SR facilities, and to explore the potential use of dynamic gain switching in fine pitch pixels for applications at X-ray free electron lasers (XFELs).

Previous characterisation results of the pixel architectures without dynamic gain switching have shown noise levels as low as 21.7 e$^{-}$ r.m.s. [2], which have now been pushed to sub-20 e$^{-}$ r.m.s at room temperature using standard 300 μm-thick silicon sensors. Achieving low noise values however requires high conversion gain and necessitates design choices such as the simplification of the pixel architecture (e.g. by limiting the available choice of in-pixel gains). These compromises ultimately restrain the available dynamic range and prevent the use of MÖNCH with LGADs [3] or high-Z sensors because of the large signals (internal amplification and high photon energies, respectively) and of large leakage currents.

In this presentation, we will introduce the MÖNCH project followed by a description of the current prototype along with characterisation results of the pixel architectures without dynamic gain switching for synchrotron applications with an emphasis on noise and dynamic range. These experimental results will be used to fine-tune the design of MÖNCH0.5 to validate the final pixel design. This small prototype should also include additional features from the continuous developments of the PSD detector group towards a full-scale 2 × 3 cm$^{2}$ MÖNCH1.0.

[1] A. Bergamaschi et al., Synchrotron Radiation News 31:6 (2018), 11‐15
[2] J. Heymes et al., Poster presented at: 23 rd iWoRiD. 27 June 2022; Riva del Garda (IT)
[3] J. Zhang et al., JINST 17 C11011 (2022)

Primary authors

Dr Julian Heymes (Paul Scherrer Institut) Filippo Baruffaldi (Paul Scherrer Insitut (Switzerland)) Anna Bergamaschi Maria del Mar Carulla Areste Roberto Dinapoli (Paul Scherrer Institut) Erik Fröjdh (Paul Scherrer Institut) Dominic Greiffenberg Dr Viktoria Hinger (Paul Scherrer Institut) Dr Davide Mezza (Paul Scherrer Institut) Konstantinos Moustakas Aldo Mozzanica Kirsty Paton (Paul Scherrer Institut) Bernd Schmitt Xiangyu Xie (Paul Scherrer Institut) Jiaguo Zhang (Paul Scherrer Institut)

Presentation materials