arXiv subjects

Patrick Sieberer

Publications and source records attributed to Patrick Sieberer.

4 recordsLinked to original sources

arXiv2026

The RD50-MPW4: A Radiation Hard HV CMOS Sensor for Future Colliders

The former CERN RD50 collaboration develops monolithic active pixel high voltage (HV) CMOS sensors for future colliders with the aim of high radiation tolerance, good time resolution, and high granularity pixel detectors. The most recent prototype, the RD50-MPW4, was produced by LFoundry in December 2023 using a 150 nm CMOS process. It features a matrix of 64x64 pixels with a 62 $\mu$m pitch and employs a column-drain readout architecture. Compared to its predecessor, it now has separate analog and digital power domains and a new biasing scheme with a guard ring structure that supports bias voltages over 600 V. This contribution will discuss the design and latest results of the MPW4, where tests with unirradiated samples showed more than 99.9% efficiency, 16 $\mu$m spatial resolution and 10 ns timing resolution. Efficiencies of over 99% were achieved for samples irradiated to fluences of $1 \times 10^{15}$ 1 MeV n$_{\mathrm{eq}}/\mathrm{cm}^2$. A 3D map of the charge collection efficiency from a measurement with two-photon absorption laser is presented that nicely outlines the depletion depth of this radiation hard, high granularity monolithic active pixel sensor.

physics.ins-det↗

arXiv2026

TPA-TCT analysis of the RD50-MPW4 monolithic pixel particle detector

The RD50-MPW4, a Depleted Monolithic Active Pixel Sensor (DMAPS) was analyzed using a Two Photon Absorption Transient Current Technique (TPA-TCT). This technique provides sensitivity maps with micrometer-scale spatial resolution, enabling the resolution of the boundaries of the detector's sensitive volume, even for small-area pixels (62 x 62 $\mu$m$^2$ in this study). With a 3D resolution, the depletion depth, the boundaries of the detector electric field, the 3D hit detection efficiency and the charge sharing between neighboring pixels were measured. The RD50-MPW4, a multi-project wafer chip developed by the HV-CMOS working group within the CERN RD50 collaboration, features a 64 x 64 DMAPS pixel matrix. Illuminating the chip from the backside, the TPA-TCT technique can characterize any pixel element in the matrix because silicon is transparent for near infrared laser light (1550 nm). Electron-hole pairs are generated only around the light focal point, deep in the silicon, so that any charge collected is precisely only from the focal point. With the TPA-TCT technique, the RD50-MPW4 was found to be have a 100% hit detection efficiency under specified conditions and an effective depletion depth of 226 $\mu$m. It was also found that part of the charge in the periphery of the pixel was collected in the neighboring pixel. A 3D map of the sensor clearly shows the in-pixel electronics and the limits of the depletion region.

physics.ins-det↗

arXiv2022

Readout system and testbeam results of the RD50-MPW2 HV-CMOS pixel chip

The RD50-CMOS group aims to design and study High Voltage CMOS (HVCMOS) chips for use in a high radiation environment. Currently, measurements are performed on RD50-MPW2 chip, the second prototype developed by this group. The active matrix of the prototype consists of 8x8 pixels with analog front end. Details of the analog front end and simulations have been already published earlier. This contribution focuses on the Caribou based readout system of the active matrix. Each pixel of the active matrix can be readout one after the other. Relevant aspects of hardware, firmware and software are introduced. As a first stage, firmware for a standalone setup is introduced and details on data flow are given. Afterwards, a second stage of the firmware capable of synchronizing with other detectors and accepting triggers is presented, focusing on operation of the chip in combination with a tracking telescope to measure efficiency and residuals.

physics.ins-det↗

arXiv2022

RD50-MPW3: A fully monolithic digital CMOS sensor for future tracking detectors

The CERN-RD50 CMOS working group develops the RD50-MPWseries of monolithic high-voltage CMOS pixel sensors for potential use in future high luminosity experiments such as the HL-LHC and FCC-hh. In this contribution, the design of the latest prototype in this series, RD50-MPW3, is presented. An overview of its pixel matrix and digital readout periphery is given, with discussion of the new structures implemented in the chip and the problems they aim to solve. The main analog and digital features of the sensor are already tested and initial laboratory characterisation of the chip is presented.

physics.ins-det↗