CERN-RD50

CERN-RD50
Name	RD50
Formation	1999
Location	Geneva, Switzerland
Parent organization	CERN
Focus	Radiation-hard semiconductor devices

CERN-RD50 CERN-RD50 is a collaborative research effort established at CERN to develop radiation hardening technologies for silicon detectors used in high-radiation environments like the Large Hadron Collider and its upgrades. The project brings together institutes from across Europe, North America, and Asia to pursue device physics, materials research, and sensor engineering for future particle physics experiments such as the High-Luminosity Large Hadron Collider, while interfacing with industrial partners and national laboratories.

Overview

RD50 coordinates long-term studies on radiation-tolerant semiconductor sensors and readout concepts for tracking and timing in experiments such as ATLAS, CMS, LHCb, and planned facilities like the Future Circular Collider and the Compact Linear Collider. The collaboration integrates expertise from institutions including DESY, INFN, CEA, NIKHEF, University of Oxford, University of California, Berkeley, Fermilab, Brookhaven National Laboratory, SLAC National Accelerator Laboratory, University of Tokyo, and IHEP (Beijing). RD50 activities span defect spectroscopy, device simulation, novel materials (e.g., diamond detectors), and prototyping for pixel and strip technologies relevant to upgrades driven by the High-Energy Physics community and the European Strategy for Particle Physics.

Research Objectives and Scope

The primary objective is to understand and mitigate radiation-induced degradation in silicon and alternative sensor materials to extend the lifetime and performance of trackers in high-fluence environments like the HL-LHC inner trackers and forward detectors. Key topics include bulk damage and defect levels characterized by techniques used at TRIGA reactors, pion and proton irradiation facilities at CERN Proton Synchrotron, and gamma irradiations at facilities such as SCK CEN. RD50 pursues development of low-gain avalanche detectors influenced by work at CNM Barcelona and Fondazione Bruno Kessler, exploration of 3D sensor geometries inspired by FBK and IMB-CNM efforts, and evaluation of wide-bandgap materials like chemical vapor deposition diamond and silicon carbide investigated at Stanford University and RWTH Aachen University.

Experimental Programs and Facilities

RD50 leverages test beams and irradiation testbeds including the CERN SPS, CERN PS, DESY II Test Beam, ELBE, IHEP test beams, and specialized facilities at Paul Scherrer Institute and TRIUMF. The program integrates detector fabrication at foundries collaborating with TSMC and Micron Technology as well as university cleanrooms like those at IMB-CNM and University of Manchester. Characterization uses apparatus from ATLAS Insertable B-Layer studies, CMS Phase-2 development, and measurement platforms derived from RD53 readout chip projects. RD50 employs simulation frameworks developed alongside GEANT4, TCAD, and software stacks contributed by CERN OpenLab partners and national computing centers such as GridPP and Open Science Grid.

Key Results and Impact on Detector Technology

RD50 has produced validated models of displacement damage and charge trapping effects that informed sensor choices for the ATLAS IBL, CMS Tracker Upgrade, and proposed High Granularity Calorimeter prototypes. The collaboration demonstrated enhanced charge collection in n-in-p and p-in-n sensor architectures and advanced annealing mitigation strategies influenced by studies at Hahn-Meitner-Institut and Max Planck Institute for Physics. Contributions include demonstration of radiation-hard 3D pixel sensors used in AFP and CMS Phase-1 Upgrade test modules, optimization of low-gain avalanche detectors aligned with timing projects at PICO and the LHCb upgrade, and material qualification campaigns for single-crystal diamond detectors used in beam condition monitors at LHC experiments. RD50 outputs have been incorporated into detector design reviews for ILC concept studies and influenced procurement specifications at major labs like CERN, Fermilab, and DESY.

Collaboration and Membership

The collaboration comprises universities, national laboratories, and research centers including University of Padua, University of Helsinki, Karlsruhe Institute of Technology, University of Geneva, University of Manchester, University of Liverpool, Czech Technical University in Prague, University of Toronto, McGill University, University of Illinois Urbana-Champaign, Seoul National University, Tsinghua University, and Kobe University. RD50 organizes working groups that coordinate with experiment-specific consortia such as ATLAS ITk, CMS Tracker, and LHCb VELO teams, and interfaces with industry partners including Hamamatsu Photonics, First Sensor, and Advacam. Governance follows collaborative structures similar to those used by CERN experiments and is supported by grant agencies like European Research Council, Marie Skłodowska-Curie Actions, National Science Foundation, Deutsche Forschungsgemeinschaft, and national ministries.

Future Directions and Upgrades

Future RD50 plans target sensor technologies for the extreme fluences expected at proposed colliders like the FCC-hh and upgrades of the HL-LHC inner trackers, emphasizing monolithic active pixel sensors influenced by developments in Tower Semiconductor and LFoundry processes, as well as advanced timing layers integrating LGAD and AC-LGAD variants. The roadmap includes expansion of irradiation campaigns at high-energy facilities such as CERN HiRadMat, development of standardized defect databases interoperable with INSPIRE-HEP and HEPData, and coordinated prototyping for experiments including ATLAS Phase-II and CMS Phase-II. Continued collaboration with materials science centers like CERN Materials Group and computational efforts using European Grid Infrastructure will support predictive modeling and accelerated qualification of next-generation radiation-hard detectors.

Category:Particle physics experiments Category:Detector development