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Introduction

The ATLAS experiment is preparing its track reconstruction software for the innermost tracking system (ITk) and the Muon Spectrometer (MS) to meet the stringent requirements of the High-Luminosity (Phase-2) upgrade. This software will be integrated into a common framework, based on the ACTS (A Common Track Reconstruction) toolkit, which is used both in the online event filter as well as for offline data reconstruction.

The ATLAS Data Processing Group (ADP), within CERN’s Experimental Physics Department (EP), is seeking for three highly skilled and motivated software specialists to boost development and take a leading role in this area. The Next Generation Trigger project was setup for this purpose.

As a successful candidate, you will:

• take core responsibilities in the ACTS project and work on the ATLAS Core Software suite with a particular focus on ensuring an optimal leverage of the capabilities of ACTS within ATLAS for event filter and offline applications. This work will include establishing automated testing and reporting pipelines that guarantee coherent development and integration efforts of ACTS into the ATLAS software stack and into other ACTS client software ecosystems.

or

• design and develop the event filter tracking strategies for the ITk and MS, and evaluate their suitability and performance for the ATLAS Phase-2 program. This will include R&D on track reconstruction offloaded to accelerators (FPGAs and GPUs), and the usage of machine learning based approaches, such as Graph Neural Networks and related fast inference models to boost the expected EF performance of ATLAS.

Functions

You will:

• Design and develop software packages for the ACTS open-source track reconstruction suite,
• Ensure the successful deployment of the completed ACTS software suite in ATLAS during the Phase-2 upgrade,
• Carry out R&D on modern reconstruction algorithms optimised for the ATLAS Phase-2 track reconstruction,
• Design and implement automated tooling and validation pipelines for performance testing and harmonisation of ACTS and ATLAS development,
• Contribute to the evolution of ATLAS’s Core Software in preparation for the Run-4 data taking,
• Supervise students and fellows who will work with you on the Phase-2 tracking software upgrade project.

PhD or equivalent relevant experience in the field of particle physics or a related field.

Experience:

• Excellent understanding of the tracking challenges in high track density environments, as for the High Luminosity LHC,
• Hands-on experience in the development of experiment software and in the design and implementation of complex tracking packages,
• Hands-on experience in managing software development workflows and release integration,
• Experience in setting up automated testing and validation workflows,
• Ability to lead development and performance evaluation teams and to define directions for future upgrade software developments.

Technical competencies:

• Knowledge and application of physics reconstruction techniques
• Knowledge of programming techniques and languages software development
• Knowledge of emerging Technology Monitoring,
• Knowledge of C++ and Python (incl. software development workflows: git, JIRA, Continuous Integration testing),
• Testing.

Behavioural competencies:

• Achieving Results: defining clear objectives, milestones and deliverables before initiating work/ project Following through on new ideas and innovations; planning and implementing application Taking appropriate corrective actions and adapting work / project plans if necessary.
• Solving Problems: addressing complex problems by breaking them down into manageable components Producing workable and timely solutions that meet requirements Being open to original ideas and creative options by which to address issues; continually driving change by seeking new ways to improve outcomes.
• Working in Teams: building and maintaining constructive and effective work relationships Working well in groups and readily fitting into a team; participating fully and taking an active role in team activities.
• Communicating Effectively: delivering presentations in a structured and clear way; adjusting style and content to the audience; responding calmly and confidently to questions Ensuring that information, procedures and decisions are appropriately documented.

Language skills:

Ability to draw-up technical specifications and/or scientific reports and to make oral presentations in English. The willigness to acquire French will be an asset.

Eligibility and closing date:

Diversity has been an integral part of CERN's mission since its foundation and is an established value of the Organization. Employing a diverse workforce is central to our success. We welcome applications from all Member States and Associate Member States.

This vacancy will be filled as soon as possible, and applications should normally reach us no later than 19.03.2024.

Employment Conditions

Contract type: Limited duration contract (3 years). Subject to certain conditions, holders of limited-duration contracts may apply for an indefinite position.

These functions require:

• Work during nights, Sundays and official holidays, when required by the needs of the Organization.

Job grade: 6-7

Job reference: EP-ADP-OS-2024-18-LD

Benchmark Job Title: Applied Physicist