Applied Physicist - Detector Simulation Software Developer (EP-SFT-2024-184-LD)

At CERN, the European Organization for Nuclear Research, physicists and engineers are probing the fundamental structure of the universe. Using the world's largest and most complex scientific instruments, they study the basic constituents of matter - fundamental particles that are made to collide together at close to the speed of light. The process gives physicists clues about how particles interact, and provides insights into the fundamental laws of nature. Find out more on http://home.cern.

Introduction

In the Experimental Physics Department (EP), Software Development for Experiment Group (SFT), you will be responsible for maintaining, developing and validating different physics codes to simulate particle interactions in HEP detectors. You will be involved in an ongoing programme of work aimed at extending physics coverage and modelling capabilities and working on new developments to improve computing performance.

You will join the Simulation team, which is responsible for maintaining and developing the Geant4 toolkit. Geant4 offers comprehensive detector and physics modelling capabilities, covering various particle interactions across an extensive energy spectrum. The toolkit incorporates various implementations of physics processes, providing multiple approaches to initial interactions and subsequent fragmentations. An ongoing initiative aims to expand the physics coverage and modelling capabilities to meet the demands of future projects, including next-generation experiments such as the Future Circular Collider, FCC. This includes software enhancements to improve computing performance, a field where you will be expected to take on a pivotal role.

Functions

In this role you will:

• Act as a bridge between physicists working on the LHC experiments and the authors of the codes implementing the various physics models, in particular comparing the results of simulations with real data recorded at the LHC and in test beams to identify and address underlying deficiencies of physics modelling.
• Take a leading role in maintaining and developing the Geant4 toolkit, focusing on validating new releases, identifying issues affecting physics accuracy and software performance, and ensuring the robustness of future releases.
• Contribute to the maintenance and development of the validation and testing suite of Geant4, Geant-Val. In particular, ensure that the relevant thin-target data and calorimeter test-beam measurements are integrated into the validation framework.
• Take part in the overall project organization, such as the plan of work, arranging for workshops and training, and representing the project and its vision.
• Engage with Geant4’s worldwide user community, foster collaboration, in the SFT group, EP department and CERN, and external contributions, e.g. from laboratories and universities.
• Supervise team members and coordinate tasks relevant to the Geant4 project.

PhD or equivalent relevant experience in the field of Particle Physics, Nuclear Physics or a related field or a related field.

Experience:

The candidate should have experience in the following areas:

• Monte Carlo techniques applied to particle transport simulation, in particular regarding hadronic physics effects.
• Scientific computing and deep knowledge of advanced programming
• Large collaborative software projects, particularly Monte Carlo simulation toolkits, relying on continuous integration, code reviews, as well as issue-based work.
• Tools and methods that support all phases of the life-cycle of large scientific code bases, in particular design, coding, testing, and optimization of software performance.
• Track record of scientific publications and high-level communication (for instance through invited conference presentations).
• Knowledge of modern software technologies, such as Machine Learning techniques, and hardware architectures, such as GPUs, would be considered an advantage.
• Supervision and managing of external contributors will be considered an advantage.

Technical competencies:

• Simulation, design and development of (parts of) detectors: with emphasis on the Monte Carlo data simulation step.
• Knowledge of programming techniques and languages: in particular, proficiency in the C++ programming language and in state-of-the-art software development tools.
• Development of application software: in particular of high-performance particle transport toolkits, including related advanced physics models.
• Testing, diagnosing and optimization of software
• Knowledge and application of software life-cycle tools and procedures

Behavioral competencies:

• Achieving Results: having a structured and organised approach towards work; being able to set priorities and plan tasks with results in mind Delivering high quality work on time and fulfilling expectations
• Learning and Sharing Knowledge: sharing knowledge and expertise freely and willingly with others; coaching others to ensure knowledge transfer
• Demonstrating Flexibility: adapting quickly and resourcefully to shifting priorities and requirements
• Communicating Effectively: expressing opinions, ideas and suggestions with conviction and in a logical/structured manner; keeping to the point

Language skills:

Spoken and written English: ability to understand, speak and write in professional contexts.

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.

This vacancy will be filled as soon as possible, and applications should normally reach us no later than 19th of January 2025 at 23:59 CET.

Employment Conditions

Contract type: Limited duration contract (5 years). Subject to certain conditions, holders of limited-duration contracts may apply for an indefinite position.

Working Hours: 40 hours per week

This position involves:

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

Job grade: 6-7

Job reference: EP-SFT-2024-184-LD

Benchmark Job Title: Applied Physicist