Your responsibilities

The Event Filter (EF) is part of the ATLAS Trigger and Data Acquisition (TDAQ) system and will consist of a multi-threaded asynchronous processing farm of commodity servers (including CPUs with or without accelerators) running a subset of offline-like reconstruction algorithms and menu-driven event selection. It processes event data from the Dataflow system and provides the accept/reject decision and selected reconstruction data for offline storage. The high luminosity (and consequently high pile-up) conditions expected in Phase-II give rise to specific challenges for the object and event reconstruction algorithms planned for the EF, in particular for track reconstruction.

ATLAS plans to develop the most effective and performant solution for the EF tracking and deploy it on the most suitable hardware architecture employing standard numerical and Machine Learning models.

The selected candidate will part of the CERN ATLAS Data Processing team. He or she will take responsibilities in the development and deployment of EF tracking solutions, with focus on ML-based approaches to tracking. In particular, the candidate will investigate the use of Graph Neural Networks (GNN) for EF track reconstruction algorithms aiming at implementing a prototype chain in which part of the algorithms are ported to systems with co-processors. The candidate will also work on providing physics and computation performance evaluation of the configuration studied.

This position is part of the Next Generation Trigger programme (https://cern.ch/nextgen-proposal).

Your profile

Skills and/or knowledge

• Experience with modern C++ programming techniques, preferably with experience with offloading to hardware accelerators.
• Competence with developing, training and evaluating performance of ML-based algorithms, particularly with GNN.
• Interfacing ML models with production HEP software stacks.
• Knowledge of track reconstruction concepts in HEP experiments.
• Proficiency with software development tools in a Linux environment is a requirement

Eligibility criteria:

• You are a national of a CERN Member or Associate Member State. 
  A limited number of positions are also available to candidates from Non-Member States. 
• You have a professional background in Particle physics / computer science (or a related field) and have either:
  • a Master's degree with 2 to 6 years of post-graduation professional experience;
  • or a PhD with no more than 3 years of post-graduation professional experience.
• You have never had a CERN fellow or graduate contract before.

Job closing date: 09.04.2024 at 12:00 AM (midnight) CET.

Job reference: EP-ADP-OS-2024-50-GRAP

Contract duration: 24 months, with a possible extension up to 36 months maximum.

Target start date: 01-May-2024

This position requires:

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

What we offer

• A monthly stipend ranging between 6194 and 6808 Swiss Francs per month (net of tax).
• Coverage by CERN's comprehensive health scheme (for yourself, your spouse and children), and membership of the CERN Pension Fund.
• Depending on your individual circumstances: installation grant; family, child and infant allowances; payment of travel expenses at the beginning and end of contract.
• 30 days of paid leave per year.
• On-the-job and formal training at CERN as well as in-house language courses for English and/or French.

About us

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.

We are on a Quest. A Journey into discovery like no other. Bring your expertise to our unique work and develop your knowledge and skills at pace. Join world-class subject matter experts on unique projects, in a Quest for greater knowledge and deeper understanding.

Begin your CERN Quest. Take Part!

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.