Post-doctoral researcher (M/F) on generative model applied to calorimeter simulationodèle génératif appliqué à la simulation calorimétrique

The post-doctoral fellow will work in the software development team of the IJCLab laboratory, together with members of the ATLAS LHC experiment.
The work will be done in the context of the European InterTwin (https://www.intertwin.eu/) project, which aims at designing and building a prototype of an interdisciplinary Digital Twin Engine. IJClab, in collaboration with CERN, is developing a High Energy Physics use case centred on calorimeter simulation using generative models.
He will develop an advanced generative model algorithm for calorimeter simulation (leveraging on existing literature and Proof-of-Concepts) and port it to itwinai, the InterTwin engine. The work will be supervised by David Rousseau and Françoise Bouvet.
In the scope of the Large Hadron Collider and future ILC and FCC colliders, the resource usage of detector simulation, in particular calorimeter simulation, has been identified as a bottleneck. This delicate task is traditionally done with Geant4, which tracks the thousands of secondary particles across a finely described virtual detector for each incoming particle. The HEP community has embarked on emulating Geant4 simulation with generative models, initially GAN and VAE, more recently diffusion model or dedicated hybrid architectures.
Current state-of-the-art architectures and open datasets will be reviewed. A baseline algorithm will be developed and ported on itwinai, the new InterTwin engine, which supports training and inference. Particular attention will be paid on in depth validation of the algorithm with physics informed features.

The post-doctoral fellow will be in charge of the following specific activities :
● Develop innovative simulation algorithms for calorimeter in High Energy Physics context
● Port and validate algorithms within the Intertwin engine
● Communicate on this work via written reports and oral presentations within InterTwin and in the HEP community via papers and conference presentations

The expected outcome is a fully functional generative algorithm for calorimeter simulation running in the InterTwin engine.

The Irène Joliot-Curie Physics Laboratory of 2 Infinities (IJCLab) is laboratory (UMR) under the supervision of the CNRS (IN2P3), the University of Paris-Saclay and the University of Paris is located on the campus of the University of Paris -Saclay in Orsay. The laboratory is located on the campus of Université Paris-Saclay in Orsay. The campus is located 20 km south of Paris and accessible by RER in 35 minutes.
IJCLab was born in 2020 from the merger of five units (CSNSM, IMNC, IPN, LAL, LPT). The staff comprises nearly 560 permanent (340 engineers, technicians and administrators and 220 researchers and teacher-researchers) and approximately 200 non-permanent, including 120 doctoral students. The research themes of the laboratory are nuclear physics, high energy physics, theoretical physics, astroparticles, astrophysics and cosmology, particle accelerators, energy and the environment and health.
IJCLab has very significant technical capacities in all the major fields required to design, develop/implement the experimental devices necessary for its scientific activity, as well as the design, development and use of instruments.
For this specific project, IJClab hosted key authors of the recently published first GAN-based fast simulation of the ATLAS electromagnetic calorimeter ( CSBS 8, 7 (2024), https://link.springer.com/article/10.1007/s41781-023-00106-9) .
The successful candidate will have access to IJCLab computing resources, to on-campus resources (Ruche, Jean Zay) as well as to IN2P3 Compute Center in Lyon (an LCG Tier1).
Depending of his/her background, he/she may be registered in ATLAS and thus will have access to CERN computing resources and all ATLAS worldwide compute powers.
IJCLAB bases its recruitment policy on the promotion of equality, diversity and inclusion. These values are essential to the professional development of our staff, who are key players in our collective success, and to the development of the laboratory itself.