Post-doctoral Position: Detector Group/SEXTANTS Beamline

Post-doctoral Position: Detector Group/SEXTANTS Beamline

SOLEIL Synchrotron

Saint-Aubin, France

As part of an instrumentation upgrade program, SOLEIL is developing a new time-resolved 2D detector system dedicated to pump–probe experiments in the soft X-ray range (300 eV – 1 keV). This project is part of the “SOLEIL” targeted project of the ANR PEPR DIADEM research program which is devoted to high throughput data acquisition, automation data analysis at Synchrotron SOLEIL.

The detector will be installed on the SEXTANTS beamline and will enable diffraction and imaging experiments with sub-nanosecond time resolution.

The system combines:

• A microchannel plate (MCP) electron multiplier for X-ray photon-to-electron conversion and amplification;
• A fast phosphor screen for electron-to-visible photon conversion;
• A dedicated optical coupling system;
• A Timepix3 Quad hybrid pixel detector (512 × 512 pixels, 55 µm pitch) with event-driven readout and pixel-level timestamping at the nanosecond scale.

This postdoctoral project focuses on the design, optimization, integration, and commissioning of the complete detection chain.

Scientific and Technical Objectives

The main objective is to design and implement a high-performance, time-resolved detector optimized for soft X-ray pump–probe experiments.

Key challenges include:

• Modelling and optimizing detection efficiency and signal-to-noise ratio;
• Designing and validating the optical coupling system;
• Ensuring nanosecond-scale gating capability;
• Maximizing spatial and temporal resolution;
• Integrating the detector into the SOLEIL control system (TANGO);

Particular emphasis will be placed on timing performance at the nanosecond scale, high-rate event-driven acquisition, and detector operation under ultra-high vacuum conditions.

Responsibilities

The postdoctoral researcher will contribute to the following tasks:

• Modelization and characterization of the detector in laboratory and beamline environments;
• Optimization of detector performance (gain, timing, and gating configuration);
• Participate in optical system design and alignment;
• Develop and validate calibration procedures;
• Development and optimization of data processing algorithms (clustering, timing corrections, centroiding);
• Lead detector commissioning and performance evaluation at the beamline;
• Contribute to technical documentation and scientific publications.

The project is interdisciplinary and involves close collaboration with detectors, optics, vacuum, and beamline scientists, as well as with mechanical engineering, data acquisition, and motion control teams.

The position is hosted within the Detector Group at Synchrotron SOLEIL, under the supervision of a detector scientist, and in close collaboration with the SEXTANTS beamline team.

Expected Profile

Required:

• PhD in experimental physics, detector physics, instrumentation, or a related field;
• Strong background in radiation detectors or fast timing systems;
• Data acquisition and analysis skills (Python and/or C++);
• Ability to work in a multidisciplinary technical environment.

Desirable:

• Experience with vacuum systems and/or photon/electron detection;
• Experience with MCP-based detectors;
• Knowledge of hybrid pixel detectors;
• Experience in synchrotron or X-FEL environments.