The Laboratory of Physics of Gases and Plasmas

Lab's review - the research at the LPGP

The ‘Laboratoire de Physique des Gaz et des Plasmas’ of Orsay, founded in the 1960s, is a
Joint Research Unit (UMR 8578) attached to CNRS - INSIS/ (Institute of Engineering
Sciences & Systems) belonging to the CNRS (National Council for Scientific Research) and
Université Paris-Saclay, France. It carries out fundamental, experimental, and theoretical
research.
As a generalist laboratory, LPGP's activities focus on hot and cold plasmas. The leading
topics in hot plasma focus on ultra-high intensity laser-plasma interaction and laser-plasma
acceleration, while the studies in low-temperature plasmas concern out-of-equilibrium
situations. The interest of the latter lies in the fact that the various species present (electrons,
ions, atoms, or neutral molecules) have very different energies, enabling interesting combined
features of the gaseous medium such as ionization, high reactivity of the species formed, and
low temperature of the heavy particles, among many others.
Plasma is a gaseous medium that is at least partly ionized. Hence, the charged particles
(electrons and ions) and their interaction with the electromagnetic fields and boundaries
impose a special and sometimes unique behavior. Most of the universe comprises matter in
the plasma state (stars, sun, interstellar dust, magnetosphere, lightning, etc.). To study it,
plasma was reproduced in the laboratory, and over the years, it has known a growing interest
covering today a wide range of applications, as an alternative source of energy such as
thermonuclear fusion, to new technologies (bio-medicine, microelectronics, materials
deposition and processing, plasma propulsion, gas treatment, pollution control, etc.).


The main application fields cover:

• Bio-medical plasma treatment - cancer therapy
• Environment: destruction of atmospheric pollutants or bacteriological agents, surface
  sterilization and decontamination, combustion control
• Ultra-high-intensity lasers and their interaction with plasmas: radiation sources, GeV electron
  acceleration, ion acceleration, etc.
• Energy from fusion controlled by magnetic confinement: technology for ITER
• Materials: ultra-thin film synthesis, metal and polymer deposition and processing, powder
  synthesis and micro- and nano-structured materials, surface cleaning, etc.
• Transportation: combustion control, plasma propulsion.
• Reducing energy consumption: high-efficiency light sources, photo-tribology.
• Aerosol process control: charge and size quantification, selectivity, metrology, core-shell
  nanoparticles;
• Energy sources for Additive Manufacturing: electron beams, lasers, beam shaping and
  characterization, etc
  

Located in the Campus of the Orsay Faculty of Science of the University of Paris-Saclay, the
LPGP is France's oldest university plasma physics laboratory. It is also among the largest,
with a staff of about 60.

Research teams:

DEA - Electric Discharges and Aerosols

Fundamental objectives and applications:

• Electro-thermal characterization of electric discharges and modeling
• Production of nanoparticles by nucleation in electric discharges
• Aerosol charging for size and concentration diagnostics
• Post-discharge polymerization of (bio)-functional thin films

Read more

DIREBIO - Pulse discharges, high-pressure REactivities, and plasma-BIOlogy interfaces

Fundamental objectives and applications:

Research works carried out by DIREBIO, and applications concerned, are linked to the three themes Energy, Environment, and Health. In recent years and currently, the topics covered are:

• The kinetics of conversion of hydrocarbons and Volatile Organic Compounds in mixtures of atmospheric gases, in different types of plasma (homogeneous, diffuse, filamentary), with the main application being the reduction of polluting emissions (industry, transport, etc.) and to a lesser extent the triggering of combustion;
• The physics and reactivity of ultra-short (10 ns) pulsed discharges at very high voltage (50 kV and more), which generate a diffuse plasma in air at atmospheric pressure;
• The physics of micro-discharges and “plasma jets”, with application to the development of new materials for electronics, the conversion and synthesis of organic molecules, and bio-medicine;
• The interaction of plasmas with liquids and living matter (cells, microorganisms), particularly for application in oncology;
• The interaction of plasmas with surfaces for the development of mass spectrometry applied to global security, the detection of weakly volatile molecules;
• RF or DC discharge plasmas for the optimization of metal powders as part of work on the additive manufacturing of objects with complex geometry.

Read more

ITFIP - Intense Beam Interaction and Transport in Plasmas

Fundamental objectives and applications:

Experimental and theoretical study of laser-matter interaction in strong fields and the
transport and guidance of high laser intensities in plasmas. The main fields of application are
relativistic electron acceleration in sub-dense plasmas, secondary particle and energetic
radiation sources, high-energy-density physics, and the development of plasmas for advanced
accelerators.

The ITFIP team is active in the modeling and experimental implementation of electron laser
acceleration in plasmas. Several key elements for future plasma laser acceleration have been
proposed, validated, and studied, particularly the guidance of intense lasers in capillary tubes,
the development of new plasma targets, and the physical mechanisms of electron trapping and
acceleration for multi-stage acceleration applications.

This work is part of the scientific program for electron acceleration at the APOLLON
research facility (Paris-Saclay). It contributes to commissioning the APOLLON laser and the
long-focus room equipment. The team coordinates working groups in the EUPRAXIA (design
study and preparatory phase) and ARIES European projects.

The team uses and contributes to developing numerical codes (WAKE, WARP, FBPIC).
Experiments are conducted on French (UHI100, APOLLON) and European (LLC, Lund
Sweden) facilities.

Read more

TMP-D&S - Plasma Theory and Modeling - Discharges and Surfaces team

Fundamental objectives and applications:

The studies performed by the TMP-D&S team aim to understand the fundamental
mechanisms governing the power transfer to the plasma, mainly for magnetron and
microwave discharges. However, this knowledge proves useful insights for optimizing
numerous plasma processes or designing new plasma sources for various applications.
.
This research includes :

• Description of energy coupling (ionization and creation of active species) in low-pressure
  plasma and, more recently, at atmospheric pressure (microwaves, arc);
• Self-consistent modeling of plasma (0D, 1D, 2D, 3D) and time-dependent simulations of
  various plasmas, magnetized or not;
• Study of electron transport across magnetic field lines (an open problem in plasma physics);
• Modeling molecular fragmentation processes, species transport in discharges, discharges, and
  instabilities;
• Shaping of power lasers for various applications, including additive manufacturing, and use of
  lasers for advanced plasma diagnostics;
• Mastering and controlling plasma processes for interaction with surfaces;
• Studies of particle jets and their interaction with each other or with surfaces.

Read more

In memoriam Jean Bretagne

In memory of Jean BRETAGNE, who lived his scientific and humanist passions to the full.

It was with deep sadness that we learned of the death of Jean BRETAGNE, retired CNRS
Research Director, on July 28, 2021.
Jean BRETAGNE was a very appreciated physicist by their peers and colleagues, specializing
in atomic spectroscopy and plasma physics. He directed the ‘Laboratoire de Physique des Gaz
et des Plasmas’ (LPGP - Laboratory of Physics of Gases and Plasmas) from 1998 to 2004.

Read more