CERISES
The CERISES (Collision and Reaction of Selected Ions by Threshold Electrons) assembly is an experimental device unique in the world, allowing the study of the elementary act of ion-molecule reactivity in a dilute medium. It is a tandem mass spectrometer, based on radiofrequency ion guides, which combines an ion source based on photoionization by synchrotron radiation with an analysis of their reactivity.
CERISES instrument schematic diagram
The use of variable wavelength VUV radiation (from SOLEIL synchrotron) combined with threshold electron coincidence methods allows the internal energy of the ions to be controlled. The control of the absolute pressure in the reaction cell via a baratron and the ion acceleration conditions make it an instrument allowing the measurement of absolute reaction cross sections as a function of the internal energy and the kinetic energy provided by the reactive species during the collision.
The platform describes chemical reactions occurring in plasmas, whether space or industrial, and provides quantitative information on internal energy effects (selected states) and collisions energy effects. The measurements provide quantitative information (absolute reaction cross sections and branching ratios) necessary for understanding and modeling the plasmas considered. Ions can be produced by photoionization and electronic impact of neutral precursors, radicals generated by pyrolysis and aggregates.
CERISES installed on the DESIRS beamline at the SOLEIL synchrotron.
Christian Alcaraz (CNRS Senior Researcher), Claire Romanzin (Associate Professor Paris-Saclay) and Roland Thissen (CNRS Senior Researcher, Manager), Nicolas Solem (PhD Student)
The CERISES platform is a platform associated with the SOLEIL synchrotron: as such, it participates in welcoming external users on the DESIRS beamline, which delivers photons in the VUV range, between 4 and 40 eV. About ten research groups, mainly international, regularly propose measurement projects on the platform via competitive calls for projects of SOLEIL synchrotron.
On average, 90 measurement shifts (8 hours) are carried out on the synchrotron each year, divided into 6 measurement sessions, requiring the instrument to be moved between the ICP laboratory and SOLEIL Synchrotron, as well as the associated dismantling, installation, and calibration operations.
The scientific production associated with the CERISES platform is accessible via this direct link.
Collaborations
Daniela Ascenzi (University of Trento, Italy), Miroslav Polasek and Jan Zabka (Heyrovsky Institute of Physical Chemistry, Prague, Czech Republic), Wolf Geppert (Stockholm University, Sweden), Emilie Zins (Sorbonne University, Paris), Ugo Jacovella (ISMO, U P Saclay), Stéphane Pasquiers (LPGP, Orsay), Alexandre Zanchet (Complutense University of Madrid, Spain), Karoly Vekey (Budapest University, Hungary), James Lyons (Arizona State University, USA).