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I am an experimental physicist interested in instrumentation and detector applications for fundamental physics and medical imaging.
Thesis and Post-Doc (1988-1992) :
After my initial education in general physics, my PhD thesis work was devoted to the calibration of a Weakly Interacting Massive Particles (so called WIMPs) dark Matter detector (Li-compensated 200 g silicon diodes) sensitive to atomic recoils within the crystal. The motivation was to the search of "Cosmions" a candidate particle, assumed to contribute to the Dark Matter of the universe and to the heat transport from the center to the periphery of the Sun.
Then I went as a Post-Doc to the Centre for Particle Astrophysics, University of California of Berkeley, under the supervision of Prof. B. Sadoulet.
This laboratory, is internationally recognized for its competence in very low temperature physics and instrumentation, such as SQUID technologies, dual-detection bolometers, and dilution cryostats. Working near the Silicon Valley, with its excellent engineers, has also proved highly instructive for me for learning very low noise electronics.
EDELWEISS Experiment - WIMPs Dark Matter search - Cosmology (1993-1997) :
Back in France, I was was able to apply and broaden my taste for high-technology instrumentation and data analysis, by contributing to the Edelweiss-0 collaboration. After three years, I became one of its managers, sharing responsibilities with L. Dumoulin for the overall design of the Edelweiss 0 collaboration instrument, installed in the « Laboratoire Souterrain de Modane ». This has been a successful experiment, which has improved the limits on low mass WIMPs cross-section by a factor 10. I was the first in France, and 2nd worldwide, to operate a dual-detection bolometer (ionization/heating). Together with L. Dumoulin, we developed the first resistive thermometry bolometers sensitive to ballistic phonons.
Planck/HFI satellite - Primordial Universe - Large Scale Structure formation - Cosmology (1997-2012) :
In 1997, I began work on the Planck satellite project, mainly on the low noise readout electronics of the bolometer detectors.
In 2001, JL Puget (Planck/HFI Principal Investigator) asked me to coordinate the design effort of the sky-observing bolometer environment, in order to ensure optimum noise performance (and the corresponding status in the collaboration: a Co-Investigator position).
This was a challenging assignment: any power dissipated in the bolometer detectors greater than 10-17 W would pollute the physical signal. Space technologies are known to be robust, but noisy. The problem to be solved was that of developing a model for the mechanisms which contaminate the bolometer signals, and then of approaching the space agencies (ESA, CNES), universities (in the UK, Italy and USA), laboratories and aerospace companies (Jet Propulsion Lab, Alcatel Space, Astrium, Galileo Avionica, etc.) in order to make the instrument insensitive to both electrical and mechanical disturbances, in a very low temperature environment.
Together with J. Panh, who is an Electromagnetic Interference/Electromagnetic Compatibility engineer at CNES, we have been involved in all the electrical aspects of the readout electronics, the wiring, and the mechanical design of the focal planes of both satellites instruments (HFI and LFI). We gained approval for the implementation of 24 isolating elements in the satellite's and instrument's mechanical structure to thus take control over the ground current flows. Ultimately, after four years of work, diplomacy, measurements, total success was achieved. No electromagnetic or microphonic disturbances have been detected within the Planck/HFI data, making this instrument the "most sensitive photometer in the universe".
More informations can be found at http://public.planck.fr/.
In parallel, I was involved in the science team, preparing the Satellite’s Data Analysis. I first worked on the science software library, produced tools for simulating the observed sky signal and an optimized sky-map reconstruction software named MIRAGE publicly available on the net (?URL?).
Then I focussed with my students and collaborators on the understanding and the Cosmological exploitation of the galaxy Clusters detected with Sunayev-Zeldovitch Effect catalogs (so called SZ-Cluster catalog), made available by the Planck satellite observations.
Archeops (1999-2003) and Olimpo (2004-2009) balloon experiments - Primordial Universe Observation :
In the Archeops collaboration, I worked on science data analysis and sky maps reconstructions developing and using the MIRAGE algorithm.
In the Olimpo experiment, I designed and managed the development of the cryogenic harness, in-flight calibration systems for the bolometer's camera, as well as the bolometer readout electronics. All devices have been delivered in advance, and their performance are better than that required by the specifications.
CaLIPSO (2009 - Today) :
The aim of the CaLIPSO project (French acronym for Calorimètre Liquide Ionisation Position Scintillation) is to develop the proof of concept of a fast-response, high efficiency gamma detector. It is a time projection chamber, with excellent spatial resolution, using an organometallic liquid, the TriMethyl Bismuth (TMBi) for the room temperature detection medium.
This innovative liquid has never been used for particle detection. It allows a very efficient and accurate detection of positron annihilation. Once fully developed and integrated with an acquisition system It may become a key technology for PET imaging (Positron Emission Tomography imaging), but also for the analysis of nanometric defects in material science.
More precisely, the detector performances would allow efficient, 1mm3 resolution PET imaging of the whole human brain, when the reference PET-scan for brain imaging, the HRRT form Siemens shows (2.5 mm)3 voxel size. Such spatial resolution is typical of clinical Magnetic Resonnance imagers (MRI).
In addition PET imaging has shown the ability to image and quantify biochemical cellular activity at concentrations down to 10-12 mol, when MRI imager have access to 10-4 mol concentrations, using contrast enhancers.
Thus such a High resolution PET imager would be an excellent complement of MRI imagers for diagnosis and follow-up in medical research, when high resolution is mandatory. This is the case in neurology, in the case of neurodegenerative diseases, as well as for drug testing on rodent animal models.
Physicist at CEA Saclay/IrfU, Department of Particle Physics since 1992.
Age : 49
1985 : Ecole Normale Supérieure de St Cloud (College, Major in Physics)
1989 : Certificate of aptitude for teaching (French ‘Agrégation’ diploma) in Physical Sciences, major in Physics (competitive examination for a teaching position)
1988-1991 : PhD in Particle Physics, (Search for Dark Matter, Paris VI University)
1991-1992 : Post-Doc at UC Berkeley.
2000 : Accreditation as Research Supervisor (Habilitation Diploma) (bolometer based instruments, Paris VI University).
Responsibilities, committees and work supervision :
1997- Today : Co-Investigator for the Planck/HFI satellite experiment. Former Member of the Satellite System Team and Science Core Team. Cordinating the effort for detector noise optimisation, readout, cryogenic harness, Electromagnetic Compatibility, in the context of large spacecraft international collaboration (ESA, CNES, ASI, NASA).
1997- 2012 : Coordinator of the “millimeter wave cosmology group” at IRFU/SPP.
2004-2009 : Coordinator of the french participation to the Olimpo Balloon experiment.
2008-2012 : Member of the department's recruitment committee.
2007 : Organising Committee Low Temperature Detector, LTD-12 Paris. http://ltd12.grenoble.cnrs.fr/
2008- Today : Scientific head of the CaLIPSO project.
2010- Today : Coordinator of the medical imaging group at IRFU/SPP.
2010-Today : Member of the "Conseil d'Unité" of the Institute.
PhD students :
Ph. Di Stéfano,(PhD 09/1998), Bolometer instrumentation and Dark Matter Search. Now Professor at Queen's University, Canada.
JB. Juin, (PhD, 09/2005), Cosmology with clusters of galaxy observed with the Sunyaev Zel'dovitch effect, (Olimpo and Planck Data).
J. Démoclès, (PhD 09/2010), Cosmology with SZ-clusters of galaxy (Simulation of observations and X-Rays XMM Data analysis). Now Post Doc. at Birmingham University.
E. Ramos, (PhD 12/2014), The CaLIPSO optical Detector, Now training to become a Medical Physicist with the French DQPRM Diploma.
135 publications, h-index : 44 (date 14/04/2015)
My publication list can be found at the following urls :
pdf list : Yvon-chrono-Brief-Format.pdf
2 Patents :
This patents have been filed to protect our work on the CaLIPSO detector
• D. Yvon, J-Ph Renault, « Détecteur de photons à haute énergie » (High energy photon detector), CEA - Patent, Ref: FR 1 052 047, 22 March 2010, and WO2011/117158 A1.
• D. Yvon, « Détecteur de photons à haute énergie », CEA - Patent, 12 Nov. 2013, Reference: 13 61037.
With the project CaLIPSO, the need for funding, independent of an international collaboration appeared.
We have been supported by:
• « Neuropôle de Recherche Francilien », Domaine d’Intéret Majeur, de la Région Ile de France, Investment project, Nov. 2010.
• « Laboratoire d’Excellence Physique des deux Infinis », LabEx P2IO, R&D call for proposal, 0ct 2011.
• « Initiative d’Excellence (IDEx) Paris-Saclay, Inovation et Entrepreneuriat » 2013-2014.
• « Programme Interdisciplinaire Technologie pour la Santé du CEA »: Financial support in 2013, 2014 et 2015.
I have been at the initiative (with Ph. Schune) of an advanced instrumentation course at the Master NPAC, Paris XI. I have been involved in the management of the corresponding students projects and the final evaluation of the student work. I gave a handfull "advanced instrumentation talks" to the Master's students (Bolometers' instrumentation).
2013-2014: Main author and Coordinator of the 21 authors of the book: “A la découverte de l’Autisme. Des Neurosciences à la vie en société”, Edt: Dunod, EAN13 : 9782100713073. This is a large audience, science-based, monography on Autistic Spectrum Disorders.
Community life :
President of the association "ADAPTED" : Agir pour le Développement d'un Avenir Professionnel pour les TED ".