The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

Photon Sciences Directorate Leadership

The Argonne National Laboratory Photon Sciences Directorate (PSC) comprises the Advanced Photon Source (APS) facility; the Accelerator Systems, APS Engineering Support, and X-ray Science divisions; and the APS Upgrade Project.
Laurent C. Chapon is the Associate Laboratory Director for PSC and Director of the Advanced Photon Source.

Laurent C. Chapon is the Associate Laboratory Director for PSC and Director of the Advanced Photon Source.

Laurent Chapon was director of physical sciences at the Diamond Light Source in the United Kingdom where he led the scientific strategy in this division and oversaw five of Diamond’s eight science groups. He led groups dedicated to technological advancements in optics, metrology, and detector technology at the facility, and oversaw the Project Office, the User Office, and the Experiment Hall groups. In parallel, Chapon was director of the Diamond-II project, recently awarded preliminary funding, for which he has developed the upgrade strategy, the science case, and the business case.

Prior to his time at Diamond, Chapon was a senior fellow and group leader of crystallography at the Institut Laue-Langevin in Grenoble, France. He spent nearly a decade at the ISIS Neutron and Muon Source at Rutherford Appleton Laboratory in the United Kingdom, as both an instrument scientist and a group leader of the diffraction and engineering group.

Chapon received his Ph.D. in Materials Science from the Université Montpellier-II, in France. He conducted research on the fundamental and thermoelectric properties of skutterudites using neutron scattering, x-ray diffraction and absorption spectroscopy.  He conducted postdoctoral research at Argonne in 2001 on molecule-based magnets and has since worked mainly on the structural and magnetic properties of complex transition metal oxides, including multiferroics, as well as probing the exotic states of matter stabilized in frustrated magnetic systems and chiral compounds. He is an expert in magnetic scattering with neutrons and x-rays, crystallography, and magnetic symmetry.

Chapon received a Prize of the Physical Crystallography Group from the British Crystallography Association in 2008 for his work on multiferroics and magnetic crystallography. He has served in many international review committees for large scale user facilities, most recently at the Canadian Light Source, the SNS Second Target Station Instrument Review Committee at Oak Ridge National Laboratory and is currently the chair of the Program Advisory Committee for the Institut Laue Langevin, France; and sa member of the XFEL Physical Science Hub at the Central Laser Facility, United Kingdom. He serves as an editorial board member for the journal npj Quantum Materials and has coauthored more than 140 scientific publications.

Jim Kerby is the Project Director of the Advanced Photon Source Upgrade Project.

Jim Kerby is the Project Director of the Advanced Photon Source (APS) Upgrade Project at Argonne. Kerby oversees the planning, construction, and implementation of the upgrade.

Kerby joined Argonne in 2012 as the principal project manager of APS-U and has more than 30 years of engineering and technical management experience.

Kerby holds bachelor’s (1984) and master’s (1986) degrees in mechanical engineering from Purdue University as well as an MBA (2006) from Purdue’s Krannert School of Management. He is a member of Argonne’s Project Management Advisory Council, mentors early career staff and collaborates with other U.S. Department of Energy laboratories, universities and industry partners.

John P. Quintana is the Deputy Associate Laboratory Director for Operations for Photon Sciences (PSC)



John P. Quintana is the Deputy Associate Laboratory Director for Operations for Photon Sciences (PSC).

Prior to this role, Quintana led PSC’s Mission Readiness Group, spearheading the efforts needed to ensure the Advanced Photon Source (APS) facility is ready to come back online promptly after the APS Upgrade project installation is complete.

Quintana’s contributions to the APS and Argonne span more than a decade. Previously, he served as a senior advisor to the former Energy and Global Security (EGS) directorate and was an APS Engineering Support Division (AES) associate division director, where he was responsible for the groups performing mechanical engineering design and mechanical maintenance, as well as radiation and experimental safety. Quintana also has served as Argonne’s deputy chief operations officer and is currently Argonne’s Accelerator Safety Program Manager.

Before joining Argonne, Quintana spent more than 12 years working at Northwestern University as a research professor and engineer specializing in the design, construction and operation of beamline experimental facilities at the APS.

Quintana holds a doctorate in materials science and engineering from Northwestern University and a bachelor’s degree in mechanical engineering from the University of California at Berkeley.

Vadim Sajaev is the interim Director of the Accelerator Systems Division.

Vadim Sajaev headshot

Vadim Sajaev is the interim Director of the Accelerator Systems Division at the Advanced Photon Source (APS). He supports the continuous improvement in performance, capability, and reliability of the APS. Vadim has done foundational work at the APS since joining Argonne as a postdoc more than two decade ago and more recently has worked closely with the APS Upgrade project team and PSC leaders on the commissioning plan for the upgraded machine. He received his Ph.D. in particle accelerator physics from Budker Institute of Nuclear Physics in Novosibirsk, Russia.

Mike Edelen is the Director of the APS Engineering Support Division.

Mike Edelen

Mike Edelen is the Director of the APS Engineering Support Division. He leads a division that provides a broad range of engineering expertise for both APS operations and the APS Upgrade Project to maintain the world-leading stature of the APS accelerator complex and beamlines, and to ensure that the APS Upgrade Project succeeds in transforming the APS into a next-generation light source. Mike brings to the Engineering Support Division a highly diverse engineering, project management, and leadership skill set, and a record of success that will continue the AES well-earned reputation for engineering excellence.

Jonathan C. Lang is the Director of the X-ray Science Division.

Jonathan Lang is the Director of the X-ray Science Division, where he oversees a team that develops cutting-edge synchrotron x-ray instrumentation and techniques for addressing the research needs of the U.S. scientific community across a range of physical, materials, chemical, environmental, and life sciences.

While at Argonne Dr. Lang has developed a number of novel synchrotron instruments and methods and applied them to investigations of the interrelationship between the magnetic, electronic, and structural degrees of freedom in condensed matter systems..

He has authored or co-authored more than 100 scientific publications.  Dr. Lang holds a Ph.D. degree in Condensed Matter Physics from Iowa State University and a B.S. degree in Physics from University of Nebraska.  He serves on a number of advisory committees for synchrotron radiation facilities world-wide.

Robert O. Hettel is the Advisor to the PSC ALD and to the Director of the Advanced Photon Source.

Robert Hettel is an advisor to the associate lab director (ALD) of the Photon Sciences (PSC) directorate and to the director of the Advanced Photon Source (APS) at Argonne. He brings his extensive experience in the design, installation and commissioning of storage-ring light sources to this role. He offers guidance on the designs for APS Upgrade project and the transition to future operation of the facility.

He is a veteran accelerator designer and expert on storage-ring light sources. He came to Argonne in November 2017 from the SLAC National Accelerator Laboratory. From 2017 to 2021, Hettel served as the Project Director of the APS Upgrade, overseeing the planning, construction, and implementation of the project.

Hettel earned his B.S. in physics with departmental honors from Harvey Mudd College in Claremont, California. He has benefited from decades of training in accelerator science and technology from many distinguished mentors at SLAC and elsewhere.