Aktuelles: Dr. Chitra Rajendran Elected Chair of the User Executive Committee at the Linac Coherent Light Source

Dr. Chitra Rajendran from the Institute of Biophysics and Physical Biochemistry at the University of Regensburg has been elected Chair of the User Executive Committee (UEC) of the Linac Coherent Light Source (LCLS) at Stanford University for the term 2024–2025.
The LCLS, located at the SLAC National Accelerator Laboratory and operated by Stanford University, is the world’s first hard X-ray free-electron laser (XFEL). It generates the most powerful X-ray laser pulses currently available, delivering up to one million flashes per second—an 8,000-fold increase over its predecessor and a major leap from 120 pulses per second to 1 million. This breakthrough marks a new era for X-ray science.
XFELs produce ultra-bright, ultra-short X-ray pulses that enable researchers to observe reactions in biological molecules in real time. These capabilities led to the creation of the first “molecular movie”, capturing complex chemical processes as they unfold and visualizing how plants and algae absorb sunlight to produce the oxygen essential for life.
LCLS-II is the first XFEL based on continuous-wave superconducting accelerator technology (CW-SCRF). With a linac energy of 4 GeV powering two tunable-gap undulators (SXU and HXU), LCLS-II will generate soft X-ray pulses ranging from 0.25 to 5 keV (2.5 ?) at repetition rates up to 1 MHz, as well as ultrafast hard X-ray pulses with uniform or programmable time structures at similarly high repetition rates. This represents a significant advance over the burst-mode operation of the European XFEL and provides a 100,000-fold increase in temporal resolution compared to storage-ring sources.
X-ray laser light scatters from electrons within a sample, revealing its atomic arrangement. Comparable to a camera with an extreme zoom lens and an ultrafast shutter, the X-ray laser can capture snapshots of molecules moving, dissociating, and interacting. XFELs allow proteins to be studied under near-native conditions—including at room temperature—and enable the use of microcrystals smaller than 10 ?m. This offers new possibilities for examining the dynamics, kinetics, and function of membrane proteins such as G protein-coupled receptors (GPCRs). Time-resolved molecular snapshots recorded at different stages of a protein’s functional cycle can be directly linked to its biological role. With these capabilities, scientists can investigate ultrafast, atomic-scale phenomena relevant to a wide range of fields, from quantum materials to clean energy technologies and medicine.
According to Dr. Chitra Rajendran, “The upcoming enhanced repetition rate of LCLS-II-HE will revolutionize our ability to obtain molecular movies of biological machines at physiological temperatures. The brilliant light is there; now it is time to explore this new light to usher in a new era of science. It is time for innovative experiments that use this light efficiently and open access to previously unreachable areas in fields such as biology, medicine, quantum materials, and new energy technologies.”

About Dr. Chitra Rajendran
Dr. Chitra Rajendran obtained her PhD at the Max Planck Institute of Biophysics in Frankfurt under the supervision of Prof. Hartmut Michel (Nobel Laureate). She later worked at the macromolecular crystallography beamlines of the Swiss Light Source before joining the University of Regensburg, where she established her own X-ray crystallography laboratory.
As Chair of the User Executive Committee of the LCLS, she represents and communicates with users of the free-electron laser facility worldwide and coordinates user meetings and conferences. The UEC Chair leads a group of internationally recognized scientists participating in XFEL experiments and engages with the U.S. Department of Energy together with LCLS management to discuss user needs and future perspectives. She also participates in the Scientific Advisory Committee (SAC) of the LCLS and in the laboratory’s quadrennial reviews.