X-ray vision: Director of ambitious CXFEL project sees the potential to unlock new knowledge

Editor's note: This is the third installment of a five-part series profiling the researchers who work on ASU’s compact X-ray free electron laser. Read the other installments: Q&As with Regents Professor Petra Fromme, CXFEL Labs Chief Scientist William Graves, Assistant Professor Sam Teitelbaum and CXFEL Chief Engineer Mark Holl.

When you think of X-rays, you may imagine a scan of a broken bone or Superman peering through walls. But when Robert Kaindl thinks of X-rays, he sees scientific potential.

As a physicist at Arizona State University, he uses extremely short laser pulses to study the properties of materials, discover and control previously unknown phases, and track the movements of electrons on quantum scales of length and time, among other uses.

“I’m most intrigued by what lies at the edge of our knowledge, pursuing phenomena that have never been observed before,” says Kaindl, a professor in the ASU Department of Physics.

To that end, Kaindl directs ASU’s Compact X-ray Free Electron Laser (CXFEL) Labs at the Biodesign Institute. The CXFEL, when complete, will generate unique, ultrashort X-rays to allow researchers to see inside molecules and matter, advancing scientific efforts in areas such as drug development, renewable energy and quantum computing.

Building the compact X-ray light source (CXLS) is the first phase of the CXFEL project. While part of a larger effort, the CXLS is a powerful tool on its own that will allow scientists to capture ultrafast images of molecular behavior and chemical reactions as they happen.

Related: First electrons generated for revolutionary new tool in biological discovery

“The development of a novel light source fits our desire for discovery perfectly, as progress in science is often based on pushing the resolution or capabilities of instruments,” says Kaindl.

Here, Kaindl discusses his journey to becoming the director of CXFEL Labs, the challenges he has helped guide the project through and the exciting opportunities that the CXFEL will offer in the years to come.

Question: What is your role at CXFEL Labs, and what do you do on a day-to-day basis?

Answer: As director of CXFEL Labs, I’m responsible for the overall management of the facility, working with a highly talented team of faculty, scientists and students. With the conclusion of the compact X-ray light source (CXLS) commissioning, our focus is shifting to early experiments with its ultrashort X-rays and the transition to a user facility. In the National Science Foundation project to implement the future CXFEL light source, I will take care of its validation phase and transition to operations.

Q: What are you known for?

A: I investigate quantum and nanoscale materials with ultrashort lasers. The focus is on understanding the fundamental nature of these materials and how their properties can be controlled with light. Part of my work has also been developing new ultrafast sources and techniques, giving us a front-row seat in observing new physical phenomena.

Q: What has been one challenge in the CXLS project and how have you and the team overcome it?

A: The project involved many challenges, but the pandemic clearly tops the list. I arrived at ASU in late February 2020, just days before the shutdowns began. While many activities ceased, the construction of CXLS was able to continue with nearly full effort, aside from several notable supply chain disruptions. This is a testament to both the strong team and ASU’s unwavering support for the project. Moreover, the Biodesign Institute set up a PCR testing lab for ASU and Arizona, which was a tremendous asset for the CXFEL team to work safely through this challenging time.

Q: Why is ASU the right place to build these instruments?

A: ASU has a unique spirit of innovation seen everywhere across campus, which is essential for pursuing a project as bold as CXFEL. Faculty here are among the pioneers of XFEL science from its early days. This includes Petra Fromme, who co-developed the core method of serial femtosecond crystallography used at XFELs worldwide. Situating an accelerator-based X-ray light source directly on campus at one of the nation’s largest public universities maximizes access to advanced X-ray science and will help educate the next generation of researchers in this forefront field.

Related: Illuminating the answers to life’s mysteries: A Q&A with XFEL pioneer Petra Fromme

Q: What were pivotal moments in your career that led you to where you are today?

A: Early on, I was fortunate to work with leading groups in the field — including my doctoral research with Thomas Elsaesser at MBI and Humboldt University in Berlin, where I developed and utilized novel mid-infrared sources to observe the dynamics of superconductors and quasi-2D semiconductors. My postdoctoral work was with the late Daniel Chemla in Berkeley, detecting for the first time excitons via their terahertz-frequency absorption. In 2007, I became a principal investigator in Berkeley Lab’s Materials Sciences Division, where we pursued ultrafast studies of complex materials with terahertz, electron and X-ray probes, including the development of a new time- and momentum-resolved photoelectron facility. Having joined ASU as a physics faculty member and to manage CXFEL labs, I am excited to be part of the development of compact X-ray sources and to pursue the next phase of ultrafast science.

Q: How do your personal interests or hobbies enhance or complement your professional endeavors?

A: When I’m not in the lab, classroom or office, you might well find me on a hiking trail somewhere around Phoenix. Some of my best ideas originate out in nature. I’m also an avid skier, though the pandemic and time pressures have taken their toll lately.

Q: What potential application or aspect of the CXLS/CXFEL is most exciting to you?

A: CXFEL entails many interesting properties, which the user community can exploit to uncover new science. Personally, I find the potential for attosecond soft X-ray pulses particularly exciting (an attosecond is one-billionth of a billionth of a second). The motion of electrons in matter occurs on such time scales. For instance, the classical orbit time of an electron in hydrogen is only about 150 attoseconds. Attosecond X-ray pulses thus provide us with a “time microscope” to observe and unlock the most fundamental electron movements responsible for chemical reactions and quantum correlations in materials.

The Biodesign Institute and its CXFEL Labs are partially supported by Arizona’s Technology and Research Initiative Fund. TRIF investment has enabled hands-on training for tens of thousands of students across Arizona’s universities, thousands of scientific discoveries and patented technologies, and hundreds of new startup companies. Publicly supported through voter approval, TRIF is an essential resource for growing Arizona’s economy and providing opportunities for Arizona residents to work, learn and thrive.