April 2024

April 15, 2024April 12, 2024

Towards Scientific AI for the simulation and optimization of complex systems

DATE/TIME:

MON, 04/15/2024 - 3:00PM TO 4:00PM

LOCATION:

3106 ETCHEVERRY HALL

SPEAKER:
Raphael Pestourie
Professor, Georgia Tech, School of Computational Science and Engineering

Abstract:

Complex systems are hard to simulate and even more difficult to optimize. In this talk, I will showcase how surrogate models accelerate the evaluation of properties of solutions to partial differential equations. I will present a precise definition of the computational benefit of surrogate models and example surrogate models. We will then show how surrogate models can be combined to solve a challenging multiscale problem in optics. We will show that, through a synergistic combination of data-driven methods and direct numerical simulations, surrogate-based models present a data-efficient and physics-enhanced approach to simulating and optimizing complex systems. This approach has the benefit of being interpretable. I will also share ways forward and opportunities for synergistical collaborations.

Bio:

Pestourie is an assistant professor at Georgia Tech in the School of Computational Science and Engineering. He earned his PhD in applied mathematics from Harvard University and pursued his postdoctoral studies in the mathematics department at MIT. His research is dedicated to developing computational methodologies that leverage both data and scientific knowledge to systematically find solutions to engineering problems.

April 8, 2024April 12, 2024

Emission Tomography: From Grayscale to Colorful Images One More Time

DATE/TIME:

MON, 04/08/2024 - 3:00PM TO 4:00PM

LOCATION:

3106 ETCHEVERRY HALL

SPEAKER:

Ling-Jian Meng, Ph.D
Professor
Department of Nuclear, Plasma, and Radiological Engineering,
Department of Bioengineering, and
Beckman Institute of Advanced Science and Technology,
The University of Illinois at Urbana-Champaign
ljmeng@illinois.edu

Abstract:

Nuclear Medicine is a critical element of modern medicine and healthcare practice, in which we use imaging instrumentation and radiopharmaceuticals to study physiological processes, and non-invasively diagnose, stage, and treat diseases. While typical diagnostic nuclear medicine modalities, such as positron emission tomography (PET) and single photon emission computed tomography (SPECT), could offer a tremendous sensitivity for detecting molecular changes in deep tissue at physiologically relevant concentrations, their imaging capabilities are confined by the tracer principle, and the mechanically and/or electronically modulated image formation process, and the limitations in the modern detector technologies. Considering that the basic idea of nuclear medicine was first introduced about 100 years ago, it is probably the right time to ask where nuclear medicine would go from here?

In this presentation, we will briefly discuss the current trends in nuclear medicine, such as recent advances in diagnostic imaging instrumentation and emerging radiopharmaceutical therapy (RPT). I will follow up to introduce a cluster of R&D efforts at the University of Illinois, ranging from the development of instrumentation for hyperspectral single photon imaging (HSPI) that could potentially transform diagnostic nuclear medicine from monochromatic to multi-color/multi-functional molecular imaging modalities, the development of ultra-low-dose molecular imaging capability based on spectral-temporal-double-coincidence (STDC) techniques, the application of these techniques for developing alpha-particle radiopharmaceutical therapy (α-RPT), to our recent exploration towards X-ray fluorecesnce emission tomography (XFET) of non-radioactive trace metal deep tissue. Through these projects, we have assembled a coherent taskforce aiming to extend the horizon of nuclear medicine and explore the natural interface between diagnostic nuclear medicine and therapeutic intervention for battling cancer, cardiovascular diseases, and neurodegenerative disorders.

Bio:

Dr. Meng obtained his Ph.D. degree from the Department of Physics and Astronomy at the University of Southampton, UK, in 2002. From 2002 to 2006, he has been working in the Department of Radiology and the Department of Nuclear Engineering and Radiological Sciences at the University of Michigan, Ann Arbor, as a Postdoc Fellow and then an Assistant Research Professor. Dr. Meng joined the University of Illinois at Urbana-Champaign (UIUC) in 2006 and is currently a Professor in the Department of Nuclear, Plasma, and Radiological Engineering, the Department of Bioengineering, and an affiliated member of the Beckman Institute of Advanced Science and Technology. Dr. Meng is also a Visiting Associate Professor at the Massachusetts General Hospital (MGH), an Associate Editor for leading research journals, such as the IEEE Transaction on Medical Imaging (TMI) and Medical Physics, and a former charter member of the NIH Imaging Technology Development (ITD) study session. Dr. Meng’s research is primarily focused on the development of nuclear imaging techniques for biomedical research through numerous NIH-funded projects. His work has also been supported by DOE, NASA, and NRC for developing advanced radiation detectors and imaging systems for astrophysics, environmental, and security applications.

April 1, 2024March 16, 2024

High-field HTS stellarators with liquid metal walls

SPEAKER:

Francesco Volpe

Founder, CEO, CTO Renaissance Fusion

DATE/TIME:

MON, 04/01/2024 - 3:00PM TO 4:00PM

LOCATION:

3106 ETCHEVERRY HALL

Abstract:

French- and Swiss-based startup Renaissance Fusion strives to build a commercial nuclear fusion reactor by reinventing and synergistically combining three main technologies. The first one is the stellarator: more stable and steady state than a tokamak, but historically complicated to build. Renaissance dramatically simplifies its “coil winding surface”. The second technology is High Temperature Superconductors (HTS) generating strong magnetic fields that miniaturize the magnetic fusion device. HTS are scarce and expensive, typically produced in tapes, then stacked into cables and finally wound as 3D stellarator coils. Instead, Renaissance directly deposits HTS on piecewise cylindrical vacuum vessels or other large surfaces. Subsequent laser-engraving imposes specific current patterns, which generate specific 3D magnetic fields. This has several non-fusion applications: from magnet undulators for synchrotrons, to magnets for gyrotrons and magnetic resonance imaging, to energy storage. The third technology consists of liquid metal walls coating the inside of the fusion device and directly facing the plasma. Such walls, based on Li-LiH and 35 cm thick, will shield structural materials and delicate HTS from fusion neutrons, and will breed tritium. In addition, they will flow, to extract heat. Experimental results will be presented for a free-surface flow of GaInSn adhering to the interior of a cylindrical chamber by means of electromagnetic and centrifugal forces, without plasmas. Rescaled for density, the experiment was equivalent to levitating a 120 cm thick layer of Li-LiH. Next steps will be discussed, together with plans for their integration with the HTS technology and, ultimately, the construction of a net-heat, Q >1 stellarator and stellarator power-plant. Optimization results will be presented in the areas of plasma equilibrium, coil forces, economic power-plant sizing and neutron shielding. A remarkably simple Tritium extraction technique will be presented. Research needs, job openings and areas of possible collaboration will also be discussed.

Bio:

Francesco Volpe is a fusion plasma physicist turned entrepreneur. He studied and conducted his research in Italy (Laurea 1998), Germany (PhD 2003), the UK and USA (post-docs ended in 2008). From 2009 to 2019 he held faculty appointments at the University of Wisconsin, Madison, and at Columbia University, in New York. Francesco conducted research on all four major magnetic confinement fusion concepts (tokamaks, spherical tokamaks, stellarators and reversed field pinches), making contributions to the physics of Electron Bernstein Waves, avoidance of tokamak disruptions, simplification of stellarators and control of liquid metal walls. He received the 2003 Otto Hahn Medal (thesis prize of the Max Planck Society), the 2011 DOE Early Career Award and the 2015 Excellence in Fusion Engineering Award by Fusion Power Associates. In 2019 he earned an Executive MBA at ESCP Europe and in 2020 he founded one of the first stellarator start-ups in the world: Renaissance Fusion.