Making Waves in Particle Accelerator Physics

Whether you鈥檙e conducting a symphony or you鈥檙e conducting an experiment in particle accelerator physics, creating perfect resonance is always a thing of beauty.

When Minghao Song (Ph.D. PHYS 鈥22) conducted his Ph.D. thesis at SLAC National Accelerator Laboratory in Menlo Park, California, his work studying autoresonant excitation of accelerator electron beams and his development and application of machine-learning methods in storage ring design and online optimizations earned him the .

What is autoresonant excitation? It鈥檚 a method that allows physicists to control the amplitude of a nonlinear oscillator鈥攁 system that moves back and forth, repeatedly returning to its initial state. By sweeping the frequency of the driver (the oscillating object), physicists are able to match the drive frequency with the particles鈥 natural oscillation frequency, resulting in larger beam amplitudes.

鈥淢y study included a derived theory of how to successfully drive the accelerator electron beams to large amplitudes with autoresonant excitation,鈥 says Song, explaining that the electron beam鈥檚 oscillation is more sustainable using this method, which results in more precise information. 鈥淲e can get thousands鈥攐r even tens of thousands鈥攐f numbers of turns of the beam oscillation. The precision of measuring nonlinear beam dynamics will be much more accurate compared to the traditional method using kicker magnets.鈥

While Song has already made a name for himself in his young career in the field of accelerator physics, it鈥檚 the interdisciplinary nature of the field that excites him most. He takes the opportunity of testing and improving his own abilities in related areas as a personal challenge.

鈥淚t involves accelerator physics, magnetic engineering, mechanical design鈥攅xperts from all kinds of fields,鈥 says Song. 鈥淒oing research in the accelerator field can really broaden your horizons and improve your personal capabilities. It鈥檚 really a great field to do research.鈥

His start in accelerator physics came while he was a master鈥檚 student and continued in 2017 when he began his Ph.D. in physics at Illinois Tech.

鈥淭here are many research opportunities in the Department of Physics,鈥 says Song. 鈥淢y Ph.D. adviser鈥擺Emeritus Professor of Physics] Linda Spentzouris鈥攇ave me the opportunity to do research with her and recommended me to [SLAC National Accelerator Laboratory Senior Scientist] Xiaobiao Huang to do my Ph.D. thesis work under his guidance.鈥

The sheer size and abilities of the particle accelerator in Menlo Park sparked Song鈥檚 curiosity and continues to drive his interest in particle physics to this day.

鈥淚 was really fascinated by the sophisticated and big particle accelerator!鈥 says Song. 鈥淚鈥檓 also curious how it could accelerate electron particles close to the speed of light and produce a very bright photon beam. I keep this curiosity and fascination.鈥

Now a research associate at Brookhaven National Laboratory in New York, he鈥檚 building on his Ph.D. work, aiming to make upgrades to the National Synchrotron Light Source II (NSLS-II).

鈥淥ne goal is to deliver a reliable storage ring lattice for the NSLS-II upgrade in the future,鈥 says Song, noting how a more reliable storage ring lattice would achieve a lower beam emittance, long straights for insertion devices, sufficient free space, optimal nonlinear beam dynamics and robustness to magnet errors. 鈥淎nother goal is to develop useful methods that are based on the machine learning technique and to optimize accelerator performance.鈥

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