Dillon Merenich, a Northern Illinois University (NIU) doctoral student, has been selected as an Office of Science Graduate Student Research (SCGSR) scholar. He will join researchers at the Berkeley Accelerator Controls & Instrumentation (BACI) Program in the Accelerator Technology & Applied Physics (ATAP) Division at Lawrence Berkeley National Laboratory (Berkeley Lab) for a year-long research project starting in December.

The SCGSR program prepares doctoral students for career success in areas that support the Department of Energy (DOE) Office of Science mission. This includes “delivering scientific discoveries and tools that help advance the country’s energy, economic, and national security.” The program is sponsored by the Office of Science’s Office of Workforce Development for Teachers and Scientists in collaboration with the DOE national laboratories.

Merenich says the award “is a chance to engage in top-tier research,” adding that Berkeley Lab “is synonymous with innovation and bright minds adventuring into the unknown. This opportunity to conduct meaningful research is rare, and I feel honored to be part of it.” His project will aid national efforts to build a muon collider and will be supervised by BACI Research Scientist Tianhuan Luo.

Muons are fundamental particles similar to electrons but about 200 hundred times heavier. Since they are much more deeply penetrating than X-rays, gamma rays, and protons, muon imaging can probe structures made from solid rock or concrete walls tens to hundreds of meters thick—well beyond the capabilities of current imaging techniques. A muon collider could offer a powerful new imaging tool for applications in scientific research, scanning for hazardous, radioactive, and explosive materials and probing deep into mountains and underground structures, such as mines and bunkers.

“Dillion will work with me on designing the radio-frequency (RF) cavities for the proposed ionization cooling demonstrator for a future muon collider,” says Luo. “This demonstrator is an important milestone in validating the feasibility of a collider and will be a focus for the muon collider accelerator community for the next decade. This project will directly contribute to the demonstrator’s development.”

The research aims to design and optimize a normal-conducting (as opposed to superconducting) RF muon ionization cooling cavity capable of mitigating limitations observed in previous designs by exploring the effects of breakdown in the presence of high magnetic fields, a compact coupling design and the material selection and geometric designs of the beam window.

“His work will focus on the cooling channel, a necessary element to reduce the large phase space of the initial muon beam,” explains Luo. “The phase space cooling happens in both the transverse and longitudinal dimensions, resulting in energy loss of the muons in the beams.”

The P5 Report, released last October, outlines the nation’s priorities for particle and high-energy physics over the next decade. It stresses the importance of building a 10 TeV parton-center-of-mass collider to study the underlying uncertainties surrounding the Higgs particle, test theories of weakly interacting massive particles, and search for evidence of new subatomic particles. However, circular lepton (elementary particles that include muons and electrons) colliders traditionally use electrons, which are limited by radiative energy loss. As muons are far heavier than electrons, they lose much less energy to synchrotron radiation as they change course. Therefore, they promise colliders capable of more precise measurements and higher-energy reach. However, “cooling” a muon beam to reduce instabilities is much more challenging because of a muon’s brief lifetime.

Merenich says he is “eager to begin work at Berkeley Lab, and I am very grateful to all the wonderful people who have aided in my training up to this point (and those to come). A special thank you is owed to my Ph.D. advisor, Xueying Lu [an associate professor in the Department of Physics at NIU], who has been a great mentor throughout my graduate studies, and her ambition, wisdom, and dedication are truly inspiring.”

 

To learn more …

Office of Science Graduate Student Research (SCGSR) Program

 

 

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