Supervisors: Dr. Taro Konomi, Prof. Ting Xu

The superconducting RF electron gun (SRF gun) is a next-generation device designed for high-quality electron beams. It consists of a laser system, a photocathode, a superconducting RF accelerating resonator, and a cryomodule. This project focuses on evaluating the performance of the SRF gun and photocathode, with an emphasis on experimental operation, data acquisition, and analysis techniques. The work involves SRF resonator assembly, photocathode coating, laser tuning and beam line experiments. This project provides a unique opportunity to gain hands-on experience with cutting-edge accelerator technology, working alongside experts in the field to contribute to the development of next-generation electron sources

Supervisors: Dr. Sang-hoon Kim, Dr. Walter Hartung

Field emission (FE) is one of the factors that limit the maximum accelerating gradients in superconducting RF resonators. Plasma processing is a technique used to mitigate field emission and can be performed in situ without disassembling the resonators or cryomodule. As a result, it is being developed and/or implemented in many large-scale superconducting linacs, such as SNS, LCLS-II, CEBAF, and FRIB. Since conventional plasma processing generates plasma in a resonator by driving RF power through a coupler, there are challenges in avoiding plasma breakdown in the coupler, which may lead to copper sputtering and/or ceramic window damage. To address this, FRIB is developing an alternative method, remote plasma cleaning, which generate oxygen plasma in a separate chamber and delivers oxygen radical or ozone to the resonator for cleaning. A student will design and build a setup to generate either inductively coupled plasma (ICP) or capacitively coupled plasma (CCP) and perform proof-of-principle experiments on cleaning effects in a superconducting niobium resonator. Through this project, the student will gain experience with RF and vacuum equipment and hands-on plasma experiments.

To be considered for this project, complete the student questionnaire.

Supervisors: Dr. Sang-hoon Kim, Prof. Ting Xu

Lorentz force detuning effect in a superconducting niobium resonator refers to resonant frequency shifts caused by radiation forces from electromagnetic fields excited in the resonator. When coupled with resonator mechanical modes, it can lead to instability unless suppressed by methods such as feedback control. The sensitivity of a resonator to potential instability can be characterized by Lorentz transfer function. A student will perform finite-element-method (FEM) simulations to calculate Lorentz transfer function in the FRIB400 energy upgrade resonator, a 644 MHz beta=0.65 5-cell elliptical superconducting niobium resonator. This is a coupled mechanical and electromagnetic problem; the student will use commercial FEM simulation programs such as ANSYS and HFSS. In addition, we will provide opportunities for the student to participate in experiments to measure Lorentz transfer function and instability thresholds in FRIB superconducting resonators.

Supervisors: Dr. Taro Konomi, Dr. Sang-hoon Kim

RF power couplers for superconducting RF resonators use low-loss dielectric material, such as high-purity aluminum oxide (alumina), as RF windows. Superconducting RF resonators are installed in a cryomodule with magnetic shielding to minimize remnant magnetic fields on the resonator surfaces, which would otherwise lead to increased RF wall losses due to trapped magnetic flux on superconducting transition. A student will measure the real and imaginary permittivity (dielectric constant and loss tangent) of material samples. The student will design and build an experimental setup based on a pillbox resonator. The student will also experimentally study the permeability of magnetic shielding materials at cryogenic temperatures. Through this project, the student will gain experience with hands-on RF and low-temperature physics experiments.

To be considered for this project, complete the student questionnaire.

Supervisors: Prof. Peter Ostroumov and Dr. Qiang Zhao  

Measurement of beam parameters is an essential task in tuning and operating accelerators. This project will provide the student an opportunity to learn preliminary beam physics, to develop software for data acquisition, analysis, and visualization in beam parameter measurement, and to get some hands-on experience on the accelerator facilities at FRIB laboratory.

Supervisors: Prof. Peter Ostroumov and Dr. Qiang Zhao

FRIB is operating a world class heavy-ion superconducting linac. It is important to efficiently set up and monitor the status of accelerator devices and beam parameters during beam study and operation. FRIB uses Control System Studio called Phoebus which provides a variety of tools and applications and is easy to learn and use. You will use Phoebus and develop graphical user interfaces to control devices and display data to facilitate beam tuning. For example, change magnet field, insert/withdraw a Faraday cup, plot/export live and archived data. Through the project, you will also get control room experience on a modern accelerator facility.

Supervisors: Dr. Takuji Kanemura and Dr. Yoichi Momozaki

In the lithium stripper, a single liquid jet hits onto a deflector, transforming the jet into a thin film (as you insert a spoon under a stream of running tap water). To improve the versatility, we are trying to develop a new scheme to form a similar fluid structure in which we use 2 colliding jets. We have a water setup to prove the concept and to do feasibility studies. The student will support the exploratory investigation of the water experiments. The work involves assembling mechanical components to support the water nozzles, PVC piping assembly etc.

Supervisor: Dr. Tong Zhang

This project focuses on developing high-level physics software applications by integrating web technologies to enhance data visualization and management. The goal is to create a more user-friendly interface that improves information accessibility, facilitates better software management and serves as a complementary tool within the broader physics controls software development workflow. The work involves implementing web-based solutions to present existing data in an intuitive and manageable way while ensuring compatibility with the current software infrastructure. By improving the usability and streamlining the development processes, the project aims to enhance the overall efficiency of physics software applications. Participant should be familiar with the fundamental software development tools, such as Git, Python and Linux. A basic understanding of web development and database systems is required, while knowledge of Qt or its Python bindings is advantageous for working with the existing codebase. Additionally, a good sense of aesthetics is valued to create effective and visually appealing solutions.

Supervisors: Prof. Yue Hao and Dr. Jinyu Wan

In the high performance computing for charged particles in an accelerator, huge amounts of data is generated by the simulation code.  The data processing is an essential part of analyzing the simulation results.  In this project, the student will learn and develop computation tools to process the data from HPC for machine learning purposes and explore the visualization schemes for the data.

Supervisors: Dr. Yoonhyuck Choi and Dr. Xiaoji Du

This project focuses on using a pick-up coil to measure the high harmonics and misalignment of quadrupole and multipole coils used in accelerator. Currently, two main methods are used for quadrupole and multipole magnets field measurements: Hall probes and pick-up coils. Hall probes can also provide point-by-point field data for beam dynamics analysis but are limited by probe accuracy and mapper positioning. In contrast, pick-up coils enable more precise axial integration of magnetic field components. This project will involve theoretical analysis and pick-up coil design, with the potential for prototype development for future quadrupole magnet testing.