Research Projects
Nuclear Physics
PROJECT TITLE:
Development and Testing of a Radial Time Projection Chamber
PROJECT MENTORS:
Prof. Stephen Bueltmann(sbueltma@odu.edu)
PROJECT DESCRIPTION:
In order to study the structure of the neutron we are preparing for an experiment (known as BONuS) in which we will scatter electrons from deuterium targets. The BONuS experiment has been identified by the Jefferson Lab Program Advisory Committee as a high impact measurement that should be run early in the 12 GeV era, and is currently scheduled for 2018. By identifying low momentum, backward recoiling protons, we can preferentially select events in which the electron scattered from the neutron in the deuteron. To detect those low momentum protons, we are building a Radial Time Projection Chamber (RTPC), which uses Gaseous Electron Multiplier (GEM) detector technology. In summer 2017 we will be testing a prototype RTPC, together with the electronics that will enable us to read out the signals. Of particular concern is the time profile, amplitude and stability of the signals from different parts of the detector, as well as the performance of the digital electronics.
REU STUDENT PARTICIPATION:
The student will learn about GEM detectors and learn how
to test them, both in a flat test bed and in the full RTPC curved prototype. The student will use
data acquisition and analysis techniques to investigate the performance of the prototype detector.
Further, the student will investigate the physics of particle interactions with matter in order to understand the test results.
PROJECT TITLE:
Quark momentum and spin distributions in the nucleon
PROJECT MENTOR:
Dr. Wally Melnitchouk (wmelnitc@jlab.org)
PROJECT DESCRIPTION:
While much has been learned about how quarks and gluons make up a nucleon, many aspects of the nucleon's flavor and spin structure are still not understood. This is especially true for quarks that carry a large fraction "x" of the nucleon's momentum. A global analysis of quark momentum and spin distributions is being carried out at Jefferson Lab, in collaboration with theorists and experimentalists nationwide, aimed at accurately describing the structure of the proton and neutron in the large-x region. This project will involve computation of several new physical effects, which have not been included in previous analyses, that are important for reliably extracting quark structure information from electron scattering and other reactions.
REU STUDENT PATICIPATION:
Assist with the derivation of theoretical formulas for observables inelectron-nucleon scattering and related experiments. Run computerprograms to calculate scattering amplitudes and cross sections numerically. It is expected that this project will result in apublication in a refereed journal. Some knowledge of quantummechanics and/or nuclear and particle physics is advantageous. Familiarity with programming languages (e.g. python, Mathematica,Fortran) is desirable. Enthusiasm for theoretical physics is essential.
PROJECT TITLE:
Machine learning for nucleon structure studies
PROJECT MENTOR:
Dr. Wally Melnitchouk (wmelnitc@jlab.org)
PROJECT DESCRIPTION:
The goal of this project is to build the next generation of global QCD analysis tools using machine learning (ML) techniques to study quantum probability distributions, such as parton distribution functions (PDFs) and transverse momentum dependent distributions (TMDs), that characterize the internal structure of the nucleon. For a given experimental observable that has a theoretical description in terms of model-dependent parameters, we aim to train neural networks (NNs) that map the observable space to parameter space using precomputed training samples. The connection between parameter and observable space is numerically intensive, and ML can be used to train NNs to map a given range of parameter space into all possible cross sections across experimental kinematics (“forward” mapping). Similarly, training the NNs can be performed in reverse for the mappings from observable space into parameter space (“inverse” mapping). With such a setup, the inverse mappers provide a simple and effective way to perform a global QCD analysis interactively. The goal of this project is to design ML strategies to build the inverse and forward mappers for observables in the context of QCD factorization theorems specifically for PDFs and TMDs.
REU STUDENT PATICIPATION:
Collaborate with members of the Jefferson Lab Theory Center and computer scientists from ODU. Assist with the development of computer codes and simulations relevant for the training of NNs. It is expected that this project will result in publication in a refereed journal. Some knowledge of nuclear and particle physics and familiarity with basic concepts in AI and machine learning is preferable. Experience with the python programming languages is desirable. Enthusiasm for computational science and subatomic physics is essential.
PROJECT TITLE:
Detector development for GEN-RP
PROJECT MENTOR:
Brad Sawatzky (brads@jlab.org)
PROJECT DESCRIPTION:
An upcoming measurement of the neutron electric form factor GEn is planned to run in 2021. This project involved repairs, testing, and calibration and mounting of 3 sub-detectors necessary for that experiment.
REU STUDENT PARTICIPATION:
The student will get hands-on experience with detector and DAQ systems used in modern experimental nuclear physics. They will learn how to operate an oscilloscope, setup a data acquisition system, develop a cosmics trigger, and analyze data.
Accelerator Physics
PROJECT TITLE:
Fixed Field Alternating Gradient Lattice for 24 GeV CEBAF
PROJECT MENTOR: Dr. Alex Bogacz
PROJECT DESCRIPTION: A proposal was formulated to increase the CEBAF energy from the present 12 GeV to 20-24 GeV by replacing the highest-energy arcs with Fixed Field Alternating Gradient (FFA) arcs. The new pair of arcs would provide six or seven new beam passes, going through this magnet array, allowing the energy to be nearly doubled using the existing CEBAF SRF cavity system. One of the immediate accelerator design tasks is to develop a proof-of-principle FFA arc magnet lattice that would support simultaneous transport of 6-7 passes with energies spanning a factor of two.
REU STUDENT PARTICIPATION: The student will be introduced too design principes in particle accelerators and will simulate beam properties in various magnetic field arrangements.
PROJECT TITLE: Active suppression of microphonics detuning in superconducting cavities.
PROJECT MENTOR: Dr. Tomasz Plawski plawski@jlab.org
PROJECT DESCRIPTION: Active suppression of microphonics detuning in superconducting cavities may reduce the demand of RF power thus allows operate SC cavities at higher gradient or avoid RF trips. I’m planning to develop single frequency ANC (active noise control) adoptive algorithm, targeting the largest microphonic modes. Matlab/Simulink model of such a filter needs to be converted into VHDL code and imbed onto an LLRF FPGA and drive cavity piezo tuner.
REU STUDENT PARTICIPATION: A student involved in this project will learn about superconducting cavity operation, resonance control systems and frequency domain measurements. Matlab/Simulink model construction and VHDL generation will be a vital a part of his/her activity.
PROJECT TITLE:
Pansophy Sample Tracking System (SamTraxs)
PROJECT MENTOR:
Valerie Bookwalter (bookwalt@jlab.org)
PROJECT DESCRIPTION:
The Superconducting Radio Frequency (SRF) Department Project Support Group (SRFPJS) is responsible for the design, development and testing of superconducting accelerator hardware for accelerators around the world. SRFPJS provides QA and Software support in an information system, Pansophy, which is a critical element in the Project's Quality Assurance program and is the prime data collection and retrieval product utilizing web/database construction. The team also supports the R&D group in Particulate, Thin Film, and Substrate studies. A software package, SamTraxs, will be designed and implemented to support the R&D group’s efforts in data collection and analysis.
REU STUDENT PARTICIPATION:
A student involved in this project will aid in the design and implementation of the SamTraxs software/database system utilizing tools, such as HTML, ColdFusion, Java, and JavaScript, as well as Oracle / MySQL.
PROJECT TITLE:
Compton Scattering in the High-Field Regime
PROJECT MENTOR:
Prof. Balsa Terzic (bterzic@odu.edu)
PROJECT DESCRIPTION:
Compton Scattering in the High-Field Regime. Thomson/Compton sources of electromagnetic radiation using relativistic electrons have seen increased use in fundamental physics research in recent years. The small frequency range, or bandwidth, of the emitted radiation is highly desirable for applications in nuclear physics, medicine, and homeland security. As the intensity of the incident laser pulse involved in the scattering event increases, the bandwidth of the emitted radiation also increases. We recently showed that the increase in bandwidth may be negated through a judicious frequency modulation of the laser pulse. This project will focus on bringing these new results closer to experimental validation.
REU STUDENT PARTICIPATION:
A student involved in this project will learn about Compton/Thomson scattering, as well as computer programming and simulations
PROJECT TITLE:
Nitrogen Infusion Study on SRF cavities
PROJECT MENTOR:
Dr. Pashupati Dhakal (dhakal@jlab.org)
PROJECT DESCRIPTION:
Recent advances in the processing of bulk superconducting radio frequency (SRF) niobium cavities via interior surface impurity diffusion have resulted in significant improvements in their quality factor (Q0). The motivation for the development of these processes is to reduce the cryogenic operating cost of current and future accelerators while providing reliable operation. The project plan to explore the systematic study on nitrogen infusion that leads the high Q, high accelerating SRF cavities
REU STUDENT PARTICIPATION:
Hands on cavity testing, data analysis
PROJECT TITLE:
Flux trapping and expulsion study in SRF cavities
PROJECT MENTOR:
Dr. Pashupati Dhakal (dhakal@jlab.org)
PROJECT DESCRIPTION:
Trapped magnetic flux during the cooldown of superconducting radio frequency cavities through the transition temperature due to incomplete Meissner state is known to be an additional sources of residual loss. The sensitivity of flux trapping depends on the distribution of defects and impurities as well as the cooldown dynamics when the cavity transition from normal conducting to superconducting state. The project involve the systematic flux expulsion and trapping study with respect to the metallurgical state on Nb.
REU STUDENT PARTICIPATION:
Cavity RF testing, data analysis
PROJECT TITLE:
Bench measurement of the radio frequency electric center in an as-built deflecting cavity and tracking its change as it is installed into a particle accelerator
PROJECT MENTOR:
Haipeng Wang (haipeng@jlab.org)
PROJECT DESCRIPTION:
Deflecting and crabbing cavities built at Jefferson Lab, ODU, and BNL, to be installed at CERN for the LHC Upgrade project, need a precision measurement to determine the beam-pass-through-center in order to obtain the best collision luminosity. A harmonic kicker cavity and a beam magnetization measurement cavity recently developed for the JLEIC electron cooler to be installed on the LERF beam test facility have also a similar requirement on precision alignment of the electric center. By learning the principle of a wire-stretching measurement technique, the student will develop a research subject to investigate the sources of error in the measurement and its application to the automation measurement of multiple fields based on the spatial Fourier analysis.
REU STUDENT PARTICIPATION:
A student involved in this project will learn about the Wire-Stretching and RF measurement techniques, using a laser tracker to transfer the electric center in vacuum space to the mechanical alignment references of assembled cavity apparatus with required accuracy.
PROJECT TITLE:
Using a magnetron (RF source from a kitchen microwave oven) to drive a superconducting RF cavity (key acceleration component in CEBAF)
PROJECT MENTOR:
Haipeng Wang (haipeng@jlab.org)
PROJECT DESCRIPTION:
An EE or Engineering Physics major student is expected to learn and assist in a proof of principle experiment to demonstrate the field amplitude and phase control of radio frequency at 2.45GHz or at 1.497GHz in a superconducting niobium cavity at 2K temperature. The ultimate goal of this project is to reduce electricity consumption of currently used klystrons in CEBAF RF source system by using a relatively low cost, high efficiency magnetron based RF source system. The student is expected to learn the RF control circuit design, simulation and participate the magnetron control experiments both on bench and on the cavity in a Dewar.
REU STUDENT PARTICIPATION:
Safety training for the electrical and radiation worker, recording, documentation and analysis of experimental data and writing a research report at the end of intern are required. Advanced physics majored student can also have the chance to learn how to design a new magnetron using CST Microwave Studio Suite software.
electric center in vacuum space to the mechanical alignment references of assembled cavity apparatus with required accuracy.
PROJECT TITLE:
Pulsed electron cooling to Kr ion beam experimental data analysis and cooling simuation
PROJECT MENTOR:
Haipeng Wang (haipeng@jlab.org), Max Bruker
PROJECT DESCRIPTION:
Initial experimental data and simulation analysis, at CSRm machine at IMP China in 2019, have indicated that when using dithering technique to cool the kypton ion beam, the ion partickels got more loss than anticipated colling effect. Further particle tracking simulations have confirmed this observation. We need to further evaluate remaining experimental data from ion BMP, IPM, Schottky spectrum to confirm these simulations and to confirm the space-charge kicking effect of electron beam to the ion beam. Scaling law of this kicking effect and its theoretical study on the synchro-betatron resonance isa critical tool to design an ERL by using short electron bunches and their friction force to cool a longer proton bunch in higher energy for Electron-Ion Collider.
REU STUDENT PARTICIPATION:
Safety training for the electrical Student intern will need to use his/her Python programming skill to do the data filtering, plotting and running the simulation codes developed at JLab and IMP to do the data comparison.