Using a microwave generator, a mixture of deuterium (D) and tritium (T) gas is excited into a plasma. The ions in the plasma are accelerated towards and embedded into a Ti target in the center of the chamber. When a D nucleus collides with and T nucleus, they may fuse into a highly unstable 5He atom, which decays via: 5He → 4He + n. The result of this fusion is a 14.1-MeV neutron and a 3.5-MeV α particle traveling in opposite directions. The α hits a ZnO scintillation layer on top of a glass window, and the light produced is recorded by a Photo Multiplier Tube (PMT). This makes a "tag" on the associated neutron. The neutron then hits a secondary target providing a flux-independent γ-ray cross section measurement. The total neutron yield is ≈2 × 108 s-1 in 4π, with tagged neutrons: up to ≈1 × 107 s-1.
API DT Neutron Generator
Associated Particle Imaging (API) Deuterium (D) + Tritium (T) Neutron Generator.
The NEXUS API DT neutron generator turned 45 degrees for demonstration, showing the different sections.
Picture with the ZnO window removed, showing the Ti target located in the center of the plasma chamber. The target is biased up to 100 kV.
Focusing elements of the microwave chamber. The microwave beam is focused into the D and T gas creating a plasma. The cable attached at the bottom of the picture is the high voltage which connects to the target.
Through the use of EJ309 liquid scintillation detectors, signals from neutrons and γ-rays can be well seperated.
The NEXUS Group
NEXUS is primarily maintained and operated by researchers and students, (both graduate and undergraduate) with technical input from our professional advisors. We are always seeking to expand our network of students, advisors, and outside experimentalists, so please contact us if you would like to become a part of the NEXUS team.
Staff/Faculty
Dr. Jon Batchelder Batch is an Associate Research Engineer in the Nuclear Engineering Department at UC Berkeley and a nuclear structure evaluator with more than three decades of experience measuring the properties of nuclei far from stability using radioactive beams and decay spectroscopy.
Prof. Lee Bernstein Lee is a Faculty Senior Scientist and the Nuclear Data Program Head at LBNL and a Professor at the UC-Berkeley Department of Nuclear Engineering. He leads the Bay Area Nuclear Data Program, whose mission is to meet the nuclear data needs of the applied and basic science andengineering community while training the next generation of nuclear scientists and engineers in the process.
Dr. Aaron Hurst Aaron is a Researcher in the Department of Nuclear Engineering at UC Berkeley and a member of the Nuclear Data Program at LBNL. He has a background in nuclear structure physics and develops software related to nuclear data. Some of these projects are available on GitHub.
Dr. David Matters David is a staff member in the Nuclear Science Division at LBNL, where he works in the Nuclear Data Program on developing projects and activities that address applications needs, including national security, nonproliferation, fusion energy, and isotope production. His research interests include gamma-ray spectroscopy, modeling neutron-capture and inelastic scattering reactions, and nuclear structure.
Graduate Students
Eugene Guan Eugene is a PhD student in the Department of Nuclear Engineering at UC Berkeley. Prior to returning to academia, he gained extensive industry experience in the manufacturing of high-yield compact neutron generators. His research focuses on the diverse applications of neutron sources, including Boron Neutron Capture Therapy (BNCT), neutron radiography, non-destructive testing, isotope production, and fusion energy for space exploration. His advisor is Prof. Lee Bernstein.
Joe Henderson Joe is a graduate student in the Department of Nuclear Engineering at UC Berkeley. His advisor is Prof. Lee Bernstein.
Wren Kawamara Wren is a PhD student in the Department of Nuclear Engineering at UC Berkeley. She works in the neutronics group studying radiation effects on electronics and her research interests include nuclear science, neutron transport, and reactor physics. When not in the lab, she enjoys ice skating, hiking and painting.
Undergraduate Students
Samik Krishnan Samik is a Chemical Engineering and Nuclear Engineering student at UC Berkeley (Class of 2028) with strong interests in nuclear physics, fission systems, reactor hydraulics, nuclear materials, and DT-generator technology. He works on the mechanical and software components of DT-generators.
Sean Tang Sean is an undergraduate student studying Nuclear Engineering and assists in the building and simulation of the DT-API setup. His research interests include developing nuclear physics simulations, fusion, and space exploration.
Danica Zagala Danica is a 4th-year Chemical Engineering and Nuclear Engineering Joint Major. Her current work focuses on medical isotope production for radiopharmaceutical applications, although her research interests extend much broader. Though she is undecided about attending graduate school or going straight to industry, she is deeply passionate and ever curious. When outside of an academic environment, you can find her at an archery range, feeding crows, or maintaining her garden.
Professional Advisor
Jay James Jay is a professional engineer (nuclear, electrical, mechanical). His current focus is on NEXUS safety, operation, and shielding design. Jay is also an Affiliate Staff Scientist at the Lawrence Berkeley National Laboratory.