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Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Xianfei Wen, Dante Nakazawa, Mat Kastner, Jason Pavlick, Haori Yang
Nuclear Technology | Volume 194 | Number 1 | April 2016 | Pages 117-125
Technical Note | doi.org/10.13182/NT15-113
Articles are hosted by Taylor and Francis Online.
Pulsed photonuclear techniques are commonly used in homeland security and nuclear safeguards applications to achieve enhanced detection sensitivity. For example, photoneutrons generated by a pulse-mode linear accelerator (linac) are commonly utilized to produce characteristic capture gamma rays for the detection of nitrogen-rich explosives. Recently, in an effort to develop innovative systems with increased sensitivity to detect diversion and prevent misuse, the authors proposed to assay used nuclear fuel for its plutonium content using a photofission technique, in support of nuclear material management in the U.S. fuel cycle.
Passive spectroscopy measurements in the presence of intense background from fission products could be very difficult. Focusing on high-energy delayed gamma rays emitted by short-lived products from photofission presents a much more promising solution. However, as discovered in this study, a commercially available standard high-purity germanium (HPGe) preamplifier can be easily saturated for tens of milliseconds after each linac pulse. This greatly reduces the live time of the system especially when the linac repetition rate is high. On the other hand, although significantly reduced by increasing the lower-level threshold, the input count rate can still easily reach 106 cps (counts per second). Developing a gamma spectroscopy system that can handle such a high count rate has been a major challenge.
In this work, a commercial HPGe preamplifier was modified to reduce the saturation time and tail time to improve its high-rate performance in a pulsed photonuclear environment. Results of the modifications were evaluated via both simulations and experiments and proven to be effective without significant degradation of energy resolution. The field-effect transistor (FET) and feedback components were first moved to the warm side to enable the modifications. The saturation time of the preamplifier following a linac pulse was greatly reduced by decreasing the value of the feedback resistor. The effect of reducing the tail time of the output signal was also studied. A traditional trapezoidal shaping approach was then employed to study the impact of the modifications on energy resolution.
