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Division Spotlight
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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Fusion Science and Technology
Latest News
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Akiyosi Itakura, Naoki Goto, Masayuki Katoh, Yuichiro Kogi, Yoriko Shima, Hitoshi Hojo, Kiyoshi Yatsu, Shigeyuki Kubota, Atsushi Mase, Tsuyoshi Onuma
Fusion Science and Technology | Volume 39 | Number 1 | January 2001 | Pages 265-268
Poster Presentations | doi.org/10.13182/FST01-A11963457
Articles are hosted by Taylor and Francis Online.
Two types of microwave reflectometries are installed in the GAMMA 10 device for electron density profile and fluctuation measurement. Microwave is injected into the plasma in the O-inode or in the X-mode and is reflected at the cutoff layer where the electron plasma frequency corresponding to the electron density is equal to the frequency of incident wave.
An ultra short pulse method uses pulse train having duration of 65 ps and repetition rale of 250 kHz generated by an impulse generator. This signal has a broad frequency spectrum in microwave region. So simple transmitting system is realized. Reflected wave is divided into five frequency channels. Their center frequencies are 7, 8, 9, 10 and 11 GHz. Time of flight of each frequency component is measured using a time to amplitude converter. Location of reflected point is calculated from the time of flight. An electron density profile is reconstructed with one-shot data.
Fast frequency-modulation method is also used. The microwave source is swept from 11.5 GHz to 17.5 GHz: The signal is injected in the X-mode. Phase difference between reference wave and reflected wave is observed. Density profile is reconstructed from the phase difference data. There is low frequency fluctuation in the plasma. When sweep time is faster than 20 μ s, reliable data are obtained. This system has a rather simple receiving system.
Though reflected wave has an information of fluctuation, several methods of frequency analysis are tried and distribution of fluctuation is observed simultaneously.
Magnetic fluctuation is also observed by cross-polarization scattering method.