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Division Spotlight
Accelerator Applications
The division was organized to promote the advancement of knowledge of the use of particle accelerator technologies for nuclear and other applications. It focuses on production of neutrons and other particles, utilization of these particles for scientific or industrial purposes, such as the production or destruction of radionuclides significant to energy, medicine, defense or other endeavors, as well as imaging and diagnostics.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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
Christmas Night
Twas the night before Christmas when all through the houseNo electrons were flowing through even my mouse.
All devices were plugged in by the chimney with careWith the hope that St. Nikola Tesla would share.
Dennis L. Youchison, Alex M. Melin, Arnold Lumsdaine, Charles R. Schaich, Gregory R. Hanson
Fusion Science and Technology | Volume 72 | Number 3 | October 2017 | Pages 324-330
Technical Paper | doi.org/10.1080/15361055.2017.1333855
Articles are hosted by Taylor and Francis Online.
The electron cyclotron heating system (ECH) on ITER uses 24 evacuated microwave transmission lines carrying up to 1.4 MW of power each at 170 GHz to provide resonance heating of electrons in the ITER plasma and to enable plasma current drive. A critically important component in this system is the microwave switch that allows the microwaves to be directed from the gyrotrons to either dummy loads or between launchers in the upper and equatorial ports of the ITER tokamak while maintaining the vacuum integrity of the transmission lines. A moveable, water-cooled CuCrZr mirror is used to redirect the microwave transmission between two orthogonal waveguides.
In this article we describe the optimized design of the mirror cooling passages produced by computational fluid dynamics analysis using ANSYS CFX with k-ε and k-ω shear stress transport turbulence models, and verify that the design parameters for mass flow rate, inlet temperature and pressure are adequate for good thermomechanical performance. Non-uniform heating of the mirror face from the incident microwaves induces deflections that should be less than 25 microns to meet the integrated transmission line efficiency specification. In the current 1.4 MW switch design, 0.03 kg/s of 36°C water at 10 bar inlet pressure can remove the 2660 W of ohmic heating in the mirror produced by the elliptical polarization power and maintain the surface temperature below 150°C. The water delta-T is 21°C with a 0.5 bar pressure drop in the mirror. The maximum predicted displacement in the center of the mirror face is less than 25 μm.