CERN Accelerating science

European Organization for Nuclear Research

High power high frequency loads for energy recovery


This technology consists of several design concepts for narrowband RF high power loads producing technically usable hot outlet water or air.
Conventional RF power loads produce cooling water at barely usable low pressure and moderate temperature (fragile ceramic parts, different expansion coefficients). Proposed are RF loads producing cooling water >150 °C at up to 100 bar pressure, as well as hot air up to 800 °C. One concept is the application of normal steel corrugated waveguide structures near cut-off. This concept could find practical use above several GHz. Another solution is resonant structures made of normal magnetic steel to be installed in large waveguides for frequencies of 500 MHz or lower. Similar resonant structures above 100 Mhz taking advantage of the rather high losses of normal steel may also be used in coaxial line geometries with large dimensions. In addition, there are concepts based on SiC foam and ferrite coated load.

Area of expertise

Radio Frequency technology; Material sciences.


Any application where dumping of high RF power is required. It can in principle be used in every accelerator facility.


The presented technologies for high power loads are mechanically robust and provide either a cooling liquid with high pressure and temperature (≤ 100 bar, ≥ 150 ̊C) at the outlet or very hot air (up to 800 ̊C). The liquid (typically water) as well as the hot air could then be used for energy recovery e.g. through a Stirling motor.


The structure will likely be more bulky than conventional loads

Intellectual Property status

Ready for licensing. PCT patent application filed.

Related Publications

I. Hischier, Diss. ETH 19723, 2011
S. Matsumoto, T. Higo, I. Syratchev, G. Riddone, W. Wuensch, CERN-ATS-2010-217, 2010
I. Preece, C. W. D. Andrews, Journal of Materials Science 8, 7, 964-967, 1973


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