Ohmic Heating (OH) Network

Abstract

Culham Centre for Fusion Energy (CCFE) has fabricated a large-scale Ohmic Heating (OH) network – a switching network that connects the driving energy source to the JET tokamak to induce and maintain the plasma current.

The bespoke OH network consists of high current opening and closing switches, a counter-pulse circuit, commutating resistors, and various safety and protection devices and their controls. The apparatus could be used for three broad areas of application:

  • Testing (e.g. high current, high voltage, withstand, load, or destructive) of industrial circuit components such as switches and busbars
  • High current or high voltage OH application onsite (e.g. smelting or chemical industries)
  • High-speed data acquisition for analysis

Description

Ohmic heating (aka resistive heating, or Joule heating) is used to induce and maintain the plasma current in the JET tokamak; raising the temperature of the plasma to around 20,000,000 °C. The OH network constructed at CCFE consists of high current opening and closing switches, a counter-pulse circuit, commutating resistors, and various safety and protection devices and their controls.

The switching network can withstand currents of up to 40 kA and has an (80 bar) air blast system to eliminate the arc when the switch is opened. A counter-pulse circuit is installed in case of arc re-strike, which charges a bank of high storage capacitors (1.2 mF at 25 kV).

Innovations and advantages of the offer

Software monitoring the air supply to the OHCThe OH network currently supplies approximately 1 MW of power to the JET tokamak, and is capable of producing plasma currents of up to 5 million amperes. The facility is thus unique in its high power capability and as such is suitable for industrial-scale testing and OH applications, while the nature of its intended use makes it suitable for high-speed data analysis applications as well.

The purpose-built facility has been used extensively for high power fusion applications. It is rigorously maintained and tested by experts. Safety and protection devices are already installed.

Application

The OHC is used to induce and maintain the plasma current in the JET nuclear fusion tokamak.

The apparatus could potentially be used for three broad domains of application:

  • High current, high voltage, withstand, or destructive testing of industrial circuit components such as switches and busbars
  • High current or high voltage OH application onsite (e.g. smelting or chemical industries)
  • High speed data acquisition for data analysis

Comments on the technology by the broker

This technology has been identified in the framework of the FUTTA (Fusion Technology Transfer Action) project, funded by the European Commission, and with the collaboration of Eurofusion.

 

    

Category
Energy
Reference No.
TDF0026
Could this technology benefit your business? Please contact Helen Rogerson STFC Innovations (UK)
Discussion
comments powered by Disqus