Two storeys for power supplies, one for wave-generating devices—the Radio Frequency Heating Building is the radio powerhouse on site, housing all wave-generating equipment for the electron and ion cyclotron heating systems.
Abutting one wall of the Assembly Hall is a three-storey structure that will house the equipment required to generate the high-frequency electromagnetic waves of ITER's electron and ion cyclotron heating systems.
These radio-wave-generating systems are designed to deliver energy at frequencies that match the oscillations of particles inside the plasma—a matching called "resonance." The energy increases the velocity of the particles' chaotic motion, and at the same time their temperature.
ITER will rely on radio-wave external heating systems to provide 40 MW of input heating power. (A third external heating system, neutral beam injection, will provide another 33 MW of input heating power.) Without the ITER heating systems to start and maintain the fusion reactions, there could be no fusion power in ITER.
In electron cyclotron resonance heating (ECRH), electrons
are targeted at a resonant frequency of 170 GHz. In ion cyclotron resonance heating (ICRH), energy is transferred to the ions
in the plasma by a high-intensity beam of electromagnetic radiation with a frequency chosen between 40 to 55 MHz. Both heating systems are based on the same principle—the conversion of electrical power into electromagnetic radiation—however, the technology they rely upon is considerably different.
The Radio Frequency Heating Building shares one wall with the Assembly Building.
The ECRH system transmits heat to the plasma through microwaves, much in the same way a microwave oven heats food. The ICRH source is more aptly compared to a powerful radio transmitter of the kind that is still used to broadcast information from one end of the world to the other—with the difference that the ITER system will require a number of amplifiers to reach a much higher level of power.
In the Radiofrequency Building, power supplies will occupy the better part of the first two floors. Thirty units (12 ECRH and 18 ICRH) will supply a total of 100 MW of input power to the wave generators installed on the top floor of the building (gyrotrons
for electron cyclotron resonance heating and high power grid tube amplifiers for ion cyclotron resonance heating).
Waves generated in the Radiofrequency Building will travel along robust transmission lines through the Assembly Building and into the Tokamak Building, where five ECRH launchers and two ICRH antennas
will deliver them deep into the plasma.
The European Domestic Agency has completed the main construction activities on the facility and plans handover to the ITER Organization in January 2022, after the final finishing activities (interior partitions, piping, electrical) are completed. The first power supplies will be installed in 2022.
Radio Frequency Building facts:
• Building dimensions: Height 25 m, length (east/west) 50 m, width (north/south) 43 m
• Number of storeys: 3
• Infrastructure construction (2016-2022): European Domestic Agency Fusion for Energy
• Electron cyclotron (ECRH): Europe (6 gyrotrons, 8 power supplies, 4 upper launchers); India (2 gyrotrons, 4 power supplies); Japan (8 gyrotrons, 1 equatorial launcher); Russia (8 gyrotrons); United States (all transmission lines)
• Ion cyclotron (ICRH): ITER Organization (2 antennas, 10 power supplies); India (9 radio frequency transmitters, 8 power supplies); United States (all transmission lines)
• Equipment delivery: 2021-2027
• Equipment installation: 2022-2028
• Start of integrated testing: ECRH expected 2025; ICRH expected 2029