China
Africa
Explore chapters and articles related to this topic
3He reaction
Published in S. V. Ryzhkov, A. Yu. Chirkov, Alternative Fusion Fuels and Systems, 2018
Studies on controlled thermonuclear fusion (CTF), conducted in many countries of the world over the past five decades, have now come very close to implementing a reactor design capable of demonstrating the possibility of industrial application of the energy of fusion of light nuclei. In 2005, the countries participating in the ITER (International Thermonuclear Experimental Reactor) project decided to build a reactor. In this reactor, the thermonuclear plasma will be held by a magnetic field in a tokamak type system, and the fuel cycle is based on the reaction of deuterium with tritium D+Tân(14.1MeV)+4He(3.5MeV).
Important Controlled Fusion Devices
Published in Hitendra K. Malik, Laser-Matter Interaction for Radiation and Energy, 2021
ITER has reached a certain mark and achieved a higher position in fusion history. In 2012, the ITER Organization was given license as a nuclear operator in France. This was given on the basis of its thorough and non-discriminatory examination of safety and protection files. Today, power plants work either on nuclear fission, fossil fuels, or renewable energy sources but mainly water or wind. The plants generate electricity by converting mechanical power, such as the rotation of a turbine, into electrical power irrespective of energy sources. In a coal-fired steam station, the combustion of coal turns water into steam and the steam in turn drives turbine generators to produce electricity. The tokamak is a machine that is made to generate the energy of thermonuclear fusion. The energy inside a tokamak, produced through the fusion of atoms when the neutrons are absorbed by the walls and their energy is expected to convert into heat. A thermonuclear fusion power plant will use this heat to generate the steam and then electricity by using the turbines and generators similar to a conventional power plant. The main portion of a tokamak is a vacuum chamber like a doughnut-shaped chamber. Gaseous hydrogen fuel inside the vessel converts into plasma in the presence of extreme heat and pressure. This attains a critical condition in which hydrogen atoms can be brought to fuse and produce the energy. The confinement and controlling of charged particles is carried out by the massive magnetic coils placed around the vessel. Scientist use this innovative idea to confine the hot plasma away from the vessel walls.
Fusion Reactor Materials
Published in C. K. Gupta, Materials in Nuclear Energy Applications, 1989
Progress has been remarkably consistent, and there are good prospects that the new generation of large TOKAMAK will achieve plasma conditions approaching those required in a fusion reactor. The first generation in the late 1960s consisted of relatively small devices, built to establish the basic confinement properties of the TOKAMAK with relatively low-temperature plasma and short confinement times. With larger apparatus, higher temperatures and larger confinement times were obtained. The introduction of powerful neutral injection systems gave much higher temperature, including the record temperature of 80 million degrees, achieved in the U.S. TOKAMAK at Princeton in 1978. There are four large TOKAMAK being commissioned or nearing completion: TFTR (U.S.), T-15 (U.S.S.R.), JT60 (Japan), and JET (western Europe). TFTR started operating in December 1982, followed by JET in mid-1983. Built by the JET Joint Undertaking at Culham in Oxfordshire, U. K., JET is approximately 12 m high and 15 m in diameter â the largest and most powerful TOKAMAK of its generation. TFTR and JET are designed to operate with deuterium and tritium plasma in the latter part of their program, generating several megawatts of heat for a few seconds. JT60 and T-15 are designed to operate with hydrogen plasmas only. A further stage of TOKAMAK must be built to establish the engineering aspects of an electricity-generating fusion device before prototype reactors are built. The collaborative effort between Europe, Japan, the U.S., and the U.S.S.R. in the TOKAMAK design known as INTOR is a step in this direction. Fusion power stations are likely to gain ground in the next century, when the need for further sources of electricity will be even more pressing.
Analysis of the Shattered Pellet Injection Fragment Plumes Generated by Machine Specific Shatter Tube Designs
Published in Fusion Science and Technology, 2021
T. E. Gebhart, L. R. Baylor, S. J. Meitner
Disruptions and their mitigation are critical issues for the tokamak as a potential fusion reactor. The damage caused by the large electromagnetic and thermal loads, along with the possibility of forming a coherent beam of runaway electrons, are potentially detrimental to the longevity of machine components. ITER has chosen shattered pellet injection (SPI) as the baseline method of disruption mitigation (DM) due to its ability to rapidly inject material deep into the core of the plasma to radiate the plasma thermal energy.1 SPI is a process in which a predetermined amount of gas is desublimated into the barrel of a pipe gun to form a solid, cylindrical pellet. The pellet is then dislodged and accelerated downstream where it transverses various guide tubes, pumping gaps, and gate valves before impacting a bent tube and subsequently shattering before entering the plasma. Pellets for thermal mitigation are primarily made of deuterium with small (<20% by mole) amounts of neon.2 Argon pellets have also been explored for runaway electron dissapation.3 These pellets are dislodged by either high-pressure gas delivered by a fast valve or a mechanical punch. Currently, shattered pellet injectors are installed on JET (Ref. 4), DIII-D (Ref. 5), and KSTAR (Ref. 6) to be used in experiments to determine optimal SPI performance and operational techniques.
Tritium Breeder Layer Evaluation of Fusion-Fission Hybrid System
Published in Fusion Science and Technology, 2020
Renato Vinicius A. Marques, Marcia Saturnino, Felipe Martins, Carlos Eduardo Velasquez Cabrera, Claubia Pereira Bezerra Lima, Maria Auxiliadora Fortini Veloso, Antonella Lombardi Costa
Deuterium (D) and Tritium (T) are two hydrogen isotopes that will be used as a fuel for fusion reactions of tokamaks based on ITER. The main components are the blanket system, divertor system, vacuum vessel, and magnetic system, formed by the toroidal and poloidal field systems, central solenoid, and cryostat.1 Tokamak development is an international and financial collaboration supported by different countries: the United States, Russia, France, European Union, China, Japan, Korea, and India, where the main goal is to achieve scientific and technological feasibility for nuclear fusion on the planet. As a result, there are many studies on a fusion device with the aim to produce energy in a self-sustaining system. There are also studies regarding hybrid systems being developed around the world to enhance transmutation aspects in order to decrease amounts of high-level waste and several studies about tritium production for self-sustaining fusion reactions.
Preliminary Design of ITER Divertor Langmuir Probe System
Published in Fusion Science and Technology, 2020
Wei Zhao, Yali Wang, Yuzhong Jin, Li Zhao, Hongxia Zhou, Lin Nie, Guangwu Zhong, Chunjia Liu, Christopher Watts, James Paul Gunn
Currently under construction, ITER will be the biggest tokamak the world over for scientific and engineering research and perhaps the most challenging scientific endeavor being undertaken today.1 There are tens of diagnostic devices in the ITER tokamak,2 and divertor Langmuir probes (DLPs) are used to measure the plasma parameters at the divertor target plates. This measurement is used for machine control and physics study. For machine control, it is envisioned that the probes will provide a signal indicating the attached/detached state of the divertor plasma, while for physics study, the system will need to supply more detailed measurements of the electron density and temperature. The Langmuir probe system consists of DLPs and back-end electronics, which includes power supply, probe operation mode switching box, signal conditioning unit, and instrument and control (I&C). The back-end electronics is located in level B1 of the Diagnostics Building. The main functions of the electronics are Langmuir probe driving, operation mode switching, and signal transmission and conditioning, and the four-quadrant power output is mandated to drive the Langmuir probes. The I&C of the Langmuir probe system complies with the requirements and can work perfectly on communication, data acquisition, configuration publishing, and various monitoring and control functions. DLP brazed on the monoblock includes a tungsten probe, insulation ceramic, and tungsten shield, and all DLP components are welded connections. From the probes to the back-end electronics, many cables are employed to drive the probes and transmit probe signals.