National Compact Stellarator Experiment
Encyclopedia
The National Compact Stellarator Experiment (NCSX) is a plasma
confinement experiment that was being conducted at the Princeton Plasma Physics Laboratory
. NCSX used magnets and layout designed through massively parallel computing to find the optimal shape for the reactor vessel, leading to a compact device. The project was cancelled on 22 May 2008 due to a failure to meet budgetary constraints.
NCSX is a variation of the stellarator
concept, with a much lower aspect ratio than a typical stellarator. One of the advantages of correctly-designed stellarators is that the confined plasma is passively stable when a steady magnetic field is applied, whereas tokamak
s require an array of active control strategies to stabilize the plasma, even under a constant magnetic field. Up to 12 MW of auxiliary heating power would have been available to the NCSX chamber, consisting of 6 MW from tangential neutral beam injection
, and 6MW from radio-frequency (RF) heating. Up to 3 MW of electron
cyclotron
heating would also have been available in future iterations of the design. The assembly tolerances were very tight and required state of the art use of metrology
systems including Laser Tracker and photogrammetry
equipment. $50 million of additional funding was needed, spread over the next 3 years, to complete the assembly within tolerance requirements. Components for the Stellerator were measured with 3d laser scanning, and inspected to design models at multiple stages in the manufacturing process.
Plasma (physics)
In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
confinement experiment that was being conducted at the Princeton Plasma Physics Laboratory
Princeton Plasma Physics Laboratory
Princeton Plasma Physics Laboratory is a United States Department of Energy national laboratory for plasma physics and nuclear fusion science located on Princeton University's Forrestal Campus in Plainsboro Township, New Jersey. Its primary mission is research into and development of fusion as an...
. NCSX used magnets and layout designed through massively parallel computing to find the optimal shape for the reactor vessel, leading to a compact device. The project was cancelled on 22 May 2008 due to a failure to meet budgetary constraints.
NCSX is a variation of the stellarator
Stellarator
A stellarator is a device used to confine a hot plasma with magnetic fields in order to sustain a controlled nuclear fusion reaction. It is one of the earliest controlled fusion devices, first invented by Lyman Spitzer in 1950 and built the next year at what later became the Princeton Plasma...
concept, with a much lower aspect ratio than a typical stellarator. One of the advantages of correctly-designed stellarators is that the confined plasma is passively stable when a steady magnetic field is applied, whereas tokamak
Tokamak
A tokamak is a device using a magnetic field to confine a plasma in the shape of a torus . Achieving a stable plasma equilibrium requires magnetic field lines that move around the torus in a helical shape...
s require an array of active control strategies to stabilize the plasma, even under a constant magnetic field. Up to 12 MW of auxiliary heating power would have been available to the NCSX chamber, consisting of 6 MW from tangential neutral beam injection
Neutral Beam Injection
To initiate a sustained fusion reaction, it is usually necessary to use many methods to heat the plasma, including RF heating, electron cyclotron resonance heating , ion cyclotron resonance heating , and neutral beam injection....
, and 6MW from radio-frequency (RF) heating. Up to 3 MW of electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
cyclotron
Cyclotron
In technology, a cyclotron is a type of particle accelerator. In physics, the cyclotron frequency or gyrofrequency is the frequency of a charged particle moving perpendicularly to the direction of a uniform magnetic field, i.e. a magnetic field of constant magnitude and direction...
heating would also have been available in future iterations of the design. The assembly tolerances were very tight and required state of the art use of metrology
Metrology
Metrology is the science of measurement. Metrology includes all theoretical and practical aspects of measurement. The word comes from Greek μέτρον , "measure" + "λόγος" , amongst others meaning "speech, oration, discourse, quote, study, calculation, reason"...
systems including Laser Tracker and photogrammetry
Photogrammetry
Photogrammetry is the practice of determining the geometric properties of objects from photographic images. Photogrammetry is as old as modern photography and can be dated to the mid-nineteenth century....
equipment. $50 million of additional funding was needed, spread over the next 3 years, to complete the assembly within tolerance requirements. Components for the Stellerator were measured with 3d laser scanning, and inspected to design models at multiple stages in the manufacturing process.