Related Experiment Video
Updated: May 27, 2026
10:37
Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Evidence for separatrix formation and sustainment with steady inductive helicity injection
B S Victor1, T R Jarboe, A C Hossack
1University of Washington, Seattle, Washington 98105, USA.
Physical Review Letters
|November 24, 2011
Summary
This study demonstrates the first sustained toroidal plasma current of 50 kA using steady inductive helicity injection in fusion research. This breakthrough advances a new method for magnetic confinement fusion current drive.
Area of Science:
- Plasma physics
- Magnetic confinement fusion
Background:
- Achieving sustained toroidal plasma currents is crucial for magnetic confinement fusion.
- Steady inductive helicity injection is a promising but developing current drive method.
Purpose of the Study:
- To describe the first sustainment of a significant toroidal plasma current using steady inductive helicity injection.
- To evaluate the performance and characteristics of this new current drive technique in a fusion device.
Main Methods:
- Utilized steady inductive helicity injection in the HIT-SI device.
- Achieved toroidal plasma current sustainment up to 50 kA, exceeding injected currents.
- Sustained separatrix currents up to 40 kA, not linking helicity injectors.
Main Results:
- Sustained toroidal plasma current of 50 kA, 3 times the injected currents.
- Sustained separatrix currents up to 40 kA.
- Observed decreased toroidal magnetic field modes at higher current amplifications, indicating quiescent current drive.
Conclusions:
- Demonstrated a breakthrough in steady inductive helicity injection for magnetic confinement fusion.
- Showcased a viable new method for direct toroidal current drive.
- Achieved significant plasma current sustainment in HIT-SI during deuterium operations.
Related Concept Videos
01:28Induced Electric Dipoles
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
01:27Significance of Displacement Current
A displacement current is analogous to a real current in Ampère's law, participating in Ampère's law the same way as the usual conduction current. However, it is produced by a changing electric field. Displacement current is defined in terms of a time-varying electric field, and also has an associated displacement current density. By adding a term accounting for displacement current, Maxwell modified the existing Ampère's law, which is now called generalized Ampère's law.
02:17Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
02:17Separation of Sister Chromatids
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
01:16Energy Stored in Inductors
An inductor is ingeniously crafted to accumulate energy within its magnetic field. This field is a direct result of the current that meanders through its coiled structure. When this current maintains a steady state, there is no detectable voltage across the inductor, prompting it to mimic the behavior of a short circuit when faced with direct current.
In terms of gauging the energy stored within an inductor, it is equivalent to the integral of the power delivered at every individual moment, all...
In terms of gauging the energy stored within an inductor, it is equivalent to the integral of the power delivered at every individual moment, all...
01:23Induced Electric Fields
The fact that emfs are induced in circuits implies that work is being done on the conduction electrons in the wires. What can possibly be the source of this work? We know that it’s neither a battery nor a magnetic field, as a battery does not have to be present in a circuit where current is induced, and magnetic fields never do any work on moving charges. The source of the work is in fact an electric field that is induced in the wires. For example, if a stationary conductor is placed in a...