Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Polar Coordinates: Problem Solving

Polar Coordinates: Problem Solving

Directional radiation patterns are central to antenna analysis, as they illustrate how signal strength varies with direction. These patterns are often modeled using polar plots, where the radial distance from the origin represents signal intensity at a given angle. A commonly used idealized form is the four-lobed rose curve, which captures the concept of directional beams in a simplified mathematical form.The four-lobed rose curve, described by r = cos⁡(2θ), features four symmetric lobes, each...

Generating Electromagnetic Radiations

Generating Electromagnetic Radiations

The German physicist Heinrich Hertz (1857–1894) was the first to generate and detect certain types of electromagnetic waves in the laboratory. Starting in 1887, he performed a series of experiments that confirmed the existence of electromagnetic waves and verified that they travel at the speed of light. Hertz used an alternating-current RLC (resistor-inductor-capacitor) circuit that resonated at a known frequency and connected it to a loop of wire. High voltages induced across the gap in the...

Mesh Analysis for AC Circuits

Mesh Analysis for AC Circuits

In the domain of radio communication, the significance of impedance matching must be considered. It is crucial to ensure the efficient transmission of signals between radio transmitters and receivers. Achieving this balance involves using impedance-matching circuits, with one fundamental configuration comprising a resistor, capacitor, and inductor.
The process of harmonizing these impedances begins with a clear understanding of the input and output signals. Once these signals are known, the...

Node Analysis for AC Circuits

Node Analysis for AC Circuits

Consider an angioplasty system featuring a catheter equipped with a turbine, a critical tool for removing plaque deposits from coronary arteries. This intricate medical device operates using a circuit model reminiscent of a dual-node RLC circuit powered by a current-controlled voltage source.
To unravel the complexities of this system, nodal analysis is employed, a powerful technique founded on Kirchhoff's current law (KCL), which remains valid for phasors. AC circuits can effectively be...

Radiation Pressure: Problem Solving

Radiation Pressure: Problem Solving

The radiation pressure applied by an electromagnetic wave on a perfectly absorbing surface equals the energy density of the wave. The wave's momentum also gets transferred to the surface when an electromagnetic wave is entirely absorbed by it. The rate at which momentum is transmitted to an absorbing surface perpendicular to the propagation direction equals the force on the surface.
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...

Radial System Protection

Radial System Protection

Radial systems employ time-delay overcurrent relays to reduce load interruptions. When a fault occurs, the nearest breaker opens first, while upstream breakers remain closed due to longer delay settings. This approach ensures minimal disruption to the rest of the system.
In a radial system with a fault downstream of the third breaker, ideally, only the third breaker will open, isolating the fault and interrupting the load connected beyond it. The second breaker has a longer delay setting,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

In-vessel design of a two-color heterodyne laser interferometer system for SPARC.

The Review of scientific instruments·2024

Same author

Overview of the early campaign diagnostics for the SPARC tokamak (invited).

The Review of scientific instruments·2024

Same author

Development of the neutral gas diagnostic system for neutral pressure measurements and gas analysis on the SPARC tokamak.

The Review of scientific instruments·2024

Same author

Development of a thermal diagnostic system for the SPARC tokamak.

The Review of scientific instruments·2024

Same author

Development of a bolometry diagnostic for SPARC.

The Review of scientific instruments·2024

Same author

Performance predictions of the SPARC x-ray crystal spectrometers for ion temperature and toroidal rotation measurements.

The Review of scientific instruments·2024

Search research articles

Related Experiment Video

Updated: Jun 27, 2026

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

Published on: August 25, 2016

Two dimensional radiated power diagnostics on Alcator C-Mod.

M L Reinke¹, I H Hutchinson

¹Massachusetts Institute of Technology, 77 Massachusetts Avenue, NW17-225, Cambridge, Massachusetts 02139, USA.

The Review of Scientific Instruments

|December 3, 2008

Summary

Upgraded diagnostics reveal significant poloidal asymmetries in tokamak core radiation. Unbiased absolute extreme ultraviolet diode arrays show a 30%-40% emissivity difference, impacting radiated power measurements.

More Related Videos

A Basic Positron Emission Tomography System Constructed to Locate a Radioactive Source in a Bi-dimensional Space

A Basic Positron Emission Tomography System Constructed to Locate a Radioactive Source in a Bi-dimensional Space

Published on: February 1, 2016

Related Experiment Videos

Last Updated: Jun 27, 2026

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

Applying X-ray Imaging Crystal Spectroscopy for Use as a High Temperature Plasma Diagnostic

Published on: August 25, 2016

A Basic Positron Emission Tomography System Constructed to Locate a Radioactive Source in a Bi-dimensional Space

A Basic Positron Emission Tomography System Constructed to Locate a Radioactive Source in a Bi-dimensional Space

Published on: February 1, 2016

Area of Science:

Nuclear Fusion Science
Plasma Physics
Diagnostic Technology

Background:

Tokamak devices require precise measurement of radiated power for operational control and understanding.
Poloidal asymmetries in plasma radiation can significantly impact core plasma properties and energy balance.
Existing diagnostics may have limitations in accurately capturing the spatial distribution of emissivity.

Purpose of the Study:

To upgrade radiated power diagnostics on the Alcator C-Mod tokamak for 2D photon emissivity profile measurement.
To investigate poloidal asymmetries in core plasma radiation.
To assess the accuracy of unbiased absolute extreme ultraviolet (AXUV) diode arrays for absolute radiated power determination.

Main Methods:

Implementation of upgraded AXUV diode arrays for plasma viewing along five horizontal planes.
Calibration of the diagnostic system and analysis of experimental data.
Comparison of emissivity profiles derived from AXUV diodes and resistive bolometers for L-mode and H-mode plasmas.

Main Results:

Observed significant 30%-40% inboard/outboard emissivity asymmetry during ELM-free H-mode plasmas.
AXUV diode and resistive bolometer emissivity profiles showed agreement in the plasma core.
AXUV diodes underpredicted total radiated power by nearly 50% compared to resistive bolometers in highly radiative L-mode plasmas.

Conclusions:

The upgraded diagnostics successfully revealed significant poloidal asymmetries in tokamak radiation.
AXUV diode arrays provide valuable core emissivity data but may underestimate total radiated power in certain plasma regimes.
Further investigation is needed to reconcile discrepancies between AXUV diode and bolometer measurements for accurate radiated power assessment.