Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Faraday Disk Dynamo01:23

Faraday Disk Dynamo

A Faraday disk dynamo is a DC generator, producing an emf that is constant in time. It consists of a conducting disk that rotates with a constant angular velocity in the magnetic field, perpendicular to the disk's plane. The rotation of the disk causes a change in magnetic flux, which induces an emf, causing opposite charges to develop on the rim and in the center of the disk. The polarity of the induced emf can be determined by the direction of the magnetic field and the direction of the...
Magnetic Fields01:27

Magnetic Fields

A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
Divergence and Curl of Magnetic Field01:26

Divergence and Curl of Magnetic Field

The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
Magnetic Damping01:17

Magnetic Damping

Eddy currents can produce significant drag on motion, called magnetic damping. For instance, when a metallic pendulum bob swings between the poles of a strong magnet, significant drag acts on the bob as it enters and leaves the field, quickly damping the motion.
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
Potential Due to a Magnetized Object01:24

Potential Due to a Magnetized Object

Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
Magnetostatic Boundary Conditions01:28

Magnetostatic Boundary Conditions

An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...

You might also read

Related Articles

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

Sort by
Same author

Universal growth of magnetic energy during the nonlinear phase of subsonic and supersonic small-scale dynamos.

Physical review. E·2026
Same author

Mtb-Specific Interferon-Gamma ELISpot Assays Have Greater Sensitivity for Detecting Mtb Infection Compared to Tuberculin Skin Test in a Cohort of Experimentally M. tuberculosis-Infected Macaques.

Journal of the American Association for Laboratory Animal Science : JAALAS·2026
Same author

The fragmentation properties of massive star-forming regions in 30Dor-10 at 2000 au resolution.

Nature communications·2026
Same author

Antiretroviral treatment does not prevent extrapulmonary tuberculosis during SIV/Mtb coinfection in macaques.

JCI insight·2026
Same author

In-depth exploration of catalytic sites on amorphous solid water: I. The astrosynthesis of aminomethanol.

Physical chemistry chemical physics : PCCP·2024
Same author

Chiral Anomaly and Dynamos from Inhomogeneous Chemical Potential Fluctuations.

Physical review letters·2024

Related Experiment Video

Updated: May 14, 2026

Magnetically Induced Rotating Rayleigh-Taylor Instability
06:42

Magnetically Induced Rotating Rayleigh-Taylor Instability

Published on: March 3, 2017

Small-scale dynamo at low magnetic Prandtl numbers.

Jennifer Schober1, Dominik Schleicher, Stefano Bovino

  • 1Universität Heidelberg, Zentrum für Astronomie, Institut für Theoretische Astrophysik, Albert-Überle-Strasse 2, D-69120 Heidelberg, Germany. schober@stud.uni-heidelberg.de

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|February 2, 2013
PubMed
Summary

The small-scale dynamo efficiently amplifies weak magnetic seed fields in the universe. This process, crucial for cosmic magnetism, operates effectively even with low magnetic Prandtl numbers, provided the magnetic Reynolds number is sufficiently high.

More Related Videos

A 100 KW Class Applied-field Magnetoplasmadynamic Thruster
11:47

A 100 KW Class Applied-field Magnetoplasmadynamic Thruster

Published on: December 22, 2018

Related Experiment Videos

Last Updated: May 14, 2026

Magnetically Induced Rotating Rayleigh-Taylor Instability
06:42

Magnetically Induced Rotating Rayleigh-Taylor Instability

Published on: March 3, 2017

A 100 KW Class Applied-field Magnetoplasmadynamic Thruster
11:47

A 100 KW Class Applied-field Magnetoplasmadynamic Thruster

Published on: December 22, 2018

Area of Science:

  • Astrophysics
  • Plasma Physics
  • Dynamo Theory

Background:

  • The present-day universe exhibits strong magnetization, despite originating from weak initial magnetic fields.
  • Fast amplification mechanisms are necessary to explain the significant growth in magnetic field strength.
  • The small-scale dynamo is the most efficient known mechanism for converting turbulent kinetic energy into magnetic energy, leading to exponential magnetic field growth.

Purpose of the Study:

  • To analyze the properties of the small-scale dynamo under conditions of low magnetic Prandtl numbers (Pm).
  • To investigate the dependence of dynamo efficiency on different types of turbulence, characterized by the turbulence spectrum slope (ϑ).
  • To determine the critical magnetic Reynolds number (Rm_crit) required for small-scale dynamo action in the low Pm regime.

Main Methods:

  • Solving the Kazantsev equation, which models small-scale magnetic field evolution.
  • Utilizing the WKB approximation for analysis.
  • Exploring turbulent spectra from Kolmogorov (ϑ=1/3) to Burgers (ϑ=1/2) turbulence.

Main Results:

  • The dynamo growth rate in the low Pm limit is found to be proportional to Rm^{(1-ϑ)/(1+ϑ)}.
  • Critical magnetic Reynolds numbers (Rm_crit) were determined: approximately 100 for Kolmogorov and 2700 for Burgers turbulence.
  • Rm_crit imposes a stronger constraint in the low Pm regime compared to high Pm.

Conclusions:

  • The small-scale dynamo can operate effectively in the low magnetic Prandtl number regime if the magnetic Reynolds number is sufficiently large.
  • This mechanism facilitates magnetic field amplification on small scales across diverse physical environments.
  • Weak magnetic seed fields can be amplified rapidly, contributing to the universe's overall magnetization.