Larmor Radius Calculator

In the domains of Electromagnetic Field Theory and Plasma Physics, understanding the motion of charged particles in a magnetic field is paramount. A pivotal concept for this is the Larmor radius, which helps us comprehend the circular motion of charged particles when affected by a magnetic field. This tutorial will discuss the Larmor radius and its associated calculations and formulas, grounded on the Speed Perpendicular to the Magnetic Flux Density and the Cyclotron Angular Frequency.

Larmor Radius Calculator
Larmor Radius Calculator Results
Larmor Radius (rL) =

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Example Formula

The Larmor radius (rL) is calculated using the following formula:

rL = v / ωc


  1. rL is the Larmor radius.
  2. v is the speed perpendicular to the magnetic flux density.
  3. ωc is the cyclotron angular frequency.

Who wrote/refined the formula

The Larmor radius is named after the Irish physicist Sir Joseph Larmor. He was one of the key figures who contributed to the understanding of electron behavior in magnetic fields. The concept of Larmor radius is essential not only in electromagnetic field theory but also in plasma physics and astrophysics, particularly in studying cosmic rays and solar wind.

Real Life Application

In practical terms, understanding the Larmor radius is crucial for the design and operation of devices such as cyclotrons and synchrotrons, which are used to accelerate charged particles to high speeds. These devices have applications in a wide range of fields, from medicine (such as cancer treatment) to fundamental physics research.

Key individuals in the discipline

Sir Joseph Larmor made significant contributions to our understanding of how charged particles behave in magnetic fields. His work has had far-reaching implications in numerous fields of physics. Despite his valuable contributions, Larmor's work is often overshadowed by his contemporaries, but he remains an influential figure in the field.

Interesting Facts

  1. The concept of the Larmor radius is used in plasma physics, cosmic ray studies, and the analysis of solar wind dynamics.
  2. Larmor's work was a precursor to the electron theory of Niels Bohr and laid the groundwork for much of modern physics.
  3. The application of the Larmor radius and cyclotrons has greatly improved the field of medical physics, especially in radiation therapy for cancer.


Understanding the Larmor radius is vital to our knowledge of how charged particles move in magnetic fields. It is a fundamental concept in electromagnetic field theory and plasma physics, with implications ranging from understanding cosmic phenomena to designing devices for medical applications. The contributions of Sir Joseph Larmor continue to play a significant role in advancing our understanding of the universe.

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