Plasma Electron Relaxation Time Calculator

This tutorial explores the concept of plasma electron relaxation time, a key variable in plasma physics that describes the characteristic timescale for a plasma electron to revert to a Maxwellian velocity distribution following a perturbation. It is fundamentally connected to electron temperature, electron number density, and the Coulomb logarithm.

Electron Relaxation Time in Plasma Calculator
Plasma Electron Relaxation Time Calculator Results
Relaxation Time = sec

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Example Formula

The formula for calculating plasma electron relaxation time (τ) in a fully ionized plasma is:

τ = (3π1/2/4) × (ε0² × Te3/2) / (ne × e4 × lnΛ)


  1. τ: The electron relaxation time
  2. ε0: The permittivity of free space
  3. Te: The electron temperature in energy units (usually electronvolts)
  4. ne: The electron number density
  5. e: The elementary charge
  6. lnΛ: The Coulomb logarithm

Who wrote/refined the formula

This formula is a result of the collective work of scientists in the field of plasma physics over many decades, rather than the work of a single individual. It is based on the fundamental principles of statistical mechanics and the properties of charged particle interactions.

Real Life Application

This formula is critical in the field of plasma physics, particularly in the study of controlled nuclear fusion, where understanding the behavior of plasma electrons is crucial for maintaining stable plasma conditions in a fusion reactor.

Key individuals in the discipline

Several notable physicists have made significant contributions to plasma physics. Among them is Irving Langmuir, who first introduced the term "plasma" to describe ionized gas. Others include Lev Davidovich Landau, who developed the Landau damping theory in plasma, and Hannes Alfvén for his work on magnetohydrodynamics.

Interesting Facts

  1. The study of plasma electron relaxation time has been instrumental in advancing our understanding of plasmas, which comprise over 99% of the visible universe.
  2. Understanding plasma electron behavior has profound implications for developing nuclear fusion as a viable energy source, which could revolutionize our energy systems.
  3. As plasma physics is a relatively new field (compared to other branches of physics), many exciting discoveries and advancements are still being made.


Understanding the plasma electron relaxation time and its calculation provides valuable insights into the complex behavior of plasmas. This knowledge plays a pivotal role in numerous applications, most notably in the development of nuclear fusion technology. This tutorial underscores the significant role that plasma physics, a comparatively new field, has in shaping our understanding of the universe and our future energy landscape.

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