New concept: collisionless plasma

[MihailoMartinovic]

I suggest to add phrases "solar wind heating", "collisionless plasma" and "stochastic heating"

[katieefrey]

Hi @MihailoMartinovic,

Would you please provide some additional information for each suggested concept?

Name the new concept Provide your preferred label for the new concept

Describe the concept Does this new concept relate to any other terms already found in the UAT? Can you describe that relationship? What does the new concept mean? Is it more general or specific?

Describe where the concept fits within the existing hierarchy Don't forget that concepts can exist in multiple locations within the UAT.

Provide 1-3 supporting articles List bibcodes or other identifiers for articles that support the need for this new concept in the literature.

Please include any additional comments/feedback

[katieefrey]

I'm interested in "collisionless plasma" which has over 9k results in ADS. The other two have much lower hits, though "stochastic heating" has over one thousand.

@MihailoMartinovic Could you provide additional detail for at least the "collisionless plasma" concept as described above?

[namurphy]

@katieefrey — Here's an attempt at the information that you requested for "collisionless plasma."

@MihailoMartinovic — if there's anything I'm missing, please feel free to post below!

Name the new concept

collisionless plasma

Describe the concept

A collisionless plasma is a plasma where there are few collisions between particles (in particular, Coulomb collisions). Instead, particles interact through long-range collective interactions.

Describe where the concept fits within the existing hierarchy

I'm attempting to put concepts that already exist in the UAT in bold, and am including other concepts related to plasma astrophysics in case they end up being included in the future.

More general concepts

• High energy astrophysics
• Plasma astrophysics
• Plasma physics
• Cosmic electrodynamics

More specific concepts

Astronomical objects that are often made of collisionless plasma:

• Solar corona
• Stellar coronae
• Solar wind
• Space plasmas
• Stellar winds
• Interstellar plasma
• Intergalactic medium
• Supernova remnants
• Planetary magnetospheres
• Plasma jets

Plasma processes that often occur in collisionless (and often also collisional) plasma:

• Magnetic reconnection
• Shocks
• Alfvén waves
• Particle acceleration (which results in cosmic rays and solar energetic particles)
• Plasma heating
• Plasma instabilities
• Accretion

Related concepts

The frameworks used to describe collisionless plasmas include:

• Kinetic theory
• Gyrokinetics
• Magnetohydrodynamics (though it's quite bad at describing collisionless plasma at short length scales)

Provide 1-3 supporting articles

ADS full text search of "collisionless plasma"

Please include any additional comments/feedback

• Would we want to add "collisional plasma" as well? Collisional plasmas occur in: stellar interiors, low stellar atmosphere (photosphere, chromosphere), protoplanetary disks, (some) stellar winds, and laboratory plasma experiments.

[BartlettAstro]

Issue #412 Stochastic heating

Issue #413 Solar wind heating

renaming this collisionless plasma to reflect that the most dicussion of that proposed concept has taken place