
Plasmas
as Multiscale
Plasmas
encompass an astronomically large range of scales in length, density and
temperature (equivalent to thermal energy). The wellknown
length scale change in going from the microscopic to
cosmic scale, as presented so effectively by Charles and Ray Eames,
is even more dramatically illustrated by plasmas
which encompass an enormous range of scales in density, temperature (energy),
and field magnitude as well as length!
Contemporary
Physics Education Project
Plasma
Experiments  Space to Laboratory
Mesoscopic or mesoscale processes are encountered from
condensed matter physics to space plasmas, from less than 107 to more
than 10+7 meters. The relationship of microscopic to macroscopic phenomena
has long been a central theme of statistical physics and other fields.
However, recognition of the natural emergence of distinct mesoscale processes
and structures, especially clear and prominent in various plasma systems,
is a new development.
Plasma Scale Variations
Scale
Lengths: 10 to +25 in cm
Mass density
(grams/cm3): 1027 to 10+10
[highest density, shortest scale comes from quarkgluon plasma where electromagnetic
force is replaced by the shortrange, strong force]
Number
density: from less than 104 to more than 10+30 cm3
Temperature
(thermal energy): from near absolute zero (crystalline states in recent nonneutral
laboratory plasmas) to more than 100 keV
Magnetic
fields: less than 106 to more than 10+14 gauss
Plasma
lifetimes: characteristic time scales from picoseconds to infinity
Tables
of Laboratory, Space and Astrophysical Parameters
second table adapted from T. Eastman, IEEE Trans. Plasma Science,
18, 1825, 1990.


Space
Plasma

Size
(km)

Laboratory

Size
(mm)


spacecraft

0.001


0.001

Microscale 
screening

1

sensor

1


gyrations

100



Mesoscale 
filaments

1000

filaments

10


plasma
sheet

10,000


100

Macroscale 
magnetosphere

100,000

chamber

1000


heliosphere

1,000,000,000



Parameter

Ionospheres
and Magnetospheres

Interstellar
Regions

Stellar
Winds and Stellar Spheres

Stars

plasma
density (cm3)

<0.0001
100,000

0.001
 10

0.001
 1000

log
7  30

neutral
density (cm3)

0
 100,000

0.01
 1

0.1
 100

0

thermal
energy (eV)

<1
 10,000

1
 10,000

1
 100

0.5
 2000

bulk
speed (km/s)

0
 1500

1
 30

10
 1000

0
 500

magnetic
field (nanotessla)

1
 10,000

<0.1
 1

0.01
 50

log
5  9

