| Plasmas as Multiscale Plasmas encompass an astronomically large range of scales in length, density and temperature (equivalent to thermal energy). The well-known 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 10-7 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): 10-27 to 10+10 [highest density, shortest scale comes from quark-gluon plasma where electromagnetic force is replaced by the short-range, strong force] Number density: from less than 10-4 to more than 10+30 cm3 Temperature (thermal energy): from near absolute zero (crystalline states in recent non-neutral laboratory plasmas) to more than 100 keV Magnetic fields: less than 10-6 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, 18-25, 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 (cm-3) | <0.0001 -100,000 | 0.001 - 10 | 0.001 - 1000 | log 7 - 30 | neutral density (cm-3) | 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 | |