Plasma parameter calculator
Contents:
Overview
This PlugIn calculates various plasma parameters such as :
- 0) magnetic pressure (Pb = B^2/mu0)
- 1) perpendicular plasma pressure (Pp = nkT_perp)
- 2) full pressure (Pf = 2nkT_perp + nkT_par)
- 3) total pressure (P = Pb + Pp)
- 4) plasma beta (Pp/Pb)
- 5) temperature anisotropy (Tpar/Tperp - 1)
- 6) pressure ratio alfa = nt(Tpar-Tperp)/B^2/mu0
- 7) entropy = Pf/n^5/3 (n=density)
- 8) sound speed, cs = 989 sqrt(P/n) [km/s
- 9) plasma frequency fpe = 8968 sqrt(n),
- 10) ion inertial length (l = 227/n)
- 11) ion gyro radius (r = 1300*[sqrt(T_perp)] / B)
- 12) Alfven speed Va = B/sqrt(mu rho)
Input data
All inputs are optional and the number of output parameters depend on the
given inputs. The inputs are automatically joined to the timetags of the
input vector from the plasma temperature (alternatively density,
velocity or B-field).
For compatibility with both Cluster and THEMIS data sets, the temperatures
can be supplied either as a tensor (typically THEMIS) or as a parallel and
a perpendicular temperature. In the former case, insert the temperature
tensor in slot 3, and leave input slot 4 empty.
Outputs
The outputs are written to the worklist. Output depends on inputs given. See
above for a complete list of output paramaters.
Outputs
20 Nov, 2008 - updated this help text.
02 Feb, 2008 - all input optional, output as function of inputs.
31 Jan, 2008 - accept temperature tensor in units of eV (i.e., Themis).
27 Jun, 2006 - added sound speed + plasma frequency
07 Oct, 2004 - revised version
Bugs/Caveats
Note that some of the calculations are estimations, proxies.
Calculations for Mach number and Alfven speeds are not double checked. Use with care.
SEH, SEHDATE, 2006