;+ ;PROCEDURE: swe_maxbol ;PURPOSE: ; Maxwell-Boltzmann distribution for fitting SWEA electron energy spectra. ; The reference frame is at the instrument aperture, after the electrons ; have been accelerated by the spacecraft potential. ; ; Correction for spacecraft potential, but no correction for bulk flow. ; ; Units are energy flux [eV/cm2-sec-ster-eV]. ; ;USAGE: ; eflux = swe_maxbol(E, par=p) ; ;INPUTS: ; ; E: Measured energy [eV]. ; ;KEYWORDS: ; ; PARAM: Parameter structure. ; ; p = {n : 1.0d , $ ; core density [cm-3] ; T : 10.0d , $ ; core temperature [eV] ; k_n : 0.0d , $ ; halo density [cm-3] ; k_vh : 4000.0d , $ ; k_k : 5.0d , $ ; pot : 0.0d } ; spacecraft potential [V] ; ; $LastChangedBy: dmitchell $ ; $LastChangedDate: 2014-09-22 09:25:06 -0700 (Mon, 22 Sep 2014) $ ; $LastChangedRevision: 15831 $ ; $URL: svn+ssh://thmsvn@ambrosia.ssl.berkeley.edu/repos/spdsoft/trunk/projects/maven/swea/swe_maxbol.pro $ ; ;CREATED BY: David L. Mitchell 03-29-13 ;FILE: swe_maxbol.pro ;- function swe_maxbol, E, parameters=p if not keyword_set(p) then begin p = {n : 4.0d , $ ; core density (cm-3) T : 10.0d , $ ; core temperature (eV) k_n : 0.0d , $ ; halo density (cm-3) k_vh : 4000.0d , $ k_k : 5.0d , $ pot : 0.0d } ; spacecraft potential (V) return, p endif mass = 5.6856297d-06 ; electron rest mass [eV/(km/s)^2] c1 = (mass/(2D*!dpi))^1.5 c2 = (2d5/(mass*mass)) ; Core distribution (Maxwell Boltzmann) [eV/cm2-sec-ster-eV] eflux = p.n * c1 * (E*E*c2) * exp(-(E - p.pot)/p.T) / (p.T^1.5) ; Halo distribution (kappa) if (p.k_n gt 0.) then begin vtot2 = 2D*(E - p.pot)/mass vh2 = (p.k_k-1.5)*p.k_vh^2 kc = (!dpi*vh2)^(-1.5) * factorial(p.k_k)/gamma(p.k_k-.5) kf = p.k_n * kc * (E*E*c2) * (1+(vtot2/vh2))^(-p.k_k-1) eflux = eflux + kf endif return, eflux end