function st_swea_secondary_flux,energy,eflux,parameter=par
if not keyword_set(par) then begin
xs = [1.0 , 3.16, 10., 31.6, 100., 316, 1000., 3160.]
ys = [1.0e-005, 1e-4, 0.0006, 0.04, 0.5, 1., 0.8 , .7]
eff = spline_fit3(energy,xs,ys,param=par,/xlog,/ylog)
par.func ='st_swea_secondary_flux'
str_element,/add,par,'gain',1e6
endif else eff = spline_fit3(energy,param=par)
if keyword_set(eflux) then begin
eff = mcp_efficiency(energy) * (energy gt 20)
nn = total( eflux/sqrt(energy) * eff)
return,nn
dprint,'compute sum here'
endif
return,eff
end