function to evaluate a simple maxwellian momentum distribution

maxwellian_ring_func(p_perp, p_par, n, p_width, p_rad, K)

Arguments

p_perp

numeric value of perpendicular momentum component

p_par

numeric value of parallel momentum component

n

numeric particle density.

p_width

numeric Width of ring momentum distribution

p_rad

numeric Radius of ring momentum distribution

K

numeric Integration constant

Value

numeric value of momentum distribution at (p_perp, p_par)