NFluxPerCell does not work

[deSUBHAM]

Hi,
I am making a setup for magnetic reconnection in pair plasma. The current sheet constitutes with particle having drift velocity. The background particles do not have drift velocity. I want to inject the background velocity. For that I used NFluxPerCell, as suggested here. But when I am doing that, the corresponding species is not detected by the code. The initialisation of background electrons are given below.

electrons_b.species_type                           = "electron"
electrons_b.injection_style                        = "NFluxPerCell"
electrons_b.surface_flux_pos                       = -Lz
electrons_b.flux_normal_axis                       = z
electrons_b.flux_direction                         = -1
electrons_b.num_particles_per_cell                 = 128
electrons_b.profile                                = "constant"
electrons_b.density                                = nb
electrons_b.momentum_distribution_type             = "gaussianflux"
#electrons_b.theta_distribution_type                = "constant"
#electrons_b.theta                                  = temp_b
electrons_b.ux_m                                   = clight * sqrt((2*temp_b)/pi)
electrons_b.ux_th                                  = clight * sqrt(temp_b)
electrons_b.uy_m                                   = clight * sqrt((2*temp_b)/pi)
electrons_b.uy_th                                  = clight * sqrt(temp_b)
electrons_b.uz_m                                   = clight * sqrt((2*temp_b)/pi)
electrons_b.uz_th                                  = clight * sqrt(temp_b)

I checked with Maxwell-Boltzmann distribution distribution, it did not work. Someone please help me out here. Thank you.

[dpgrote]

Is the surface_flux_pos = -Lz the lower bound of the domain? I notice that flux_direction = -1 which means that the particles will be injected with a negative velocity and never enter the domain. Also, are those typos in the expressions 2temp_b? Should those be 2*temp_b?

[deSUBHAM]

Thank you so much. I had a bit confusion about 'flux_direction'. Now it is clear. Also I do not find any typo of 2temp_b in the part of the code.
However, I have a couple of doubts though.

1. For the injection style "NFluxPerCell", does one have to have the momentum distribution style "gaussianflux"? I require the Maxwell_boltzmann distribution of momentum.
2. In my reconnection setup, it appears that the background particles are not participating in the reconnection process if they are injected as "NFluxPerCell". Otherwise, there seems to be no problem if they are injected as "RandomPerCell". Is there a special way to initialise them or am I doing something wrong?

[dpgrote]

1 The gaussianflux is what you want. If this detail is unclear in the documentation, can you make a recommendation about how to change the documentation to make it more clear?
2 Can you check the particle properties, the charge, mass, and weight, to make sure that they are initialized correctly?