Earlier, I mentioned a possible magnetic field effect. I was thinking along
the lines of a conductor moving in a changing magnetic flux. A person, being
somewhat of a conductor, should experience opposing forces to motion in a
changing magnetic field (if dB/dt through their body is large enough) and
these opposing forces would be consistant with your earlier message. From
the dimensions you gave, I suspected that the field would have significant
fringing, and when a person tried to walk into it they would experience
opposition (because of dB/dt). However, doing some rough calculations, I
don't see how the system you describe could produce a magnetic field large
enough. Using the maximum electric field strength in air to arrive at a
maximum surface charge density, along with the roll dimensions and velocity,
one can calculate a current. Then treating this as a moving sheet of charge,
a B field can also be calculated. Finally, assuming a person's velocity as
they enter the field, one can calculate a rough dB/dt and an opposing force.
However, my rough calculations are orders of magnitude too small. I would
guess that any opposing force would have to be on the order of hundreds of
Newtons to impede a person's progress as described in your earlier message.
It is an interesting story. Back to the drawing board.