Room A5 (2) "White Hole"

The setup here seems quite similar to the previous puzzle.

Naturally, there's a twist.

Last time you had to move the arrow whilst the particle was in flight.

This time you'll need to move one of the portal gates.

Set the components up such that the up-arrow will direct the particle back into the first portal gate. Move the exit portal gate in front of the receiver after the particle has made its first portal traversal, but before the second.