Room B3 "Whale"

There are two receivers again in this room. You've already seen how they work.

When one is activated, it stays activated.

Meaning you're free to take your time with the other one.

Are there enough arrows to set up permanent paths to both receivers?

No - you'll need to reuse change the position of one of them for the second receiver.

Activate the left-hand receiver, then move the left-most arrow up to send the particle back to the right and towards the last receiver.