I have had this exact problem. I have one domesticated cat and got a new cat that was a feral cat; I got him fixed but this did not help, he still chased and hurt my other cat. I did feed them in two different places to try to avoid the fighting.
This went so far as to my original cat losing a lot of weight, while the feral one had gained a lot of weight; he was about 8 years old when I got him. He was the nicest cat toward me but a nightmare to the other cat. I had been trying to do everything to make it work for over a year.
To trap your cat, take a cardboard box, tape it closed and cut a hole in one end of the box, and put some food (tuna) inside, then wait until your cat enters; this might take some time and several tries.
Once the cat is inside, tilt the box so that its opening hole faces upwards and cover the hole with a book or something larger than the hole so he doesn't escape. Place your carrier cage against the wall so it can't move and is positioned in a way that its opened door faces outwards, place the cardboard box against the carrier, then remove the book so the cat can enter the carrier cage, when the cat enters, use the book to cover the opening of the cage while you close it; this will, probably, possibly work.
My feral cat was not able to adjust so I had to take him down. I am saying this so you know what you might have to do if it doesn't work out for you and the cats.