In the second screenshot, you need to dig out that netherrack to create a bracket ] shape of water. Those blocks will create steam! Inversely, you could raise your water level by 1 block and cover the tops of the middle electromagnets, those create steam too. The design that you are using looks like one of the first videos from TacticalLion, I'd advise giving them another look to perfect your very-close replica.
I see you are using insulated silver wire. Fusion reactors produce gobs and gobs of power. Aside from superconductor wire, you're going to have a % of resistance in each of the different types of wires. The more power you attempt to put through one, the more power will be lost in the material. I would recommend making the upgrade to superconductor wire ASAP.
You have fire and no plasma in your tubes. That is a sign that the actual reactor itself is starved of power. Likely due to power loss in your cabling.