Antimatter

Desperate Measures

The feed cuts out as I position the ship above the wreckage. "Fraeia?"
I hear them growl before their reply, "It's following me."
"You need to leave now, before the antimatter can make contact with the hull." My voice is urgent. I'm worried, jostling in my seat as I wait. "I'm right outside. Just get out of there."
"No air," they say, clearly out of breath, "no more talking."
I watch through the panoramic view and see small sparks of light through cracks in the hull. The light reveals Fraeia as they run through the corridors. I watch as they take a leap off the edge of a floating metal plate, leaving the stable ground for the embrace of empty space.
I speak into the mic, "Fraeia?"
There's no response. I match their speed, and direction, positioning the ship alongside them. I then jump up from the pilot's chair and run to the back of the ship, the airlock. I don't think I've ever been able to put on my suit this fast, and with a perfect seal I might add.
I open the airlock and see Fraeia's body drifting maybe twenty meters away. I can't explain how strange the shift in perspective feels when you leap into space. From where I am, Freaia appears to be motionless. Once you're out in the void, and see the debris slowly getting further away, you learn to appreciate all that talk of relativity. It helps handle the inevitable nausea.
I anchor myself to the ship via a cable and jump without hesitation. One moment I'm stable with the feet on the metal hull, and in the next I'm weightless, drifting closer and using the boosters on my suit to angle myself just right. When able, I reach out and grab Fraeia's arm. I pull them in, ensuring I have a good grip before giving the cable a firm tug.
We drift back to the airlock and then I notice the blood. My suit is covered in black fluid, with little droplets dancing around us in floating orbs. When my feet touch the floor of the airlock, the higgstech starts to work its magic. I don't even need to use the magnets in my boots.
Fraeia tries to stand but their body goes limp, dead weight I now have to drag into the ship. I strain as the weight bears down on my shoulder, their feet dragging behind until we enter the safety of the ship. I catch a quick breath, trying to figure out just how they could possibly weigh so much. That's when I realize they aren't breathing.

Antimatter can be a tricky topic to discuss in scientific circles. I remember a spark of debate back at the wayfarer academy regarding its potential, but it never took off. Humanity lacks and never even had a fraction of the infrastructure needed to produce a single gram of the stuff. It's just not in the cards for us.
Antimatter is the opposite of matter. Any partner of standard matter will have an antiparticle. Protons have anti-protons, neutrons have anti-neutrons, and even electrons have an opposite in the form of positrons. Think of it like an electric charge where standard matter is positive and antimatter is negative. You know the rules: opposites attract. It takes a lot of effort to contain antimatter, let alone create it. Containing it is the hardest part, though. You have to use an electromagnetic field to suspend it in a near perfect vacuum, a panning trap.
Antimatter will drift towards standard matter. It's attracted to it. If it makes contact, the result is total annihilation of both, an explosive burst of energy. There will be zero wasted energy potential. An antimatter weapon leaves nothing behind. There's not even a trace of radiation when the bombs go off.

The problem with antimatter

On the surface, antimatter seems like a perfect weapon. You could wipe a fleet off the field with little effort. Point defense turrets used to destroy incoming missiles won't even work. Breaking the trap doesnt disable the bomb. The missile is merely a delivery system. Breaking it just frees the beast. You'll probably just get hit anyway.
The problem with antimatter is twofold: it's extremely expensive to make, sure, but most of all, it's overkill. Why would you even want a weapon like this? It could win you a war but the economic depression that follows will do you in anyway. It's not efficient, especially when you have so many other options.
Then you have the problem of storage and transportation. I would never haul this cargo. It could fail at any given moment. If something happened, there's no if, and, or but about it. You're gone. Existing is no longer a thing you do. There won't even be ashes to scatter. You just disappear.

Other uses

Antimatter isn't just a way to wage war. You could theoretically use it to power your ship. It would be exponentially more powerful and fuel efficient compared to fusion technology. That being said, it's still a bad idea.
Again you have the costs and potential hazards associated with storing large quantities of antimatter on your ship, but your access to fuel would be limited as well. You're not going to find antimatter somewhere to harvest or a fuel ship ready to fill your tank.
Fusion engines run on deuterium and tritium, both being isotopes of hydrogen. Just so we're clear, hydrogen is the most abundant element in the universe. You can't help but run into the stuff. Everywhere you go, you have fuel, it's practically a law of the universe. Antimatter doesn't have that luxury. It's why fusion is so widely used across all species.

The trade war

No one even tried to use antimatter weapons until the trade war. Dhitol somehow managed to make it work. Their ground troops even use it. Granted, small arms would be much cheaper compared to arming ships.
Still… It's an act of desperation. Imagine the mentality your soldiers would need to have to be willing to carry antimatter rounds. These rounds could fracture or shatter in the heat of combat and they're literally attached to you.
The Dhitol are fighting for survival. The Eden would wipe out their species if they fail. I get it. Their soldiers are sacrificing themselves for their cause. I wish I believed in something that much.