Antimatter Catalyzed Microfusion Engine (The ACME)

Antimatter Catalyzed Microfusion Engine (The ACME)

The name is something of a misnomer, because the antimatter is not actually a true catalyst, it is consumed. Antimatter Triggered Fission Implosion MicroFusion Pulse Engine (ATFIMPE) makes for a very uninteresting and unwieldy acronym.

Soooo, ACME it is.

Antimatter is a pain in the neck to manufacture, with highly problematic storage issues. While antimatter produces over 1000 times more total energy per unit mass than traditional Deuterium/Tritium Fusion, it is also minimum ten times more expensive per unit energy output than modern efficient fusion Most people do not consider it, but antimatter induces a more efficient fission reaction than normal fission methods.

Antimatter is way better at liberating neutrons from Uranium-235. Liberating Neutrons is what Fission is (write that down, it will be on the final exam). Regular fission, 1 or 2 neutrons are liberated, which then like dominoes liberates 1 or 2 neutrons in the next atom those neutrons bump into, so on and so forth until they run out of Uranium-235 or other fissile substance. Antimatter Triggered Fission, each antiprotons liberates 143 neutrons, and awayyyy we go. Pop Zing Pow! 100 Billion such reactions from the injected antiprotons and you are good to go with a self sustaining fission reaction.

The fuel is a hollow ball of Depleted Uranium (Duranium, U-238) filled with a compressed mixture of Deuterium and Tritium. About 9 grams of Deuterium and Tritium for every gram of Depleted Uranium (Duranium, U-238). In early versions, the Deuterium and Tritium are not compressed and are compressed right before ignition using an array of 180 lasers.

One of the reasons I like the ACME is that it requires very little Antimatter. 1 nanogram for every 180 kilograms of the ACME fuel pellets.

One of the frequent comments I get is about using Depleted Uranium (Duranium, U-238). People might not be aware, but the even actinides such as Uranium-234 and Uranium-238 crn be made to fission, just not a runaway self sustaining domino effect fission reaction like you would expect from a traditional fission based nuclear device using odd actinides like Uranium-235 or Plutonium, but good enough for our purposes. The antimatter is sufficient to cause the Duranium to fission as is needed for the ACME.

Every 'hydrogen bomb' you have ever heard or learned about is actually a fission implosion initiated fusion bomb. They trigger a fission explosion and the massive pressure from the implosion induces the fission in the deuterium/tritium mixture.

First the pellet is irradiated with a 2 nanosecond burst of about antiprotons. (as little as 100 billion antiprotons for our smallest 30 gram pellet size. 1/6,000th of a nanogram) The antiprotons annihilate some of the outer uranium coating of the pellet, producing enough energy to cause the U-238 to fission. In turn, the fission reaction ignites a fusion reaction via implosion within the Deuterium-Tritium core. A new pellet is than inserted, and the process repeats itself.

The fusion reaction is about 60 times that of the fission implosion reaction trigger.

The largest 'pellet' is 350 kilograms, composed of 35 kilogram shell of Duranium and 315 kilograms of Deuterium/Tritium. About 2 micrograms of antiprotons are needed to initiate the reaction. Its total output is nearly 26 megatons TNT equivalent per pellet.

One of the main problems about fission and fusion is that it does not scale down very well.

The ACME was originally conceived because of the difficulties is scaling down fusion reactions. Using traditional techniques, nuclear reactions of less than 25 kilograms creating explosions of a relatively modest 10 tons TNT equivalent, were not thrilling. Yield ratios of only 400 Tons TNT Equivalent per tons are paltry compared to the 5-7 megatons TNT Equivalent per ton with full sized nuclear weapons.

The ACME scales down to as little as 2200 Tons TNT Equivalent with only 30 gram ACME Fuel Pellets, nearly 190,000 times the yield of tactical nuke scale experiments.

Using AntiProtons as a triggering mechanism, the fission implosion ignites the much larger fusion reaction can be forced with humble Depleted Uranium which is much less expensive, much more plentiful, and easier to obtain.

Compared to other forms of fusion, the ACME is easy peasy. You have a Penning trap that holds the antimatter, and you release it with a magnetic containment (that you can order from a catalog, seriously, kid you not, even in early 21^st century Earth state level Universities), and deliver it to the pellet. We’re talking undergraduate intern level mechanical skill here, not snooty nobel laureate diva’s. The fuel injector in your car is more complex.

The robustness of the ACME, they make wonderfully reliable fusion warheads, no fiddly mechanisms which might get jostled and disable the weapon by some lucky shot. The ACEM fusion warheads are innately salvage fused, so if they are shot, they will detonate. We have two standard sized warheads. A 1.75 Megaton TNT equivalent Ortillery (orbital artillery, which means we drop it like a bomb instead of propel it like a missile) and a 1.25 Megaton TNT equivalent missile. They both mass about 250 kilograms, 40 to a crate.

Experiments with the Tellar Antimatter Triggered Microfusion were also successful, but required orders of magnitude (albeit still miniscule) quantities of antimatter, and was much more technically complex and prone to difficulties.

Some people (but not me) prefer the pure fusion version. Pfft, Tellarites, know what I’m saying? I prefer the elegant simplicity of the Duranium shell version of the ACME. I can have the reactor maintained with regular techs, and not have to maintain a stable of snooty Nobel Laureates on standby making excuses all the time and fibbing about how long repairs will take so they look like miracle workers. The fuel injectors of a traditional internal combustion engine is more complex.

I like things simple and robust.

600 years ago, I was promoting the simplicity of the Plutonium Salt Water Rocket, it can be maintained by a plumber.

The reaction has an impressive exhaust velocity of nearly 10 million meters/second and a very hefty thrust to reactor ratio over 83 to 1.

To be completely fair, while the ACME Orion Fusion Pulse Reactor is more efficient than the Rocketdyne Magnetic Confinement Fusion Reactor, it is not as efficient as the Dyson-Yoyodyne Inertial Containment Drive Fusion Reactor, the Epstein Hybrid Magnetic Inertial Containment Drive Fusion Reactors, or the Weyland-Yutani Gravitic Confinement Fusion Reactors. But as I said, I like it because of its simplicity and ease of maintenance. For the same fuel, the Epstein family of reactors is about twice as efficient, but is much more costly and requires much more complex maintenance. The ACME is only 90% of the efficiency of the DY reactors the Federationalists are so fond of, but are much more robust.

Anyway, the overall efficiency of the ACEM is much higher than Rocketdyne Magnetic Confinement Fusion Reactor, mostly because they require loads more complex doodads.

The ACME’s main advantage is that it is easy to build, easy to operate, easy to maintain, and easy to repair, using undergraduate physics and engineering interns if need be.

I can also change out the fuel relatively easily, to use "Red Mercury" (Lithium-6), Tyllium-(Lithium-7), or Sirrilium (Helium-3, also known as Tibanna Gas) when they are available. Either of those, alone or mixed with Deuterium have hyuge proton exhaust products which are easily diverted for use for weapon or shields. Or even aneutronic fusionables like Boron-11 (Fifth Element) or Nitrogen-15 if I am really slumming it. Also, when using the magsails as a ramscoop, we are only gathering deuterium, but we can use straight up deuterium if we want. The deuterium pellet duranium casings are easy to fill, we have a machine onboard.

The Weyland-Yutani Gravitic Confinement Fusion is amazing, it uses the cheapest possible fuel, combustion grade hydrogen. I have long implied (and vigorously) from those 34 Tau docudrama’s, since the first time Kaylee said "Grav-Line", that the fusion reactors in the UAP use gravitic confinement fusion. Kayley had to reroute the G-Line to get the Grav Boot back on line. The Trace-Compression Block of the Firefly engine also uses a device known as the Grav Dampener. All these and their effects imply strongly (to me at least) that the fusion reactors they use utilized Gravitic Confinement Fusion. It’s the fusion the sun uses by the way. The WY has exhaust velocity up to 35.75 MILLION m/s, more than triple that of regular ol’ fusion reactors like those hacks in Starfleet using tired old magnetic confinement fusion, and 70% higher thrust to reactor mass radio (170 to 1). Despite its great exhaust velocity, it is a 5 times larger minimum reactor size, so it is not well suited for smaller ships. It also requires a full time skilled fusion mechanic as it needs near continual repairs. Those things need more attention than a newborn baby. It requires obscure and very complex artificial gravity technology, getting the parts is hell. The super big plus, is that you can use combustion grade hydrogen, which is a tenth of the price of Deuterium. I am not going to risk my life in a ship which the fusion reactor is continually falling apart. "They fall right out of the sky."