Ancient weapons technology from old Earth. CIMD, also known as Concussive or Chemical Impulse Mass Driver uses a sold-state chemical explosive charge stored in a cartridge to propel a payload shell at reasonable speed. CIMD-based weapons have been almost entirely replaced by FIMD based designs in modern use, due to their significantly higher muzzle velocity: requiring a smaller, more efficient payload to inflict similar damage with greater accuracy at range.
The Antimatter Impulse Mass Driver is the latest development of Mass Driver technology. Only recently developed by the Naval Research Labs, the AIMD utilises the Nuclear Energies released by colliding Matter with Anti-matter particles.
(UTN/UAS) Magnetically Assisted Fusion Impulse Mass Driver
The MA-FIMD is a development of the FIMD, first developed in the late 22nd century but wasn't introduced until the 23rd century, due to manufacturing limitations with then existing super-conducting technologies. The MA-FIMD utilises a Magnetic Accelerator built into the barrel construct that increases accuracy and muzzle velocity, similar to a coilgun. The MA-FIMD is now the standard weapon system of the Federal Navy, and has been upgraded significantly.
The FIMD, or Fission Impulse Mass Driver is a weapon system invented in the late 21st century by the Terran Space Research Corporation, that has been in use with the UTN Armed Forces since it's founding, and remains in use with the United Aquarian Systems over 3000 years later.
CTM shielding technology was first developed in 2412 A.D, 174 years after the founding of the UTN. The technology is based on a concept of energy crystals first discovered by the Terran Space Research Corporation many years before the Exodus of Earth.