Mor'tonium

Mor'tonium is a radioactive substance discovered and used by the Tau primarily in powering their Ion Weapons. A fairly recent discovery, Mor'tonium decays upon exposure to air and releases extremely large amounts of ion particles in the process. Tau Ion Weapons can choose use this property in overcharging their shots and making them far more explosively powerful, simply by exposing their power source to the atmosphere.

History
For many years the Earth Caste has been seeking ways to produce Ion weaponry usable by the infantry. Previously, in order to generate the high-energy particles that characterize Tau Ion Weapons, a powerful generator or small reactor was necessary. Thus, only vehicles or Tau Battlesuits were large enough to utilise the potent Ion Weapons, as only they could carry the bulky power sources required. Recent developments, however, have produced a new finding - a new alloy was discovered after enriching Iridium far past the point previously thought possible. This highly reactive material was named Mor'tonium and, although dangerous, it has proven highly useful.

When exposed to air, Mor'tonium immediately begins to deteriorate, creating a profusion of ion streams that can be harnessed and focused into a beam to fire a highly charged shot. This discovery meant that a heavy generator was no longer needed, allowing for an infantry-portable versions of Ion Weapons to immediately go into Earth Caste production; most notably the [Ion Rifle]].

A cylindrical slab of Mor'tonium powers an Ion Rifle, and its power source can be recharged or overcharged simply by exposing the unstable alloy to the atmosphere. When the alloy has entirely degraded, a new slab can be quickly fitted into the protective housing. While there are issues - the average Fire Warrior’s vital functions becoming compromised within a matter of months under the barrage of such intense radiation exposure - the high strength and long range of the Ion Rifle have made such inherent risks worthwhile. Already the Earth Caste is working on higher degrees of protection for infantry users, although thus far no results have proven cost-effective.