Energy Shields (Necros)

Energy Shielding is one of the most important developments in infantry protection systems in the history of the UNSC since the beginning of its exoskeletal power armour development (Producing the MJOLNIR armour, Cyclops suit, the Wolf ATAAS and Dragon MAW to name a few). The UNSC's system was original developed from captured examples of the Shield Gauntlet, while Covenant and Plainsfierian systems were developed from Forerunner devices, while Machina and Vorenus systems were developed independently.

Operation
The Energy Shield systems take the form of a number of shield projectors which are placed strategically on the user and tailor made for their anatomy (which is why, without modifications, a Sangheili Combat Harness shield system won't work on a MJOLNIR suit. These work by ionizing gas and containing it in a weak magnetic field around the user. When an incoming projectile interrupts the magnetic field, it instantaneously reacts, dumping energy from the energy supply into the generators, making the energy shield denser and dispersing the kinetic or thermal energy of the incoming projectile. The higher the energy of the opposing projectile be it kinetic energy, heat energy or a mixture of both, can cause the energetic response of the shield generator to vary. As a result, energy weapon discharge, such as plasma, armour piercing bullets that deliver heavy kinetic force and fire based weapons require a more energetic response. Thus high calibre rounds and large plasma weapons, or more powerful energy weapons, can drain its energy even more quickly. The energy reserve is capable of being regenerated, but this requires the shields to be inactive. Once the shield energy reserves are gone, while it still can be recharged, the user is vulnerable.

With technology such as this, there is a drawback. In order to keep the user operable, the variance for what causes an energetic response must be carefully controlled. In order to allow the user a normal range of motions, from as simple as standing, sitting down, picking objects up, wielding a weapon, allowing them to carry extra equipment or allow medics to attend to their injuries, objects incoming under a certain speed will not deploy the repulsive effect of the shield. This brings about its downfall, in which crude but effective melee attacks will not set off the energy shields defensive system or not to their full capacity.

As with any defensive systems, its uses have been widely explored. The most common, variation is as solid state shields. Using similar magnetic fields, it keeps a dense field, denser than infantry mounted shields are capable of, across a small area, allowing for infantry portable shields. These have the unique talent of actually being capable of fully deflecting kinetic energy through their denser ionized fields, meaning most firearms will simple bounce off it. However, some of the kinetic energy does travel through the shield and the user, creating a jarring motion. As a result, sustained, heavier, weapon fire can cause the operator to be severely shaken, and may loose their defensive posture. Also, explosive ammunition and energy weapons cause considerable damage to them.

The other explored method is a temporary shield with almost incredible defensive abilities. Adapted from Forerunner technology, it creates a series of self supported, incredibly dense ionic fields, capable of absorbing massive amounts of energy across a small area then dispersing it across the multiple shields, a similar system to the composite armour on UNSC heavy vehicles. This allows it to absorb ridiculous amounts of punishment, if only for a short time, until the generator gives out. It is capable of stopping several blasts from 105mm guns, 102mm HEAT rockets, SPARTAN LASERs (though newer models have the ability to, with reduced effect, pierce them through adaptive lasing). However, 90mm Gauss Cannons, TITAN LASERs, 155mm artillery and missiles of larger size than the 102mm HEAT, along with some smaller classes of bombs, will overload it instantly. Ordnance larger than this will completely destroy its defences.