Forcefield
A forcefield, within the scope of applied physics, is generally an artificial barrier of charged exotic particles which may stop or slow particles colliding with others, usually at the cost of energy. Several forcefield implementations exist, but the most prevalent type is the Dynamic Containment Array (DCA) produced by Metatron.
Forcefields are used in industrial applications for protecting tools from damage, in the healthcare sector for cell repair, and in the defence industry to protect objects and personnel against projectiles. They also serve an important role in the containment of manifolds, which makes them both useful in singularity reactors and bridge generators. And they are important in interstellar spaceflight as a component of relativistic impact mitigation systems (RIMS).
Behaviour
Forcefield projectors use both a "projection" system and a "shaping" system. The projection system is a linear accelerator that generates and directionally emits exotic particles; the shaping system magnetically constrains these particles to make them assume the desired form of the forcefield. Once aligned, the particles "crosslink" and become fully coherent, preventing any particles from passing through from either side, as long as the field is sustained by fresh charged particles from the projector. After particles are crosslinked, they are no longer able to be modified by the shaping system. Even most waves are disrupted and deflected by the field.
Forcefield constraints are bidirectional, so particles inside the protected area also cannot exit the protected area. However, it should be noted that this does not provide security against a hostile party inside escaping containment, because they could tamper with or destroy the forcefield generator; in such a scenario, a number of forcefield generators arranged outside the area pointing inwards should be used, inverting the field.
By altering the charge and composition of the emitted exotic particles, the field can be made to block some types of particles but allow others. For example, one may want to allow only certain wavelengths of visible light below a certain energy limit to pass through the field in order to allow the field to appear translucent while preventing high-energy photon based attacks. This also allows information to be transmitted and received through the field at certain controlled points, for example, so one can communicate with a computer system inside a forcefield-protected area while ensuring said area remains secure. This mechanism also allows the enclosed area to move with its surroundings without making it vulnerable to kinetic attacks, as particle interactions above a certain energy or velocity can be blocked; however, this would still not allow objects to pass through the field, just transfer their momentum to the area inside it.
Fields can be protected through or even in walls, as non-crosslinked particles can pass through matter before joining the field. Higher power levels are required to pass through higher densities. Additionally, because of the directionality of projectors, in order to create a field enveloping a specific area (i.e. a sphere of protection), multiple projectors are required to cover each angle. Verifying complete projector coverage is especially important for high-security applications, as even a gap a few microns wide exposes the projector to attack and renders the entire system useless; the most effective solution is to utilise overlapping projectors.
When two forcefields collide, a massive amount of heat, light, and radiation is emitted at the contact point as the exotic particles annihilate each other. Assuming both fields continue to be sustained by energy from their projectors, the field with greater backing power will eventually overcome the other and pass through, albeit with a significant amount of resistance.
Power
Forcefield projectors consume the maximum amount of power when the field is actively being stressed, but at idle, they always continue to draw a minimum amount of energy, as they interact with and block atmospheric gases and stray particles. The amount of energy in the idle state also depends on the size of the field, which makes requirements grow linearly. Operating a forcefield in "pulses" to save power is possible but not recommended for high-security applications as it opens up the protected area to timing-based attacks on the projector.
For a standard forcefield system utilised in exosuits, the idle power draw is around 8-9 megawatts; power is generally supplied by an array of fission batteries. Vehicular fields, such as those used in armoured vehicles, often use around 60-70 MW. Those used to protect massive facilities, such as the Descent in Black Mountain, can draw constant energies well in the range of hundreds of gigawatts. Antimatter-powered RIMS systems used on spacecraft consume the most energy of all, in the low terawatt range.