The primary defensive arms carried by Starfleet crew members are the phaser Type I and Type II. Both are high-energy devices sized for personal use and can be stowed in or attached to the uniform. Type III phaser rifles are also available for special situations, although these are rarely necessary on normal Starfleet away missions.
Type I Personnel Phaser
The type I phaser is a small hand-held Phaser, approximately the size of a pack of cards, that can be easily concealed. It is ideal for diplomatic missions, or similarly sensitive missions where it would be unwise to appear heavily armed. They can fire up to setting 8, including stun, heat and disruption. It has a maximum range of 3 kilometers.Type I phaser weapon is issued to all officers as a personal side arm for the purposes of self defense.
Type II Personnel Phaser
This larger hand unit has an added power pack allowing the weapon to produce phaser output at settings 1 through 16. It has a maximum range of 3 kilometers. With its curve broom-handle design, this slender and light weapon is usually worn in a velcro hip-holster that doubles as a recharging unit.
As with other phaser designs, the Type II offers a variety of lethal and non-lethal settings. At the higher levels the phaser pistol can operate at the thermal effect of the weapon results in physical damage to most organic compounds producing an effect similar to a laser. A type II phaser is however significantly more powerful than a type I phaser, or laser. At higher levels this will result in the complete breakdown of the nuclear bonds, and the target will "disintegrate". type II phasers are typically issued to away teams when danger, hostile resistance or need to show force is expected.
Type III Phaser Rifle
The type III is a rifle version of the type II phaser, with extended power packs. It is 1.2 meters in length and is also capable of firing to setting 16. The advantages of the type III are a 50% greater energy reserve, a multiple target acquisition system and a gyrostabilizer system. This gives the weapon a maximum effective range of 4 kilometers.
When fired the energy beam can be seen moving through the prefire chamber of the weapon. This acts as a self diagnostic for the weapon to determine whether it has jammed or is out of power. The weapon is only carried in situations when it has been established that there is an extreme threat.
Type IV Phaser Rifle
The type IV phaser, also known as the Compressed Phaser Rifle, because it is capable of creating a concentrated burst of phaser energy. The power release for each setting is the same but the effect is much more destructive in nature. Up to 50% more damage than type III is possible.
The type IV rifle also includes a much more effective and elaborate targeting system, a more powerful gyrostabilizer, and a larger energy reserve.
To aid in the compression of the beam, the design team built a small isolinear artificial intelligence unit into the rifle which has complete control of the energy discharge. This approach met with considerable success in a testing program that was surprisingly free of difficulties. The use of a computer control system also allows the beam characteristics to be modified much more easily than in previous phaser rifles, a measure clearly important when dealing with the Borg.
