Name: Imperial Munitions HVCPA
Model: Imperial Munitions Hyper Velocity Circular Particle Accelerator
Scale: Speeder
Skill: Blaster; HVCPA
Ammo: 50, see below
Cost: 10000, 50 (power pack)
Availability: 3, X
Range: 3-25/60/150
Damage: See below

The HVCPA does 2d damage for every round it is charged (and consumes 1 unit of energy per round charging), up to a max of 10d, it also spends a unit of energy when it is fired, and 1 unit every round it is kept charged.  Also, at medium range the HVCPA inflicts damage over a 1 meter radius blast at -2d to its damage, and at long range over 3 meter radius at -4d.

Description: The HVCPA is a creative weapon designed by Imperial Munitions for use by Storm Commandos nd other elite Imperial Forces, though its intended use is a bit unclear and it is suspected the research was undertaken primarily as a technical challenge.  Bearing some resemblance to a light repeating blaster externally, the HVCPA is distinguished by its very large bore barrel and the circular acceleration chamber on top of the weapon.  The weapons stock lifts up and can be removed, the power pack fitting under the stock at the back of the weapon.
The HVCPA works by releasing a cloud of tiny particles into the acceleration chamber where small repulsors accelerate them to extreme velocities by continuing rotations about the chamber such that in effect they have a kilometers long acceleration area, then when fired they are shunted down the barrel which is lined with repulsors channeling the hyper accelerated particles into an effective burst.  To fire the user depresses the trigger half way, creating a noticeable (but quieter than a blaster shot) rumble as the weapon prepares to fire, and after the weapon is charged to the desired state the user depresses the trigger the rest of the way.  The recoil is heavy, and weapon has strong rotational tendencies when charging (+5 to difficulties when not using its included bipod), but its power is quite commendable.  
Imperial Forces sometimes use the HVCPA, but it isn't commonly issued as the Rebels have few things durable enough to warrant its power, and Imperial doctrine calls for crushing those things with starfighters or walkers, not man portable weapons.  Not to mention its bulk, lack of range, and inaccuracy all being problems, as is the noise it generates for stealthy missions.