The particle beam blaster utilizes, as its name implies, a particle beam. A particle beam is essentially a stream of particles (electrons, protons, or neutrons) that is accelerated to a high speed. Thus, the particle beam blaster would shoot out electrons, protons, neutrons, or in some cases whole atoms.

We have particle accelerators already; in fact, the screen you are looking at right now may utilize a cathode ray tube - a device that shoots out electrons, in this case at a screen that lights up when the electrons hit it. There are also particle accelerators used in scientific experiments that are capable of accelerating particles to extremely high velocities. Research is being done to use these particles as weapons in the military, but the current particle accelerators are too large to be practicle. Some particle accelerators are even miles long.

In addition, there is an effect called "blooming" that occurs when shooting out a stream of charged particles -- since they have like charges, they tend to repel each other and diffuse the beam. This would diminish the range of the beam; a plausible alternative would be to use neutrons, since they have no charge and would not repel each other.

Another plausible workaround for this "blooming" effect is to use atoms, particularly hydrogen atoms. First, electrons are added to the atoms, creating negatively charged ions. The ions are then put in a chamber that has an electrode powered by an extremely high voltage (up to 1,000,000,000 volts) current. When the electrode is positively charged, the ions are attracted to it; when the electrode's polarity is reversed, they are repelled from it and shoot into a gas that strips the extra electrons off of the hydrogen ions. The now neutral hydrogen atoms then continue out to strike the target. (This process is described in more detail here.)

One obvious problem with this is the power supply. Unless you can find a billion-volt battery that can fit in a small pistol, we will have to work around this. Perhaps a lower voltage would work, or maybe one could put a second electrode on the opposite side of the chamber that has the opposite voltage as the first one. The current would have to be timed so that when the ions get close to one electrode, the electrode reverses polarity and the ion is repelled to the other one. This would theoretically repeat until the ion got enough speed to break past the electrode and then go into the gas that strips the extra electrons. This whole process is actually similar to how a laser works.

This modified ion accelerator is just my idea -- I don't know if it would work or not. Let me know if you have any suggestions or see a problem with my idea.