See the following video for a more detailed look at this idea:

Imagine for a minute how a cathode ray tube (CRT) screen works. Maybe you're even looking at one now. In a CRT, millions of electrons fly through a vacuum chamber and collide with a screen to produce images. In a 1024x768 screen (a typical resolution for a monitor), there are 141,557,760 electrons -- over 141 million -- colliding with the screen per second.

Now imagine that these electrons were suddenly released into the atmosphere and made to follow a path determined by a magnetic field. According to this theory, developed mainly by myself and the other members at The Lightsmith, the electrons would be contained in a magnetic field which would make them go out to a certain point and then arc back to the source. A light source from the hilt would illuminate the electron beam, allowing its creator to choose whatever color they want for the beam.

In order to create an electron beam like those found in CRTs, there needs to be a vacuum surrounding the cathode. This poses a potential problem, as the beam needs to get to the atmosphere at some point. One possible way would be to use an electron-permeable barrier, such as boron nitride. This would effectively separate the atmosphere on the outside and the vacuum on the inside, while allowing the high-velocity electrons to pass through.

There are a number of flaws in this idea, however. For example, high-velocity electrons colliding with the air will probably produce harmful radiation. Also, it would be difficult to control the path of the electrons, and the atmosphere might simply be too dense for the electrons to pass through it far enough. There is also the issue of powering a miniature CRT in a hilt and the danger that comes with the high voltages required to do so.

This idea came from the collective brainstorming of members at The Lightsmith. Feel free to join the discussion and share your ideas!