Working Principle
Solenoids are mechanisms that use electric induction to convert electrical energy into linear movement very quickly. They consist of a long coil of wire which can create a magnetic field when current passes through it. A solenoid can become stronger if there is a ferrous material inside of the coil, because it would align the material’s poles to essentially become a magnet controlled by electrical current, also known as an electromagnet. We can predict certain aspects of solenoids when we use the equation below.

In the figure, B is the magnetic field, n is the number of turns per length (N/L), μ is the relative permeability (k) times the μ₀ which is constant 4 π*10^-7 T/amp*m, and I is the current measured in Amperes. The figure is not entirely accurate, since it would technically be the case for an infinitely long solenoid. Also, B is proportional to the current (I) passing through the coil. The magnetic field is concentrated into almost a uniform filed in the center of a very long solenoid. However, outside the solenoid, the field is almost nonexistent. Solenoids are very useful for applications like these, but for this air gun, we need a high speed, full dump valve for maximum efficiency.