A new type of fusion reactor device produces fusion by the collision of two oscillating plasma rings. This is a linear device similar in shape to a magnetic mirror with direct energy converters on its ends. Analysis shows that this system can create net energy gain, even with an advanced fuel like p-11B. This advanced fuel eliminates neutrons and thus eliminates radioactive byproducts. It is compact and can provide terrestrial power and power for space propulsion. This device performs best at low electron plasma temperatures which makes radiation and transport losses small.