Here are a couple more nice graphics describing a little more detail of Saturday night's planned Lunar crash landing of the Smart-1 spacecraft.
Let's hope for a big plume so that we can see it.
Also, here are some more details on the ion engine drive architecture:
1. Xenon gas atoms are pumped into a cylindrical chamber, where they collide with electrons from the cathode. The electrons - which are negatively charged - knock electrons off the xenon atoms, creating xenon ions - which are positively charged.2. Coils outside the chamber create a magnetic field, which causes electrons from the cathode to spiral and become trapped at the mouth of the chamber.3. The build-up of negatively charged electrons at the mouth of the chamber attracts the positively charged ions, accelerating them out of the chamber.4. The stream of accelerated ions leaving the chamber thrusts the spacecraft forward. Although the force is small, over time it creates great speed in the frictionless environment of space.