To do this, the facility will train 192 laser beams on a hollow gold cylinder smaller than a pen cap. The gold will then radiate x-rays on a pellet of hydrogen placed inside the cylinder, and this radiation, coming from all directions, will crush the hydrogen so densely that it will ignite. Unfortunately, however, there is no guarantee that the fusion reaction will take place as planned. Even the project's supporters give only about a 50-50 chance of ignition, while some physicists are skeptical that there is any chance at all. While the facility will still be useful if ignition is not achieved, it would be a major disappointment.
Several factors make the goal difficult to achieve.
For one thing, scientists have little knowledge of the extreme conditions that the laser will create. In fact, the amount of energy thought to be necessary for ignition has increased over the years. One major technical challenge is to ensure that the x-rays produced by the gold cylinder bombard the hydrogen pellet uniformly. Compressing the hydrogen enough to cause ignition is an extraordinary task that has been compared to shrinking a basketball down to the size of a pea. If any asymmetry is present in the radiation, the hydrogen would squirt out in all directions instead of being compressed.