A tiny chamber made of gold, called a hohlraum, is used to contain the pellet of heavy hydrogen fuel at the center of a fusion reaction at the National Ignition Facility. Laser beams enter through the two open ends of the hohlraum and are reflected in toward the fuel, heating it up to produce the fusion reaction.  The Below Image shows the artist's rendering how a NIF target pellet (the white ball) inside a hohlraum capsule with laser beams entering through openings on either end.

From the day this Universe came into existence (from Big Bang Or Else) Energy is everywhere in every form. But what powers most of the Energy centers( The stars) of the Universe are the Fusion of Hydrogen Atoms.

Man is trying all along his intelligent career to harness various forms of Energy. The most promising and most ambitious of all this trails is the Fusion Power. Fusion is the process by which Stars (our own Sun) produce Energy. 

A recent post on MIT website reports a significant progress in harnessing of Fusion Power.After more than five decades of research, a major milestone toward the harnessing of fusion power is expected within the next year or two. This milestone, known as “fusion ignition,” should take place at an experimental facility built for that purpose in California. Known as the National Ignition Facility, or NIF, it started initial experiments last fall.

This popular research by MIT is featured in a paper published in the journal Science. In a nutshell, they’ve figured out how to use a second fusion reaction as a kind of backlight, allowing them to see the details of what’s happening inside the primary reaction. 

NIF(National Ignition Facility / US) uses an approach called indirect drive inertial fusion, in which the tiny capsule of heavy hydrogen fuel is centered inside a cavity called a hohlraum. Laser beams bombard the inside walls of the hohlraum, heating it and generating x-rays that cause the capsule to implode. Ignition, the goal of the NIF, means the point at which the energy released by some fusing atoms at the center of the capsule provides the “sparkplug” that causes other surrounding super-dense atoms to fuse, and so on, in a chain reaction. Basically the thing is to initiate the Fusion reaction (just like the starting of a Petrol(spark-ignition) Engine where the initial required heat for combustion is given by a spark plug)  with this "Spark Plug". 

NIF recently released a Press Release stating Initial Experiments meet the requirements of For Fusion Ignition- "In inertial confinement fusion (ICF) experiments on NIF, the energy of 192 powerful laser beams is fired into a pencil-eraser-sized cylinder called a hohlraum, which contains a tiny spherical target filled with deuterium and tritium, two isotopes of hydrogen. Rocket-like compression of the fuel capsule forces the hydrogen nuclei to combine, or fuse, releasing many times more energy than the laser energy that was required to spark the reaction. "
 

“This accomplishment is a major milestone that demonstrates both the power and the reliability of NIF’s integrated laser system, the precision targets and the integration of the scientific diagnostics needed to begin ignition experiments,” said NIF Director Ed Moses. “NIF has shown that it can consistently deliver the energy required to conduct ignition experiments later this year.”  

A Video on The Giant Laser

It's the largest laser beam in the world and it's  built in the Bay Area. The National Ignition Facility at Lawrence Livermore National Laboratory will shoot tremendous bursts of energy at an area the size of a pencil eraser. The goal? To recreate fusion -- which powers the sun and some nuclear bombs -- perhaps harnessing a new source of clean energy for the 21st century.

In This backdrop a brief review through what is Fusion, which happens inside that Twinkling Star? And why it is so Important for our Future Energy Needs?

What is Fusion?

In This Tiny Twinkles Fuses Millions of Tonnes Of Hydrogen To Glow and Sparkle

Fusion is the process at the core of our Sun. What we see as light and feel as warmth is the result of a fusion reaction: Hydrogen nuclei collide, fuse into heavier Helium atoms and release tremendous amounts of energy in the process. Basically the fused nuclei mass will be less than sum of the colliding nuclei, and this lost mass is turned in to Energy ( Thanks to Einstein's E=mc² we can calculate it ) In the stars of our universe, gravitational forces have created the necessary conditions for fusion. Over billions of years, gravity gathered the Hydrogen clouds of the early Universe into massive stellar bodies. In the extreme density and temperature of their cores, fusion occurs.For Example every second, our Sun turns 600 million tons of Hydrogen into Helium, releasing an enormous amount of energy. But without the benefit of gravitational forces at work in our Universe, achieving fusion on Earth has required a different approach.

How to Do On Earth?

 We require huge temperatures. Basically it is how Hydrogen Bomb Works, first a Nuclear Fusion is done which develops required conditions for Fusion. But we want it in a controlled fashion to harness power to run my Laptop or your refrigerator.

Already a Project is going on in France for harnessing Nuclear Fusion. It is called ITER. Scientists from all over the world have come together in ITER to work toward a lofty goal: harness the energy produced by the fusion of atoms to help meet mankind's future energy needs. ITER is a large-scale scientific experiment intended to prove the viability of fusion as an energy source, and to collect the data necessary for the design and subsequent operation of the first electricity-producing fusion power plant. Launched as an idea for international collaboration in 1985, the ITER Agreement includes China, the European Union, India, Japan, Korea, Russia and the United States, representing over half of the world's population. In ITER, the fusion reaction will be achieved in a tokamak device that uses magnetic fields to contain and control the hot plasma. The fusion between Deuterium and Tritium (D-T) will produce one Helium nuclei, one neutron and energy. The Helium nucleus carries an electric charge which will respond to the magnetic fields of the tokamak, and remain confined within the plasma. However some 80% of the energy produced is carried away from the plasma by the neutron which has no electrical charge and is therefore unaffected by magnetic fields. The neutrons will be absorbed by the surrounding walls of the tokamak, transferring their energy to the walls as heat. In ITER, this heat will be dispersed through cooling towers. In the subsequent fusion plant prototype DEMO and in future industrial fusion installations, the heat will be used to produce steam and - by way of turbines and alternators - electricity.  

More information and videos will be soon provided.. (the Article is under refinement)