The new 31-kilometer-long (19.2 mi) International Linear Collider (ILC) is finally ready for construction, according to CERN and the Linear Collider Collaboration. The ILC will initially augment the LHC’s attempt to identify and characterize the Higgs boson, but in the future it could investigate new areas such as supersymmetry, dark matter and energy, and the superstring theory of multiple dimensions, significantly advancing our knowledge of the universe.

To investigate particle physics, the generally approved method is to smash particles together, such as protons or electrons, and see what happens. To do this, you must first accelerate the particles to speeds approaching the speed of light — and to do this, you can either use a synchotron (circular accelerator), or a linear accelerator. All of the world’s major particle accelerators, including the LHC and Tevatron, are circular accelerators — which is why the International Linear Collider is so interesting.

Whereas circular accelerators smash together large particles, such as protons, linear accelerators are much more accurate and are thus capable of smashing together much smaller elementary particles such as electrons and positrons. The collision energy of linear accelerators is much lower (the ILC will max out at around 1 TeV, while the LHC can reach 13 TeV), but the higher accuracy and use of smaller particles result in unprecedented scientific precision. According to the ILC website, the collider’s initial collision energy of 500 GeV is perfectly suited for further analysis of the LHC’s recently discovered Higgs boson, to verify whether or not it’s the same Higgs boson as postulated by the Standard Model of particle physics.

To create the electrons, a nanosecond laser strikes a gallium-arsenide photocathode. These electrons are then accelerated using a superconducting linac (linear particle accelerator). To create the positrons, the primary electron beam is pushed through a helical undulator to create photons, which then strike a titanium alloy target and create electron-positron pairs. Finally, the electrons and any remaining photons are dumped, leaving a stream of positrons. The primary electron beam is then collided with these positrons, and the results are picked up by two very sensitive detectors (SiD and ILD).

In the future, after the ILC has fully investigated the Higgs boson, the collider will be perfectly placed to investigate the fringes of physics. Supersymmetry, dark matter and energy, and superstring theory are all within reach of the ILC’s electron-positron collisions. For more data on the International Linear Collider, read the recently-released Technical Design Report [PDF]. For a more human-readable document, the ILC website has a lovely page that details the collider’s form and function.

Moving forward, the next stage is to decide where the ILC will actually be built. Europe (CERN), America (Fermilab), and Japan are all possibilities, with a Japanese mountain currently looking like the most likely choice. Construction could begin in 2015, but isn’t expected to be finished before 2026. The total cost of the build is estimated to be anywhere from $10 to $25 billion.

Now read: What is the Higgs boson and why is it important to science?