Super Large Hadron Collider (sLHC)
The sLHC would be a massively upgraded LHC. If all goes to plan, it will come online in around a decade (2018, about 1 billion euro) after upgrades. The beams would be 10 times as bright, which would involve increasing the number of protons in each beam by a factor of 10, and result in 10 times as many collisions per hour.
The International Linear Collider (ILC)
If the project receives financial backing after technical reports due in 2012, the ILC would be a 35-kilometre-long straight accelerator.
Complete in the 2020s for about $8 billion.
The Compact Linear Collider (CLIC)
The CLIC would be a positron and electron linear accelerator like the ILC - and is also yet to be approved - but it would be shorter and have collisions at higher energies. 2020s and cost about ~$10 billion. Equal to an ILC 140 kilometers long.
Other proposals include the Very Large Hadron Collider, which would have a collision energy of 40 to 200 TeV and would have to be built from scratch. Muon colliders, and an LHeC - smashing an electron beam into a proton beam - are also being considered
Plasma Acceleration Could Transform the Future of Colliders
Plasma acceleration is a technique for accelerating charged particles, such as electrons, positrons and ions, using an electric field associated with an electron plasma wave. The wave is created either using electron pulses or through the passage of a very brief laser pulses, a technique known as laser plasma acceleration. These techniques appear to offer a way to build high performance particle accelerators of much smaller size than conventional devices at the expense of coherency. Current experimental devices show accelerating gradients several orders of magnitude better than current particle accelerators. For example, an experimental laser plasma accelerator at Lawrence Berkeley National Laboratory accelerates electrons to 1 GeV over about 3.3 cm, whereas the SLAC conventional accelerator requires 64 m to reach the same energy. A recent experiment performed by a team at SLAC achieved an energy gain to 42 GeV over 85 cm using a plasma wakefield accelerator
It is hoped that a compact particle accelerator can be created based on plasma acceleration techniques or accelerators for much higher energy can be built, if long accelerators are realizable with an accelerating field of 10 GV/m.
Plasma acceleration is categorized into several types according to how the electron plasma wave is formed:
* plasma wakefield acceleration (PWFA): The electron plasma wave is formed by an electron bunch
* laser wakefield acceleration (LWFA): A laser pulse is introduced to form an electron plasma wave.
* laser beat-wave acceleration (LBWA): The electron plasma wave arises based on different frequency generation of two laser pulses.
* self-modulated laser wakefield acceleration (SMLWFA): The formation of an electron plasma wave is achieved by a laser pulse modulated by stimulated Raman forward scattering instability.
Design considerations for a Trillion Electron Volt (TEV) laser plasma accelerator Lasers need to keep improving to enable really powerful laser plasma accelerators.
Plasma Afterburners for Linear Colliders
Plasma wakefield acceleration can sustain acceleration gradients three orders of magnitude larger than conventional RF accelerator. In the recent E164X experiment, substantial energy gain of about 3 − 4 GeV has been observed. Thus, a plasma afterburner, which has been proposed to double the incoming beam energy for a future linear collider, is now of great interest
Presentation from 2004 With Technical Details
Advanced Accelerators Near and Far Future Options -
Here is an older paper on a path to petavolt colliders.
Very large hadron collider (not a petavolt design but up to 200 Tev) design documents