Now entering phase two...

Building on the success of their feasibility phase, the CLIC test facility, CTF3, has just launched into a five-year project development phase. This will involve detailed performance optimisation studies, marking the project’s transition from pure research and development to prototyping and construction.


CLIC accelerator modules under construction at CERN.

“With the feasibility phase now complete, we have established that CLIC can be built,” says Roberto Corsini, CLIC Collaboration spokesperson. “Now we want to be sure that it can provide the luminosity and energy performance needed. We will be looking at the engineering, performance and cost of a real CLIC machine also seeing if we can reduce it.”

CTF3’s second phase will focus on selected performance-related research areas for further investigation. The largest of these involves the construction and testing of several authentic CLIC accelerator modules that are currently being assembled at CERN (see images). “Our primary focus will be the testing of these systems, as they can provide a ‘real’ results for the CLIC project,” says Roberto.

Four of the CLIC modules will undergo mechanical testing in laboratory conditions, where they will have their alignment, stabilization and thermal cycling tested. These tests will be done over the next 2 years outside of the CTF3 facility. The remaining three modules will be installed in CTF3’s experimental area. “The laboratory tests have been purposefully scheduled to begin a year before those in CTF3,” explains Roberto. “This way whatever we learn can be re-injected into the programme before the first module is installed in CTF3.” Two further modules will be added in 2014, and will incorporate results from both the laboratory and CTF3 tests.

A CLIC accelerator module.

Alongside the module testing, the CTF3 team will be working to provide synchronicity between CLIC’s drive beam and its main beam. This is accomplished by compensating for any phase “jitters” by adjusting the path length of the drive beam. Phase monitors and a kicker system (which will adjust the beam path) are currently being installed in the facility, and the first system tests are planned for next summer.

“We will also be examining the break-down rate within our accelerating structures,” explains Roberto. “This is the rate of sparking within the structure, an important performance parameter. Current results are very promising but which may be affected by the presence of the beam.” To do this, CTF3 will resurrect an old beam line that hasn’t been in use since the early days of the facility. This line is currently being converted by installing an accelerating structure in it, and it should be running by late 2013.

CLIC’s project development phase will wrap up in 2016-17, at a time where LHC results at full energy are expected to be available. These will provide the information needed for decisions to be made about potential new energy frontier accelerator projects at CERN beyond the LHC.

by Katarina Anthony