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Proton beams are back in CERN's Large Hadron Collider
Proton beams are back in CERN's Large Hadron Collider
After two years of intense maintenance and consolidation, and several months of preparation for restart, the Large Hadron Collider (LHC), the most powerful particle accelerator in the world, is back in operation. On 5 April at 10:41 a.m., a proton beam was back in the 27-kilometre ring, followed at 12:27 p.m. by a second beam rotating in the opposite direction. These beams circulated at their injection energy of 450 GeV. Over the coming days, operators will check all systems before increasing energy of the beams.
"Operating accelerators for the benefit of the physics community is what CERN's here for," said CERN Director-General Rolf Heuer. "Today, CERN's heart beats once more to the rhythm of the LHC."
"The return of beams to the LHC rewards a lot of intense, hard work from many teams of people," said the head of CERN's Beam Department, Paul Collier. "It's very satisfying for our operators to be back in the driver's seat, with what's effectively a new accelerator to bring on-stream, carefully, step by step."
The technical stop of the LHC was a Herculean task. Some 10,000 electrical interconnections between the magnets were consolidated. Magnet protection systems were added, while cryogenic, vacuum and electronics were improved and strengthened. Furthermore, the beams will be set up in such a way that they will produce more collisions by bunching protons closer together, with the time separating bunches being reduced from 50 nanoseconds to 25 nanoseconds.
By Raphael Rosen, Princeton Plasma Physics Laboratory
NASA's Magnetospheric Multiscale mission (MMS), a set of four spacecraft that will study the magnetic fields surrounding Earth, may employ data provided by Princeton Plasma Physics Laboratory (PPPL), which operates the Magnetic Reconnection Experiment (MRX)—the world's leading laboratory facility for studying reconnection. Results of the MRX research could elucidate the space probes' findings, said Masaaki Yamada, principal investigator of the MRX project.
Reconnection takes place when the magnetic field lines in plasma merge and snap apart with violent force. But NASA is flying blind in a sense when seeking such events, since mission operators don't know precisely where reconnection will occur in space or what the data it produces will look like. And since the explosive events occur in milliseconds, the MMS craft, orbiting in tight formation at an average speed of some 20,000 miles per hour, will have only fleeting moments to detect and measure the phenomena.
The MRX data could facilitate such detection. Comparing the data with signals from space will enable instruments aboard the craft to spot actual instances of reconnection taking place.
10 years old and counting on its 50,000 processors
10 years old and counting on its 50,000 processors
When ITER scientists needed to simulate how particles travel and transport radiation in the ITER machine, they bought time in one of the most powerful supercomputers in Europe: Mare Nostrum, the flagship machine of the Barcelona Supercomputing Centre (BSC).
The collaboration with the Spanish public institution, whose 10th anniversary was celebrated on 1 April, has now shifted to simulation studies of ELM control techniques — another field of study that requires crunching huge quantities of numbers.
High performance computing has become essential to the progress of science and technology. With close to 50,000 processors and a computing power of one thousand billion operations per second, Mare Nostrum has contributed to establishing three-dimensional maps of the galaxy, mathematical models of the expansion rate of the Universe, the sequencing of the human genome...
In a video address to the participants of the 10th anniversary ceremony, ITER Director-General Bernard Bigot stressed the importance of BSC's contribution to ITER.
ITER and the Spanish institution have crossed ways many times: former ITER Deputy-Director Carlos Alejaldre was part of BSC's executive board in the mid-2000s and, more recently, one of the ITER Monaco Postdoctoral Fellows joined BSC's computational physics group, bringing with him the valuable experience he gained while at ITER.
Collaboration in European fusion research has a long history. In 1961, the Max Plank Institute of Plasma Physics became an associate of the European Fusion Programme, which comprised the fusion laboratories of the European Union and Switzerland. In the 1970s, the European fusion laboratories decided to build and operate the Joint European Torus (JET). In 2014, the program was restructured and EUROfusion formed as a consortium of 29 national fusion laboratories (Research Units).
A goal of this reorganization is to efficiently implement a roadmap to the realization of fusion energy. The roadmap has been developed within a goal-oriented approach articulated in eight different missions (#8 focuses on the stellarator). It also prioritizes the financing of the fusion program.
In mission 8, the stellarator is being developed as an alternative concept for fusion electricity. The program concentrates on optimized stellarators based on the HELIAS principle—a stellarator line which was invented and developed at IPP. Wendelstein 7-X is a cornerstone of this line which is decisive for mission 8 and which will give answers to fundamental questions in plasma physics.
Read more in the Wendelstein 7-X March newsletter.