The LHC restarted in a blaze of media interest on 5 April.
After almost exactly two years of consolidation and maintenance, CERN’s Beams department had prepared meticulously for the moment when the two operators of the world’s largest and most powerful particle accelerator started the restart sequence.
The atmosphere in the CERN Control Centre was upbeat and anticipatory as first the anticlockwise beam was injected at 450 GeV from the SPS accelerator into the LHC. Everyone held their breath as it gradually moved through the eight sectors of the LHC.The process went exactly as planned and the beam circulated 25 times to check stability. Then it was the turn of the clockwise beam. That too was injected without incident, and by lunch time both beams were circulating and CERN’s Director General, Rolf Heuer was commenting that “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 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.”
Since 5 April, the LHC Operations team, led by Mike Lamont, has been gradually testing the accelerator's subsystems and optimising the beam parameters as they work through the process of increasing beam energy to the anticipated 6.5TeV per beam. They have already solved a myriad of minor technical issues that are all part of the normal commissioning process for a machine of this complexity.
Increasing the beam energy is a simple enough process; ramp up the current in the magnets and allow the radiofrequency system to increase the energy of the beams. The current in all the magnets (and hence the magnetic field seen by the beam) is carefully increased as the beam energy rises. The main dipole magnets provide the necessary centripetal force to bend the beams around the ring. Other magnets such as the quadrupoles have to carefully track along with the increasing dipole field.
An important milestone was achieved on 10 April when Mike’s team successfully circulated a beam at 6.5 TeV. This was an encouraging step, but there was still much work to do.
Since then the Operations team has continued the commissioning process, and on 5 May, the LHC saw its first collisions of run 2.
Although only at the beam injection energy of 450 GeV, the collisions caused great excitement in the four LHC experiments; each low-energy (900GeV) collision sends showers of particles flying through an experiment's many layers. The experimental teams can use this data to check their subdetectors and ensure they fire in the correct place at the precise instant that a particle passes. Reconstructing flight paths of the particles from many parts of the detector at once helps the experiments to check the alignment and synchronization of various subdetector elements.
The LHC Operations team is now more than halfway through its eight weeks of scheduled beam commissioning and only when the machine is sufficiently tuned – and the Operations team declares "Stable Beams" with the beams in collision at the new energy of 6.5 TeV per beam – will the real physics data taking begin. You can feel the excitement mounting!
Leaving your home country to live and work abroad for the first time can be a daunting prospect, but the professional and personal benefits far outweigh the challenges.
That’s the unanimous view of three UK technician fellows who are taking part in CERN’s Technician Training Experience (TTE); Jamie Pinnell is six months into his fellowship, Fay Chicken is halfway through hers, and Elliott Rose is about to finish his two year placement.
The TTE is CERN’s response to a Europe-wide shortage of highly skilled technicians. It offers a 1-2 year fellowships to recently qualified apprentices, giving them valuable experience in a supportive, international environment.
Jamie has joined a small group designing, testing and manufacturing kinematic mounts for a detector upgrade for ATLAS. It’s challenging work; before coming to CERN, Jamie was working on very small mechanical engineering components including target alignment systems for high power lasers at the STFC Rutherford Appleton Laboratory, at CERN he’s working on huge structures that are 10m in diameter and weigh 140 tonnes.
He has been surprised by the level of responsibility that he’s been given, “my expertise is valued even though I’ve only got four years’ experience – the team is genuinely interested in my contribution and lots of my design ideas have been taken up.”
Based in the Radiation Protection Group, Fay has had a similar experience. She’s been given responsibility for installing new radiation monitoring stations in many of the underground areas of the accelerator complex. It’s a role that has taken her to an impressive number of CERN locations; during LS1, she’s spent a lot of time fitting and checking essential instrumentation in the experiment caverns and accelerator tunnels.
Giving newly-qualified technicians this level of responsibility is the essence of the TTE – CERN has high expectations, but it also has a very high regard for its technicians.“You don’t get treated as ‘the apprentice’”, says Fay.
For both Fay and Jamie, the TTE offered the perfect route to getting experience working abroad, and both already have an eye on what comes next. “I’d love to stay at CERN,” says Jamie, “but I’ve also got a hit list of places that I’d like to work.”They’re both revelling in the opportunity of living and working in an international environment. And CERN is certainly a big name to have on your CV so early in your career. As Jamie says, "I'll finish here with two years’ experience at CERN on my CV – how many 24 year olds can say that?”
Elliott’s time at CERN has certainly enhanced his employment prospects – he’s been offered several jobs back in the UK. Whilst he’s in the enviable position of being able to choose what he does next, it’s clear that he doesn’t want to be away from CERN for too long.
He’s sad to be leaving, and already looking for opportunities to come back, “I arrived at the start of the Long Shutdown, and I’m leaving just as the LHC restarts. I’d really like to come back and see the projects that I’ve been working on being used in the machine – that’s a big draw. It’s very satisfying to be part of the CERN team; I’ve felt very proud to see CERN featured on the TV and I’d like to be involved in the next stage of its progress.”
“Before I started, I knew that the work would be out of the ordinary, but it’s other things that have made my time here so special.”For Elliott, that has included the opportunity to discuss promoting engineering opportunities for young people with former Science Minister, David Willetts MP, and being one of the six early career researchers selected to have lunch with HRH Duke of York as part of CERN’s 60th anniversary celebrations.
Of course, being part of VIP (or even VVIP) visits doesn’t happen every day and, like Fay and Jamie, one of the aspects of life at CERN that Elliott has particularly enjoyed is the day-to-day interaction with his European colleagues, “you learn so much about the traditions and cultures of the people that you work with.Our countries are so close geographically, but they couldn’t be more different.”
Fay agrees, “the best bit about CERN is meeting so many other people who are all here for the same reason; just walking down my corridor, I can speak to colleagues from five different nationalities.”
But what about speaking French? Having arrived with just ‘schoolboy’ French, Jamie says it’s a challenge but, thanks to the classes offered by CERN, he can now chat with his colleagues, as well as managing the more technical discussions. A second language is clearly an asset and Elliott plans to continue learning French when he returns to the UK.
All three fellows are enthusiastic advocates for the TTE but the last word goes to Elliott - his advice to any recently qualified apprentice? “Take a look the CERN web site – you’ll like what you see!”
The closing date for applications is 11 May 2015.
No-one likes to see left-overs go to waste, and especially not nuclear physicists. And now the UK’s National Physical Laboratory is helping to get the recipe right.
Great effort goes into generating the rare isotopes that are the focus of research at CERN’s ISOLDE nuclear physics facility by bombarding different targets with beams of protons. The facility is a world leader. But only about 10% of the proton beam is stopped by the target, leaving 90% to be absorbed by a beam dump.
To the ISOLDE nuclear physicists, this seemed like a terrible waste, particularly as there is a widespread shortage of medical isotopes to diagnose and treat diseases. By putting a second target in the proton beam, downstream of the first target, more radioactive isotopes can be generated without interrupting the experimental schedule.
The MEDICIS project, which was first announced in 2012, initially brought together the two university hospitals closest to CERN and the cancer research institute at the École Polytechnique Fédérale de Lausanne. Since then, the ISOLDE collaboration has completed test collections of isotopes and shipped them to the university hospital in Lausanne.
Initially, the facility will produce ‘made-to-order’ small batches of isotopes by selecting the right combination of target material that will be suitable for fundamental and pre-clinical medical research.
Any new product that will be injected into a patient needs to undergo clinical trials and toxicology studies; the manufacturer must be able to demonstrate that when the product goes into regular manufacture, every batch will be consistent with the samples used in the clinical trials. The strict quality controls are called Good Manufacturing Process (GMP), and that’s where MEDICIS is benefitting from the expertise of the UK’s National Physical Laboratory (NPL).
“It’s a really interesting project,” says Steven Judge, NPL’s Radioactivity Group Leader.“We’re keen to contribute to the issue of medical isotope production to support the growth in the use of these isotopes for diagnostic studies and for cancer therapy."
NPL will be helping MEDICIS meet the GMP criteria by contributing reference materials, calibration sources, expertise to help with radiochemical separation and calibration, and loaning equipment.
“We’ll also be helping MEDICIS with the measurement protocols and compliance documentation for the isotopes,” explains Steven.“I’m very excited to be working with CERN; NPL’s mission is to enable accurate measurement and MEDICIS fits very well with our mission.”
Kate Shaw (ICTP and ATLAS) has been awarded the European Physical Society prize for outstanding outreach achievement connected with High Energy Physics and/or Particle Astrophysics.
Kate has received the prize in recognition of her contribution to the international particle physics masterclass programme and her pioneering role in bringing masterclasses to countries with no strong tradition in particle physics.
You can read more about Kate’s activities in UKNFC 39.
30 reasons NOT to be a particle physicist from Quantum Diaries blogger, Aidan Randle-Conde.