Ferdinand Hahn may not be strictly ATLAS, but his work on gas systems is vital to all four experiments.

Raksapol is both reserved and very friendly – a common Thai characteristic. In September, it will be one year since he left his native Bangkok to join, as a research assistant, the Department of Physics at the University of Geneva. This is where he is doing performance studies of the electron triggers to optimize the physics discovery potential. With his hard work, he is hoping to turn this research into a PhD project in September.

“I’ve always wanted to do it I guess,” considers ATLAS PhD student Kate Shaw. “It was probably books by Stephen Hawking, Roger Penrose… They inspired me to start with – to understand the fundamentals of the Universe.”

Forty million beam crossings, each containing about twenty collisions, must be processed and analysed each second with only two hundred of those selected and saved for further analysis. There are no second chances! That is the challenge of the ATLAS trigger system: forefront in the analysis of new discoveries at the LHC. Srini Rajagopalan, a physicist from Brookhaven National Laboratory (BNL) in New York, has taken up this challenge and is one of the scientists responsible for making sure that the trigger selects events that are rich in physics.

Building the ATLAS detector has been a mammoth and innovative project. Sociologists, economists, and entrepreneurs have studied how such projects benefit society and the economy. The ATLAS collaboration has a number of unique characteristics, because of the size of the project, together with its complex scientific nature. It is the largest collaborative effort ever attempted in the physical sciences with more than 2200 physicists from 38 countries.

The search for exotic particle has led Alan Litke and his ATLAS colleagues to design a system that has allowed the discovery of a new type of cell in the retina of primates, and this technology is helping to find solutions for certain types of blindness.

Like many ATLAS collaborators, Troels Petersen’s current project is not his first CERN experience. He came here a decade ago as a summer student on NA48 and NA59, working on kaons and polarised photon beams.

As the 2008 Summer Student Program is just about to start, here is an example of how the Program is successful at bringing talented physics students into the field of particle physics: “The CERN summer school changed my life,” says Sofia Chouridou, a Greek physicist working on the SCT at ATLAS. Since Sofia first came to CERN in 1995 while enrolled in Physics at the University of Thessaloniki, she always wanted to work in the biggest particle physics lab in the world.

“Of course, at the very beginning, I had no idea how complex it would be. I think most people didn't. I thought it might take two or three years, but not almost six,” says Sergei Malyukov of the ATLAS cabling project which will finally reach its completion at the end of June. As Cabling Project Coordinator, Sergei has certainly had his hands full, both metaphorically and physically.

I come from Michigan, the northern US state that looks like a mitten in the middle of the Great Lakes, and graduated from Michigan State University just last May (2007). I knew from the start that I wanted to write science and decided that professional writing and physics would be an excellent combination.

Yann Coadou may have begun his CERN fellowship just last year, but he is no stranger to the ATLAS project – it is the third time in his short career that he has worked on ATLAS.

German Federal Chancellor Angela Merkel made a historic visit to CERN at the end of last month. During her brief 1.5 hours on site, she was taken on a whistle-stop tour of the ATLAS control room and cavern, and given the chance to look down on the largest particle physics experiment in the world from a dizzying height of 100 metres through the access shaft which links the massive underground cavern to the surface.

Polish-born PhD student Katarina Pajchel moved to Norway when she was very young. She studied physics in Bergen and went on to complete a Master’s degree there too, analysing DELPHI data coming off LEP. Now part of the University of Oslo’s experimental HEP group, she has spent the last three years involved in developing Grid computing for ATLAS.

The ATLAS collaboration is continuously expanding, and recently its message has reached new shores – South America. Three new countries, Argentina, Chile and Colombia joined the collaboration at the beginning of the year, when Peter Jenni, ATLAS spokesperson, signed collaboration agreements formalising the presence of the Latin American research teams within the ATLAS experiment.

CERN holds a special place in the hearts of Christian Schmitt and Lucia Masetti. Not only are they both working on the ATLAS project, but also the recently wedded couple first met each other on the summer student programme at CERN in 1999.

They say there’s no such thing as bad publicity, but how would recent attempts in a Hawaiian court to stop the opening of the LHC because of safety concerns affect the general public’s perception of CERN? The Open Day on 5-6 April gave the ATLAS Collaboration a chance to find out.

All members of the ATLAS collaboration have been working to a demanding schedule over the last few years as they prepare for the LHC turn-on, but few can claim to have been as busy as Kirill Egorov, affiliated with Indiana University. In the five years since he arrived at ATLAS from the Petersburg Nuclear Physics Institute in Russia, Kirill has worked on the TRT Barrel, cabling, the connection of the TRT end-cap, the gas and cooling system, and the SCT. His next task is helping with the cooling system for the pixel detector.

The anticipation on site in Switzerland is tangible as the final steps in the construction of the ATLAS detector get underway, ahead of the LHC switch-on later this year. But whilst all the hard work is going on down in the pit, a small team of people are toiling equally hard to bring that sense of excitement and wonder out into the wider world, and throw open a window onto what will be the biggest experiment in the history of human kind.

When the Venezuelan Antonio Cárdenas discovered the program HELEN –the High Energy Physics Latin American European network – he did not doubt it a second and applied for it. For this physics student from the University of Los Andes in Venezuela, HELEN was a unique chance to come to Europe and get hands on particle physics, a field that he had only read about in books before.

Anyone working on the ATLAS experiment right now will agree that it is more than a full-time job. But Monica Dunford is not your average woman. On top of working on the Tile Calorimeter, helping to commission the Level-one Trigger, and coordinating Tile Cal’s operation running, she somehow finds the time and energy to row, ski, run marathons, and tell the world about life here at ATLAS.

Ned Spencer may be a key member of the ATLAS grounding and shielding team, but he came to physics at the relatively late age of 32. “All through my twenties I spent a lot of time at the San Francisco Zen Center,” he says. “Zen Buddhism is really a kind of yoga in which the main asana, or position, is sitting cross-legged.” That was something Ned had difficulties with. “I began to have trouble with the nerves in my legs so I couldn’t sit and meditate much. That limited what I felt I could do in the community.”

Kamal Benslama is a young professor of physics leading the ATLAS-Regina group, a recently formed and international high energy physics research team at the University of Regina in Canada. The group was set up in 2006, and all its members - Kamal, post docs, graduate and undergraduate students are devoting their efforts to the ATLAS detector. Their research operates on two fronts: the Liquid Argon calorimeter and the High Level Trigger.

Celebrations are underway in the ATLAS Experiment, as the final element of the detector was lowered into the cavern on Friday February 29th, 2008. The second “small wheel” is also the final part of the muon subsystem, but the wheels themselves are small in name only. At 9.3 metres in diameter, and weighing in at 100 tons each, moving them from their construction warehouse, at the north-west tip of the CERN site in Geneva, to the underground ATLAS cavern was a challenge which was anything but small.

We’ve all heard the story about the End Cap Toroid magnets having only a few centimetres clearance on either side as they were eased into place in the detector last year. Well, Tatiana Klioutchnikova and her colleagues are the ones to thank for that carefully controlled close-shave not ending up in a disastrous scrape.

As happens with many good things in life, Steve Goldfarb came across physics by chance: “When I went to undergraduate school, I was planning to become a medical doctor,” says Steve. The revelation moment happened when he opened an organic chemistry textbook. That was when he realized that what he had found seductive in chemistry were the rules that dictate the order of the chemical elements in the periodic table. “Behind those rules were fascinating physics equations,” he says.