LHC( Large Hadron Collider) :ATLAS big wheel triumph

LHC ( Large Hadron Collider)
ATLAS celebrates installing the last of the eight big wheels. These wheels form the end-cap muon spectrometer of the detector.
The ATLAS end-cap muon detectors, the ‘big wheels’, have been compared to many things: flowers, orange halves, clock faces and works of art. But, more importantly, each is an incredible feat of engineering. On Friday last week the team celebrated the completion of the last wheel, and moved into the final stages of installation.

"I must admit that at the end of last year I would not have believed that we would manage to install these eight big wheels essentially on schedule," admitted Peter Jenni, ATLAS spokesperson. The first of the wheels took a long time to install, but the last one took just a couple of weeks. "This is really a great achievement."

The big wheels harbour ATLAS’s middle layer of muon chambers in the forward region and are one of the last large pieces to be installed. Each is 25m across, weighs between 40 and 50 tonnes and contains around 80 precision chambers or 200 trigger chambers. The support structure itself is just one third of the weight of the total wheel.

Because of their sheer size, each wheel had to be made in 12 pieces for the trigger planes and 16 pieces for the precision-measurement planes, or "petals", of aluminium, the last of which was installed on Friday. Each was assembled at CERN using components from all over the world before being fitted together, piece by piece like a jigsaw.

Because of the need for space for the chambers, designing a suitable structure presented a unique challenge, one that project engineers, Raphaël Vuillermet, Dimitar Mladenov and Giancarlo Spigo were happy to take on.

"The detectors themselves have been on drawings for 15 years; everyone knew where they would go but no one knew about the structure," explains Dimitar. "There were chambers everywhere so our design had to build around them and in the small spaces in between them."

The result after 3 years of calculation, design and sleepless nights was a uniquely thin and light structure that is precise to less than a millimetre.

The 100-member collaboration from Israel, Japan, the US, China, Russia, Europe and Pakistan began assembly of components in 2005 and installation in 2006. "Because the pieces are so delicate we had to be careful throughout the whole process," explains Raphaël. "I was very afraid about something happening to the chambers and also to the people, because you are working 30 metres up. But we didn’t have any problems."

The completion of the big wheels is symbolic for ATLAS because, as technical coordinator Marzio Nessi explains, "the big wheels were always seen as something we would do at the end. And now we have done them."

For Dimitar the biggest challenge was the timing. "I feel proud, but not for myself, for everyone. It was the result of hard work. The only thing that we were lucky about was the weather; if there had been a single day of heavy rain we might have been delayed. But Marzio said not to worry and to leave the weather to him, and the weather was great. I don’t know how he did it!"

Now just two smaller scale wheels and the end-wall chambers remain to be installed, and the big wheels have already begun to give read-outs as part of test runs using cosmic ray data that ATLAS performs every six weeks.

With their striking symmetry and aesthetic appeal the big wheels are likely to become icons of the experiment. But to Marzio, all pieces of ATLAS are beautiful. "This piece just happens to be 25m high."

Kids' $100 Laptop Jumps in Price to $188

The famous laptop project by the OLPC project will now cost $188 instead of $100. The One Laptop Per Child project has been plagued with problems for some time now. The price has nearly been doubled by the not-for-profit organization to cover losses and fill a void with the inability to book orders.

The One Laptop Per Child (OLPC) project has raised the price of its XO laptop to US$188, according to an Associated Press report.

OLPC spokesman George Snell confirmed the price change on Friday, the AP report said. Snell blamed the price hike on "currency fluctuations" and the rising cost of raw materials like nickel and silicon.

OLPC executives in the U.S. were not immediately available for comment. Previously, OLPC said the XO would cost $176.

The reported price hike comes at a critical juncture for OLPC. The XO laptop has gone through four prototype stages, and the design has been locked down for weeks. In August, Quanta Computer Inc. completed a manufacturing run of 300 units to test the production process -- the final step before mass production of the XO begins later this month or in early October.

OLPC customers are counting on a low-cost laptop, and it was not immediately clear what, if any, impact the latest price hike will have on orders for the XO.

OLPC laptop gets minor delay along with price bump
Rumors that the XO laptop still has some refinement in terms of both pricing and configuration were confirmed late last week. A spokesperson for the One Laptop Per Child (OLPC) Project told the AP on Friday that the price of the XO laptop has risen to $188 per unit and that the project faces product delays. The cost increase of approximately $12 may not seem like much, but given that initial orders from governments must amount to at least 100,000 units, it all adds up quickly.

The OLPC project designed the XO laptop to be used by students in developing countries. The non-profit organization will sell the laptops to foreign governments to distribute to children through schools. Although the systems were originally intended to sell for $100 each, the price has steadily climbed as a result of additional features and unexpected costs.

The XO laptops, which are being manufactured by Quanta in Taiwan, include innovative hardware features like a dual-mode LCD screen, a pull-string charger, a wide touchpad, and a unique wireless mesh network system. The XO's Linux-based operating system also includes innovative features including a highly unusual user interface.

The OLPC Project now faces competition from Intel's Classmate PC and a new laptop developed by Asus called the Eee PC that is scheduled for release this month.

The OLPC Project reportedly faces delays as well, but the severity of those delays isn't apparent yet. In the latest OLPC community newsletter, which was written last week, OLPC president Walter Bender says "there were Sugar, network, and security reviews this week resulting in the reporting of some new bugs and future features. One outcome was the identification of some last-minute features, so we will not be ready for code freeze on Monday—we are probably off by about a week. Next week, we will have a major push to get all remaining blocking bugs addressed."

Although the XO laptop has fallen short of initial expectations and far exceeded the original anticipated price of $100, the project is still heading towards a strong launch with a product that has lots of potential. The project is still confident that it can reach $100 per unit (if not below) over the next year or two with scale, but achieving that scale is going to be hard in the face of price increases.