 | Monday, April 17, 2006 |
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Monday, April 17
Tuesday, April 18 |
Mostly Sunny 61º/39º
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Secon Level 3 |
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Monday, April 17 -Potato Au Gratin -Monte Cristo -Savory Roasted Chicken Quarters -Lasagna Bolognaise -Chicken Ranch Wrapper -Assorted Pizza Slices -Szechuan Style Pork Lo Mein The Wilson Hall Cafe accepts Visa, Master Card, Discover and American Express. |
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Wednesday, April 19
Thursday, April 20
Chez Leon Menu |
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| Layer 0: Stuck between silicon and a hard place | ||
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Have you ever tried to thread a needle while blindfolded? If not, try to imagine it.
Now imagine that if the thread doesn't have perfect clearance--if the inside of the needle's eye touches the thread at all, both the thread and the needle might be damaged. That sounds pretty hard, but it gets worse: this particular needle is worth about 10 million dollars and can't be replaced.
Think you'd have a shaky hand?
DZero recently did something harder. They installed a brand new layer of silicon tracker into their detector. About 70 inches long and the width of a golf-ball, the new layer was inserted just inside the current detector layers that surround the beampipe--kind of like placing a fresh new layer on the inside of an onion. "There was only about 8/10 of a millimeter of radial clearance for the new layer," said Mechanical Installation Manager Bill Cooper. "If it moved to one side by less than a millimeter during insertion, it could have been damaged. And if it moved any further, it could have damaged the detector itself." In addition to these challenges, DZero was not able to see what they were doing during the insertion, because other parts of the giant detector blocked their view. "As Layer Zero was slowly and carefully rolled into place, we could only imagine its path," said Cooper. "Everything had to be aligned almost perfectly in advance." For years, DZero physicists and engineers have been designing and testing tools to help control this installation, starting with an optical survey in 2004 to make sure they knew what kind of clearance they'd be dealing with. "The mechanical design was the most challenging part," said Ron Lipton, Layer Zero project co-manager. "It's really a tribute to the team, led by Bill Cooper, who fabricated and designed this thing that fits in a very small space and is virtually massless."
The new layer will give DZero better precision. With a layer of tracking detector closer to the collision point, they'll have a better idea which particle tracks came directly from the proton-antiproton collision, and which are the result of particle decay. "This new layer of silicon detector will allow us to have a better picture of
B decays
and therefore B mixing," said Vivian O'Dell, Project Manager for DZero's Run IIb Upgrade. "And those interactions are of great interest, especially now."
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From The Beacon News (opinion section), April 14, 2006: New challenge for Fermilab: future viability The issue: The future at Batavia's Fermilab is uncertain. With a new, more advanced collider set to open in Switzerland next year, the viability of the current facility is in question. We say: Congress should support construction of a new underground research facility on site. A proposed 20-mile-long underground tunnel should be built to enable Fermilab to continue its scientific exploration for another generation. Eighteen years ago, Fermilab in Batavia was in the running to build what was called the Superconducting Super Collider — a high-energy particle accelerator.
Ultimately, instead of Fermilab, more clout-heavy legislators and officials from Texas got the project approved for that state and construction began near Waxahachie, south of Dallas. The SSC, as it was known, was always controversial because of its cost — last estimated at some $8.25 billion. After some 14 miles of tunnel had been dug and some $2 billion had been spent, Congress killed the unfinished project in 1993.
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| Uneven surfaces | ||
Several times a year, Fermilab workers get hurt from stepping onto something. While 60 percent are caused by trip-type hazards, 40 percent are associated with uneven surfaces. Based on a lifetime of experience, people have come to expect that the floor within a given space will have consistent characteristics. That is, it will have the same irregularities, friction and softness throughout. When these unexpectedly change, mis-steps are likely to occur. Here are some suggestions for dealing with uneven surfaces.
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| The new babies are growing fast; come down to the pasture and check them out before it's too late! (Click on image for larger version.) |
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P5 Meeting this week HEPAP's "Particle Physics Project Prioritization Panel" (P5) will meet at Fermilab with the goal of learning more about some of the proposed projects for neutrino physics and for dark matter detection. The meeting will take place at Fermilab on April 18 and 19. You can find more information here.
Spring Fling Book Fair, April 26, 27
Calling all bridge fans
May Murder Mystery Dinner Theater: "Death in the Family"
Professional Development |
