Jefferson Lab Weekly Briefs
September 2, 2009
12 GeV Upgrade
The contract for fabrication of the septa magnets for the beam transport and extraction systems has been awarded. JLab representatives visited the vendors for the beamline quadrupole magnets and for the klystron microwave sources. Good progress was seen at both vendors. The visit to the klystron vendor included a review of its preliminary design for the klystrons; the design was approved.
The three sigma discrepancy between the Standard Model and the NuTeV measurement of the weak mixing angle sin2ϑW is one of the most interesting and controversial experimental results of this decade. Recently, the importance of the isovector nuclear EMC effect in interpreting the NuTeV result was demonstrated in Phys. Rev. Lett. 102, 252301 (2009). In a new article from the Theory Center <arXiv:0908.3198> this important result is combined with other Standard Model effects - notably charge symmetry violation and possible strange quark asymmetry - to provide a comprehensive reassessment of the NuTeV determination of sin2ϑW. The revised value is in excellent agreement with the value predicted by the scale dependence of the mixing angle within the Standard Model, albeit with a larger systematic error.
On Aug. 25, the accelerator energy was increased by about 0.35 percent and the optics was optimized. Hall A went from pass 1 to pass 3 on Aug. 26.
On Monday, the Central Helium Liquefier (CHL) tripped and was recovered several hours later. Also on Monday, a spin dance was performed and the Wien angle was set to 14 degrees to give the highest beam polarization to Hall A.
Pavel Evtushenko, FEL staff scientist, was awarded the FEL Young Scientist Prize for 2009 at the 2009 FEL Conference in Liverpool. This is a significant honor that draws competition from many young scientists at large international labs and universities. Evtushenko was cited for his promise in diagnostic work and for the developments he did on the ELBE injector, the JLab FEL and CEBAF.
FEL staff spent the week fixing the FEL gun that developed a field point leading to a leak in the ceramic. The group fixed the leak and is planning to operate at reduced voltage if the gun behaves stably this week.
JLab's Safety Numbers
49 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
Sept. 7: Labor Day holiday
Environment, Safety, Health & Quality
The National Highway Traffic Safety Administration has estimated that there are 630,000 Lane Change/Merge crashes with 225 fatalities annually. The agency also found that about 60 percent of drivers involved in LCM crashes did not see the other vehicle, and about 30 percent of drivers misjudged the position or speed of the other vehicle. Although every LCM crash cannot be blamed on blind zones, blind zones are involved in every lane change/merge maneuver.
A vehicle is in your blind zone when you cannot see it with your inside mirror or peripheral vision. In order for you to safely change lanes, you must turn and look into the blind zones. You can also turn the two outside mirrors outward to look into the sides of your vehicle. This would create four smaller blind zones that would not be large enough to hide a vehicle.
Changing the mirror setting has five major advantages:
When the mirrors are used in this manner, it is referred to as the "Blindzone/Glare Elimination Setting" or "BGE Setting." This new setting does take time to get used to, but it enhances driving safety and comfort.
United Way School Tools Drive Ends Friday, Sept. 4
Flu Vaccines Available Early This Year
JLab Adopt-A-Spot Litter Pickup Set For Sept. 18
Special Colloquium on Sept. 9