12 GeV Upgrade
The first four of 48 Barrel Calorimeter (BCAL) modules for Hall D have been machined, given final quality assurance checks and readied for shipping to JLab by the team at the University of Regina in Saskatchewan, Canada. The fifth and sixth modules have been built and sent for final machining, and the seventh and eighth are being built. A contract for construction of the Hall D Forward Calorimeter has been awarded to Indiana University. This calorimeter consists of some 3,000 lead-glass blocks that are read out by FEU-84 photomultiplier tubes via new Cockcroft-Walton type high-voltage synthesizer-and-divider bases designed at Indiana University. A contract for fabrication of the Hall D Central Drift Chamber has been awarded to Carnegie Mellon University. This chamber consists of 28 cylindrical layers of straw tubes arranged in groups of radial and axial straws, held between two large precision endplates which were recently received from the vendor and checked at JLab prior to shipment to CMU.
Application Deadline Nears for Scholarships and Fellowships
The accelerator was running well, with low trip rates. Operations personnel were only delivering beam to Hall B last week. Hall A had been down due to target and vacuum-related issues.
The FEL team continued to set up the machine last week and was making good progress toward lasing. By the end of the week, the team had energy-recovered beam with continuous-wave operation and were optimizing the match for lasing.
A new paper <arXiv:1004.1949 [hep-ph]> shows that at large photon virtuality Q2, the coupling to the vector meson production channels provides a natural explanation of the surprisingly large cross section of the neutral pion electroproduction recently measured at JLab, without destroying the good agreement between the Regge pole model and the data at the real photon point. Elastic rescattering of the π0 provides theorists a way to explain why the node that appears at t ~ 0.5 GeV2 at the real photon point disappears as soon as Q2 differs from zero.
Facilities Management and Logistics
Construction is underway adjacent to Building 102 (End Station Refrigerator Building) on a new building to house a 4 kilowatt cold box that will increase the lab's cryogenics capability. Currently, an existing potable waterline is being relocated to allow construction of a concrete pit to house a 4 kW refrigerator. Construction has closed the use of the sidewalk between CEBAF Boulevard and the Counting House. Sidewalk Detour: Please walk along the West Arc section of the accelerator footprint road and cross CEBAF Boulevard to access the pedestrian sidewalk that runs along the north side of CEBAF Boulevard. This sidewalk will remain closed until October, when the project is scheduled for completion. Facilities Management and Logistics apologizes for any inconvenience.
JLab's Safety Numbers
29 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
April 14-15: AVS Mid-Atlantic chapter meeting and short course
Environment, Safety, Health & Quality
Having an emergency exit does little good if you can't get through it. For exits to be useful, people must be able to find and navigate through them. Fire codes govern the placement and design of exits for the safety of building occupants. Recent safety inspections at JLab found some emergency exits or pathways to emergency exits that were obstructed. It is part of everyone's job to make sure that exit signs, lights and pathways are working, unobstructed and up-to-date.
Exit signs: The purpose of exit signs is to guide people to the best exit pathway in the event of fire or other emergency. You have probably seen them posted at exit doors and along paths of travel. Exit signs can fall short, because they are not sufficiently apparent (due to placement or number), they are misleading, or, in the case of illuminated signs, because they are not lit.
Exit lights: These help to identify exit pathways as well as afford visibility under low-light conditions. Common problems are misdirected, broken or limited lighting.
If you find an exit pathway blocked, clear it! If it is a consistent problem, contact your supervisor and Safety Warden. Also, contact your area Safety Warden to report faulty or questionable exit lights and signs. A list of area safety wardens can be found online.
JSA Research Assistantship Offered
Lunch Seminar: Driving Ahead in Challenging Times
Open House Countdown
JLab Campus Construction Update Online
Volunteer for a Project for National Lab Day!
Free Seminar on Vacuum