Jefferson Lab Weekly Briefs March 19, 2008
Jefferson Lab Weekly Briefs
March 19, 2008
12 GeV Upgrade
Excellent progress continues on the design work for the 12 GeV Upgrade of the accelerator systems; in February, ~10 percent more progress was achieved than was planned. The Beam Transport quadrupole prototyping had a setback when the vendor for the laminations was unable to meet the specifications. A contract has been placed with an alternate vendor. The draft specification for the klystron procurement has been approved; the draft specification for the 4.5K coldbox procurement for the cryogenics system is undergoing review. An informal, internal review of the design work on the digital board for the low-level radio frequency controls endorsed the planned work.
In Hall A, the installation work for the next experiments, E04-007 (Pi-Zero Electroproduction near Threshold) and E08-007 (GEp/GMp at low Q2-values), is progressing on schedule. The BigBite magnet has been installed at the pivot together with the newly designed shield walls. The associated detector system is being assembled.
The gas Cerenkov for SANE (Spin Asymmetries on the Nucleon Experiment), built by Temple University, has been delivered to Hall C. It will be tested with beam when operations resume. The lead glass blocks in the BigCal detector were, as expected, darkened by exposure to beam during the running of the GEp experiment. This darkening, which reduces the light yield from the blocks, can be "cured" by exposure to UV light. The 1744 blocks of BigCal are currently being exposed to UV in preparation for resumption of the GEp experiment.
Scheduled Accelerator Down (SAD) activities continued their march to completion, conducted by the steady hand of the program deputy. Twin tours by Gov. Kaine and two DOE officials were highlights of the week.
Free-Electron Laser (FEL)
FEL staff achieved an important milestone this week: The first beam from the gun test stand. Staffers will now proceed to characterize the beam and run high charge.
A collaboration between Theory Center staff and Hampton University experimentalists recently completed an analysis, arXiv:0803.2055 [nucl-th], of local quark-hadron duality in structure functions using a novel new approach in terms of "truncated moments," or integrals of structure functions over restricted regions of kinematics. Because truncated moments obey the same evolution equations as the usual parton distributions, this approach makes possible for the first time a description of resonance region data and the phenomenon of local quark-hadron duality directly from QCD. The analysis was able to quantify the degree to which individual resonance regions (such as the Δ, S11 and F15 regions) are dominated by the single-quark scattering process.
JLab's Safety Numbers
182 Days since Last Recordable Accident (JLab record: 319)
Environment, Safety, Health & Quality
National Poison Prevention Week is March 16-22. Congress established National Poison Prevention Week in 1961 to highlight the dangers of poisonings and how to prevent them. More than 2 million poisonings are reported each year to U.S. Poison Control Centers. More than 90 percent of these poisonings occur in the home. The majority of non-fatal poisonings involve children younger than six years old, and poisonings are one of the leading causes of death among adults. The Consumer Product Safety Commission recommends the following safety tips to prevent unintentional poisonings:
More information can be found on the National Poison Prevention Week website.
Lawrence Berkeley National Lab Electrical Shock
A provision of the OSHA Lockout/Tagout standard states that Lock and Tag application is not required for systems that allow complete energy control via simple plug disconnection. This provision allows remedial activities to occur without the formality of locks and tags, providing the worker remains in complete control of the plug throughout the maintenance task. As this LBNL electrical shock event points out, workers must not get complacent in knowing the energized state of the equipment in repetitive power on/off tasks. Lab Lockout, Tagout and Try information can be found in the online ES&H Manual in Chapter 6110.
The 23nd Annual JLab T-shirt Design Contest submission deadline nears!
ISM Progress Tallied Online
Think Green, JLab!
JLab Calendar of Events