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.

  • Injector: Beam setup for production beam delivery was begun. Photocathode lifetime was checked: looks good. Pockels cells were aligned.
  • Injector RF: A capture klystron was replaced and the amplifiers were balanced.
  • RF: 70 MHz Master Oscillator failed, and it was temporarily replaces by a signal generator until the unit can be repaired. South Linac RF was turned on and is undergoing optimization.
  • Vacuum: Valve at VBV1L06A failed and is being replaced.
  • Magnets: All box supplies were successfully turned on and cycled.
  • Alignment: Level runs of Beam Switchyard (BSY) to the halls were completed. Personnel Safety System (PSS) certification of the accelerator was finished and the accelerator is ready for normal Beam Operations.


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.

Theory Center

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)
501 Days since Last Lost Workday Accident (JLab record: 501)


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:

  • Keep all household chemicals and medicines locked up, out of sight and out of reach.
  • Use child-resistant packaging properly by closing the container securely after each use.
  • Call 800-222-1222 immediately in the case of poisoning.
  • Keep items in original containers.
  • Always turn the light on when giving or taking medicine.
  • Leave the original labels on all products, and read the label before using. 

More information can be found on the National Poison Prevention Week website.

Lawrence Berkeley National Lab Electrical Shock
An LBNL maintenance technician received an electric shock while troubleshooting an open chassis of a vacuum process controller at the LBNL Advanced Light Source. The electrician had been de-energizing and re-energizing the unit for testing by unplugging and plugging it into the bench power strip. While the chassis was still energized, the technician grasped it with both hands to pivot it to a standing position to expose the top and bottom for further diagnostics. While lifting it, the technician felt a shock when his left middle finger came in contact with the solder points on a printed circuit board on the power supply side of the controller.

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!
The deadline for submissions has been extended to Friday, March 28. Submissions should be in color, on 8.5 x 11 paper, and include a front (pocket) and back design. Past winning designs may be viewed online. Submission rules are posted on the JAG website.

ISM Progress Tallied Online
The Lab is preparing to receive a visit from DOE’s Office of Health, Safety and Security in June. The ISM website features updates on the Lab's progress. Check out the updates each week in the tan column on the left side of the ISM homepage.


Think Green, JLab!
As Earth Day approaches, now is a good time to consider simple measures we can all take to mitigate our effect on the environment. At work, we can each reduce energy use by turning off all under-counter lights, computers, printers and radios before leaving the office at night or when out of the office for a long period of time. In addition, these simple steps can potentially reduce carbon emissions and mitigate the effects of high energy costs on JLab's budget. For more energy-saving and environmentally friendly tips for the office, visit the U.S. DOE Energy Efficiency and Renewable Energy website.

JLab Calendar of Events

March 25: Science Series Lecture: The Civil War Unplugged
April 4-5: USQCD All Hands Meeting
April 8-11: 2008 International Technical Safety Forum
April 12-15: APS April Meeting, St. Louis


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