Jefferson Lab Weekly Briefs April 15, 2009

Jefferson Lab Weekly Briefs

April 15, 2009

12 GeV Upgrade

Yesterday, April 14, the official groundbreaking ceremony for the 12 GeV CEBAF Upgrade project was accomplished with great success in spite of the rain.  The ceremony was held on the Hall D Complex construction site adjacent to the tunnel connection to the existing accelerator enclosure.  The ceremony was attended by national, state, and local politicians, DOE Office of Science and local representatives, local university representatives, former Jefferson Lab directors, and many Jefferson Lab staff and users. Video of the 12 GeV Upgrade Groundbreaking Ceremony is now available online.

The construction contractor for the CHL Building addition, Ritchie-Curbow, started worked last week.  Workers installed silt fence for erosion control, relocated the fire hydrant and prepared the aggregate subbase for the expanded asphalt pavement on the east side of the CHL Building.  The constructor is scheduled to complete the paving and guardrail installation this week.  CEBAF Boulevard is scheduled to be closed on April 20.


The scheduled accelerator down has started to wrap up. Continuous wave beam (130uA) from Gun2 was restored to the injector inline dump. Gun3 vacuum chamber was baked. Commissioning of cryomodules NL12 and SL07 continued. The new beam switchyard raster magnet was installed. Other general maintenance work continued. Preparations for construction of the Central Helium Liquefier building addition started.

Free-Electron Laser (FEL)

FEL staffers are making small upgrades and fixes to the FEL while work to repair/replace the low-conductivity water feed goes on. At present, the FEL is still working toward coming back up May 18.

Theory Center

In a recent paper (arXiv:0904.1586 [hep-lat]), a novel method was successfully demonstrated for the first time to calculate the electric polarizabilities of charged hadrons with lattice QCD. This work, made possible by an allocation at the High Performance Computing Center at Jefferson Lab, is the first in a series aimed at calculating the low-energy electromagnetic structure of hadrons, from pion and kaon polarizabilities to the nucleon (and hyperon) magnetic moments, polarizabilities and spin polarizabilites. A comparison between first-principles calculations of these quantities with the measured hadronic structure from low-energy Compton scattering experiments will then be possible, in particular a comparison to the anticipated results from COMPASS at CERN and HIGS at TUNL.


The survey and alignment group performed a control survey of a portion of the accelerator network. This consisted of sparsely spaced points around the circumference of the accelerator and not the entire set of monuments. The results agree well with surveys carried out last summer, where the laser tracker was used in the accelerator (which did measure all the monuments) and a conventional above-ground surface control survey. The greatest standard error is approximately 1 part in 2.5 million, with an average standard error of 1 part in 4.5 million for this latest survey. As a reference, typical land survey standard error is 1 part in 50,000 and traditional 1st order national geodetic survey accuracy is 1 part in 600,000.

JLab's Safety Numbers

100 Days since Last Recordable Accident (JLab record: 331)
217 Days since Last Lost Workday Accident (JLab record: 676)

JLab Calendar of Events

April 15: Science Teacher Night
May 2-5: APS April Meeting in Denver
May 20: JLab Annual Run-A-Round
May 25: Memorial Day holiday, lab closed




Environment, Safety, Health & Quality

Highway work zone safety is especially important as JLab begins construction for the 12 GeV Upgrade. According to EHS Today, there are three work-zone fatalities and 160 work-zone injuries per day.

Road work is necessary for providing safe and efficient transit, although road-work zones often seem nothing more than an inconvenience to motoring public, which can lead to irritable, quick tempered, irrational behavior and emotions. Many times, the only thing that is protecting a pedestrian and a work-zone employee are painted stripes, cones or barrels.

Some safe practices when entering work zones, including those at Jlab, are:

  • Stay Alert. Dedicate your full attention to the roadway;
  • Pay close attention to signs and work zone flaggers;
  • Turn on headlights. Workers, pedestrians and motorists must see you;
  • Don’t tailgate;
  • Adhere to the JLab Do Not Pass rule, regardless of what's in front of you;
  • Obey posted speeds;
  • Keep up with the traffic flow;
  • Do not change lanes;
  • Minimize distractions in vehicles, i.e. changing radio stations, talking on the cell, texting, attending children, etc.;
  • Expect the unexpected. Keep an eye on pedestrians, workers and their equipment;
  • Be patient and understanding - the roads are being repaired or constructed for your improved safety and travels.


Check Out the Latest Montage
Mont's latest column is now available online. Click the link to read about the director's take on his first spring at Jefferson Lab.

Last Chance to Register for JLab's "Biggest Loser" Contest
A 12-week weight-loss contest will begin Friday, April 17. Weekly, confidential weigh-ins will be taken by Occupational Medicine on Fridays, 2-4 p.m. The winner will be determined by the highest percentage of weight loss. The $20 entry fee collected from each contestant will go into the prize pot. Click the link for more details. Participants must register with Christine Wheeler (VARC, Room 76) no later than 2 p.m. on April 17.

National Library Week: April 12-18
This annual celebration is even more significant as the library enters into its 25th year of service to the lab. To commemorate 25 years of library service, a selection of historic audiotape interviews from the archives have been made available through the library's online catalog. Search for names such as Grunder, Gross, Norum, and McCarthy to hear first-hand perspectives on the science, technology and politics surrounding the growth and development of the lab. The staff is encouraged to visit the library's web page for information on the latest resource additions.

Don't Forget to Register for AVS Dinner/Student Poster Session
The American Vacuum Society Mid-Atlantic Chapter is having its annual meeting at JLab on Thursday, April 23, from 4-8 p.m in the CEBAF Center lobby. Vendors will show new products and answer questions (MDC, VAT, etc.) between 4-6 p.m., and there will be a student poster competition. Anyone wishing to stay for dinner ($15) or enter the poster competition, R.S.V.P. to Marcy Stutzman x7073 by Friday, April 17.

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