Jefferson Lab Weekly Briefs December 19, 2007

Jefferson Lab Weekly Briefs

December 19, 2007

Site Power Outage

The Test Lab electrical substation will be taken offline over the holiday break to replace aging equipment. The power outage will begin at noon on Friday, Dec. 21. The following buildings will be without power: EEL, Test Lab, CEBAF Center, Buildings 31, 33, 52, 54, 57, & 59, Rad Con Trailers 52A, B, C, Trailers 34A, 34B, 34D & Safety Trailer (35). Electrical power will remain off in these buildings until Dec. 31. No one will be allowed in these buildings until after 8 a.m., Jan. 1, 2008. For additional information, please see the website or contact Paul Powers at ext. 7258. 

12 GeV Upgrade

The main focus of attention for the 12 GeV Upgrade of Halls A, B, C and D is now the Project Engineering and Design for the various components in anticipation of the Critical Decision 3 reviews next summer followed by the start of construction. Associated with this, a series of design and safety reviews of various major experimental equipment subsystems is being planned for January through May, 2008. Two internal detector reviews, Hall C and Hall D, are scheduled for the second half of January. 


Experiment E04-019, a study of two-photon contributions to ep elastic scattering using recoil polarization, is continuing to take production data in Hall C. Measurements are made at a momentum transfer of 2.5 (GeV/c)2, using three different beam energies. Data taking has completed for one of these data points, using a 2.84 GeV beam. Data taking has started for the 1.87 and 3.6 GeV measurements; these measurements will be completed in January.

Free-Electron Laser (FEL)

The FEL ran full time last week and made excellent progress in high-voltage conditioning of the new Gun Test Stand and made a new record for these coated electrodes. In addition, the FEL gun was  prepared for a bakeout.

Theory Center

In two recent publications (Phys. Rev. C76, 065201 (2007) and arXiv:0712.2283 from the Excited Baryon Analysis Center (EBAC), results from dynamical coupled-channel analyses of pion-nucleon scattering and pion photoproduction have provided new information on the quark-gluon substructure of the nucleon excited states (N*). The structure parameters associated with 20 N* states have thus been determined. This advance has paved the way for accomplishing EBAC's goal of analyzing the world's data on photoproduction and electroproduction of pion, two-pion, eta, omega, and K mesons.

JLab's Safety Numbers

91 Days since Last Recordable Accident (JLab Record: 319)
410 Days since Last Lost Workday Accident (JLab record: 455)

JLab Calendar of Events

Dec. 24-Jan. 1: Holidays/Shutdown Days
Jan. 11: APS April Meeting Abstract Submission Deadline
Jan. 14-18: PAC 33
Jan. 21: Martin Luther King, Jr. Day


Environment, Safety, Health & Quality

As we move into the holiday period, many of us were involved in decorating during the past few weeks with our friends and families. The National Safety Council recently provided these holiday safety tips:

  • When displaying a cut tree, cut off about two inches of the trunk and put the tree in a sturdy, water-containing stand. Keep the stand filled with water so that the tree does not dry out quickly.
  • If you use an artificial tree, choose one that is tested and labeled as fire resistant. Artificial trees with built-in electrical systems should have an Underwriters Laboratory (UL) label.
  • Only use indoor lights indoors (and outdoor lights only outdoors). Look for the UL label. Check lights for broken or cracked sockets, frayed or bare wires, and loose connections. Replace or repair any damaged light sets.
  • Turn off all lights on trees and decorations when you go to bed or leave the house.
  • When putting up holiday decorations, always use the step stool or ladder to reach the high places.


Recognizing Changed Workplace Conditions Lesson Learned
The DOE Y-12 facility in Oak Ridge recently provided the following tips as a lesson learned for what to do when encountering changed conditions or situations at work or at home:

  • Change in location - Planned work is understood to be done in a certain location. Changes in location can introduce new hazards. The hazards of each task must be understood and controlled.
  • Change in sequence - Hazard controls for a series of work steps may be based on the order in which the steps are performed. When the sequence is changed, a hazard control may be skipped.
  • Changes in equipment - Every piece of equipment, or a tool itself, introduces hazards. If new equipment/tools are used, the associated hazards must be understood.
  • Changes in roles and responsibilities - Normally we assume that each person involved in work will be doing a certain part of the work. When people change or there is additional work, there is potential for an unplanned event.
  • Similar work - We can fall into the trap that one task is similar to another task and not take the time necessary to understand the hazards. This is sometimes the hardest changed condition to recognize.

Computing and Networking Infrastructure

Scientific Computing Outage
Scientific Computing, including the Auger batch farms, JASMine mass storage system and LQCD clusters, will be unavailable starting Dec. 21, for the holiday power outage. Auger batch job submissions will be closed on Dec. 19, to allow running jobs to complete. The Auger batch farm and the LQCD clusters will remain down through the holidays; some interactive scientific computing services will return to service after maintenance work (see next brief) is completed. All services will be restored starting Wednesday, Jan. 2, 2008.


Network Outage Dec. 21
All Central Computing Services (those systems that provide JLab's file services, e-mail, internet, web presence and other critical services) will be taken offline for system maintenance at noon on Dec. 21. Services should be back up by 10 p.m.

Site Power Outage Ramifications
Following system maintenance on Dec. 21, Central Computing Services will remain online during the site power outage, using the Computer Center's secondary power source. However, networks and non-critical workgroup computing resources located in buildings without power will remain down through the holidays.


End-Of-Year TLD Change out
Due to the extended power outage beginning Dec. 21, the semi-annual TLD change out for all badge racks in CEBAF Center, the EEL and the Test Lab will take place after 5 p.m. on Thursday, Dec. 20. If your TLD badge rack location is in one of these buildings, please put your TLD badge in its assigned slot before leaving JLab on Thursday. All other TLD badge change outs will take place over the holiday shutdown. Anyone leaving JLab before noon Dec. 21, is asked to put their badge in the rack before leaving. Anyone with questions may call Becky Mosbrucker, x7236 or page 584-7236.

Holiday Shutdown – Cafeteria Meal Notice 
Quark Cafe will close after breakfast on Dec. 21 so cafeteria staff can prepare for the holiday shutdown power outage. When Quark Cafe re-opens for business on Wednesday, Jan. 2, the breakfast menu may be limited as all food deliveries may not be in before breakfast service.

JLab Children's Holiday Party Photos
Click the link to view photos from the JLab Children's Holiday Party online.

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