Jefferson Lab Weekly Briefs July 29, 2009

Jefferson Lab Weekly Briefs

July 29, 2009

12 GeV Upgrade

The first superconducting magnet contract (for the Hall C/SHMS Q1 magnet) was awarded July 10, thus completing an important milestone in the project plan. Hall D recently held reviews of two of their subsystems. A review committee validated the tagger magnet final design and advised the team to finalize the detailing in-house rather than incorporating it into the construction contract award. A second review committee evaluated two readout choices of the Barrel Calorimeter detector. Committee members felt the first readout option, with silicon photomultipliers, looked very promising and recommended a test plan be developed for final certification and quality assurance of prototypes during the remainder of this calendar year. The more conventional backup option with fine-mesh photomultiplier readout was again found to be viable with a sufficiently detailed implementation plan, if needed.


The Scheduled Accelerator Down period continued with maintenance on RF (radiofrequency) systems, magnets, the vacuum system, the control system, the personnel safety system and more. On July 22, a hurricane power test was conducted and some problems were identified. The accelerator sprinkler system was tested. On July 25, beam was steered up to the 500 KeV dump in the injector.

Free-Electron Laser

FEL staff performed some key measurements this week on optical coatings. Last Friday, the team held a User Workshop in support of plans for a Soft X-ray capability of the FEL called JLAMP. The plans were well received and the group is developing a science case for presenting it to DOE. 

Theory Center

A new paper <arXiv:0907.2395> derives mass corrections for semi-inclusive deep-inelastic scattering of electrons from nucleons, using a framework which incorporates the initial state mass of the target nucleon and the final state mass of the produced hadron. The hadron mass corrections are made by introducing a generalized, finite-Q2 scaling variable for the hadron fragmentation function and are found to be even larger than for inclusive structure functions. The mass corrections compete with the experimental uncertainties at kinematics typical of JLab experiments and will be important to efforts at extracting parton distributions or fragmentation functions from semi-inclusive processes at intermediate energies. 

JLab's Safety Numbers

14 Days since Last Recordable Accident (JLab record: 331)
322 Days since Last Lost Workday Accident (JLab record: 676)

JLab Calendar of Events

July 29: American Red Cross Blood Drive
July 31: Science Education Summer Poster Session
Aug. 5: Safety Glasses Vendor onsite
Aug. 19: Jefferson Activities Group Luau
Aug. 19-21: GPUs for Lattice QCD Workshop
Aug. 27: Safety Shoe Vendor onsite
Sept. 7: Labor Day holiday
Sept. 17: JSA's Electronic Commerce Vendor Show




Environment, Safety, Health & Quality

Many JLab personnel have personal electric appliances in their cubes, trailers or offices.  Here are some general tips to keep these types of items safe both at work and at home:

  • Do not use an electric appliance near water; you could be electrocuted. If an electric appliance falls into a sink or tub of water, or if you touch an appliance with wet hands or while standing in water, you risk severe electric shock and possibly death.
  • Never use any electric appliances (radios, televisions, hair dryers, etc.) near sinks, toilets or bathtubs.
  • Always dry your hands before touching electric appliances, computers, power tools and televisions.
  • Keep the floor around your washer and dryer clean and dry.
  • Check appliance cords for frays, broken plugs, damaged wires, knots or melted insulation. They can cause electrical shocks or fires. Have them repaired or replace them promptly.
  • Unplug small appliances when washing them.
  • When using an electric appliance with removable cords, always connect the cord to the appliance first, then plug it into the wall outlet. To disconnect the appliance, unplug it from the wall outlet first, and then disconnect the appliance cord.
  • Do not pull on an appliance cord to disconnect it from the socket. You could damage it.
  • Disconnect all appliances by grasping the plug directly from the socket. Be careful not to let fingers touch the metal prongs.
  • Do not overload electric outlets with too many appliances or lamps.
  • Unplug your iron and other appliances when not in use.
  • Make sure appliance cords do not come in contact with hot surfaces.
  • Use extension cords with three-pronged plugs for appliances that require grounding.
  • Do not place electric cords under rugs or mats where they can be walked on or damage can go unnoticed.
  • Unplug all electric appliances before you work on them. Even when replacing a light bulb, it’s best to unplug the lamp or turn the power off to the light fixture.
  • Do not touch an electric appliance with a metal object; you could be electrocuted. For example, do not use a kitchen knife to retrieve items from toasters, dishwashers, dryers or any other electric appliance.
  • If you receive any kind of shock from a large appliance or any other electrical device, other than from static electricity, have an electrician check it.
  • If an appliance emits smoke or sparks, or if you feel a tingle or light shock when it’s on, stop using it. Discard or replace the appliance or electrical device, or have it repaired.
  • Put safety covers over unused electric outlets. This is very important if you have children in your home. Never let children play around outlets.


Today: American Red Cross Blood Drive
The  American Red Cross Blood Drive is taking place today from 10 a.m. - 4 p.m. in CEBAF Center Room F113. Walk-ins are welcome! Nearly 30 individuals made reservations, but blood drive planners are hoping walk-ins will stop by to meet the goal of 50 donations today. Blood supplies tend to run low in the summer due to seasonal travel that prevents donors from giving. For more information, contact Johnie Banks, Occupational Medicine, x7539.

New JLab Video: Special Viewing Today

Public Affairs will hold a viewing today at 11 a.m. in the CEBAF Center auditorium of the lab's new video: Exploring the Nature of Matter. The viewing is open to everyone at the lab. The video provides an introduction to the lab and a nontechnical explanation of the Continuous Electron Beam Accelerator Facility and the kind of research this unique facility is used for. The video mentions several of JLab's areas of special expertise as well as its technology transfer and science education endeavors.

Free DVD copies of the video will be available for pick up afterward in the CEBAF Center lobby. One per person, please. The video may also be viewed online.

Visit JLab Summer Poster Session
The JLab community is invited to visit the 2009 Summer Science Education Poster Session taking place Friday, July 31, from 11:45 a.m. to 2 p.m. in the CEBAF Center lobby. The more than 40 participants of this year's High School Summer Honors Internship Program, the Science Undergraduate Laboratory Internship (SULI) program, the ODU Research Experience for Undergraduates program and the Academies Creating Teacher Scientists (ACTS) program will be on hand with posters they developed based on their work or research projects. Drop by for a few minutes and share in their discoveries and passion for science and science education.

Call for Papers for the International Symposium on Hydrogen in Matter
The Third International Symposium on Hydrogen in Matter will take place Dec. 13-16 at the Indian Institute of Technology Madras, Chennai, India. Symposium sponsors have announced an Aug. 31 deadline for submitting abstracts. Abstract selections will be made on Sept. 15. Selected full-length papers will need to be submitted by Oct. 30.
For more information, see the ISOHIM-2009 website or posters around the JLab campus.

Back-to-School Sales Tax Holiday Begins August 7
Virginia's tax holiday will take place August 7 - 9. During the three-day period, many school supplies costing $20 or less each and clothing items and footwear costing $100 or less each will be exempt from the state's five percent sales tax. For the entire list of exempt items, visit