Jefferson Lab Weekly Briefs August 5, 2009

Jefferson Lab Weekly Briefs

August 5, 2009

12 GeV Upgrade

The contractor for the Central Helium Liquefier building addition has completed pouring concrete for the trench and is installing the waterproofing, foundation drains and grating. Next up is the floor slab, with formwork and reinforcing steel now being installed.

Installation of the groundwater dewatering system for Hall D also has started. Hall D requires an excavation depth of approximately 20 feet below existing grade, and the water table is approximately 5 feet below grade. The dewatering system will temporarily depress the water table to allow construction. Also, the contractor is continuing installation of utilities and a construction entrance from Canon Boulevard.


In Hall B, the preparation of the third part of the eg1-dvcs run group is well underway. The run group covers two highly rated experiments on Deeply Virtual Compton Scattering and on the measurement of Target Spin Asymmetries for pion production, repectively.  Also, the maintenance and repair effort of the drift chamber system has been completed. Some additional maintenance is underway on the time-of-flight system.

The target magnet and the polarized target cryostat are now cold and check-out and testing by the Target Group is underway. One problem occurred during cool down when the run valve froze up and a bypass valve had to be used to allow operation of the system. The plan is to fix this problem by either forcing the valve open mechanically, or if this fails, by warming up the entire system. The latter may require up to two weeks, but could still be completed before the start of the run.

Finally, the preparation of the eg6 run group, which immediately follows the eg1-dvcs run, is also continuing. This run group serves two highly rated experiments, one on the search for hybrid mesons, the other on DVCS from the He-4 nucleus. Both experiments require the use of a pressurized He-4 gas target. A new radial TPC (RTCP) has been built for the detection of the low energy recoiling alpha particle. The RTCP is now being tested, and first signals from a radioactive source have been observed.

In Hall C, final preparations for the hypernuclear experiment are underway.  All  beamline and spectrometer magnets are installed and controls for beamline elements are being established and tested. The detectors are installed at the HKS and HES spectrometer focal planes and are being tested.

Theory Center

Apart from their intrinsic attractions, supersymmetric extensions
of the Standard Model naturally suggest a candidate for dark matter, one of the outstanding challenges of modern astrophysics. The neutralino with mass of order 100 GeV is a natural candidate, and it is crucial for dark matter searches that scientists have accurate estimates of its scattering cross section for hadronic matter. In a recent cross-disciplinary paper <arXiv:0907.4177 [hep-ph]> involving authors from RPI, ANL and JLab, it has been shown that lattice QCD provide crucial information on the sigma commutators, which in turn yields much more precise estimates of the neutralino-matter cross sections. While the results are an order of magnitude smaller than hitherto expected, a positive result would enable one to chose between the existing models that are consistent with Wilkinson Microwave Anistropy Probe (WMAP) data.The paper can be found at


The Accelerator Scheduled Down continued with maintenance on RF (radio frequency), magnets, vacuum system, control system, personnel safety system, fire safety system and more. CW beam was established with over 100uA to the injector inline dump. On July 30, Virginia Power fixed the power fluctuation problems experienced at the accelerator site.  The chilled water to the north linac service building was interrupted, but fixed on July 31. Certification of the personnel safety system started.             

Free-Electon Laser (FEL)

It was a spaghetti western week for the FEL.  The Good: the FEL had a very successful demonstration of 5 MeV injection producing full efficiency above 1kW/mA and complete energy recovery for our Joint Technology Office contract. The Bad: the FEL had tuning problems on one cryomodule that took up half a day of effort to resolve after fixing The Ugly: the FEL lost 2 1/2 days of running because of the discovery of an earlier failure of an unnecessary interlock on a redundant enclosure protecting staff from a non-hazard during an envisioned repair procedure that never occurs. It took 2 hours to fix the interlock. Repair of the documentation continues.

JLab's Safety Numbers

21 Days since Last Recordable Accident (JLab record: 331)
329 Days since Last Lost Workday Accident (JLab record: 676)

JLab Calendar of Events

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

Jefferson Lab began a Medical Event reporting emphasis campaign in September 2008 with the objective of obtaining more and better safety data. Various communication modes were used, including a Montage, multiple weekly briefs inputs, and consistent reinforcement at both large and small meetings across the site. 

Reported medical events at the lab rose almost 400 percent when compared year over year. Feedback shows that the management emphasis campaign was the primary driver.You can see graphs on Insight.

One important point to remember is that although the number of reported medical events has increased significantly, the lab's DART (Days Away, Restricted or Transferred) and TRC (Total Recordable Cases) remain extremely low. The FY09 DART is 0, while the TRC is 0.32, well below the 0.65 PEMP contract goal.

ESH&Q has used this data to identify the most significant improvement category - Hand and Finger Issues. These issues comprise almost two-thirds of all reported medical events.  Identified causes include equipment movements, handling cut sheet metal, pulling cable and various other activities, usually without gloves or other hand PPE. An ESH&Q liaison has been assigned to work with each Division's Safety Officer in identifying the specific work activities causing these events, and ensuring the availability and use of proper hand PPE.  Additionally, the appropriate divisional work policies will be updated to ensure the information is available during work planning.


Blood Drive A Success
The July 29th Red Cross Blood Drive was very successful! A total of 71 people signed up to donate blood. The Red Cross still collected 54 pints of whole blood and six donations of red cells using the Double Red process, exceeding the lab's goal of 56 units! Occupational Medicine offers its thanks to everyone that participated and volunteered in the blood drive.

Join the fun, festivities at Aug. 19 JAG Luau

Plans are in full swing for the lab'ssummer luau. The free event, open to all lab employees and their families, users and students, will be from 3-6 p.m. Wednesday, Aug. 19, on the lawn behind the Residence Facility.


Refreshments will include summer favorites: hamburgers, hotdogs, chips, side dishes, cold beverages, and special treats like snow cones.


Activities planned for the afternoon include a Hawaiian shirt contest, slip & slide, bean bag toss, limbo, hula hoop contest and tug-o-war.


The luau is geared toward families, but adults will be able to join in on the fun as well.


The success of JAG-sponsored events depends on everyone's participation. Volunteering just one hour of your time to assist with set up, or help with an activity or event, or clean up, will go a long way toward making this event a success.  JAG needs volunteers to help with a variety of tasks. Please volunteer today.


More information about the event and volunteer sign up are available at:



TIAA-CREF Retirement Counseling Sessions

The summer/autumn dates for individual counseling sessions with Individual Consultant Robert Jean are now posted. This is an opportunity to discuss the current status of your account, investment strategy and retirement goals. The dates are:

Wednesday, Aug. 12
Thursday, Aug.13
Friday, Sept. 25th
Friday, Nov.13
Thursday, Dec.10.

The Individual Counseling Session helps you plan your retirement by:
- Providing objective advice and asset allocation based on your individual needs;
- Showing you how you can get a personalized actionable plan;
- Reviewing your retirement income options.

To sign up for an appointment go to and click on Meetings & Counseling and follow the menu. The sessions will be held in VARC Room 42.

Back-to-School Sales Tax Holiday Begins Aug. 7
Virginia's tax holiday will take place Aug. 7-9. During the three-day period, many school supplies costing $20 or less, and clothing items and footwear costing $100 or less will be exempt from the state's 5 percent sales tax. For the list of exempt items, visit