Jefferson Lab Weekly Briefs
April 21, 2010
Major JLab Campus Power Outage to Impact Building Access and Janitorial Services
In preparation for this power outage, janitorial services will empty all trash in these areas on Thursday evening instead of Friday evening. Janitorial services will also empty all impact-area refrigerators on Thursday evening. For more details, see the outage announcement.
Accelerator Site Trailer 53C Inaccessible on April 22
Microsoft Patches for Windows Systems
12 GeV Upgrade
Civil construction continues to make progress. The construction contractor for the North and South Access Building additions is building forms for the concrete footings. The Central Helium Liquefier building addition is completing the startup and testing of equipment, including the bridge crane. CEBAF Boulevard was re-opened on April 17. A site visit for interested contractors for the CHL utility upgrade was held on April 12, and proposals are due at the end of the month. On the Hall D complex construction site, the contractor continues to excavate for the Tagger Area.
In Hall A, the PREX experiment E06-002, measuring the neutron radius in 208Pb to 1 percent, has smoothly taken production data since April 16, following replacement of a vacuum seal on the scattering chamber that had suffered severe radiation damage.
Installation of the Q-weak experiment in Hall C continues. The three acceptance-defining collimators have been installed before the Q-weak toroidal magnet. The four "Region 2" drift chambers, built by Virginia Tech, have been installed between the second and third collimators. These detectors can be moved in and out of the acceptance and rotated to cover each of the octants of Q-weak. These detectors will be used in the Q-weak tracking mode to characterize the kinematics of the measurement. Reconstruction of the beamline to accommodate the new Compton polarimeter is well advanced. Most of the beamline in the alcove is under vacuum.
Application Deadline Nears for Scholarships and Fellowships
Overall, the accelerator was running well, with low trip rates. Two shifts were used for beam studies. During these shifts, some maintenance was done parasitically. Hall A was back online Tuesday (April 14) swing shift. Hall A Compton noise level was lowered after the Hall A line optics was optimized.
The FEL team re-established lasing early last week and was able to perform optical coating tests. The team had a good set of successful experiment runs. Improvements in long-term machine stability are still wanted, so a plan has been initiated to alter the method for setting the drive laser pulse length; it will be tested this week.
A new article <arXiv:1004.2935 [hep-lat]> presents a review of lattice QCD calculations relevant to the nuclear physics of few- and many-hadron systems. Calculations of the properties of systems of up to four baryons are summarized, and the methodologies for studying complex mesonic systems (containing many hadrons) are discussed. The review concludes with an outlook of progress expected in the field over the next few years.
Environment, Safety, Health & Quality
Put It Down! Campaign Calls for End to Distracted Driving
Transportation Secretary Ray LaHood has banned the practice of "texting while driving" for commercial vehicle drivers. In addition, many states have also begun to ban the use of handheld cell phones by motorists. Texting while driving is now against the law in Virginia. The District of Columbia has gone a step further, banning the use of all handheld devices behind the wheel. A full list of state bans is available on the Distraction.gov website.
JSA Research Assistantship Applications Due Friday
National Library Week
E-books from Springer, Wiley and CRC are a significant boost to library holdings; these books can be found in the online catalog using the search terms Springerlink, Wiley Interscience, or CRCnetBase. Also, Springer will provide staff members a personal copy of any e-book that Library Services has purchased (2005 - 2008), as long as it is a Springer imprint/publication and not longer than 800 pages. Users pay only $24.95 per copy. See the "Mycopy" icon at the top of the specific Springerlink page. For an example page, click here. For assistance, contact library staff at x7525 or x7524.
Open House Countdown
JLab Campus Construction Update Online
Free Seminar on Vacuum
JLab's Safety Numbers
36 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
April 21: JLab Teachers Science Night