Jefferson Lab Weekly Briefs

August 26, 2009

12 GeV Upgrade

Jefferson Lab Facilities & Logistics personnel have completed the re-packaging of the North & South Access Building Additions to include the electrical upgrades for an FY10 procurement. The electrical upgrades had previously been planned as an FY11 procurement. The contract package is under review by ESH&Q, Facilities and Accelerator personnel.

Construction on the FY09 procurements continues to progress. On the Central Helium Liquefier (CHL) Building Addition, the concrete work is complete and the structural steel work started this week with setting of the columns. On the Hall D Complex, the groundwater dewatering system is fully operational and the Hall D excavation is near the required depth of approximately 20 feet.

Physics

In Hall A, the summer down, in which the polarized helium-3 target and the BigBite spectrometer were removed and the standard cryotarget was installed, has been completed on schedule. Experiment E05-109, HAPPEx-III, a measurement of the nucleon strange form factors at high Q2, has started taking commissioning data at one pass.

The third and final part of the eg1-dvcs run group started last weekend in Hall B. Polarized ammonia (NH3) and polarized triply deuterated ammonia (ND3) targets will be used during this run. As the beam polarization was low, part of the weekend was spent to administer a cold irradiation dose to the ND3 target sample. The cold dose is needed to achieve optimal deuteron polarization during production data taking. In addition to the original physics goal of the eg1-dvcs run group, the ND3 part of the run will also serve to partly achieve the physics goal of the A-rated Hall C experiment E07-011. This experiment was canceled to run in Hall C due to a major failure of the polarized target. If the ND3 part of the eg1-dvcs run goes well, it will significantly improve our knowledge of the polarized structure function g1d.

In Hall C, commissioning of the beamline and spectrometers for the hypernuclear experiment, E05-115, has started. Beam was tuned through the new chicane relatively easily, which is a credit to the design, installation and alignment of this beamline. Beam has been used to shakedown beamline instrumentation and checkout detectors.

Accelerator

On Aug. 18, the Accelerator was scaled to unbalanced linacs to provide the halls with the highest beam polarization. Some time was spent on optics, radiofrequency, RSEP8A, shunt adders, vacuum and viewers. On Friday, the beamline flange at MBZ9E02 developed a leak, most likely due to beam tuning, which caused several hours of down time. Ops delivered some continuous wave beam to Halls A and B. Hall C High Resolution Kaon Spectrometer commissioning started.

Free-Electron Laser

Staffers operated the FEL during the week for the Light Pseudoscalar and Scalar Search experiment, getting a calibration run in but were bothered by loss of quantum efficiency in the gun due to vacuum trips. The FEL team is setting up to do a krypton processing to remove a field emission site that has developed. The Gun Test Stand gun demonstrated over five hours soaking at 400 kiloVolts DC, with no evidence of field emission affecting the ultra-high-vacuum environment.

Theory Center

The probability distributions of quarks and gluons (or "partons") in nuclei are suppressed at small values of the partons' momentum fraction x (x < 0.05) compared to the free nucleon - known as nuclear shadowing. Nuclear shadowing is explained by the multiple interactions of the incoming virtual photon with the target nucleons. A recent paper <arXiv:0908.1149 [hep-ph]> develops a new approach to the treatment of such multiple interactions by using the formalism of color fluctuations and updates predictions for nuclear parton distributions at small x using the leading-twist theory of nuclear shadowing.

JLab's Safety Numbers

42 Days since Last Recordable Accident (JLab record: 331)
350 Days since Last Lost Workday Accident (JLab record: 676)

JLab Calendar of Events

Aug. 26: Colloquium and Public Lecture
Aug. 27: Safety Shoe Vendor onsite
Sept. 2: EAP Seminar: Stretching Your Dollar
Sept. 7: Labor Day holiday
Sept. 14 - Nov. 20: The Jefferson Laboratory Upgrade to 12 GeV INT Program
Sept. 11: United Way Day of Caring
Sept. 17: JSA's Electronic Commerce Vendor Show
Sept. 18: Adopt-A-Spot Litter Pickup
Sept. 22-24: DOE SC OPA Independent Project Review of the 12 GeV CEBAF Upgrade Project
Sept. 24: Safety Shoe Vendor onsite
Sept. 29: Jefferson Lab's 25th Anniversary Celebration
Oct. 6: American Red Cross Blood Drive
Oct. 8: Farewell Reception for Chief Scientist Tony Thomas
Oct. 20: Science Series Lecture - The Founders of Modern Astronomy

 

 

 

Environment, Safety, Health & Quality

Excessive heat exposure can pose a risk on the job. To protect your health and that of your co-workers when temperatures are extremely high, remember to keep cool, use common sense and use the following JLab-specific tips:

  • Be aware of elevated temperatures by monitoring them online or call Industrial Hygiene at x7882 or x6381 for local heat stress monitoring.
  • Watch for adverse reactions in fellow employees/contractors.
  • Review and follow the guidelines in ES&H Manual 6670 Thermal Stress, as well as approved standard operating procedures and any Industrial Hygiene recommendations on modifications to work.
  • If you see someone in a potentially dangerous situation, exercise ES&H Manual 3330 Stop-Work Orders.
  • For heat stress symptoms or any emergency onsite, call Occupational Medicine at x7539 or call 9-1-1.

For more information, visit the OSHA guide for heat stress.

Computing and Networking Infrastructure

Acrobat Reader Printing Issues
The CNI group has received intermittent reports of issues involving the printing of PDF files from within Acrobat Reader 9. If you are getting only one page printed or get odd formatting errors when printing PDF files from within Acrobat Reader, do the following:

1) With a document open in Acrobat Reader, click the "File" menu and select "Print"
2) In the print dialogue box, click the "Advanced" button, located near the lower-left corner
3) In the Advanced dialogue box, select the "Print as image" radio button near the bottom
4) Click "OK" and then click "OK" again to actually print the document.

Once this setting is selected, all PDF documents will be printed using this setting. If further assistance is required, contact the Helpdesk, x7155.

Announcements

Nuclear and Particle Physics at the Spallation Neutron Source
Dr. Geoff Greene, University of Tennessee and Oak Ridge National Lab, will present a colloquium and public lecture in the CEBAF Center auditorium at 4 p.m. today.

Land Clearing Starts Near CEBAF Center for New Connector Road
Construction of the new JLab South Connector Road is about to start. The work will extend from the CEBAF Center traffic circle to Lawrence Drive as shown in this document. Installation of silt fence and tree protection barriers has begun around the construction area. Tree clearing for the connector road's path is planned to start on Thursday, Aug. 27. This area is designated a construction zone, and only authorized staff and subcontractors may enter it. This is the first of a three-phase process to improve JLab traffic flow and accommodate the footprint for the new Technology and Engineering Development Facility (TEDF). Additional announcements will be made as needed as the project proceeds. Pedestrians and drivers: While the work isn't expected to impact traffic flow on Lawrence Drive, use caution when driving by construction equipment and vehicles. If you have questions or concerns, contact Debra Brand, x7684.

Register for a Personal Finance Lunchtime Seminar: Stretching Your Dollar
This bring-your-own-lunch seminar will take place in CEBAF Center room F113, noon-1 p.m. on Wednesday, Sept. 2. It offers tips and techniques on how to save money, no matter how much you make! It will offer useful short and long-term savings options and insightful ideas on how to make effective decisions about tracking and spending your money. Make a budget and make a difference. Facilitated by Optima's Employee Assistance Program. Registration is required due to limited space. To sign up, contact Betty Beeler, x6999 or Bruce Ullman, x7170.

School Tools Drive Ends Sept. 4
The Annual United Way School Tools drive is underway at JLab. Collection boxes for donations of new school supplies have been placed in the VARC, CEBAF Center, MCC and ARC lobbies. Appropriate items include: pens, pencils, student scissors, crayons, spiral notebooks, 3-ring binders, binder paper, pocket folders, rulers, protractor/compass sets, etc. The United Way will collect and disburse the materials to area schools. For more information, call Joshua Cameron, x7628.


JLab Adopt-A-Spot Litter Pick Up Set For Sept. 18
The next JLab Adopt-A-Spot Litter Pick up will be Friday, Sept. 18. Everyone at JLab is invited to take part in this community service project. Sign up on the webpage in advance so adequate supplies can be provided. Litter pick up will cover the sidewalk and grass areas paralleling Jefferson Avenue, from the JLab property line just south of Onnes Drive to Oyster Point Road. Meet in the CEBAF Center lobby at 11:15 a.m. for a short safety briefing, trash bags and to get area assignments. Wear comfortable clothes; long-sleeved shirt, long pants and sturdy shoes and gloves are best. More information and an electronic volunteer signup sheet is available online. If you have questions, contact Deb Magaldi, x5102.