Jefferson Lab Weekly Briefs May 4, 2011

Jefferson Lab Weekly Briefs
May 4, 2011

12 GeV Upgrade

At the Hall D construction site, the final portion of the new Accelerator site boundary fence is being installed. With the start of the CEBAF accelerator shutdown in mid-May, the contractor will remove the existing fence between the Accelerator site and the Hall D construction site, making Hall D part of the Accelerator site. This fence change will signal the start of excavation to the existing northeast stub of the accelerator tunnel for connection during the shutdown. The northeast portion of the accelerator ring road and the Hall D construction area will be posted as a construction work site with specific requirements for training and personal protective equipment (PPE). For safety reasons, access to these work sites will be limited to personnel involved with the civil construction project. 

The Hall D construction contractor has transferred the last of the SEG shielding blocks and placed them in the electron beam dump. A number of concrete pours have taken place over the last few weeks, including the tagger area roof, the electron beam dump roof, the first sequence of the tagger truck ramp floor slab, the service building floor slab and the second lift of the service building south wall.


Hall A continued taking data for the x>2 experiment. The data taking on the deuteron and helium-4 was completed earlier. Last week, data were taken on helium-3, carbon, calcium-40 and calcium-48. Running was smooth and productive. Of the total eight kinematic settings, five settings were completed and one was mostly done. Data taking for the experiment is well on track to completion.

Research Assistantship Nominations Due May 31
JLab has extended the deadline for candidates from SURA universities for a research assistantship. The program will sponsor a minority undergraduate student to work on projects that are part of the lab’s research program or directly related to the scientific or engineering aspects of the research program. This assistantship is funded by the JSA Initiatives Fund and will provide funds to support the student at the university during the 2011-2012 academic year. Nominations must be submitted by the faculty sponsor before the student may apply. Faculty sponsors may obtain more information and submit their nomination online.


Last week was another record-setting week for CEBAF accelerator operations. New records for peak injector current of 295 microamps and for the integrated charge in a 24-hour period of 17.98 Coulombs were established. Additionally, the beam availability was 82.4 percent for the week. The physics program for the week continues with the delivery of high-current beam to Halls A and C.  Hall-B continues HDice target installation. Beam studies were performed Tuesday and Thursday. These studies included measuring the arc optics to document the present 6 GeV machine and in preparation for the 12 GeV machine. Beam studies time was also used to upgrade the bunch length optimization tool to be compatible with the new 130 keV gun/injector setup. On Thursday, the injector laser spot was moved to maintain high beam current, and the Wien was flipped from right to left for Q-weak. Over the weekend, an arc dipole box supply and a beam line vacuum valve malfunctioned, which interrupted beam delivery for a few hours. The faulty parts were replaced.

Free-Electron Laser

The FEL group established lasing at 2.15 microns for mirror testing and ran up to around 1 kilowatt in the initial setup. No signs of spurious mirror heating were observed at this level, and the group is in the process of optimizing the match so that higher efficiencies and powers can be produced.

Theoretical and Computational Physics

Members of the Theory Center, together with a collaborator at the University of Maryland, have computed the excited states of the nucleon and Δ within lattice QCD <arXiv:1104.5152>. They have, for the first time in a lattice calculation, determined the mass of baryons of high spin, up to 7/2, with many of the masses computed to high precision. The pattern of states observed is consistent with the non-relativistic quark model, but is inconsistent with and richer than the pattern of states observed in a quark-diquark model.

Facilities Management and Logistics

Now that Rattley Road is no longer closed after hours, it has been designated as the preferred route for all delivery vehicles. A new delivery route map has been posted to the JLab Construction Corner portlet on Insight. The map may also be accessed directly here.

Environment, Safety, Health and Quality

Use JLab Safety Knowledge to Protect Your Eyes
With the arrival of spring, many of us will be working outside or on other home and hobby projects. Four out of 10 accidents that cause blindness happen at home. Wear eye protection while doing repair jobs and working with chemicals at home and while playing sports - even over contact lenses and prescription eyeglasses. Wear ultraviolet-blocking sunglasses when working outside.

If you do injure your eye(s), always seek immediate medical attention. Here are some important first steps following a variety of common injuries that may help minimize the damage as you wait for treatment:

  • Chemical splash - Hold eye(s) open with thumb and index finger and flood with water (never use another chemical to "neutralize" the first one). If possible, take chemical container or container label to help doctors determine the appropriate treatment.
  • Flying particles - Cover affected eye(s) to prevent movement and seek treatment; never attempt to remove an object that has become embedded in the eye, since doing so could cause further damage.
  • Burns - Whether the burn is due to intense heat, flames, lasers or welding
    radiation, apply ice pack to alleviate the pain.
  • Blow to the Eye(s) - Apply ice packs to control swelling and relieve the pain and cover the eye(s) to prevent movement.


Worldwide Travel Caution Update
With the death of Osama Bin Laden, the U.S. Department of State has updated its worldwide travel caution. Intelligence and security agencies are on heightened alert for terrorist attacks against U.S. interests both at home and abroad. If you have an approved foreign trip coming up, the foreign travel section in the JLab Travel office will update you if there is any change before your travel date. For more information, visit the JLab travel announcement and the U.S. State Department travel advisory webpage.

Information Session Offered on May 5 Reguarding Permits for Digging, Excavating or Making Floor/Wall Penetrations at JLab
JLab has extensive buried utilities. Many buildings also have electrical conduit, piping and data/communication cables within walls and embedded in floor slabs. If you have work that requires digging or drilling into soil or making a blind penetration into walls or floors with tools or fasteners, you should attend a special 30-minute presentation at 1:30 p.m. in the CEBAF Center auditorium on May 5. The brief information session will cover everything you need to know regarding the processes for this type of work at JLab.

Onsite TIAA-CREF Counseling Offered
TIAA-CREF will offer individual counseling sessions onsite on May 19-20. In these sessions, employees can discuss their personal financial situation with a TIAA-CREF consultant on a confidential basis. To discuss your plan and options for managing your retirement savings or to schedule an appointment with a TIAA-CREF individual consultant, call TIAA-CREF at (800) 732-8353, Monday-Friday, 9 a.m.-8 p.m.

Run-A-Round Is Set for May 11
The 26th annual JLab Run-A-Round will be held Wednesday, May 11, 3-6 p.m. JLab staff, users, students, full-time contractors and immediate family members are invited to participate. Staff and users who participate in the run or who volunteer can receive a free 2011 JLab T-shirt. Online registration is open on the JAG webpage. All runners/walkers must register before 5 p.m. on Tuesday, May 10, to be eligible for prizes. Race bibs will be available for pickup on Wednesday, May 11, 9 a.m.-2:30 p.m. in the CEBAF Center lobby.

Volunteers Needed for Run-A-Round
Limited volunteer opportunities in nearly every category are still open for the Run-A-Round. This event could not happen without JLab volunteers. Click here now to get your choice of volunteer assignments and help everyone have a fun, safe and entertaining event.

Radiation Worker Classes Scheduled
The next full day in-person Radiation Worker I class and half-day Radiation Worker II class will be scheduled slightly out of turn on Wednesday, July 6 and Thursday, July 7, respectively. Normally, these courses are offered the first and second Tuesday of each new quarter. Visit the Training website to sign up. Questions may be addressed to Maya Keller, x6021.

Tracking Thomas at JLab
Little Thomas has headed indoors to escape the pollen. If you can identify his location, email Kandice Carter with your guess. The first correct response will receive special recognition on this page. Guesses are accepted through Fridays.

Congratulations to Stephen Smith, who was the first person to correctly identify the April 27 location. Honorable mentions go out to Kelly Tremblay, Jim Follkie, Danny Machie and Will Oren. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.

JLab Calendar of Events

May 6-7: USQCD Collaboration Meeting
May 9: Safety Shoe vendor onsite
May 16: Nucleon Resonance Structure Workshop
May 17-20: NSTAR 2011
May 23: Safety Shoe vendor onsite
May 30: Memorial Day holiday - JLab closed