Jefferson Lab Weekly Briefs October 27, 2010

Jefferson Lab Weekly Briefs
October 27, 2010

12 GeV Upgrade

The North and South Access Building additions and power upgrades to support the accelerator operations at 12 GeV are complete. Ready-for-equipment (RFE) inspections were conducted on Oct. 14 and 25, including representatives from 12 GeV management, Facilities Management & Logistics and ESH&Q. The cooling towers and pumps for the Central Helium Liquefier utility upgrades are set in place, and the subcontractor is installing the associated piping. Metal wall panels for Hall D were delivered to the site on Oct. 25, and installation will commence this week. Accelerator group welders are completing the leak test on the portion of the beam pipe entering into the photon beam dump at Hall D.


In Hall C, the pump that circulates liquid hydrogen in the Q-weak target stopped turning and failed to restart. The target was removed from the scattering chamber, and examination of the pump revealed that one of two bearings failed. In addition to repairing the pump with a different type of bearing, this event is being used as an opportunity to make minor improvements and repairs to the target.

Q-weak commissioning has continued productively without a target, focusing on tuning parity beam feedback systems, studying backgrounds and commissioning the Compton polarimeter. In an important milestone, the polarimeter has now observed an asymmetry in the scattering of laser photons off of the electron beam.


The accelerator was running well, with low trip rates. On Friday, Hall A beam was changed from pass 5 to pass 4. On Saturday evening, the west arc lost power briefly, which affected beam delivery for about one and a half hours. In addition, the Hall C line may have 500 Hertz noise vertically, which the experts have been investigating.

Free-Electron Laser

The FEL team was limited in running last week by vacuum issues in the injector, but the team was able to take power data on the laser to begin to resolve discrepancies in power measurements between several meters.

Center for Theoretical and Computational Physics

In a joint Excited Baryon Analysis Center-Hall B paper <arXiv:1010.4555>, the relations between the multipole amplitudes and all possible 16 spin observables of pseudoscalar meson photo-production reactions are established. It is found that presently available hyperon photo-production data determine only bands of solutions that are far from the precision needed to extract nucleon resonances. The importance of a new generation of ongoing experiments underway in Hall B to measure all 16 spin observables is emphasized.

JLab Calendar of Events

Oct. 28: JAG/JSA Oktoberfest, 3-6 p.m.
Oct. 28-29: Transverse Spin Phenomena and Their Impact on QCD Workshop
Nov. 3: United Way Fund-Raising Campaign ends
Nov. 4: Safety Shoe vendor onsite
Nov. 4: JSA's Electronic Commerce Vendor Show
Nov. 7: Daylight Saving Time ends
Nov. 23: Science Series Public Lecture
Nov. 25-26 Thanksgiving Holiday - JLab closed

JLab's Safety Numbers

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




Environment, Safety, Health & Quality

Halloween is a fun time for kids, but it is also an important time to be extra vigilant for possible safety hazards so that your children have a fun and safe holiday. Click the link for timely tips from the U.S. Product Safety Commission to keep your little trick-or-treaters out of harm's way.

Computing and Networking Infrastructure

Introduction to Mailman for List Owners/Administrators
If you are the list owner or administrator of a mailman mailing list, this informative seminar is for you. The seminar will cover important mailing list topics, such as: how to start a mailing list, where to find the directory of mailing lists provided by JLab, how to get information concerning a mailing list (including its owner), and where to find help in administering a mailing list. The seminar will be held in the CEBAF Center auditorium on Monday, Nov. 1, 1:30-2:30 p.m. Plan to attend if you are currently the list owner or administrator of a JLab mailing list, or if you are planning on requesting a new mailing list for use at JLab. For more information, contact the IT Division Helpdesk at x7155.

Discontinuation of Dial-up Modem Pool (RAS) Service
On Nov. 1, the lab's dial up modem pool (RAS) service will be decommissioned. The service, once widely used for off-site access, has been effectively replaced by the Internet. Questions about remote access to lab resources can be directed to the IT Division Helpdesk, x7155.

CNI Maintenance Day
The CNI group is planning a short maintenance period on Thursday, Nov. 4,  5-7 p.m. During this time, there may be a short wireless outage in some parts of CEBAF Center. In addition, Linux patches will be released to all Common User Environment (CUE)-managed Linux systems. Leave your Linux desktop powered up during the evening for patch delivery and plan on rebooting your Linux system at a convenient time on Friday, Nov. 5.


JLab employees, immediate family members and Users are invited to the annual JAG/JSA Oktoberfest on Thursday, Oct. 28, 3-6 p.m., in the field behind the Residence Facility. Come early to enjoy the Brunswick stew, chili, grilled foods and beverages. Stay for the adults’ costume contest, giant slide, arts & crafts and much more. In addition, donations of new, canned or boxed, nonperishable food items for the Peninsula Food Bank will be accepted in drop barrles near the entry points for Oktoberfest.

Volunteers make this event possible. If you haven’t yet signed up to help, visit the JAG Oktoberfest volunteer page and sign up today. Just one hour of your time helps immensely.

Sentara Mobile Mammography Unit Onsite Dec. 6
The Sentara Mobile Mammography Unit will be at JLab on Monday, Dec. 6, 9 a.m.-3 p.m., in the ARC parking lot. This service is open to all employees as well as family members or friends, since personal health insurances will be billed. The procedure takes 15 minutes. To make an appointment, call 1-800-SENTARA (736-8272) or see the Screenings and Events section on the frontpage of the Sentara website.

Pet First-Aid Class
The JAG Dog Club will hold a day-long Petsaver Class on Sunday, Dec. 5, if enough interest exists. The class will cover CPR, rescue breathing, conscious and unconscious airway obstruction (choking), shock management, bleeding protocols, injury and wellness assessments, heat injuries, restraint, dental care and care for elderly pets. The cost of the course is $125 per student; class size is limited to eight (six minimum). More information about the program is available online. If you're interested in registering for the class, contact Joyce Miller, x7163 before Nov. 5. The class will be held in the VARC classrooms, Building 28, rooms 72A and B.