Jefferson Lab Weekly Briefs
August 22, 2012
PhysicsDe-installation of Q-weak is near completion in Hall C. All Q-weak detectors, instrumentation, collimators and shielding have been removed from the hall. The Q-weak-specific beamline and instrumentation from the Moller platform to the short stub near the beam dump have also been taken down and are being moved to storage. The Q-weak toroidal magnet has been disassembled and is also being prepared for storage. Work has started on removing detector hut shielding from the Short Orbit Spectrometer in preparation for its full removal.
Free-Electron LaserThe FEL team has made significant progress in planning the upgrades to ensure that the machine is ready for operations as soon as the new Central Helium Liquefier is operational. The FEL was one of the participants in the surveillance audit to maintain certification in the OHSAS 18001 Occupational Health and Safety Management System, for which JLab qualified last year. Carlos Hernandez-Garcia chaired the FEL and Synchrotron session at the Conference on Accelerator Applications for Research and Industry (CAARI) held in Fort Worth last week.
Center for Theoretical and Computational PhysicsA new paper reports a state-of-the-art calculation of the photon-Z boson box radiative correction to weak charges of bound protons and neutrons in atomic parity-violation measurements on heavy nuclei, such as 133Cs and 213Ra. For the first time, a small but important additional correction arising from Pauli blocking of nucleons in a heavy nucleus has been evaluated, resulting in a significant shift to the weak charge of 133Cs, approximately four times larger than the current uncertainty on the weak mixing angle, sin2θW, but with a reduced error compared to earlier estimates. This calculation will refine the baseline Standard Model result with which JLab's Q-weak experiment will compare its findings.
EngineeringHall D Cryogenics Design and Installation
Fabrication and installation of the warm helium and cooling water wall piping is nearly complete. Fabrication of the cryogenic valve box that will sit on top of the four coils of the superconducting solenoid magnet is progressing. Work continues on the internal piping, and installation of temperature sensors and internal wiring is underway. Fabrication is progressing on the straight sections of the cold transfer line. The C7 recovery compressor has been removed from the CHL. It will be installed in the Hall D cryo plant as main compressor C3. Checkout of the field cabling, PLC and IOC control software, and EPICS control screens is progressing.
CHL-2 Warm Compressor and Warm Gas/Oil/Water/Air Management Systems
The contractor, PHPK Technologies, completed the final work on the compressor systems. Fabrication work on the piping systems is nearly complete. Leak checks and final pressure tests are underway.
CHL2 300K-4.5K Cold Box Systems
The Linde Group and PHPK Technologies returned to JLab and completed more assembly of the 300-60 Kelvin outside and 60-4.5 K inside cold boxes. JLab is continuing fabrication of the support piping tie ins. Work continues terminating the cabling. Large helium gas headers connecting the compressor and cold box systems have been installed.
CHL1 and Linac Summer Shutdown
The CHL1 and linac warm up to room temperature was completed. Approximately 55,000 liters of liquid helium was recovered, placed in a tanker, and returned to the vendor. Work is progressing on removal of the linac cryomodule U-tubes to support valve maintenance. Additional Linac transfer line maintenance work is being planned.
End Station Refrigerator and Cryogenic Test Facility Refrigerator
The ESR was shut down, and the halls were warmed to conserve utilities during the Long Shutdown. The ESR will be restarted in January. The CTF was recently shut down to allow demolition and refurbishment work to continue in the Test Lab. The CTF should be restarted in approximately six-eight weeks.
Facilities Management and LogisticsARC Building: Power Outage All Day Saturday, Aug. 25
The Applied Research Center will undergo a power outage, 7 a.m.-5 p.m. on Saturday, Aug. 25 for testing of the emergency generator. Due to safety requirements, no one can be in the building during the test, and the emergency generator will not be available in case there is an actual power outage. Hood ventilation systems won't be available, so all chemicals and gases should be secured by COB Friday, Aug. 24. If you have office/work space in the ARC, it is advisable to power down and unplug your computers and other electronics before leaving. The computers in L119 will be shut down for the power outage. Refrigerators should be left on and left plugged in. For more details, visit the JLab Facilities Management Utilities Outages webpage.
JLab Calendar of EventsAug. 22: Colloquium and Public Lecture - Studying the Quark-Gluon Plasma
Aug. 27-28: Zimbra Training Sessions Offered
Sept. 3: Labor Day holiday, JLab closed
Sept. 10: Safety Shoe vendor onsite
Computing and Networking InfrastructureZimbra Calendar Testing Continues
The CNI group has opened the Zimbra calendar for testing. During the test phase, all entries in the calendar will be considered "test entries" and will be deleted prior to the actual cutover during the weekend of Sept. 1. During the cutover, all meetings from Jan. 1, 2011 through Dec. 31, 2014 will be migrated from the Oracle calendar into Zimbra. To access the new Zimbra calendar, just bring up the Zimbra web interface, log in, and click on the Calendar tab. Some frequently asked questions and answers to help you get started are documented online. Frequent calendar users are encouraged to take advantage of the calendar testing period to generate any questions they want answered in the Zimbra training seminar (next brief).
Zimbra Training Offered in August
To smooth the transition to the new system, the CNI group will be offering training seminars on the use of the Zimbra calendar and email system on Monday, Aug. 27 and Tuesday, Aug. 28 in the CEBAF Center auditorium. Two sessions will be offered each day: 9:30-11 a.m. and 2-3:30 p.m.
AnnouncementsJLab Rocks Video on YouTube
If you haven't visited JLab's popular YouTube channel recently, two new videos have been posted that show the dismantling of equipment in Experimental Hall C. The time-lapsed videos were taken using a camera mounted near the ceiling in Hall C. You can view the videos via the link above, or by clicking the YouTube icon located at the bottom of JLab's homepage and then looking in the Playlist "Experimental Hall C Uninstall." Part 1 covers work done in July and Part 2 shows the work done in August.
New Dates Offered for Onsite TIAA-CREF Counseling
TIAA-CREF will offer individual counseling sessions onsite in the Support Service Center (formerly VARC) room 53A on Oct. 26, Nov. 29 and Nov. 30. 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.
JLab Publications Refresher Training Offered
If you are an author who needs a refresher course on the requirements and use of JLab Publications, the next one will take place on Sept. 12, 9-10 a.m. in CEBAF Center room F226. If you plan to attend, R.S.V.P. by Friday, Sept. 7 to Kim Kindrew. Topics that will be covered in this brief course include: What kinds of publications are submitted; How to submit and resubmit your paper into the signature queue; How to review and approve papers. Come with your questions and become a master of JLab publications. Refreshments will be provided.
Studying the Quark-Gluon Plasma - Colloquium and Public Lecture
Johanna Stachel, Physikalisches Institut der Universitaet Heidelberg, will present "Studying the Quark-Gluon-Plasma in Nuclear Collisions at the LHC" in a colloquium on Wednesday, Aug. 22 in the CEBAF Center auditorium at 2 p.m. The theory of the strong interaction, quantum-chromodynamics, predicts for high temperature and density a new state of matter in which the confinement of quarks and gluons is lifted. This state, the quark-gluon plasma, existed in the early universe after the electroweak phase transition up to about 10 microseconds. In the past 25 years, accelerator-based experiments have been conducted in order to recreate this state of matter for a short time. In this talk, selected first results from the ALICE experiment, conducted at the Large Hadron Collider at CERN, will be presented and discussed in the context of results at lower beam energies and theoretical interpretation.
The United Way School Tools Drive Is Underway
JLab is once again participating in this community outreach program to assist students as they prepare to return to school next month. Collection boxes for donations of new school supplies are available in the lobbies of Building 85, the Support Service Center, CEBAF Center and the ARC until Friday, Sept. 7. 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.
Tracking Thomas at JLab
Little Thomas is visiting all corners of the JLab campus. If you can identify his location this week, email Kandice Carter with your guess. Guesses are accepted through Friday.
A belated congratulations for identifying the Aug. 8 location goes out to Doug Higinbotham. Congratulations this week go to Samika Hawkins, Kevin Jordan, Chase Dubbe, Brita Hampton and Lori Zukerman, who were the first to correctly identify the location for Aug. 15. Honorable mentions go to Michael Haddox-Schatz, Narciso Gomez, Michelle Shinn, Ron Bartek, Debbie Campbell, Jason Willoughby, Harry Fanning, Robert Martin and Mike Lewellen. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.