Jefferson Lab Weekly Briefs March 12, 2014
Jefferson Lab Weekly Briefs
March 12, 2014
12 GeV Upgrade
All sectors of the Forward Time of Flight 1-a and FTOF 1-b detector arrays for the CLAS12 spectrometer have been mounted on the forward carriage in Hall B. All “1-a” sectors and three “1-b” sectors have been connected to the new FADCs, discriminators and high voltage and have been read out. Three of the Region 1 Drift Chambers were shipped from Idaho State University to Jefferson Lab, with the remaining two to be shipped in late March. The sixth Region 3 Drift Chamber has had all of its guard and tension wires installed, and about half of its field wires have been strung. This is the last Drift Chamber sector to be built. The next set of production modules of the Silicon Vertex Tracker detector are being assembled and tested at Fermilab, with assembly expected to continue until the fall of 2014. The parts for the SVT assembly structure are now being acquired. The internal frame for the containment vessel for the High Threshold Cerenkov Counter (HTCC) has been assembled, and the carbon-fiber entry dish, Moller cone and related parts have been added. Nineteen coated production mirror segments for the HTCC have arrived and been tested. The mirror refurbishment is complete for the first of three types of mirrors for the existing Low Threshold Cerenkov Counter (LTCC). The box modifications and new supports for the LTCC are also underway.
The practice coil for the CLAS12 Torus magnet was shipped from Fermilab to Jefferson Lab, placed in a test box and cooled to liquid nitrogen temperatures to check stresses and electrical-plus-cooling behavior. The first production coil has been wound at Fermilab and transferred to the coil case. The second coil is being wound, and preparations are underway for the conductor for the third coil. The Torus cryostat factory has been set up and readied to receive the first production coil from Fermilab. The vendor for the CLAS12 Solenoid magnet has submitted the necessary documentation for the final design review scheduled for March 18 at Jefferson Lab.
Jefferson Lab Published Journal Articles, March 3-9
Remember to submit your papers for approval to the Jefferson Lab Publications database.
Center for Theoretical and Computational Physics
An update of the "JR" global fits for parton distribution functions, together with the highly correlated strong coupling, has been presented up to next-to-next-to-leading order in QCD utilizing most world data, including those from Jefferson Lab at high parton momentum fractions x. The stability and reliability of the results are ensured by including nonperturbative higher-twist terms, nuclear corrections as well as target mass corrections, and by applying various kinematic cuts on available data. In addition, the dependence on the input scale used in the analysis has been studied in detail. Predictions have been given, in particular for the LHC, on gauge and Higgs bosons, as well as for top-quark pair production.
With the resumption of beam operations scheduled to start shortly, the various groups within electrical engineering support (EES) have been busy preparing for the turn-on of accelerator systems. The Safety Systems Group spent many long hours re-certifying the accelerator Personnel Safety System interlocks and getting the Hall A interlocks integrated into the system. Re-establishing Hall A interlocks is necessary to get ready for beam delivery commissioning to the hall. The Radiofrequency (RF) Group has been engaged in commissioning injector RF Zone 0L04 with the new R100 cryomodule and new controls. They also have been performing maintenance on the other 50-some RF systems and completing installation and testing of new RF separator hardware. Both the Instrument and Controls (I&C) and DC Power groups are busy completing 12 GeV installation and hot checkout on the last remaining items needed for the Hall A beam spinup and the first commissioning run to Hall D, scheduled for the end of April. The systems being worked by these groups include: instrumentation and controls, vacuum controls and many magnet power supplies. The Support Group shop has been working to help complete cable terminations or fabricate other items needed in the field by the other electrical groups. The Support Group electricians have been kept busy with AC power hookup as new equipment is placed. Many hours of overtime has been expended in the last month making sure all is ready for beam operation.
JLab Calendar of Events
March 12: Colloquium: Daniel McKinsey, Yale University
Environment, Safety, Health and Quality
Spring Critter Migration
To prevent any surprise encounters in your area, look for signs of critters on or around boxes, disused items or seldom-accessed shelving, racks or quiet storage areas before you access these spaces. Critter clues can be chewed papers, holes that are not normally associated with that type of box or even webs or droppings. When outside, watch for snakes and deer along the road and in grassy areas; stay on the road or on sidewalks or cleared walking paths and don’t sit on logs or curbing.
If you encounter creatures and need to have them controlled immediately, call Facilities Maintenance at x7400. In less-urgent situations, you may submit a Facilities Work Request detailing the exact location and what type of animal or insect (or their indicators) was observed or report the encounter to Mike Lewellen. Jefferson Lab has standing contracts with the animal/insect control companies who frequently are on site; the contractors are properly credentialed and have experience in addressing these issues.
Computing and Networking Infrastructure
CNI Systems Maintenance Period Set for Tuesday, March 18, 5-7 p.m.
Windows XP Systems Require Upgrades By April 1
Introducing the BlueJeans Multimedia Collaboration System
Required Reading on Workplace Harassment and Violence
How to Respond to a Threatening Situation
Colloquium: First Science Results from the LUX Dark Matter Experiment
Ends Soon: Diversity and Inclusion Survey
2014 Annual T-Shirt Design Contest Is Underway
Spread the Word About May 17 Open House
Upgrade to Timesheet System
Tracking Thomas at Jefferson Lab
Silvia Niccolai correctly guessed the location for March 5. Honorable mentions go to Michael Haddox-Schatz, Marcy Stutzman, Jared Martin, and Dick Owen. Check out Tracking Thomas on flickr for a better view of his last location and this week's new mystery photo.
|JLab Weekly Briefs is an ongoing publication providing information on the status of safety, accelerator operations, experiments, free-electron laser, reviews, upcoming activities and special events. Deadline for submission is every Tuesday by 10 a.m. Submit new items to: Public Affairs or contact Kandice Carter at x7263.|