Jefferson Lab Weekly Briefs July 8, 2015

Jefferson Lab Weekly Briefs
July 8, 2015

12 GeV Upgrade

The construction of the four regions of the Silicon Vertex Tracker (SVT) for CLAS12 has been successfully completed. The first three regions are operating as one unit in the Experimental Equipment Lab Rm 124 clean room, and the fourth is operating separately. The remaining step will be to rotate both units to a horizontal position and check their fit as one integrated tracker, after which the SVT will await installation into CLAS12 in late 2016. The High Threshold Cerenkov Counter has completed alignment of all the photomultiplier tube (PMT) mounts and is undergoing addition of the covers and access plates for its containment vessel. The next steps include re-installation of the main mirror and the addition of gas windows. The construction of the 48 counters of the Central Time-of-Flight detector is complete, and the custom three-layer magnetic shields do indeed work as predicted in the gradient fields that will be encountered outside the solenoid magnet at the PMT positions. Refurbishment of the first of the six sectors of the Low Threshold Cerenkov Counter (LTCC) is finished. This has included re-covering the mirrors with aluminized Lexan strips, coating the PMTs with p-Terphenyl, and re-coating the Winston Cones to improve ultraviolet response and overall photon statistics to aid in the LTCC’s new role as a tagging Cerenkov for pions in CLAS12.

Center for Theoretical and Computational Physics

The possibility that QCD Hamiltonian matrix elements between physical states can be approximated with "lattice-improved" tree diagrams has been explored in a new paper.  Results for the coordinate space lattice gluon correlation functions are presented and applied in the computation of the static quark potential. This example illustrates the possible emergence of constituent gluons.

Facilities Management and Logistics

Demolition/Construction to Close Parking Areas Near Accelerator Site Entrance
Demolition of the two Radiation Control Department trailers and Building 52 is expected to begin on July 13 and will take about one month. The parking area around these buildings will be closed beginning the evening of July 10 and will remain closed until construction of the new EHS&Q building on the same site is complete in 2016. A sketch showing the area to be blocked can be found on the linked all-staff memo.

All personnel are reminded to stay out of this area. If you have any questions about this project, contact Suresh Chandra at x7248.

Jefferson Lab Calendar of Events

July 3: Independence Day holiday observed; Jefferson Lab closed
July 7-10: Program Advisory Committee Meeting (PAC43)
July 15-16: Super BigBite Spectrometer Collaboration Meeting
July 17-18: Hall A/C Summer Collaboration Meeting
July 20: Safety Shoe vendor onsite
Aug. 18: American Red Cross Blood Drive
Aug. 19-21: Q-weak Collaboration Meeting
Sept. 7: Labor Day holiday; Jefferson Lab closed

Environment, Safety, Health & Quality

Summer Brings out Local Wildlife and Insects
Construction and land-clearing adjacent to Jefferson Lab has disturbed the habitat of a variety of wildlife. Natural and manmade landscapes found both indoors and outdoors on site may seem attractive for some of these animals, reptiles and insects. Most are harmless, but some wildlife can be disruptive to lab operations, and dangerous if confronted, especially when they are sick, injured or choose to relocate to indoor workspaces. Consequently, you are urged to show extra care, and adhere to the following guidance:

•    Inspect dark or concealed areas with a flashlight; avoid using your hand to check for spiders, snakes, or other pests. Be extra careful around all pipes and under the gas-flow handles on gas-storage bottles and overhanging eaves on buildings – use appropriate repellents and/or stay away from paper wasps that are known to make nests in these locations;
•    Be observant around asphalt, concrete slabs and wide metal pipes, which provide warm spots for snakes to sun themselves;
•    Stay clear of tall grasses, water in ditches, and rotting wood, which can hide snakes and ticks and other potential hazards such as animal tunnels and dens;
•    STAY AWAY from snakes, raccoons, geese, deer, fox and other wildlife that may have wandered onto Jefferson Lab property. If you see wildlife, warn others to stay away from the immediate area where they were seen; and
•    If wildlife poses an immediate threat to Jefferson Lab workers, an animal’s behavior is threatening, or a suspected protected species is observed, immediately report what you observed to Jefferson Lab security at 269-5822 or to Facilities Management & Logistics at x7400. Pest Control services will be notified of the potential hazards or protected species.

If you are stung or bitten, report to Occupational Medicine in the Support Service Center (Bldg. 28) as soon as feasible. Prompt medical care can help prevent infection and complications that could result in unnecessary pain and lost work. You may also see this notice as an all-staff memo.


Tornado Warning Siren Test Set for Friday, July 10
Jefferson Lab's tornado warning siren will undergo its monthly operational test at 10:30 a.m. on Friday, July 10. Don't respond to the siren; this is a test of the siren system and not a personnel response exercise. Individuals planning to be in the Central Materials Storage Area (where the siren is located) while the test is taking place must have with them and wear two layers of hearing protection.

Jefferson Lab Employee Tour Set for Thursday, Aug. 27
Have you ever wanted to see the experimental halls and the accelerator tunnel, but have not had the opportunity to do so? Jefferson Lab employees, users, students and contractors will have that opportunity on Thursday, Aug. 27, 1-3:30 p.m. The tour will include stops at the Test Lab, the Machine Control Center, the CEBAF Accelerator tunnel, and Experimental Halls A and B. The visit to each facility will be guided by subject-matter experts. Photos may be taken. Space is limited and your supervisor's approval and advance registration is required. For signup instructions and more information, contact Mike Robbins, x7617.

Looking for Summer Fun? Discount Entertainment Tickets Available
Jefferson Lab employees, users and contractors may access Tickets at Work, a website that offers employee discounts and corporate prices for entertainment. Locally, discounts include savings at Busch Gardens and Water Country USA, as well as discounts on movie tickets. The site also offers discounts on tickets to other major theme parks, tickets to Broadway shows, hotels and rental cars. A link to the site is available in the Popular Applications section on Insight.

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.