Jefferson Lab Weekly Briefs November 12, 2015

Jefferson Lab Weekly Briefs
November 12, 2015

12 GeV Upgrade

Cosmic ray tests of the Silicon Vertex Tracker for CLAS12 have been ongoing since September, and the events recorded have been used to test track-reconstruction routines for the SVT, as well as establish correct readout, good noise performance, and full response for the entire detector. The High Threshold Cerenkov Counter has been completed and is undergoing testing as it awaits installation in Hall B. This includes monitoring of the relative humidity inside the gas volume, which is a key parameter for maintaining good optical behavior of the large mirror. The construction of the upstream support structure for the Central Time of Flight has been completed, as has fabrication of most parts for its light monitoring system and its transport crate. Refurbishment of the fourth and fifth of the six sectors of the Low Threshold Cerenkov Counter is well advanced. The sealing of the new LTCC window has been demonstrated on the first three boxes and tested successfully on the first box with actual counter gas. An order has been placed for the remaining fast electronic modules, the Crate Trigger Processors, needed to complete the DAQ and triggering systems for Hall B. Work is underway for the slow controls needed to operate all elements of CLAS12. Finally, the work to upgrade beamline elements has started.


Jefferson Lab Published Journal Articles, Nov. 2-6

  • YN. Guler et al. (CLAS Collaboration). "Precise Determination of the Deuteron Spin Structure at Low to Moderate Q2 with CLAS and Extraction of the Neutron Contribution." Phys. Rev. C 92, 055201.
  • David J. Wilson, Raúl A. Briceño, Jozef J. Dudek, Robert G. Edwards, and Christopher E. Thomas (for the Hadron Spectrum Collaboration). "Coupled pipi,KK scattering in P-wave and the rho resonance from lattice QCD." Phys. Rev. D 92, 094502.
  • M. Defurne et al. (Jefferson Lab Hall A Collaboration). "E00-110 experiment at Jefferson Lab Hall A: Deeply virtual Compton scattering off the proton at 6 GeV."  Phys. Rev. C 92, 055202.

Remember to submit your papers for approval to the Jefferson Lab Publications database.

Center for Theoretical and Computational Physics

A new approach has been developed for describing the transverse momentum dependence of observables in hard exclusive processes, such as the photon-pion transition form factor and the pion electromagnetic form factor. Its basic ingredients are functions describing the distribution of pion constituents in virtuality and transverse momentum. Simple models for the soft part of these functions were used for comparison with experimental data (from BaBar and Belle) on the pion transition form factor. The paper also shows how one can generate high transverse momentum tails from initially soft distributions.


The Electrical Engineering group has been working two fronts in recent weeks: restoring the Low Energy Recirculator Facility (LERF) back to operational status and performing hot checkout on CEBAF. DC Power has been running all magnet systems at full 12 GeV settings, which has also had the further effect of warming the tunnel, providing the 'load' for the newly installed tunnel air conditioning system. The group has also successfully completed preliminary tests on one of the Hall B superconducting power supplies to 3,800 Amps.

The RF group has had its share of challenges recently, working constantly to provide the RF power for the gradients required for 12 GeV running. The group has been supporting the collection of RF trip rate data that has been taking place over the past two weeks.

The I&C group inherited many non-functional systems at the LERF, which they had to troubleshoot and repair. These systems were often unique to that machine and required a lot of effort to get up and running in a short space of time. While the group was completing these tasks, group members were also working to complete hot checkout in the CEBAF accelerator.

The Safety Systems group also had new systems to support at the LERF, meanwhile making sure that the personnel and machine safety of CEBAF was not compromised in any way. The Electrical Support group, as well as supporting the other EES groups, has also been working in Hall B with the Torus and Solenoid instrumentation and control efforts. This has been a very busy and productive start to the fiscal year for EES and will likely continue to be.

Facilities Management and Logistics

Construction Near Lawrence Drive and the Walking Trail
Facilities Management personnel expect the clearing of trees from the Jefferson Lab south property boundary to the Lawrence Drive entrance on Jefferson Avenue to begin within the next week. Installation of a 30" diameter sewer force main will follow, beginning in December and continuing into January 2016. Traffic on Lawrence Drive should not be affected until February.

The walking trail is now closed to pedestrian traffic, as it is in the path of the construction. FM&L will evaluate the condition of the trail and advise the Jefferson Lab community on its status once the construction project is complete. If you have any questions or concerns about this work, contact Bob Sperlazza, x6241.

Environment, Safety, Health & Quality

Cold Weather Alerts
Now that the heat of the summer has passed, it seems like the Tidewater area has moved quickly into colder temperatures. The Jefferson Lab weather station, too, has been updated to reflect the colder weather, with an update to its alert notifications. Gone is the Heat Stress Index, with the Wind Chill alert now in its place. The weather station issues Wind Chill (cold conditions) alerts electronically. This alert allows workers to take appropriate action for better clothing, gloves and head/ear protection.

If you haven't already taken a couple of minutes to prepare for winter working conditions, make the effort now to brush up on cold stress indicators by reading the ES&H Safety Manual Chapter 6670 Heat and Cold Stress Mitigation Program. Remember that a person's medications and overall health may make them more susceptible to the effects of the colder temperatures. If an employee appears to be adversely affected by the weather, get them inside a building or to Occupational Medicine.

Computing and Networking Infrastructure

IT Maintenance Day Set for Tuesday, Nov. 17, 5-8 p.m.
The IT Division is planning a maintenance period for Tuesday, Nov. 17, 5-8 p.m. During this period, Windows and Linux patches will be released to all Linux CNI-managed desktops and servers. All web servers and Linux login servers will be rebooted overnight Tuesday (between midnight and 7 a.m.) to finalize patch installations. Updates to core Common User Environment software, such as Firefox, Thunderbird and Java, will also be released. Plan on logging out of your desktop system when you leave on Tuesday, so that systems can be rebooted automatically to finalize patch installations. Otherwise, plan to reboot your Windows or Linux desktop no later than Friday, Nov. 20. If you have any questions or concerns about this maintenance period, contact the IT Division Helpdesk at, or x7155.


CEBAF Center's F Wing Closed on Saturday, Nov. 14, During Electrical Work
On Saturday, Utilities Infrastructure Modernization work being conducted by the contractor will temporarily disable the emergency lighting in the CEBAF Center F Wing – to include the elevator lighting and all emergency egress lighting. The F Wing will be closed to all normal work activities from 7 a.m. – 5 p.m. The contractor will conduct an electrical load bank test and relocate an emergency panel transformer. Facilities Management and Logistics Electrical Engineer Paul Powers will be at the lab while the work is taking place. Additional information is available on the Facilities Management Utilities Outage page at:

Jefferson Lab 2016 Holiday Calendar Posted
The Jefferson Lab schedule of holidays for 2016 has been posted to the Human Resources website. You may also view the 2015 calendar here.

Thanksgiving Buffet in the Quark Café
The annual Quark Café Thanksgiving Feast is set for Thursday, Nov. 19, 11:30 a.m.-1:30 p.m. This year's buffet will feature roast turkey with cornbread sage dressing, country style gravy, fresh orange-cranberry sauce, butternut squash risotto, carved prime rib of beef, Yukon gold garlic mashed potatoes, sweet potato casserole, green beans, green peas with mushrooms, dinner rolls and assorted pies. The buffet is $10.13 (plus tax) and includes a medium fountain drink. Buffet items will be available for a la carte purchase.

Order a Quark Cafe Dessert for Your Holiday Celebration
Quark Cafe staff is taking holiday dessert orders through Friday, Nov. 20. Orders may be made for the following types of pies: Southern Pecan, Sweet Potato, French Silk and Pumpkin. Pumpkin cheesecake is also available. Orders must be picked up on Tuesday or Wednesday, Nov. 24 or 25. Pick up Wednesday orders no later than 1:30 p.m. Order forms are available in the cafeteria.

Applications Due for Summer Student Internships at Jefferson Lab
Undergraduate students majoring in math, science or engineering may now apply for a Department of Energy summer internship at Jefferson Lab or any of the other 16 national laboratories via the Science Undergraduate Laboratory Internship program. SULI is a ten-week summer internship program that provides a $500 weekly stipend and housing at the SURA Residence Facility for students that live more than 60 miles away from Jefferson Lab. Undergraduate sophomores, juniors and seniors are eligible to apply (a student must have completed one full year at a college before he or she can apply). The application deadline for the program is Jan. 8, 2016. For more information and for the application, visit the SULI website. If you have any questions about SULI at Jefferson Lab, contact Lisa Surles-Law or Jan Tyler.

Inventors & Entrepreneurs: Sign up Now for START! Peninsula 4.0 Event Nov. 13-15
If you have a business idea or invention and need funding or guidance to get it off the ground, you may want to attend the START! Peninsula 4.0 event Nov. 13-15 at the Applied Research Center (ARC) building adjacent to Jefferson Lab. The event will bring together dozens of passionate entrepreneurs who will have the chance to pitch their best ideas and compete to win up to $7,500 in initial start-up funding, as well as many other support services donated by sponsors, to get their ideas off the drawing board and into the marketplace.See the linked flyer or visit the START! Peninsula webpage for more information.
See other announcements that may be of interest to Jefferson Lab staff and users on the We Hear That webpage.

Jefferson Lab Calendar of Events

Nov. 16-17: Q-weak Collaboration Meeting
Nov. 26-27: Thanksgiving holiday; Lab closed

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.