Jefferson Lab Weekly Briefs September 28, 2011

Jefferson Lab Weekly Briefs
September 28, 2011

12 GeV Upgrade

Civil construction had two highlights last week. First, on the Hall D construction site, the last exterior concrete pour for the tunnel connection was completed on Friday morning, just ahead of the rain. The construction contractor has revised the sequence of activities to allow interior and exterior work to be performed in parallel to recover some weather-related schedule delays. Second, the upgraded low conductivity water systems in the South Access building for the east arc magnets and the south linac radiofrequency zones were commissioned on Thursday. The punchlist items are being addressed and the systems are scheduled for turnover to operations this week. At the North Access building, water is being circulated through the upgraded LCW systems. The west arc magnet and the north linac RF zones will be brought online starting this week, with commissioning to follow.


The Polarized Electrons for Polarized Positrons experiment alignment has been performed and fabrication of the forms around the stand bases has been completed; staffers continued pulling cables to the new rack and performing detector tests. The old 500 KeV Mott line has been decommissioned, and a new Mott ladder was installed and tested. Lead and poly shielding bricks around the 0L07 dump that were previously removed have been re-stacked, and the repaired 0L07 magnet power supply was returned to service. Additional concrete block shield walls were installed behind the dump for injector beam testing next month. Arc 10 survey and alignment was completed. Installation of interlock cables for 2L22 and 2L23 was completed. During the day, 2L24 low-level RF testing continues with signal checking, control system response tests and software corrections; at night, 2L24 cable calibration and correction continued, along with loop gains and overall system optimizations. On 2L25, the prototype solenoid power supply cable was replaced and klystrons 2, 6, 7 and 8 were retested. Work continued on the Hall D communication trench; the main trench box was installed, along with the concrete block covers, and work on the junction box began.

Free-Electron Laser

The FEL team determined that the gun cathode was unusable due to lack of quantum efficiency, despite several tries at cesiation; the solution is to open up and replace the cathode with a new one. At the same time, the team will address discharge issues that have limited the operating voltage. The new ultraviolet wiggler was set in the pit, wired up and is being surveyed into position. Lastly, the team is performing a warmup to room temperature of the FL03 cryomodule to drive off condensed gas, which limited the achievable gradient in at least one of the cavities.

Center for Theoretical and Computational Physics

Quark confinement is believed to control the structure and dynamics of hadrons. This, in turn, depends on the long-range behavior of the gluons (and ghosts) that bind quarks together. A new Theory Center paper discusses the limitations of present strong coupling QCD calculations in determining this long-range behavior and how a better understanding of the ghost-gluon interactions is required to make predictions robust.


The Machine Shop is presently manufacturing:

  • components for the first of three SPX cryomodule cavity assemblies, "CRM crab cavities for Argonne"
  • 12 GeV Upgrade pole-lengthening shims for the XA thru XZ dipole magnets
  • accelerator injector positron spectrometer vacuum chamber

The shop has processed 171 job requests since Aug. 15.

JLab Calendar of Events

Oct. 3: Safety Shoe vendor onsite
Oct. 4: American Red Cross Blood Drive
Oct. 7: United Way Kickoff Picnic at Quark Cafe
Oct. 18-20: DOE Project Review of the 12 GeV Upgrade
Oct. 19: Colloquium and Public Lecture, 4 p.m., CC auditorium
Oct 24: Safety Shoe vendor onsite
Oct. 25: Science Series public lecture
Nov. 6: Daylight Saving Time ends
Nov. 24-25: Thanksgiving holiday; JLab closed

Environment, Safety, Health and Quality

According to the National Safety Council, there is an injury on the job every nine seconds, and there is a death on the job every 112 minutes. It is vital to the safety and wellbeing of ourselves and our co-workers that we at JLab not contribute to this statistic.

JLab's Integrated Safety Management System features practices and policies designed to keep us and our co-workers safe, and it should always be used in the planning and execution of work. ISMS includes steps for:

  • Defining the Scope of Work
  • Analyzing the Hazards
  • Developing and Implementing Hazard Controls
  • Performing Work Within Controls
  • Providing Feedback and Continuous Improvement

For more information about JLab's ISMS and impementing the procedure in your work, see ES&H Manual 3210 Appendix T1.


Partial Closure of CEBAF Center Circle, Sept. 29-30
There will be a partial closure of the CEBAF Center Circle on the South Connector Road (in front of CEBAF Center) this Thursday and Friday as contractors repave a section of the Circle/Connector Road. Traffic cones and flag operators will direct traffic.

Test Lab Area Access Restricted During Exterior Painting
Beginning Monday, Oct. 3, areas around the Test Lab (Bldg. 58) will be blocked off temporarily while the contractor spray paints the exterior. Areas that will be impacted intermittently during the project include BCS Drive, Hadron Drive, the Test Lab north parking lot (adjacent to Bldgs. 34D and 34E), around the CTF (Bldg. 57), and the south end of the EEL parking lot (Bldg. 90). These areas will be blocked off as needed to protect people and property from paint overspray. Hadron Drive will remain open; follow traffic cones and posted detour signage or flag operators. The work could take weeks to complete, as weather permits. This multi-step project includes cleaning and caulking joints, spraying a primer coat over the entire building, and then spraying a finishing coat.

Blood Drive Set for Next Week
The next American Red Cross Blood Drive is scheduled for Tuesday, Oct. 4, 10 a.m.- 4 p.m. in CEBAF Center, Room F113. New and repeat donors are encouraged to attend. Appointments and walk-ins are welcome. To schedule an appointment, contact Johnie Banks, x7539.

Flu Vaccinations Available
Occupational Medicine is now taking appointments for Influenza vaccinations. If you would like to be vaccinated, contact Occupational Medicine at x7539 to schedule an appointment. Keep in mind that for 15 minutes after vaccination, you should remain at JLab in the presence of other people and avoid safety-sensitive activities, including driving.

Robotics Team Needs a Coach
The FIRST (For Inspiration and Recognition of Science and Technology) organization stages robotic competitions among teams of students from Kindergarten to Grade 12. Warwick High School has some students interested in this activity, and they are looking for a coach for the team. Coaches help to motivate youngsters into pursuing a college degree in the scientific and engineering fields; a technical background is not required. For more information, visit the FIRST website.

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 Fridays.

Congratulations this week go to Dave Fazenbaker, Jason Willoughby, Doug Higinbotham and Narciso Gomez, who were the first to correctly identify the Sept. 21 location. Honorable mentions go to Tonya Evans, Zhe Vick Chen, Michelle Shinn, David Anthony, Andy Kowalski, Stephen Smith, Dick Owen and Cindy Eller. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.