Jefferson Lab Weekly Briefs July 23, 2008

Jefferson Lab Weekly Briefs

July 23, 2008


The removal of the G0 superconducting magnet from Hall C has begun. The magnet has been moved from its stand and is being rotated about its axis, so that it can fit through the hall access ramp. Testing of the restored High Momentum Spectrometer focal plane detector stack is proceeding well. All phototube signals from the hodoscopes, Cerenkov and shower counter detectors have been verified to reach the counting house.


The major event during this reporting period was the failure of site transformer LN1. Repairs are estimated to take at least four weeks. Accelerator Personnel Safety System (PSS) certification began. All eight ceramic windows on cryomodule SL09 were replaced. The repair of the tuners of cryomodule NL04 are well underway. The DC Power group reports that the scheduled overhaul of all box supplies has made significant progress.

Free-Electron Laser (FEL)

The FEL team has continued to make significant strides both in installation of the UV/amplifier line and of the turning mirror cassettes for the IR beam transport, two out of three of which are now mounted on ceiling fixtures. Installation of sextupoles in the IR transport restarted this week following re-qualification of the lifting systems.


The Safety System Group completed preliminary semi-annual certification of CEBAF accelerator and end stations. Final certification is pending completion of maintenance on several high-voltage power supplies. The SSG also completed preliminary and final certification of the FEL PSS. The Instrumentation and Controls group (I&C) is continuing the conversion project of CAMAC to VME (Computer Automated Measurement And Control serial buses to VERSA-module Europe serial buses) in building W5. For the BPM (beam position monitor) system conversion for W5, documentation is complete, the hardware is installed, and work continues on the software. I&C also reports that the FEL viewer assembly is progressing well.

JLab's Safety Numbers

282 Days since Last Recordable Accident (JLab record: 319)
627 Days since Last Lost Workday Accident (JLab record: 627)




Environment, Safety, Health & Quality

At Jefferson Lab portable electric generators offer great benefits when power outages affect the lab or when temporary power is needed. But generators can pose serious health and safety hazards if they are not used properly. Below are some guidelines for safely operating portable generators at work and at home:

  • Use only in a well-ventilated area.
  • Use a heavy duty, grounded extension cord when plugging utilization equipment into the generator.
  • Use a ground fault circuit interrupter (GFCI) to help prevent electrocutions and electrical shock injuries.
  • Have electrical connections to a generator installed by a qualified electrical worker.

More information on generator safety can be found on the Electrical Safety Foundation International (ESFI) website.

Safety Notice: Wildlife Onsite
A fox and groundhog were sighted inside the accelerator fence, apparently squared off for a fight. It is unusual to see foxes out in daylight. Wild foxes are potential rabies carriers, and there have been several cases of rabid foxes and badgers in our area. Please remain clear of wildlife at JLab and report any unusual wild animal activity to Facilities Logistics and Management at x7400. For more information on the types of critters seen onsite and the potential safety issues they entail, read this OnTarget newsletter article.


JLab Colloquium and Public Lecture: Sustainable Energy
George Crabtree, Argonne National Laboratory, will discuss how the global dependence on fossil fuel is among the greatest challenges facing our economic, social and political future in a colloquium set for 4 p.m. on Aug. 6. The full abstract is available on the Events Calendar.

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JLab Calendar of Events

July 22-24: DOE Office of Science OPA Independent Project Review of the 12 GeV CEBAF Upgrade Project
July 22-25: Thin Film - Superconducting Radiofrequency Technology Workshop
July 30: American Red Cross Blood Drive
August 6: Colloquium: The Sustainable Energy Challenge
August 12-14: DOE Accelerator Safety Workshop
August 17-19: Lead Radius Experiment (PREX) Workshop
Sept. 1: Labor Day holiday: JLab closed



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