Jefferson Lab Weekly Briefs
May 25, 2011
12 GeV Upgrade
The 12 GeV accelerator installation activities are underway. An initial survey of the beamline elements is almost complete; the information will be used as the basis for returning these elements to their present positions following removal and rework. Assembly of the first 12 GeV cryomodule is nearing completion; assembly of the second cavity string into a cryomodule is well along. Onsite powered testing of production klystrons has begun. Preparations are underway for preliminary measurements of in-tunnel characteristics of an R-100 and a C-100 cryomodule during the coming weeks.
Stacking of lead sheets and scintillator bars threaded with wavelength-shifting fibers has started for the first sector of the pre-shower calorimeter (PCAL) for CLAS12. The second Region 2 wire chamber sector is nearing completion at Old Dominion University, the first Region 1 sector is being strung at JLab, and cleanroom preparations for the remaining Region 1 sectors is underway at Idaho State University. The first assembled bars of the forward time-of-flight 1-b are assembled and undergoing testing at the University of South Carolina. The first mirror for the high threshold Cerenkov counter is being assembled. The new JLab cleanroom for the silicon vertex tracker (SVT) is complete and being equipped, and the notice to proceed was given to the vendor to produce the first items of the three different sensor types that will be used to form the stave modules for the SVT barrel region.
Hall A is in a de-installation phase. The work has just begun, but it's going well and is on track.
As planned, the activity level has been high on the accelerator site during the first full week of the six-month accelerator shutdown. The low-conductivity water system that supplies purified water to magnet and radiofrequency systems was turned off, and contractors started upgrading the 20-year-old system. The accelerator northeast stub dump area was de-posted from a Radiologically Controlled Area (RCA) to a Radioactive Materials Area (RMA), and civil contractors started to tie in the Hall D tunnel.
Saturday’s scheduled 40 Megavolt-Ampere (MVA) power outage occurred with minimal impact to critical accelerator systems and without loss of any accelerator or Central Helium Liquefier control networks. The 500 Kilovolt-Ampere (KVA) generator was pre-started, and when the 40 MVA power was switched off, there was a seamless transition from 40 MVA line power to the Machine Control Center uninterruptible power supplies and then to the 500 KVA generator that provides emergency power to the MCC and critical systems.
Tunnel safety training resumed for new staff needing unescorted access to the accelerator tunnel. Also, the personal protective equipment requirement for the accelerator tunnel has been revised to indicate that tunnel workers must wear long pants.
Finally, Harry Fanning has been appointed as the Accelerator Division Safety Officer Deputy and will be leaving the Operations Group as of June 1. He will be the new safety contact for the accelerator site.
A Director's review was held of proposed vacuum ultraviolet pilot experiments at the FEL. The review addressed combustion dynamics by a group representing Sandia National Lab and Lawrence Livermore National Lab and krypton dating by a group representing Argonne National Lab and Old Dominion University. In addition, the FEL group was engaged with preparations for moving the gun test stand gun into the FEL.
The machine shop is in the process of modifying "H" steel for the three-meter magnets.
Additionally, the shop is reworking the C100 wave guide assemblies. This involves taking a skim cut on the stainless steel end to remove the indentation caused by the aluminum seal. This will allow the wave guides to be re-used without re-manufacturing. Since April 8, the shop has processed 195 job requests.
The alignment group has completed the as-found survey of the west arc magnets and approximately 90 percent of the east arc magnet survey. The installation/vacuum group has followed closely behind the survey crews and has begun the vacuum bleed down and removal of the west arc dipoles for refurbishment.
Environment, Safety, Health and Quality
Work Zone and Vehicle Safety
The same vehicle and pedestrian awareness should also be applied for the JLab site. Now that the six-month down has begun, there are many more automobiles and pedestrians onsite, including additional personnel working in and around the accelerator site buildings, summer students in areas across the site, and construction workers for the TEDF site. All of these additional work areas and people on JLab roads make it that much more critical to remain attentive while driving and walking onsite.
Stockroom Takes On Water
Book Swap Lunch Party Planned for Friday, May 27
One-Week Tax Holiday on Hurricane Supplies
Fire Academy Graduation Ceremony
Sign Up Your Kids for a Summer Physics Fest
Tracking Thomas at JLab
Congratulations to Russell Mammei, who was the first person to correctly identify the May 18 location. Honorable mentions go out to Stephen Smith, Mike Martin, Dick Owen, Jim Follkie, Kelly Tremblay, Tina Johnson, John Conger, David Fazenbaker and Jason Willoughby. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.
JLab Calendar of Events
May 30: Memorial Day holiday - JLab closed
JLab Summer 2011 Education Calendar
May 31- June 17: Hampton University Graduate Studies