Jefferson Lab Weekly Briefs
November 27, 2013
12 GeV Upgrade
The Hall D Barrel Calorimeter (BCAL) has been inserted into the solenoid magnet bore. The silicon photomultipliers that sense the light generated in BCAL have been mounted on the light guides, the light monitoring system built by the University of Athens has been added, and the electronics cabling and cooling piping added. The lead-glass Forward Calorimeter, which sits downstream of BCAL, has had its readout electronics added and its light-monitoring system installed, and it is being powered and tested. The Central Drift Chamber (CDC) has arrived at Jefferson Lab after having been constructed and receiving a full checkout at Carnegie Mellon University. It has been uncrated and tested, showing that no wires came loose during the trip. The Forward Drift Chamber has been assembled, moved to Hall D, surveyed, and is being prepared for installation by addition of its readout cabling. Florida State University has completed assembly of the time-of-flight wall to be located just upstream of the lead-glass calorimeter, and it has been delivered to Jefferson Lab. Preparation has started of the thinned diamonds that will serve as the bremsstrahlung target; scattered electrons from this target will be detected in the tagger hodoscope and tagger microscope, which in turn are being assembled by Catholic University and University of Connecticut staff, respectively. Installation of front-end electronics, data acquisition electronics, online computers and trigger electronics to render all the above equipment ‘live’ is proceeding apace, as is installation of needed infrastructure, such as cable race, racks, power transformers and distribution, chilled water distribution, and the gas distribution system. The tagger magnet is being readied for field mapping, as is the magnets for the pair spectrometer.
Jefferson Lab Published Articles, Nov. 18-22
Remember to submit your papers for approval to the Jefferson Lab Publications database. The next Publications Refresher Course will take place Monday, Dec. 9 at 9 a.m. in CEBAF Center room F226. To attend, R.S.V.P. to Kim Kindrew.
Center for Theoretical and Computational Physics
A new paper explores the role of final-state interactions (FSI) in inclusive deep-inelastic scattering from the deuteron, which give corrections to the usual approximation in which the beam scatters incoherently from the bound nucleons. Sizable FSI contributions are found for parton momentum fractions x > 0.6 and momentum transfer Q2 < 10 GeV2, increasing in magnitude for lower Q2, but vanishing in the high-energy limit due to phase space constraints. The results will be used to provide more reliable calculations of electron-deuteron scattering cross sections at Jefferson Lab energies.
The Installation and Vacuum groups continue to wrap up their work on the accelerator ring portion of the 12 GeV upgrade and are getting ready for Accelerator Run 1. Accelerator ring vacuum leak checking and pump down are nearing completion. Low-conductivity water system plumbing installation has been completed in the transport recombiner and continues in the line D tunnel ramp. Penetrations have been filled back up with stone and sealed. The 4D (123 MeV) spectrometer dump final shielding is in place. The Hall D Tagger shield wall final steel and fire stop is complete. The last beam switchyard (BSY) dipoles and girders have been installed, and the LCW has been connected. Beamline supports have been added in the 2E and transport recombiner. The Vacuum group hot check out process is well underway and will continue to support the first machine run.
The group also supported Hall A window dump inspection, electrical panel installation in the injector service building, removing material from the injector hatch, relocating liquid nitrogen lines in the BSY service building, installing lift plates for Hall B crane repair, removing two YB magnets for repair, and equipment removal and cleanup of the accelerator tunnel.
JLab Calendar of Events
Nov. 28-29: Thanksgiving Holiday, Lab closed
Environment, Safety, Health and Quality
Cold Weather Tire Care
While you're checking the pressure, it's also a good time to check your tires' tread depth. Tires should have at least 1/16 of an inch of tread. While Hampton Roads may not get snow very often, we do get heavy rain, and thin tread can contribute to an increased risk of hydroplaning. If you don't have a tire depth gauge, you can use a Lincoln penny. Take the penny and insert it head first into several grooves on the tire. If part of Lincoln's head is covered by the tread, then you have more than 1/16 of an inch. However, if you can see above Lincoln's head, you have less than that and should consider getting new tires very soon.
Computing and Networking Infrastructure
Voicemail Outage Scheduled for Dec. 3
Difficulty Accessing Hazard Comm. Training?
Sentara Mobile Mammography
Open Enrollment for Jefferson Lab's 401k Scheduled
All elections will be reflected in the Jan. 15, 2014 paycheck. Human Resources will provide web-based enrollment for your convenience, beginning Dec. 3. To access the 401(k) GSRA enrollment link, see the Spotlight News section of the lab's Insight page.
JSA Initiatives Fund Program Call for Proposals Issued
2014 General Access RWP Is Available
JAG Holiday Party for Jefferson Lab Children and the Young at Heart
Volunteers Needed to Help With the Holiday Party
Toys for Tots Toy Drive
Ready, Set, Hang Those Decorations
Tracking Thomas at Jefferson Lab
Samika Hawkins correctly guessed the location for Nov. 20. Honorable mentions go to Chris Wicker, April Sessoms, Dick Owen and Anna Shabalina. Check out Tracking Thomas on flickr for a better view of his last location and this week's new mystery photo.
|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.|