Jefferson Lab Weekly Briefs February 19, 2014
Jefferson Lab Weekly Briefs
February 19, 2014
12 GeV Upgrade
The silicon photomultipliers for the Hall D Barrel Calorimeter (BCAL) have been mounted on the light guides. The final parts of the BCAL cooling system are being added in preparation for temperature stabilization tests. The BCAL light monitoring system, built by the University of Athens, is being exercised. Cables are being run to the electronics located in racks below the solenoid magnet. The lead-glass Forward Calorimeter (FCAL), which sits downstream of the BCAL, is having its readout electronics and light monitoring system tested.
The Forward Drift Chamber (FDC) has had its readout cabling added, and it has just had a successful trial insertion into the bore of the BCAL. Work has started to complete FDC electronics installation and then checkout with counter gas and high voltage. The Central Drift Chamber is having preamps added and is being tested section by section prior to being moved to Hall D next month.
One of the two planes of the Time-Of-Flight wall built by Florida State University has been assembled onto the support frame at Jefferson Lab. A source of thin diamond crystals has been found for use just upstream of the tagger magnet as radiators of the bremsstrahlung photons used in Hall D. The resulting scattered electrons from this radiator target will be detected in the tagger hodoscope and tagger microscope, which are being assembled by staff at The Catholic University of America and the University of Connecticut, respectively.
The tagger magnet has been tested and field-mapped at the planned operating field. 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 bundles of fibers use to transport trigger information and data variously between Hall D floor, counting house and online archiving are on order and being installed.
Jefferson Lab Published Journal Articles, Feb. 10 - 16
Remember to submit your papers for approval to the Jefferson Lab Publications database.
Apply Now for the JSA/JLab Graduate Fellowship Program
Center for Theoretical and Computational Physics
A new global analysis of electron-deuteron quasielastic (QE) scattering data has been performed using a formalism that was previously applied to deep-inelastic electron-deuteron scattering. The analysis studied the dependence of the QE cross sections on the deuteron wave function and the off-shell extrapolation of the elastic electron-nucleon cross sections, which show particular sensitivity at large values of the Bjorken-x variable. The excellent overall agreement with data over a large range of energies and scattering angles suggests a limited need for effects beyond the impulse approximation, with the possible exception of the very high-x or very low-energy regions, where short-distance effects or scattering from non-nucleonic constituents in the deuteron may become more relevant.
JLab Calendar of Events
Feb. 20-22: GlueX Collaboration Meeting
Environment, Safety, Health and Quality
Remember, the safest place during a tornado is typically a building's basement away from any windows. If there is no basement, go to a windowless interior room such as a closet, bathroom or interior hall on the lowest level of the building. Here at Jefferson Lab, ES&H Manual Chapter 3510 Appendix T3 Tornado Response Procedure describes the appropriate steps to take if you should hear the lab's tornado siren or receive an alert on your pager, VOIP phone or email. If you aren't familiar with the severe wind "take cover" areas in buildings you frequently enter, take a moment to look over the building evacuation maps here or posted in those buildings.
Computing and Networking Infrastructure
Computer User Audit Is Underway
A Cookie for Your Thoughts!
2014 Annual T-Shirt Design Contest Is Underway
Mark Your Calendar: Jefferson Lab to Host Open House on May 17
Jefferson Lab Benefits Open Enrollment Is Underway
Help Keep CEBAF Clean
Jefferson Lab Golf League Forming for Season - Sign Up Now
TIAA-CREF Individual Counseling Available by Appointment
Tracking Thomas at Jefferson Lab
Pashupati Dhakal correctly guessed the location for Feb. 12. Honorable mentions go to Harry Fanning and Ryan Bodenstein. 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.|