Jefferson Lab Weekly Briefs
January 13, 2010
12 GeV Upgrade
Testing of the first article beamline quads was completed and the vendor was approved to proceed with full production. The final step of the superconducting radiofrequency cavity contract was awarded; this phase of the work encompasses the first chemical processing and the rough frequency tuning. The contract for the cryomodule end cans was awarded in December as were the contracts for the rf system’s waveguide circulators and the beam transport corrector magnets. Installation work for 12 GeV began during the holiday machine shutdown with replacement of the baseplates for the cryomodule stands and removal of the stones in the penetrations where the rf waveguides for the new cryomodules will be installed.
In Hall A, experiment E08-011, Parity Violation in Deep Inelastic Scattering, was completed before the shutdown, accumulating close to 80 percent of the scheduled production data. After the break, the installation of the PREX experiment E06-002, measuring the neutron radius in 208Pb to 1 percent, has been initiated. This is a major installation, involving the installation of a pair of room-temperature septum magnets and the upgrade of both beam polarimeters, the Compton and the Moeller. Due to a shortage of technical manpower it is unlikely, but not impossible, that the installation will be completed on schedule.
In Hall B, the eg6 run group, which serves two experiments running in parallel, was completed with about 75 percent of the scheduled run time used for data taking. The novel Radial Time Projection Chamber overall worked well. The preparation for the upcoming g9-FROST run is underway. Many components of the polarized target have been moved to the hall. The construction of the HDIce Lab is now in its final stretch. After a more than three-months delay in construction, occupancy is now planned for Jan. 25. The Experimental Equipment Lab class 10,000 cleanroom has been refurbished and components needed for the CLAS12 drift chamber construction are being moved in. The CLAS12 solenoid magnet had its Specification Requirements Review (SRR) Jan. 5, with nine participants from Wang NMR Inc. and six participants from the JLab side.
JSA/JLab Graduate Fellowship Program
JSA/JLab Sabbatical Support Program
The first week of the Scheduled Accelerator Down was a busy one. Work began on removing the old dump and much shielding from the north stub dump tunnel. Progress continued on the injector two-Wien filter spin flipper project. Investigation of the vacuum at 1L06 showed the vacuum deteriorating despite additional pumping capacity. More troubleshooting is required. Preparations were begun in anticipation of removing Cryomodule SL-21 and installing it in the FEL. Dominion Power completed its capacitor bank preventive maintenance; a power surge when the bank was switched back online is being investigated. A large volume of maintenance and upgrade work is going on in many systems around the site as is usual during a SAD.
The FEL team has received the chamber for the new inverted FEL gun. Preparation is underway for the installation of a new cryomodule in zone 3 on Jan 14.
In a recent paper <arXiv:0909.1356 [nucl-th]>, to appear in Physical Review Letters, the Excited Baryon Analysis Center (EBAC) has reported that all nucleon resonances evolve from a quark-gluon core through its coupling with reaction channels. Their most striking finding is that the two lowest P11 nucleon resonances, the Roper N*(1440) and N*(1710), originate from a single bare state. This advance has an important implication in understanding how nucleon resonances arise in QCD, the fundemental theory of strong interactions.
Environment, Safety, Health & Quality
At JLab, protecting the public, workers and the environment is a priority whenever activities are planned and performed. As such, assurance and safety are intertwined in all laboratory activities.
The Quality Assurance and Continuous Improvement department manages the assurance program, which ensures JLab meets the criteria contained in DOE Order 414.1C, Quality Assurance. A new procedure describes the process by which JLab responds to program and performance issues. The Issues Management Procedure document describes how issues are identified, recurrence is prevented and issues are closed. It is located on the QACI webpage under Quality Programs.
Computing and Networking Infrastructure
IT Helpdesk Hours
Main Phone Number for SURA Residence Facility is 757-223-1167
Red Cross Blood Drive at JLab Jan. 22
Volunteers Needed for 2010 Science Bowls
Puppy Obedience Training at JLab
JLab Open House Set for May 1
JLab's Safety Numbers
55 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
Jan. 18: Martin Luther King, Jr. Day holiday - JLab closed