Jefferson Lab Weekly Briefs February 25, 2009
Jefferson Lab Weekly Briefs
February 25, 2009
12 GeV Upgrade
The request for Best-and-Final Offers (BAFO) for the klystron fabrication contract has been issued. Discussions are underway with the potential vendors for the new quadrupoles and four-meter dipoles to be used for electron beam transport. Discussions are also underway with the potential vendors for the 4 Kelvin coldbox for the 12 GeV cryogenics plant. The Request-for-Information was issued for the large magnet power supplies for upgrading the electron beam transport system; responses have been positive. An engineering test unit for the 70 Amp power supply was evaluated and found to meet the performance requirements; units like this one will be used to power septa in the electron beam extraction system.
In Hall A, experiment E06-014, Precision Measurements of the Neutron d2: Towards the Electric and Magnetic Color Polarizabilities, continues to take production data and is on schedule.
Hall B continues to run the eg1-dvcs run group using a 5.9 GeV longitudinally polarized electron beam and a dynamically polarized ammonia target. The ammonia target uses a 5 Tesla superconducting Helmholtz coil as a polarizing magnet. The experiment is currently in production data taking and enjoying good quality beam and a well-performing polarized target with polarization of the free hydrogen in the ammonia molecule of 70-80 percent. Data taking alternates between positive and negative target polarizations and with unpolarized carbon as a target.
The Spin Asymmetries of the Nucleon (SANE) experiment has been running smoothly in Hall C. It is expected that about 70 percent of the proposal statistics will be obtained for the five-pass transversely polarized target configuration. The experiment plans to return to the pass transverse configuration to improve statistics and then complete the run with the target polarized parallel to the beam. A readiness review for the upcoming Hall C hypernuclear experiment (E05-115) was conducted. The review raised no issues, but it raised a number of concerns that will be helpful to the collaboration, Hall C and the laboratory to successfully mount the experiment.
The accelerator performed reasonably well, with a continued low trip rate. Six hours were spent on Tuesday, Feb. 17, for beam studies and replacing one of the Hall A Moller power supplies. On Sunday, the injector dropped to restricted access and Ops was able to bring it back to beam permit. A few hours were spent on Monday to recover some radiofrequency cavities. Hall A was changed from pass 5 to pass 4. The Wien angle was changed to optimize the beam polarization for Halls B and C.
Free-Electron Laser (FEL)
This week, FEL staffers operated the machine with a longer pulse width and saw dramatically improved machine performance. Initial analysis of horizontal phase space tomography was also completed. The reconstructed phase space agrees well with simulations, and the extracted beam emittance agrees with measurements taken via a quadrupole scan. This work has been on our "should" list for a long time and provides important anchoring and confirmation of the validity of our simulations.
In a big step toward the ultimate aim of computing GlueX hybrid photoproduction rates, JLab lattice QCD group members have developed methods to extract photon current matrix elements between excited and exotic hadron states. These new techniques have been tested in the heavy-quark charmonium system, where they successfully reproduce a number of experimental radiative transition rates. The first QCD calculation (arXiv:0902.2241) of the exotic transition 1-+ to 1--γ indicates a large rate, one that if duplicated in the light-quark sector would signal copious production of exotics in GlueX.
JLab's Safety Numbers
51 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
March 7: Virginia Regional Middle School Science Bowl
Environment, Safety, Health & Quality
A cross-functional team met to conduct causal analyses on eight P-2 findings from a recent DOE Fall Protection Surveillance Assessment. P-2 is a finding that represents nonconformances, deviations and/or deficiencies in the implementation of requirements, procedures, standards and/or regulatory requirements. These fall protection findings dealt with various aspects of JLab's program, including scaffolding, ladders and chains, as well as how the items are managed and maintained. Causal analyses will be developed into actionable items to be included with the overall Corrective Action Plan being submitted by Facilities Management and Logistics.
Progress continues on corrective actions associated with the 2008 Health Safety and Security assessment. Five of the 32 corrective actions approved by DOE have been closed out thus far, including submission of the overall Corrective Action Plan and an ESH&Q Communications Benchmark Study. These items are being reviewed with the Thomas Jefferson Site Office in regularly scheduled meetings.
Upcoming assessments in March include Halls A and B Formality of Operations, which deals with Integrated Safety Management implementation in these specific areas, and Radiological Material Inventory. The Site Office will conduct these assessments; the JLab administrative contact is Bob Doane.
Computing and Networking Infrastructure (CNI)
E-mail Outage and Reconfiguration, Friday, March 20, 10 p.m. Through 3 p.m., Saturday, March 21
The location of e-mail folders is being changed. Currently, JLab account holders have e-mail folders that are stored in their home directories (/home/user on Unix or J: drive on Windows). The reconfiguration will move these folders out of account holders' home directories and place them on a standalone, isolated file system. Account holders will not have direct access to this new file system. All access to these folders will require an IMAP mail client (i.e. Thunderbird, Pine configured as an IMAP client, etc). Further information about this reconfiguration will be available on the CNI group web page as the date approaches.
Windows Common User Environment (CUE) Software Refresh
If you miss the advertisement and would like to install the software before the next maintenance day, you can go to the Control Panel->Add or Remove Programs->Add New Programs and select the updated packages. If you have any questions about installing the new software, you can contact the helpdesk at x7155 or firstname.lastname@example.org.
2009 Benefits Open Enrollment Is Underway
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