Jefferson Lab Weekly Briefs
April 22, 2009
12 GeV Upgrade
Responses to the request for Best-and-Final Offers (BAFOs) for the fabrication of the superconducting radiofrequency cavities have been received and evaluation has begun. Evaluation of the BAFOs for the 4-meter dipole magnet fabrication have been completed. The award package for the klystrons has been reviewed and approved by DOE. Final review of the design and number of new quadrupole magnets for the accelerator beam transport system has been completed. The Request for Proposals (RFP) has been issued for the cryomodule space frames. Finally, the award package for the purchase of cryomodule waveguides is under review by DOE.
In Hall A, the BigBite spectrometer was successfully moved to backwards of the right High Resolution Spectrometer in preparation for the three upcoming polarized helium-3 experiments, E05-015, A Measurement of the Quasi-elastic Single Spin Asymmetry, E08-005, Measuring the Transverse Asymmetry in the 3He(e,e'n) Reaction and E05-102, Measuring the Transverse Asymmetries in the 3He(e,e'd) Reaction. The laser for the Compton polarimeter was exchanged for a version with double the power, and the power supplies of the Q1 and Q3 magnets of the right HRS were repaired. The replacement of one of the vertical drift chambers in the right HRS has been completed.
Hall B is on track with preparations for the upcoming eg1-dvcs (II) run period.
Installation work continues in Hall C for the hypernuclear experiment, E05-115. The raised concrete floor has been completely poured. The High Resolution Kaon Spectrometer and High Resolution Electron Spectrometer (HES) have been moved to approximate positions, and a wall of the HES bunker has been assembled.
The scheduled accelerator down was transitioned to the beam restoration period on Friday, April 17. Over the weekend, Operations personnel restored 5.90 GeV, 5-pass beam and then scaled the accelerator to 5.968 GeV. Continuous wave beam (15uA) was successfully delivered to the beam switchyard beam dump by Sunday. All the magnets, radiofrequency and other sub-systems have been performing well.
Free-Electron Laser (FEL)
The FEL group made progress in providing active stabilization of the resonator mirrors while the low-conductivity water piping is being worked. Staffers are also trying to identify possible sources of arcing in the high-voltage power supply. The group is on track to resume operations on May 18.
With the hadronic parameters constrained by the world data of π N reactions, a recent paper <arXiv:0904.1918 [nucl-th]> from the Excited Baryon Analysis Center demonstrates how the pion electroproduction data from the CEBAF Large Acceptance Spectrometer can be used to extract the electromagnetic structure of nucleon resonances. This advance paves the way for extracting nucleon resonance parameters by performing a dynamical coupled-channel analysis of one-pion and two-pion production data from CLAS.
JLab's Safety Numbers
107 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
April 22: Earth Day
Environment, Safety, Health & Quality
JLab’s Environmental Management System (EMS) will undergo an audit April 27-30, conducted by a joint team from Oak Ridge and the Thomas Jefferson Site Office. Personnel from multiple areas of the lab will be interviewed during this assessment.
Certain elements of JLab activities, products or services interact with the environment, including light bulbs, coolants and other fluids generated during the course of our normal activities. Significant environmental aspects of these activities are those that have been identified as having the possibility of a large impact. Examples of significant aspects are wastewater discharge and normal energy use. JLab's EMS helps us to minimize environmental impacts from lab activities, processes and services. Under the EMS, everyone has a role. Some ways you can help with JLab's EMS effort are:
ESH&Q will continue to provide EMS briefings to specific organizations and individuals involved with significant aspects. If you have any questions, call Linda Even at x7308, Gina Dixon at x7417, or your organization’s EMS Committee member. For more information, see the related posting in Spotlight news on Insight.
Computing and Networking Infrastructure
Computer User Audit
Change the World, Start With Energy Star
Department of Energy Promotes Special Earth Week Feature on Energy.gov
National Instruments Mobile Expo to Visit JLab
2009 Jefferson Activities Group Run-A-Round Set for May 20