Jefferson Lab Weekly Briefs April 23, 2008
Jefferson Lab Weekly Briefs
April 23, 2008
12 GeV Upgrade
A review of the planned Silicon Vertex Tracker (SVT) Detector for the Hall B CLAS12 spectrometer was held on April 2. Since this is a new detector technique for JLab, three outside experts on the design, construction and operation of these detectors and associated electronics formed the review committee. The Hall B team of scientists and engineers received very valuable technical input and three recommendations for further work. On April 15-17, a design and safety review of the seven superconducting magnets planned for the Halls B and C spectrometers was held. Key collaborators from Michigan State University (Hall C) and from the Efremov Institute (Hall B) attended the review to present their work alongside the JLab team. The review committee gave very high marks for the significant progress since the 2006 magnet review, and lively technical discussions provided valuable feedback to fold into further work to complete the reference designs of these magnets.
In Hall C, E04-108, the measurement of GEp/GMp continues to take data at its highest Q2 point of 8.8 (GeV/c)2. At the beginning of April, tests of the detectors to be used for SANE (Spin Asymmetries on the Nucleon Experiment) were made under beam conditions similar to those expected for the experiment. Portions of all three SANE detectors (Fiber tracker, Gas Cerenkov and Lucite hodoscope) were instrumented and placed in front of BigCal to make a first test of BETA, the Big Electron Telescope Array. The SANE experiment is scheduled to run this October.
The accelerator is settling in well for the current scheduled run to the halls. Total beam hours distributed between the three experimental halls increased to 343 hours for this reporting period. The increase in accelerator beam delivery hours is a reflection of the well-managed effort being put forth to optimize the RF. Also many thanks go to expert and timely support from numerous staff members of various equipment maintenance groups.
Free-Electron Laser (FEL)
The gun test stand (GTS) effort began the long task of fully characterizing the performance at high charge and comparing it with theory. The first of such studies involved verification of the temporal behavior of the drive laser pulse.
Location Change for Ultimate Frisbee at JLab
Safety Shoe Truck Fills Approved Orders Thursday, April 24
Environment, Safety, Health & Quality
Lightning can occur at any time of the year, but it's much more frequent during the warmer months. Here are some simple tips from the National Lightning Safety Institute for lightning safety:
More lightning and other severe weather safety information is available in Chapter 3510-T4, Severe Weather Procedures in the JLab EH&S Manual.
DOE Five-Wheeled Dolly Use Lesson Learned
The lift levelers slight downward curve to the truck bed caused two of the five dolly wheels to lose contact with the surface, creating instability that contributed to the event. Workers indicated that once the dolly wheel caught in the gap, the container slid within the dolly ring prior to tipping over. The event evaluation concluded that the geometry of the truck and the dock lift leveler was the major factor in this event. Event lessons learned included:
Computing and Networking Infrastructure (CNI)
Attention JLab Wireless Network Users
JLab's Safety Numbers
217 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
April 24: Safety Shoe Truck onsite