Jefferson Lab Weekly Briefs
February 27, 2008
In Hall A, installation work for the next experiment, E04-007 (Pi-Zero Electroproduction near Threshold), is progressing on schedule. Both the BigBite magnet and the associated detector system are in the hall and are being assembled.
Hall B completed the g9-FROST run, a search for new excited nucleon states. The run was carried out with a longitudinally polarized target and linearly as well as circularly polarized photons. At the end of the run, the transverse holding coil was installed in the Frozen Spin Target (FROST), and, for the first time, the longitudinal polarization was transferred adiabatically to a transverse polarization by ramping up the transverse holding saddle coil and simultaneously de-energizing the solenoid coil. The degree of polarization was fully preserved during this process. This configuration of FROST will be used in the next g9 run.
The Scheduled Accelerator Down (SAD) continued in full force during the past week. Some notable points of the work performed include the following areas:
Free-Electron Laser (FEL)
The FEL gun is in processing and evolving surface gas. It is expected to reach its operating voltage late this week. The drive laser is being set up for operation of the Gun Test Stand (GTS). The FEL has an approved Laser Safety Operations Procedure for the GTS. FEL staff members have also been working on the ultraviolet beamline layout and are about 75 percent done with magnet and diagnostic locations, so assembly and installation can proceed when the money arrives from the Air Force Research Laboratory.
Photoproduction of pion and omega meson reactions studied in all JLab experimental halls is a powerful probe of the resonance structure of the nucleon. A simultaneous description of these reactions has been made in a dynamical coupled channel calculation, arXiv:0802.3383 [nucl-th], at the Excited Baryon Analysis Center (EBAC). The calculation provides insight into the nucleon resonances, production of omega mesons with polarized photons, and the cross section for the important and elusive reaction of omega mesons with nucleons.
JLab's Safety Numbers
161 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
March 1: Virginia Regional Middle School Science Bowl
Environment, Safety, Health & Quality
Pennsylvania motorists recently encountered an unusual traffic hazard: a three-ton wood-chipper on wheels that had broken loose from a truck and collided with a minivan, resulting in three deaths. The truck driver had not checked to make sure the chipper was securely hitched. He also failed to connect the safety chains, which are supposed to keep a trailer attached if the hookup fails.
Runaway trailers are a little-known but persistent cause of devastating crashes, deaths and injuries across the country. A large majority of runaway trailers were light- and medium-duty trailers, as opposed to big rigs. Many of the crashes stemmed from elementary mistakes, such as failing to engage a locking device when hitching a trailer, and rarely was just one mistake responsible. More often, drivers neglected a series of precautions, any one of which might have prevented a tragedy.
A survey of more than 300 trailer owners in 2006 indicated that most were "lacking in knowledge of basic safety and proper towing procedures, and few have had any real training or instruction." If you, a friend or a family member own or use a light- or medium-duty trailer, you can help keep roads safe by making sure that all of the manufacturer's instructions are followed for each use.
Consumer Product Safety Commission Recalls
Computing and Networking Infrastructure
CNI Systems Maintenance next week
Automatic Installation of Microsoft Office
JLab Colloquium and Public Lecture
Property Validation Season Nears
JAG Dog Sports Training Club Informational Meeting Tommorrow