Jefferson Lab Weekly Briefs

June 11, 2008


In Hall A, production running for experiment E08-007 (Measurement of the Proton Elastic Form Factor Ratio at low Q2) has been successfully completed. All of the data at the nine scheduled kinematics have accomplished the projected error bars.

The g12 run group in Hall B was successfully completed Monday at 10 p.m. g12 combines two photoproduction experiments: searches for new hadronic matter in the meson and the baryon sector. Besides this major focus, the run also included a measurement of pion production from protons at large scattering angles to test scaling in exclusive reactions, a study of vector meson decays into e+e- pairs, and a pioneering study of time-like deeply virtual Compton scattering (DVCS), i.e. gamma + proton => electron + positron + proton, where the electron-positron pair has an invariant mass above the phi meson.


This period of beam delivery was very successful and ended with the start of the Scheduled Accelerator Down (SAD). The three experimental halls divided 308 hours of beam delivery. The only significant problems were due to Central Helium Liquefier (CHL) compressors tripping off. CHL staff quickly fixed the problems and brought the compressors back online, which allowed Operations staff to restore the accelerator to continuous wave beam operations.

Free-Electron Laser (FEL)

The FEL trained the first set of folks in the new Laser Personnel Safety System. FEL staff also supported the DOE ES&H Inspection audit, including nanotube material controls, beamline installation activities and gun test stand operations.


A fully relativistic calculation of the D(e,e'p)n reaction in the impulse approximation has been performed (arXiv:0805.3115 [nucl-th]) using the SAID parametrization of the full NN scattering amplitude to describe the final state interactions (FSI) of the proton and neutron. Kinematic regions where various parts of the FSI are relevant are identified and the theoretical uncertainties connected with calculations at high missing momenta are discussed.

JLab's Safety Numbers

266 Days since Last Recordable Accident (JLab record: 319)
585 Days since Last Lost Workday Accident (JLab record: 585)

JLab Calendar of Events

June 2-13: DOE ES&H Inspection - Onsite Inspection Visit
June 16-19: Users Group Workshop and Annual Meeting
June 30-July 2: Science & Technology Review
July 4: Independence Day Holiday (JLab closed)
July 8-10: DOE ES&H Inspection - Report Validation and Closeout
July 10-11: Teacher-to-Teacher Workshop at JLab
July 14-19: Lattice 2008
July 22-24: DOE Office of Science OPA Independent Project Review of the 12 GeV CEBAF Upgrade Project
July 22-25: Thin Film - Superconducting Radiofrequency Technology Workshop




Environment, Safety, Health & Quality

FEMA is reminding the public that this is National Safety Month, sponsored  by the National Safety Council. Throughout June, the NSC is targeting the most significant causes of unintentional inuries and deaths at home, in the workplace, and on the road.

FEMA Regional Administrator Susan Reinertson urges people to enhance their awareness of the importance of personal preparedness, 72-hour emergency kits and family disaster planning. Take the first step by viewing Are You Ready? In-depth Guide to Citizen Preparedness online from the Department of Homeland Security. JLab's emergency procedures can be found in JLab ES&H Manual Chapter 3510, Emergency Management Plan.

For more information on National Safety Month, visit the NSC website.

Computing and Networking Infrastructure

Adobe Flash Player Plug-in Upgrade
A new version of the Adobe Flash Player plug-in has been released to fix a major security hole in all previous versions. If your system is not managed by the Computer Center, you are using a Mac, or you are using Internet Explorer for your web browsing, you will need to go to the Adobe website for an upgrade of the Flashplayer plug-in. Please do this as soon as possible, as the security hole is being actively exploited. If you have any questions, contact the HelpDesk at x7155, or send an e-mail to


Pager System Fully Functional
Alpha paging using web-based and e-mail utilities is available, and dial-up paging has been restored. Questions regarding the paging service at JLab may be referred to Dawn McGinnis, x7206 or

Safety Shoe Truck Fills Approved Orders on June 12
Safety-shoe vendor Veteran Shoes will be at the ARC loading dock Thursday, June 12, from 2-4 p.m. to fill approved JLab Purchase Requisitions. Only approved PRs can be filled. Get PRs in as soon as possible through Webstock. For assistance, call Estelle Seeley, x7238, or Renee Carter, x7954.

JLab Property Inventory Begins This Week
The annual property inventory starts this week. Twenty percent of JLab's property custodians have been selected for a complete property inventory. In addition to those listed, any custodians who have not completed the annual property validation will also be included in the inventory group for this year. Listed custodians will be contacted by a property office staffer to set up a time to have the assigned property inventoried (this includes all property on your property validation list). For a list of custodians included in the inventory and more information regarding the inventory process, visit the All Staff Memo page.



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