Jefferson Lab Weekly Briefs May 7, 2008
Jefferson Lab Weekly Briefs
May 7, 2008
12 GeV Upgrade
An important milestone for the civil design portion of the 12 GeV Upgrade Project was achieved April 25. Approximately 75 percent of the total civil design effort is complete including the final design documents for the Hall D Complex and the Central Helium Liquefier (CHL) Addition. This includes more than 50 drawings and approximately 1,500 pages of specifications.
The in-house civil design effort continues to progress. On April 22, Facilities Management team members met to discuss the internal design and safety review comments of the 100 percent design documents for the North & South (N&S) Access Utility Upgrades for the accelerator.
In Hall A, Experiment E04-007, Precision Measurement of the Electroproduction of the Neutral Pion near Threshhold: A Test of chiral QCD Dynamics, is running well and making good progress. Problems encountered have been tripping of the BigBite detector high voltage due to beam steering and the cryogenic target circulation fan system.
The Hall B g12 experiment run, which is conducting a search for hybrid mesons with exotic quantum numbers, is proceeding well. Very stable beam conditions have been achieved during the past week. A new trigger processor has been fully implemented for the g12 run, allowing researchers to collect data with many triggers in parallel.
In Hall C, production running continues for Experiment E04-108, the measurement of GEp/GMp. Data are being taken at the highest Q2 point of 8.8 (GeV/c)2.
Exclusive electroproduction of strange mesons (φ, K*, K) at high Q^2 offers many interesting opportunities for probing the gluonic and strange quark structure of the nucleon, including strangeness polarization. A collaboration of physicists recently summarized the physics issues which could be addressed by such measurements at JLab with 12 GeV beam energy (arXiv:0804.0456 [hep-ph]). Proposed studies focus on the analysis of cross section ratios, which can more readily be compared to (generalized parton distributions) GPD-based theoretical calculations than absolute meson production cross sections.
This reporting period experienced very successful beam delivery by the accelerator. The three experimental halls shared 376 hours of continuous wave (CW) beam delivery. The only significant amount of down time was caused by a malfunctioning vacuum valve controller chassis that was replaced after troubleshooting. The accelerator is performing extremely well as the June scheduled accelerator down (SAD) approaches.
The Alignment group continued calibration of distance instruments on the 730m baseline for the accelerator site. So far, two instruments have been calibrated resulting in an accuracy/standard error better than 0.2mm, and agreement between the two instruments of less than 0.5mm. After hundreds of observations, the data is analyzed and the results are used when taking measurements in the accelerator to determine how accurately a particular instrument can be expected to perform.
FEL staff members have been taking careful data on the charge emission process and diagnostics of the Gun Test Stand and achieved very interesting results. The quality of the magnetic transport and the emittance of the electron beam is sufficiently good to be able to observe extremely small diffraction ripples at the edge of beam produced by the passage of drive-laser beam through the apertures forming its transport. This exceptional performance means that any degradation observed in the future under more demanding operation can only be due to beam physics effects such as space charge and not any imperfections in the electron beam transport magnetic fields.
Staff members have disassembled the FEL gun and are preparing to rebuild it after fixing the ceramic and stalk issues which prevented the machine from running.
Environment, Safety, Health & Quality
ESH&Q reporting line temporarily changes
From Bob May, Acting AD, ESH&Q: Until a new ESH&Q reporting manager is hired, the Environment, Safety, Health & Quality reporting line (ph. 269-7007) is being forwarded to Bob May, x7632. Once a new Lead Quality & Safety Engineer has been hired, the reporting number will return to x7007.
United Way Seeks Yard Clean Up Volunteers for Tornado-Hit Areas
The United Way of South Hampton Roads contacted Ned Walker, ESH&Q Division, seeking volunteers to help clean up neighborhoods hit by last week's tornadoes. The United Way needs volunteers for Saturday, May 10. The United Way will pick up volunteers from a designated location and bus them to the clean up area, arrange for lunch and give each volunteer a small gift for helping. Anyone interested in helping may contact Walker, x6638 or email firstname.lastname@example.org.
More information about volunteering and disaster relief organizations accepting donations is on the We Hear That page.
Integrated Safety Management Reminders
The DOE Office of Health, Safety and Security inspection team will begin evaluating JLab's ES&H program during its planning visit May 19-22. The team will return and conduct a Lab-wide inspection June 2-12. Now is the time to look over your work areas, clean them up and address any concerns. Contact your supervisor or safety warden with questions or if you need help. Take time to review the material in your Jefferson Lab Safety Toolbox (flip pad) and posted on the ISMS webpage. Additional flip pads will be available at the VARC and CEBAF Center reception desks – one Safety Toolbox flip pad per person.
Beware: Theft takes place in JLab parking lot
Nothing suspicious had been noted by the roving Top Guard patrol, employees that had used adjacent picnic tables at lunch time, or by an employee who had taken breaks during the afternoon at the end of the building.
Kris Burrows, JLab's Security officer, reminds everyone to:
Handle Unneeded Property, Rubbish Properly During Spring Clean Up
Bar code tagged JLab property CANNOT be thrown away – even if you consider it junk. Tagged property must be turned in through the Property office so it can be properly removed from the inventory. DOE requires JSA/JLab to record, track and inventory property at its original acquisition cost. This means there is a significant negative impact to the Lab and the custodian when property cannot be located, because it was improperly disposed, even if the item has little functional value. This entire notice is posted on the All Staff memos page.
Custodians may now excess Property completely electronically at: https://mis.jlab.org/mis/apps/cis/property/transfer/index.cfm?app_id=125
JLab's Safety Numbers
231 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
May 5-9: JLab Spring Cleanup Week
JLab Education Calendar