Jefferson Lab Weekly Briefs February 23, 2011

Jefferson Lab Weekly Briefs
February 23, 2011

Open Letter on the Budget From Mont

Dear Colleagues,

It will not have escaped your attention that Congress is engaged in many discussions of budgets. A little more than a week ago, we made our presentations to the Office of Nuclear Physics in preparation for the FY2013 budget. The President made his FY2012 budget proposal, which is generally favorable to the DOE Office of Science and Nuclear Physics. For FY2011 we are still under a continuing resolution. There is an enormous range of possibilities and some would indeed be very difficult for the laboratory, others are relatively good given the perceived economic situation. We track many of the changes but do not try to develop detailed reactions to each possibility reported in the press.

You can be assured that we will provide you with any concrete developments as soon as we can. In particular, we are trying to understand the commitment we can make to running the accelerator during the period from April 1 to May 15, when the six-month installation shutdown begins.

Stay tuned.

Hugh Montgomery,

12 GeV Upgrade

The first of the 13 kilowatt klystrons was received last week; onsite testing will begin after completion of the non-electrical checks. Assembly of the first 12 GeV cryomodule continues. The first two of the new curved spreader/recombiner magnets have been received; initial testing indicates that the field quality is well within the specification. The arc dipole rework/refurbishment plans were reviewed by the Accelerator Division and the 12 GeV team. Assembly has started on the quadrupole-beam position monitor-corrector girder assemblies for arc 10. 


The first Hall A experiment scheduled to run this spring, E08-008: Electrodisintegration of the deuteron near threshold, was completed on schedule.

Q-weak data taking in Hall C was interrupted by worsening vacuum in the beamline downstream of the target. Hall C technicians patched a suspected leak location on a bellows, a replacement for which is under fabrication. While the downstream vacuum fluctuates with beam on, the vacuum has remained good enough to continue production data taking at 150 microamps.


The accelerator has been running well, with beam to three halls. The injector may need some fine tuning to improve beam quality for Hall C; the width of Hall C’s beam charge asymmetry is larger than the specification. Last week, a few hours were lost due to a bad fast shutdown card, a faulty beamline valve position indicator and a failed viewer camera. Over the holiday weekend, two injector radiofrequency control modules and the arc 2 box supply current regulator board were replaced, which caused several hours of downtime.

Free-Electron Laser

The Gun Test Stand gun held 500 kilovolts for more than eight total hours, using krypton at 1E-4 torr with no evidence of field emission. This is a major achievement and the culmination of almost six years of effort to improve the voltage standoff of DC Guns. It will make feasible significantly higher brightness from DC gun injectors. The ultraviolet optical transport to lab 1, including the collimator and alignment system, were all completed and placed under vacuum last week in preparation for operations.

Theoretical and Computational Physics

A new global analysis <arXiv:1102.3686 [hep-ph]> of parton distribution functions (PDFs) by the "CJ" (CTEQ-JLab) Collaboration has critically examined uncertainties in PDFs arising from nuclear effects in deuterium structure function data. The down quark and gluon PDFs are found to vary significantly with the choice of nuclear model, which impacts the determination of the neutron structure function, as well as W-boson production and parton luminosity at the Tevatron and the LHC. The report discusses prospects for new measurements at JLab sensitive to the down quark and gluon distributions but insensitive to nuclear corrections.

Environment, Safety, Health and Quality

Ladder footing
Recently, a YouTube video of a crane toppling into a river has been circulating among safety professionals. The main cause was soft soil under the stabilizing outriggers on the crane. When the load shifted, the soft wet ground collapsed, and the crane toppled.
What does this have to do with ladder safety? A ladder has a smaller footprint (think load-bearing surface area) but a comparable load in pounds per square inch. Many people use ladders, both at JLab and around the home, for a variety of tasks, such as replacing lights, cleaning gutters and painting.
Be aware that the winter/spring snow and rains may have softened the area where you are placing the ladder’s feet. If unsure or if soft when standing on this area, put a wide sheet of plywood or wide board under the ladder’s feet to spread your weight across a larger area. A few seconds of proper job planning could save you a trip to the emergency room.


As noted in the 12 GeV brief, the first 12 GeV klystron has been delivered to the radiofrequency systems group for final acceptance testing. The tube and solenoid has undergone rigorous testing at the vendor already.

The alignment group inspected eight end plates, which will be used for the new CLAS region 2 as part of the Hall B 12 GeV upgrade. Control survey work continued in support of Hall D construction to connect the main accelerator to the new end station. The Hall D tagger pipe was verified and work continues on verification of the position of the photon beam pipe into the hall D end station.

Congratulations to Jenord Alston, who has received the Daniel E. Hamilton Memorial Certified Welding Inspector of the Year citation for District 4, Tidewater Section of the American Welding Society. The award is to honor outstanding performance in the practice of welding inspection and qualifies Alston as a candidate for the national award.


2011 Benefits Open Enrollment Underway
JLab's 2011 Health Benefits Open Enrollment is offered until March 4, via the Employee Self Service System. All regular and term employees are eligible for medical, dental, health and dependent care flexible spending accounts, short-term disability and supplemental life insurance. For complete information on benefits options, visit the Human Resources Benefits webpage. This is also your opportunity to enroll your eligible adult dependent children, up to age 26, on your medical and dental coverage. Eligibility rules are available via ESS and the benefits webpage.

Excess Property
A list of excess property available for re-use, but located at other government facilities, is now available online. Recipients of any excess property from this list are responsible for shipping/transportation of awarded property. If you are interested in the listed property, contact Lamont Williams, x6270, or Carl Iannacone, x5430, by 5 p.m. on Feb. 28.

Lost and Found
If you've misplaced a personal item at JLab, there's a good chance it's been found. Check out the complete list of Lost & Found items, located in the Classified Marketplace listings online. If you've found an item, you can turn it in at the CEBAF Center reception desk during business hours.

JLab Calendar of Events

Feb. 23-25: Excited Hadronic States and the Deconfinement Transition Workshop
Feb. 28: Safety Shoe vendor onsite
March 5: Va. Regional Middle School Science Bowl
March 7: Safety Shoe vendor onsite
March 29: Science Series Lecture - DNA: The Strand That Connects Us All