Jefferson Lab Weekly Briefs March 26, 2008

Jefferson Lab Weekly Briefs

March 26, 2008

12 GeV Upgrade

Design effort on the conventional facilities to support the 12 GeV CEBAF Upgrade continues to progress. The 100 percent design package for the North and South Access utility upgrades was completed by the JLab Facilities Design Team. This project expands the low-conductivity water (LCW) systems for the linac service buildings and the arc magnets and adds electrical substations to increase the power capacity at each building. The design package has been distributed for an internal design and safety review.  

The JLab Procurement group has posted the Sources Sought notice for construction contractors interested in the Hall D Complex. This will be a best-value procurement, which evaluates a vendor's capability in addition to the price as part of the selection process.

A Change Request has been approved authorizing three additional R&D tasks for the Upgrade cryomodules: (1) precise re-measurement of the damping of higher-order modes in two 12 GeV cavities in the Horizontal Test Bed (HTB), (2) repeat of those measurements in the Vertical Test Area (VTA) to vet a new step in the cryomodule quality assurance process, and (3) explore alternate thermal strapping strategies for the cavity endgroups for potential cost savings.


Hall B is in the final preparations for the startup of the g12 run group. This run group will search for unusual hadronic matter, such as mesons with quantum numbers that cannot be produced with a quark/anti-quark pair. These mesons are candidates for so-called "hybrid" mesons, representing gluonic excitations.



This week was marked by the windup of Scheduled Accelerator Down (SAD) activities and the startup of threading beam around the machine in preparation for resuming beam operations to the experimental halls on April 1.


Free-Electron Laser (FEL)

FEL staff continued preparations toward producing 1 nanoCoulomb (nC) bunches in the gun test stand (GTS) by optimizing drive laser performance and  revisiting the PARMELA modeling to account for the final configuration. The team is working to produce and measure the nC bunches as this is being written. The FEL gun is repairing some insulators which appear to be conducting excessively. FEL staff also finished mapping the last sextupole and received a new ultra-sensitive terahertz (THz) detector for that lab.

Theory Center

Understanding the true nature of excited nucleon states may be most easily gained by studying its structure and form factors. Recent results by the CLAS collaboration show interesting behavior in the Q2 dependence of the nucleon-Roper transition. In a new Theory Center paper, arXiv:0803.3020 [hep-lat], the first ever model-independent calculation of the nucleon-Roper transition form factor has been performing using lattice QCD, which explored this transition for Q2 up to 3 GeV2.


JLab's Safety Numbers

189 Days since Last Recordable Accident (JLab record: 319)
508 Days since Last Lost Workday Accident (JLab record: 508)


Environment, Safety, Health & Quality

One influenza virus has emerged recently as the predominant virus for the season. This virus is not included in the current 2007-08 U.S. vaccine, so even those who have been vaccinated are highly susceptible. According to the Centers for Disease Control (CDC), 44 states report widespread flu activity; five states report regional activity; and one state and the District of Columbia report local activity. Flu viruses spread mainly from person to person through coughing or sneezing. Healthy adults are able to infect others beginning one day before symptoms develop and up to five days after becoming sick. That means that you may be able to pass the flu on to someone else before you know you are sick, as well as while you are sick. The flu season is expected to continue through May. The CDC suggest the following precautions:

  • Frequently washing your hands with soap and water will help protect you from germs.
  • Avoid close contact with people who are sick. When you are sick, keep your distance from others to protect them from getting sick too. 
  • If possible, stay home from work, school and errands when you are sick. You will help prevent others from catching your illness.
  • Cover your mouth and nose with a tissue or your sleeve when coughing or sneezing. It may prevent those around you from getting sick. 
  • Germs are often spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth.
  • Get plenty of sleep, be physically active, manage your stress, drink plenty of fluids, and eat nutritious food.

JLab Finger Injury Lesson Learned
An engineering technician cut his index finger with an Exacto knife on March 13. The technician and a co-worker were working in the FEL gun test stand area troubleshooting an improperly closing laser amplifier plastic cover. They were fixing the problem by elongating the mounting holes by using a drill press and later an Exacto hobby knife. When the technician used the knife to clean out remaining material using a sawing motion, the knife binded, popping out and contacted his index finger. Fortunately, this injury received prompt treatment by Medical Services staff and only required "first aid" measures.

The injury investigation noted the following lessons learned:

1. Personnel need to take the time to review and plan work. Identify proper procedures, tools, and equipment.
2. Sometimes it is difficult to identify just when and where conditions change sufficiently to warrant one to stop and re-evaluate a task. A rule of thumb would be when methods or tools change. This implies that methods and tools are sufficiently identified at the onset. Designs should be reviewed for implications of anticipated field adjustments.

Computing and Networking Infrastructure (CNI)

Don't Get Tricked into Downloading
Recently, the number of Lab computers with trojans, spyware and other malicious software installed has increased. In many cases, these infections can be traced back to a user who has downloaded and installed so-called video CODECs, system tune-up utilities or spyware scanners. If you visit a website that claims you need to have their own special software to view their video clips, it is probably a scam. Likewise, some websites advertise system utilities or spyware scanners that turn out to be virus-ridden or malicious software aimed at disabling or infiltrating your computer. For more information on these insidious ploys, visit the Computer Center website.


JLab T-shirt Design Contest submission deadline is Friday!
The deadline for submissions is Friday, March 28. Submissions should be in color, on 8.5 x 11 paper, and include a front (pocket) and back design. Past winning designs may be viewed online. Submission rules are posted on the JAG website.

JLab Calendar of Events

April 4-5: USQCD All Hands Meeting
April 8-11: 2008 International Technical Safety Forum
April 12-15: APS April Meeting, St. Louis
May 19-23: The 4th Electron Ion Collider Workshop
May 26: Memorial Day Holiday (JLab closed)


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