Jefferson Lab Weekly Briefs April 2, 2008

Jefferson Lab Weekly Briefs

April 2, 2008

12 GeV Upgrade

Over the last few months, four independent reviews have been held of various physics detector systems, and five more reviews are planned in April and May. These reviews give valuable feedback to the scientists and engineers as they complete system design packages in preparation for the July 2008 DOE SC Office of Project Assessment Independent Project Review. Last week, the Hall D tracking and related particle identification systems were reviewed. During the closeout, reviewers provided high marks on progress in the last year and the quality of the presentations. A review of the CLAS12 Silicon Vertex Tracker detector will be held this week. Both Halls B and C are in the final preparations for a design review of their seven superconducting spectrometer magnets. In Hall C, particle background simulations are ongoing to finalize the shield house design.


Hall A has successfully completed installation activities for experiments E04-007 (Pi-Zero Electroproduction near Threshold) and E08-007 (GEp/GMp at low Q2-values) on schedule. On Monday, March 31, the cryotarget system was cooled down as the final step before taking beam into the hall.



This week saw the Scheduled Accelerator Down (SAD) come to a successful conclusion and the ramp up of Accelerator Operations to get ready for beam delivery to the experimental halls. Various factors made the optics setup very difficult. However, an excellent setup was achieved after some very hard work by many staff members. Production beam delivery was started to all three experimental halls. Efforts of Note:

  • Vacuum: There was a vacuum event in the machine where a flange sprang a leak over the weekend. Multiple staff members quickly responded and brought the accelerator back online so setup could resume.
  • RF: All of the available cryomodules were brought online and the RF was optimized for the 5.7 GeV setup.


Free-Electron Laser (FEL)

FEL staff continued preparations toward producing high-charge bunches in the gun test stand 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 bunches as this is being written. Staff also finished mapping the last sextupole and received a new ultra-sensitive terahertz (THz) detector for that lab.

Theory Center

Recently, Myhrer and Thomas showed (arXiv:0709.4067 [hep-ph]) that the fraction of the spin of the proton carried by its quarks, now experimentally around 33 percent, can be understood in terms of the basic features of its nonperturbative structure, namely relativity, chiral symmetry and the one-gluon-exchange hyperfine interaction. A new Theory Center paper (arXiv:0803.2775 [hep-ph]) has now shown that the missing spin is actually carried as orbital angular momentum, primarily by up and anti-up quarks. While this picture changes dramatically under QCD evolution, the predictions are in rather good agreement with recent lattice calculations, as well as with the recent results from deeply virtual Compton scattering from JLab and Hermes.


Property Custodians Must Complete Validation of Personal Property by April 15
The annual property custodian validation process continues through April 15. Each custodian must "validate" all of the items on his or her inventory list and take the Property Custodian Refresher GEN 150 training (about 5 minutes).

As noted in the March On Target newsletter, changes in the property program have reduced the number of items that the Lab must track and inventory. For example, the dollar threshold for “sensitive” items that have no electronic memory has been raised from $150 to $300. The validation link can be found on the JLab Insight page. On the Insight Front Page tab, look down the Personal Information column on the left, and click on the “Property validation” link.

National Library Week is April 13 - 19
The 2008 theme is "Join the Circle of Knowledge@Your Library." Information Resources wishes to thank all JLab staff and users for their cooperation and support over the years. Information Resources staff takes your needs and concerns seriously and wants to provide the best resources possible. Tell us what you think: Complete the online survey.

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
April 18: Adopt-A-Spot litter pickup
May 14: JLab Run-A-Round
May 19-23: The 4th Electron Ion Collider Workshop
May 26: Memorial Day Holiday (JLab closed)



Environment, Safety, Health & Quality

With the weather starting to turn warmer, many of us are starting another year of yard work. The American Society of Hand Therapists suggests some basic gardening safety practices. It is important to remember that yard/gardening activities involve many repetitive tasks such as raking, weeding, digging and pruning. You can help avoid injuries by following these safety tips:

  • Always wear gloves: The soil is full of bacteria and fungus that could cause an infection in a small irritation or cut in your skin.
  • Keep you arms covered, too. Coverage protects you against the sun, poison ivy, and other small residents (rodents or spiders) of your garden or yard. 
  • Use wide-handled, lightweight tools. Tools with padded or thicker handles protect the smaller joints in your hands.
  • Take a break about every hour or switch to another activity. Repetitive motions, such as digging, can cause tendonitis of the elbow or lead to carpal tunnel syndrome. 
  • Use tools to dig in new areas. Buried sharp objects can cut or puncture your skin.
  • Avoid the habit of sitting back on your knees. Bending your knees this far is a hard position for the knee joints. Instead, use a short gardening stool or bench.
  • Plan you activities. Consider using a small cart or wagon to carry supplies; some even provide convenient seating. Always put tools away to prevent anyone from tripping over them.

"Suspect" Rigging Items Discovery
A number of rigging hardware items (2-ton lifting shackles) discovered recently in the JLab machine shop did not have appropriate markings, such as manufacturer information. These rigging hardware items were identified as "suspect" using applicable DOE Suspect/Counterfeit item (S/CI) criteria. The items were withdrawn from use. These types of items present not only a potential personnel safety hazard but an operational threat to the success of critical equipment handling. Contact Brian Murphy of the Lab's Quality Assurance/Continuous Improvement Department at x5515 if you have questions about any materials or items that do not have appropriate required markings.

Computing and Networking Infrastructure (CNI)

User Audit Starting
On Monday, April 7, the CNI group will be begin the semi-annual User Audit. If you supervise someone at JLab or sponsor a user account, you are required to review and re-authorize these accounts on a semi-annual basis. This audit ensures that all inactive accounts are retired and that all active users have a valid reason to maintain an account on the computer systems at JLab. This is critical for achieving cyber security on the JLab systems. Please take a few minutes during the next few weeks to perform this essential function.

Maple 11 Available
Maple 11 will become the default version available for centrally managed Unix and Linux systems on the next Computer Center maintenance day, currently scheduled for June 3. To use this version of Maple prior to it becoming the default, just type the command string 'use maple/11'

Mathematica 6.0.1 Available
Mathematica 6.0.1 will become the default version available for centrally managed Unix and Linux systems on the next Computer Center maintenance day, currently scheduled for June 3. To use this version of Mathematica prior to it becoming the default, just type the command string: 'use mathematica/6'

Phishing Scams
The Lab has recently received several types of banking scam e-mails, especially some that purport to be from a local bank or credit union. For your own Internet safety, we encourage you to be skeptical about any and all e-mail that claims to come from your bank. Key scam indicators include topics such as impending account termination, fraud alerts or other unusual activity that you must log on or call in to investigate.

If you receive such a fraudulent email, the safest thing to do is simply delete it. If you have any questions, call the bank's customer service line using the phone number printed on your latest statement and ask them to verify its authenticity. If you think that you may have already fallen victim to a banking scam, contact your institution immediately.

As always, you may feel free to forward a copy of any suspicious email you receive to


JLab's Safety Numbers

196 Days since Last Recordable Accident (JLab record: 319)
515 Days since Last Lost Workday Accident (JLab record: 515)



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