Jefferson Lab Weekly Briefs April 9, 2008

Jefferson Lab Weekly Briefs

April 9, 2008

12 GeV Upgrade

A design & safety review of the 12 GeV Cryomodules system was held March 28; the review panel strongly endorsed the team’s work and projected that the design packages will be completed on schedule. The panel also found that the team had responded appropriately to the recent beam-breakup problems seen with Renascence during beam operations.

A vertically integrated test of the low-level RF (LLRF) controls with the self-excited–loop software was performed successfully; the test included the latest versions of the digital board, RF board, and PC/104 IOC-replacement with all operating in concert. 

The Arc 10 quadrupole girder drawings were signed off. 

The 2008 DOE Office of Science Office of Project Assessment Independent Project Review of the 12 GeV Upgrade Project will be held July 22-24. As in the past, it will be led by Dan Lehman, who heads the Office of Project Assessment in DOE’s Office of Science.


Hall A successfully completed commissioning for experiment E04-007 (Pi-Zero Electroproduction near Threshold) on schedule. On Saturday, April 5, production running was started.

Hall B is currently running the g12 run group that consists of two experiments; One of them searches for hybrid mesons with quantum numbers that cannot be obtained from mesons made from a quark-antiquark pair only. The other is searching for unusual baryons and excited doubly strange cascade baryons.



This reporting period had the three experimental halls splitting 240 hours of continuous wave (CW) beam delivery. As is usual after a long accelerator down period, a few items had to be addressed. The number one issue was various radio frequency cavity problems. As each problem appeared, staff quickly troubleshot the issues and brought RF back online as soon as was possible. The other misbehaving element was a beam loss monitor, which was limiting the current to Hall C located at AT07; it was replaced, and the current limitation disappeared. The accelerator overall is performing very well.


Free-Electron Laser (FEL)

The Optical Transport System (OTS) is now fully functional to every User Lab except Lab 3a. This lab was excluded so as not to disrupt the nanotube generation with the local laser. It has been a very good week for gun test stand (GTS) operation; FEL staff members have learned a lot about what they need to do regarding high-charge generation. Power tests have begun for the three-stage linear ramp for the ultraviolet (UV) QX quadrupoles.

Theory Center

A relativistic model that describes the nucleon as a system of three quarks (Phys. Rev. C77, 015202 (2008)) was applied to the electromagnetic transition of the nucleon to its first excited state, the Δ (1232) (arXiv:0803.3034 [hep-ph]). In this relativistic approach, no relative angular momentum between the spectator quark pair and the quark interacting with the photon is considered. Within this framework, the main contribution to the N -> Δ electromagnetic transition form factor, the magnetic dipole M1, is predicted, although a successful description of this form factor requires significant quark-antiquark effects for Q2 < 3 GeV2.


Safety Shoe Truck
The Safety Shoe Truck will be at JLab on Thursday, April 10, at the ARC loading dock from 2-4 p.m. Those needing this vendor, please put your purchase request in through JLab webstock and click on Veteran Shoes. If you need assistance, call Estelle Seeley, x7238, or Renee Carter, x7954.

JLab Adopt-A-Spot Event Needs Volunteers
The 12 GeV Upgrade Project team and ESH&Q staff are planning a joint Adopt-A-Spot/Earth Day litter pickup along Jefferson Ave. and on the JLab campus on Friday, April 18. Participants will meet in the CEBAF Center lobby at 11:15 a.m. for a short safety briefing and then disperse to pick up litter on the JLab campus. More information and signup can be found on the Adopt-A-Spot webpage. Volunteers should sign up by Wednesday, April 16. For additional information, contact Cindy Saban, x5981.

Ultimate Frisbee at JLab
Looking for fun, excitement and a great way to work off your stress during lunch? Come out and play Ultimate Frisbee on Tuesdays and Thursdays, noon-1 p.m. The group currently plays in the field adjacent to Hall A. Beginners and experienced players welcome. For more information on JLab's Ultimate Frisbee group, visit the Jefferson Lab Activities Group webpage. For specific questions, contact Ross Bailes at or x7623.

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).

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.


Environment, Safety, Health & Quality

With spring weather around the corner, this is a good time to review bicycle safety both at JLab and at home. Remember, everyone is required to wear an approved, properly fitting helmet while riding a bicycle (or using any type of scooter, in-line skates, or skateboard) at the Lab. Here are a few basic bicycle safety tips:

  • Obey traffic signs and signals
  • Never ride against traffic (state law requires that cyclists drive like other vehicles) 
  • Avoid road hazards (watch out for gravel, debris and uneven pavement)
  • Follow lane markings 
  • Use hand signals (they tell motorists what you intend to do)
  • Keep both hands on the handlebars (except when signaling)
  • Be prepared to brake (allow extra time for stopping in wet weather).

FEL Fall Protection Net Lesson Learned
Portable large shielding blocks are relocated several times annually at the FEL based on operational schedules. This shielding block relocation activity requires Lab staff to work at heights requiring fall protection measures. Lab staff used a commercially available fall protection net for this worker safety issue. Concerns surfaced over the fall protection net's appropriateness for all worker fall protection aspects. Line management for the shielding block relocation work requested that a licensed professional engineer (P.E.) review the fall protection net. This P.E. review evaluates if the fall protection net's mounting satisfied applicable OSHA requirements. This P.E. recommended that the fall protection net not be used. However, the P.E.'s recommendation was not adequately communicated to line management and workers responsible for the FEL shield block movements. The line organization doing the shield block relocation continued to use the fall protection net when needed, since its members were not aware of the evaluation results.

The investigation team analyzing this fall protection net discovery noted three primary causes: (1) the line organization assumed that the net was safe and did not verify the completion of the review, (2) the P.E. and his organization failed to properly communicate safety-critical information in a timely manner, and (3) the work supervisor tagged out the net but did not remove his administrative Lockout/Tagout prior to the net's reuse. The FEL shield block relocation worker fall protection is now provided by personal fall arrest systems, which includes full-body harnesses.

Lessons learned are:

  • Clear roles and responsibilities are necessary for all types of safety equipment.
  • The Lab Issues Management Procedure should be followed as written to ensure thorough communication of issues and their resolution. 
  • Careful inspection of all types of safety equipment before use is required.
  • If possible, administrative lockout/tagout (LO/TO) should be applied so that the equipment cannot be used without LO/TO removal.

Computing and Networking Infrastructure (CNI)

User Audit Starting
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, 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, scheduled for June 3. To use this version of Mathematica prior to it becoming the default, just type the command string: 'use mathematica/6'


JLab's Safety Numbers

203 Days since Last Recordable Accident (JLab record: 319)
522 Days since Last Lost Workday Accident (JLab record: 522)

JLab Calendar of Events

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)




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