Jefferson Lab Weekly Briefs June 20, 2012

Jefferson Lab Weekly Briefs
June 20, 2012

JLab All-Hands Memo

JLab Landline Phone Outage Set for Saturday, June 23
On Saturday, June 23, 9 a.m.-2 p.m., the JLab landline telephone system will undergo an upgrade. It is expected that landline phones will be offline for brief periods during the upgrade. When the system is offline, no calls may be made onsite or offsite and no dial tone will be available. JLab cell phones and pagers and personal cell phone operations and service won't be impacted by the upgrade work.

To report an emergency at JLab during this time:
-- Use a JLab cell phone or a personal cell phone to call 911. Then immediately call the JLab Security cell phone at 757-342-9868 to let officers know 911 has been called. Advise Security of the nature and location of the emergency.
-- Or activate the closest fire alarm box. Follow this by calling the Security cell at 757-342-9868 to advise them of the situation.

For more information regarding this outage, contact the IT Division Helpdesk. For further information regarding Emergency Response steps to take during this scheduled phone outage, contact JLab's Emergency Manager, Tina Menefee, 768-4030.

12 GeV Upgrade

The second sector of the PreShower Calorimeter for Hall B's CLAS12 is complete and has been tested successfully with cosmic rays. Stacking of lead sheets and scintillator bars threaded with wavelength-shifting fibers is complete for the third sector and is being readied for the fourth. The third and fourth Region 1 wire chambers are being strung at Idaho State University; the fifth Region 2 chamber is complete at Old Dominion University, and the first two Region 3 chambers are being strung at JLab. High-voltage and readout boards are being added to sectors that are strung, and cosmic ray testing is underway. The first complete module of the Silicon Vertex Tracker was tested in CLAS during the recent accelerator run, and the flex-cables and support staves with all recent improvements are being manufactured. The last two of five types of mirror substrates are being built for the high threshold Cerenkov counter. Delivery of the final orders of photomultiplier tubes and scintillator material to the University of South Carolina has begun, where assembly of the forward time-of-flight 1-b slats is progressing well. An agreement was signed with FermiLab to produce the six large cold masses with the coils for the torus magnet.


Q-weak disassembly work continues in Hall C. The electronics bunker and much of the main detector shielding have been removed. Detector removal has started with the unmounting of one of the large region 3 drift chamber packages. The Hall C Summer Workshop is Friday, June 22, and Saturday, June 23.


This began the first week in the Long Shut Down where all areas of the accelerator were open for access during the day. The intent is at the end of each day, the South Linac will be locked for superconducting radiofrequency cryomodule commissioning and the injector and North Linac will be locked to allow work on the Polarized Electrons for Polarized Positrons (PEPPo) experiment to continue overnight and into the morning. On Monday, the lock up of the injector was delayed due to an issue with air pressure interlocks preventing the opening of vacuum valves. Starting Wednesday, the injector status was changed to remain locked during the day when possible to allow work on the PEPPo magnets and to aid in ensuring no inadvertent changes are made in the injector area. On Wednesday, the PEPPo power supplies were worked on by Engineering Support, resulting in a more stable output. Also on Wednesday, the accelerator participated in a sitewide load reduction test, which resulted in the shedding of approximately 2500 kilowatts of load. The remainder of the week and into the weekend was smooth running, with PEPPo work continuing in the injector and cryomodule commissioning continuing in the South Linac.

Free-Electron Laser

The FEL team delivered ultraviolet light at 370.5 and 427 nanometers to a metastable krypton beam, observing only small effects. This is a very important result, because it validates the use of un-filtered 3rd harmonic vacuum ultraviolet light to try to create a metastable beam. The gun performed extremely well this week. The DarkLight test chamber was installed in the 3F region of the FEL.

Center for Theoretical and Computational Physics

A new paper points out an important difference between two different versions of the theory describing interactions of pions and nucleons. The theory based on the "pseudovector" πN coupling is consistent with properties of QCD in the limit of vanishing quark mass, whereas that based on the "pseudoscalar" coupling (which is often used in the literature) is shown to give incorrect behavior in this limit. The paper stresses the importance of using the correct theory to reliably describe the effects of the pion cloud on nucleon properties.


The survey and alignment group has been busy since the start of the May shutdown of the 6 GeV machine. The group has completed an elevation survey (levels) around the accelerator ring. This comprised more than 400 survey monuments being measured. The closure over this distance was 0.6 millimeters, an error of 1 in 2.2 million or 4.6 x 10-7. The group is now carrying out a three-dimensional survey of the entire accelerator. This is required as the tunnel has shifted and expanded by millimeters over its lifetime. After the completion of the Q-weak and g2p experiments in Halls C and A respectively, the alignment group surveyed the final position of the detectors and targets. The survey of monuments in Hall D and the tie in of the main accelerator to the new hall is continuing. The group also laid out the stands for the new equipment in the Hall D target area.

Environment, Safety, Health and Quality

National Safety Month
The National Safety Council is celebrating June as National Safety Month. The program provides a variety of safety tip sheets for work and home, addressing such topics as employee wellness, ergonomics, driving safety and preventing slips, trips and falls. These resources can be accessed on the NSC website.

Important Golf Cart Safety Reminder
All golf cart drivers are reminded that carts aren't allowed on Hogan Drive, which is a City of Newport News street. Carts are only permitted on JLab roads, paths and parking lots and other approved work areas.

Computing and Networking Infrastructure

Planned Network Maintenance, June 27, 5-7 p.m.
On Wednesday, June 27, the network group will update a central router in a maintenance period, 5-7 p.m. During this time, several outages may occur throughout the lab. In particular, there will be an outage of the Internet connection, an outage of the wireless network and outages to the TED building networks. Additional outages may occur during this time, as well. The IT Division will strive to make the outages as brief as possible. If you have any questions or concerns about this planned work, contact the IT Division Helpdesk, x7155.

Email Migrations into New System Continue
The CNI group is continuing to migrate staff and some users into the new email and calendar suite, Zimbra. These migrations are going well, with nearly 821 staff and users migrated into Zimbra and about 68 still left to migrate. These migrations are occurring overnight, and you will receive an email around noon on the day you are scheduled to be migrated. For more information, see the article in the March 16 OnTarget newsletter.


JLab Personal Dosimeter Change Out Set For July 2
JLab's semi-annual personal dosimeter change out will take place during the afternoon of Monday, July 2. This includes the dosimeters of all JLab staff, users, subcontractors and summer students. If you need to use your dosimeter during the change out period on July 2, you may exchange it that morning in the Radiation Control Dosimetry Office in Bldg. 52B, Room 4, 8 a.m.-1 p.m. Make sure to put your personal dosimeter in its dedicated spot in the dosimeter racks no later than 4 p.m. on July 2. If you will be leaving the lab before then for vacation, business travel or a long holiday, make sure to put your dosimeter in its place in the racks before leaving the lab.
If you have questions or concerns, contact Becky Mosbrucker, x7236.

JSA Initiatives Fund Call for Proposals Announced
A call for proposals for support from the 2013 JSA Initiatives Fund program has been issued. Proposals with JLab principal investigators will be forwarded to Bob McKeown for the first round of review. Proposals with User PI's will be forwarded to Sebastian Kuhn for the first round of review. Details on the full application process can be found on the JSA website. All proposals are due by Aug. 3.

Tracking Thomas at JLab
Little Thomas is visiting all corners of the JLab campus. If you can identify his location this week, email Kandice Carter with your guess. Guesses are accepted through Friday.

No one submitted a correct answer for the June 13 location, so Little Thomas has provided another picture with a different background in the same location as an additional hint. Check out the Tracking Thomas webpage for a better view of this mystery location.

JLab Calendar of Events

June 18-22: Program Advisory Committee Meeting (PAC39)
June 26: Colloquium and Public Lecture: Hurricanes!
July 4: Independence Day holiday, JLab closed
Jule 9-13: Geant4 Tutorial
July 16-17: 7th SRF Materials Workshop
July 18-20: 5th International Workshop on Thin Films and New Ideas for Pushing the Limits of RF Superconductivity
July 23: Safety Shoe vendor onsite