Jefferson Lab Weekly Briefs
March 16, 2011
12 GeV Upgrade12 GeV activities for the upcoming six-month shutdown are fully integrated in the JLab sitewide schedule, and logistic planning is in full force. The goals for civil construction during this period include construction of the beam switchyard building addition with two new penetrations to the tunnel, connection of the existing tunnel to the Hall D tagger enclosure, and low-conductivity water upgrades. Upgrade activities for the accelerator include removal, refurbishment and reinstallation of all west arc dipole magnets and some east arc dipole magnets as well as the installation of the new four-meter magnets and girder assemblies in arc 10. In addition, three new C100 cryomodules will be installed in the south linac along with new radiofrequency zones and upgrades to the safety system. Two (potentially three) of the cryomodules will be commissioned.
PhysicsLast week, Hall A switched from the N→Δ experiment to the short-range correlations experiment on Monday and made a target configuration change Tuesday and Wednesday. Meanwhile, several magnet repairs were underway. Unfortunately, the hall was down until Saturday because of the magnet power supplies, as techs struggled to repair them. As of Saturday, staffers found they could not run one of the magnets at full current and decided to run the rest of the weekend in a compromise configuration with that magnet at 85 percent current, which was good enough for some aims of the experiment. Presently, Hall A staffers are formulating a plan with electrical engineering support from the Accelerator Division to fix the faulty power supply, while the SRC experiment continues to run.
After replacement last week of the bellows near the Hall C beam dump, another leak was found, this time in the beamline exit window. The window was replaced, establishing an excellent vacuum. The Q-weak target was re-cooled and data taking was resumed, starting with event mode and background measurements, including an important "dilution" measurement, which establishes the correction required from the aluminum windows of the hydrogen target cell.
Research Assistantship Offered
JLab is seeking candidates from SURA universities for a research assistantship. The program will sponsor a minority undergraduate student to work on projects that are part of the lab’s research program or directly related to the scientific or engineering aspects of the research program. This assistantship is funded by the JSA Initiatives Fund and will provide funds to support the student at the university during the 2011-2012 academic year. Nominations must be submitted by the faculty sponsor before the student may apply. Faculty sponsors may obtain more information and submit their nomination online.
AcceleratorOver the weekend, the CEBAF accelerator delivered beam to both Halls A and C. During the week, none of the halls were ready for beam: Hall A was changing to a different experiment and also worked on its left spectrometer Q1 magnet; Hall B was installing a new experiment; Hall C was working on its beamline vacuum and the QTor power supply. Accelerator staffers used the time to perform subsystem maintenance and beam studies. Beam studies performed included: improving beam quality for Q-weak, new injector optics, arc 1 rematch using the elegant decks and optimization of the accelerator optics.
Free-Electron LaserThe FEL team continued setup of ultraviolet generation in Lab 4 for the Laser Micro-Engineering Station. The team was successful in doubling the light frequency, but performance optimization continues. Staffers also installed the optical transport system to Lab 1 for vacuum UV and demonstrated operation of the vacuum monochrometer. Measurements of UV-driven thermal loading on the cavity mirrors was inconclusive due to issues with the measurement instrumentation.
EngineeringThe Mechanical Engineering Group has been gathering historical design data and drawings for the super-harp and the harp diagnostic devices. The g2P experiment requires super-harps to obtain measurements of the impacting beam angle at the target. Since there was no single design for the many configurations of the super-harp and the harp, the MEG design team sought to consolidate the two designs. The new design incorporates features from both devices so that only a few components are needed to produce either device. The design will be reviewed by various groups to ensure that it meets physics requirements. Fabrication will proceed shortly after.
Additionally, MEG's 12 GeV beam transport team has been focused on making final preparations for the May installation down. Presently, 26 of the 32 new arc 10 quadrupole girders have been assembled and are ready for installation. The arc 10 four-meter dipoles are making their way through the measurement process and will soon be outfitted with vacuum chambers and synchrotron radiation compensation coils. The magnet refurbishment bay double bridge crane has been installed, and the area is being organized to support arc dipole refurbishment.
Environment, Safety, Health and QualityApplying JLab Work Safety Principles at Home
Many Americans are not exposed to safety information that could help them work around the house safely, resulting in many injuries at home. Recent information from the National Safety Council listed, in one year, about 3.5 million on-the-job injuries; there were 8.2 million injuries off the job, evenly split between injuries in public areas and injuries at home.
You can reduce your risk of injury at home by following some of the same safety principles you use at JLab:
Computing and Networking InfrastructureWindows Patch Delivery Set for Today
Microsoft has released several critical patches for Windows systems. Due to the nature of these patches, the CNI group has decided to send them out to all Computer Center-managed Windows machines starting tonight. If you work on one of these systems, log out of all desktop computers at the end of your workday on Wednesday, but leave them powered on so that the patches can be installed. If you experience difficulties with your computer in the morning, reboot to see if that fixes the problem before calling the IT Division Helpdesk at x7155 for assistance.
Maintenance Day Scheduled for Tuesday, 5-7 p.m.
The CNI group is planning a maintenance period for 5-7 p.m. on Tuesday, March 22. During this time, the Hall D webserver, halldweb1, will be unavailable while it is transitioned to a new server. In addition, several other web servers may experience short outages while configurations are upgraded.
Linux Patches Scheduled for Maintenance Day
Additonally, the CNI group will be pushing out Linux patches to all desktop systems onsite. Plan to reboot your Redhat Enterprise Linux system on the morning of Wednesday, March 23, to complete the patch installation. The public Linux systems, jlabl1-4, will be rebooted on Tuesday evening to complete patch installation.
AnnouncementsAnnual Property Validation Underway
Nearly every employee at JLab is a property custodian. A property custodian is responsible for the proper use, control, physical protection and disposition of his or her assigned property. Part of this responsibility includes property validation and taking the Property Custodian Refresher training on an annual basis. Each custodian must log in to their Property Validation account and validate each item on their respective inventory list and take the Property Custodian Refresher GEN 150 training (about 5 minutes) before COB April 30.
Annual Key Validation Also Underway
Every person who has been issued one or more JLab keys must validate each key issued to them during the property validation period. If you currently have any non-essential or non-functional JLab keys, return them to Dennis Merritt, Mail Stop 28G. Any questions about the validation should be e-mailed. Note: The key validation webpage link only works onsite. To complete the key validation from offsite, e-mail Dennis Merritt with your first and last name, your key ID number and the key serial number (usually a separate, a one- or two-digit number located above the key ID number).
JAG Seeks Design Entries for JLab 2011 T-shirt Contest
The Jefferson Activities Group is looking for the winning design for JLab's 2011 T-shirt design contest. The deadline for submitting designs is Friday, March 25. Each submission must include a front (pocket) and back design; "Jefferson Lab", "DOE", "JSA, LLC" and "2011" must be incorporated into each design submission. All entries must include the entrant's name(s), division and telephone number; all entry requirements can be found on the JAG website. The winning design will be unveiled at JLab's annual Run-A-Round, and the winning designer(s) will receive a free T-shirt and recognition. View past winning T-shirt designs.
Tracking Thomas at JLab
The lab's bust of Thomas Jefferson has been touring the lab. Each week, a new picture of Thomas will be unveiled when the Briefs go out on Wednesdays. If you can identify his location, e-mail Kandice Carter with your guess. The first correct response will receive special recognition on this page and in the JLab Weekly Briefs. Guesses are accepted through Fridays. Good Luck!
JLab Calendar of EventsMarch 28: Safety Shoe vendor onsite
March 29: Science Series Lecture - DNA: The Strand That Connects Us All
April 8-9: QCD Evolution Workshop
April 11-15: DIS2011
April 19: Science Series Lecture - The Science of Chocolate
April 20: JLab's Annual Region II Teacher Night