Jefferson Lab Weekly Briefs
April 6, 2011

12 GeV Upgrade

The pre-construction meeting for the beam switchyard addition contract was held on March 28 and included initial discussions on installation details for the new tunnel penetrations. The cooling towers for the North and South Access low-conductivity water upgrades have been set on the structural steel framing. The Hall D construction contractor is finishing the formwork for the 3-foot-thick concrete roof on the Tagger Area. The concrete pour, totaling approximately 700 cubic yards, is anticipated the week of April 11. 

Physics

Hall A has been in a smooth production mode this week for the short-range correlations experiment, except for one problem that caused a loss of a day. During a spectrometer move, some cables snagged on the power cord of a vacuum pump for one of the quads on the spectrometer, causing the insulating vacuum to degrade. Future spectrometer moves during this running period will be coordinated by qualified techs with inspection of the area to verify no obstructions. However, apart from this problem, the experiment efficiency has been very high and the data looks good.

Hall B has completed a re-commissioning run for the photon tagging system. Scintillator counters of the photon tagger were removed before the Two Photon Exchange experiment to prevent exposure to high radiation during that run. The tagger focal plane detectors (over four hundred scintillators) were reinstalled after the TPE run was completed and a calibration run with CLAS and a liquid hydrogen target took place March 25-31. The goals of the calibration run were to verify the working order of the counters and collect enough data in exclusive channels to be able to check energy calibration (focal plane alignment) of the tagger. The Hall B tagger and the CLAS detector performed well during the run. Some broken counters were identified and will be repaired. A total of 1 billion triggers were collected with a single- and two-charged-track triggers to check energy calibration of the tagger. The Hall B tagger is ready for the upcoming G14-HD experiment.

Hall C was down until last week while a gasket was replaced on a leaking bellows flange near the dump. Water cooling was added to the bellows, which showed signs of heating from the beam. In addition, the bellows was instrumented with several temperature sensors to monitor beam heating effects. Since these repairs, Q-weak has returned to production data taking at currents up to 160 microamps with high efficiency.

Accelerator

Last week, the CEBAF accelerator delivered beam to all three halls with 92.5 percent beam availability. The highest combined current out of the injector was 190 microamps. Hall A was off for several hours due to a configuration change. The Hall C vacuum issue was resolved by Tuesday, and the hall started to take high current beam. After finishing its tagger calibration Thursday morning, Hall B stayed offline for HDice installation. On Sunday, the laser spot was moved to maintain high current for Q-weak.

Free-Electron Laser

The FEL team switched the system back to infrared operations and successfully lased at 1 micron and provided continuous wave electron beam in preparation for mirror and Terahertz tests in the coming week. The team also had a significant presence at the 2011 Particle Accelerator Conference in New York, with several papers and posters.

Engineering

The Survey and Alignment (Metrology) group has measured and run quality control checks on the space frame and end cans for the next C-100 cryomodule. Metrology also fiducialized an R-100 cryomodule, the 12 GeV QP magnets and the Hall A g2p septum magnet. Fiducialization is a process that relates a component's mechanical and/or magnetic center to  targets on the exterior. These targets are then used to position the component in the ideal beam location in the accelerator or end stations. The magnet measurement group continued to measure and qualify the XP family of 4 meter dipoles that will be installed in pass 10 of the west  arc. Twenty of the 37 XPs have been measured so far. No problems have been identified.

Environment, Safety, Health and Quality

Safety Reminder from Radiation Control
To minimize the intake of radioactive material by personnel, smoking, eating, and chewing are not permitted in radiological areas. This is documented in the RadCon Manual, the General Access RWP and Radiation Worker I training. In addition, there are signs in work areas stating this fact. Disregarding this and similar requirements may lead to your training and authorization to work being revoked and can lead to unnecessary and possibly harmful radiation exposures.

Spring Yardwork without the Headaches
Springtime often means digging in the yard. However, do you know where your utilities are buried? A free service is available to help you locate buried gas, electrical and water lines and communications cables. Simply visit the Virginia Miss Utility website or call 811 or 1-800-552-7001 at least three working days before you plan to dig. Any time you plan to dig in your yard, make sure you use CARE: Call before you dig; Allow time for marking; Respect the marks; and Excavate carefully.

Announcements

CCPR from Anywhere
The Information Technology Division is pleased to report that the CCPR system (Computer Center Problem Reporting) is now available from offsite. This is one of the steps in an ongoing effort to improve service for the JLab community and to fully address JLab community requests that have been received both before and during the IT survey. The CCPR link can be found on the Computer Center webpage.

Free Stock Has Furniture and Materials Available
Check out Free Stock before you order office furniture, supplies or materials for small jobs, or if you run short during a bigger job. Free Stock is located adjacent to the Stockroom in Bldg. 90, the Experimental Equipment Lab. The Free Stock inventory currently includes a variety of excess office furniture items, wiring, cabling, switches (resistors, connectors and other electronic items), fasteners (nuts, bolts and washers), and some general office supplies. Individuals with purchase accounts may access the list of Free Stock items in WebStock. In WebStock, click the Adv Search button and enter a search term. Free Stock items will indicate FREESTK as the source with $0.00 price. For more information, contact Lawrence Ferbee, x6297.

Refresher Session: Getting Your Paper Approved for Publication
Getting ready to have a journal article published or preparing to present results from JLab research at a conference or workshop? If so, plan to attend the Publications Refresher information session on Tuesday, April 12, 9-10 a.m. in CEBAF Center Room L102/104. The session will provide attendees with an overview of the process authors follow to have their papers reviewed and approved before public distribution. The process isn't difficult, but may be confusing for new staff and students as well as for individuals who haven't submitted a paper or other type of publication in recent years. Information sessions are held quarterly. Staff, users and students are invited to attend. Email Kim Kindrew to sign up for the session. Capacity is 40.

An App in Every iPot
Do you develop apps for Apple or Android products? Would you have an interest in sitting down with others from around the lab complex to exchange ideas and, perhaps, propose new apps for the JLab community? If your answer is yes, send a note expressing your interest to Dean Golembeski. Public Affairs is interested in hearing your ideas about apps and how these apps could enhance the lab's internal and external communication and outreach efforts.

Tracking Thomas at JLab
Little Thomas is in a new spot this week; even if you haven't been there, you could probably still guess the location. If you can identify his location, email Kandice Carter with your guess. The first correct response will receive special recognition on this page. Guesses are accepted through Fridays.

Congratulations to Jason Willoughby, who was the first person to correctly identify the March 30 location. Honorable mentions go out to Mike Martin and Elaine Zuchowitz. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.

JLab Calendar of Events

April 8-9: QCD Evolution Workshop
April 11: Safety Shoe vendor onsite
April 11-15: DIS2011
April 19: Science Series Lecture - The Science of Chocolate
April 20: JLab's Annual Region II Teacher Night
April 25: Safety Shoe vendor onsite