Jefferson Lab Weekly Briefs
June 27, 2012
12 GeV Upgrade
With the Long Shutdown in full swing, many employees have been assigned to other organizations to provide needed resource support. Although the work is often similar, the work environment could be different. These differences increase the potential for human error. Many management tools can be used to minimize this risk, such as interactive pre-job briefs, mentoring, maintaining a questioning attitude, repeat-back style of communication, review of training requirements, and frequent first-line supervision interaction. Consult with Dr. Chandler to assure "new" work assignments for employees are safe and appropriate.
Hall C technical staff and Q-weak collaborators continue to de-cable and dis-assemble the Q-weak experiment. The eight quartz main detector bars and the two large wire chamber packages have been dismounted and are being moved to storage.
Nuclear Physics: Exploring the Heart of Matter
Last week, the accelerator alternated installation work during day shifts with running of the Polarized Electrons for Polarized Positrons (PEPPo) experiment and the commissioning of superconducting radiofrequency cavities in cryomodule 2L23 during swing and owl shifts. Late Wednesday night, the water temperature for the injector chopper became unstable, eventually reaching a point where the chopper would not stay on. This forced PEPPo to end the night early. On Thursday, Engineering Support personnel were able to trace the problem to a loose connector for the chopper water heater; Operations also recovered from a problem that arose due to inadvertent operation of an electrical breaker during the replacement of a Lock Out Tag Out (LOTO) tag on a nearby breaker. Accelerator running was quiet for the remainder of the week and the weekend.
Next week, operations with the CEBAF injector will wrap up, and CEBAF will not resume operation until the start of the machine commissioning at 12 GeV, planned for Fall 2013. So, until "Humpty Dumpty" is back together again, the Accelerator brief will report on the Long Shutdown coordination activities. The LSD organization, modeled after last year's six-month shutdown, coordinates 12 GeV, FEL, Facilities, Maintenance and all other activities at the lab relevant to the LSD and tracks the overall progress of the work planned for the LSD. The LSD, started on May 18, is off to a good start. The first schedule progress report, collected at the end of May, showed minor delays that can be easily absorbed, and LSD coordinators look forward to the progress report at the end of June as a better indicator of the overall status. Last week, work in the tunnel focused on C100 cryomodule installation and the removal of the girders. De-installation of existing 6 GeV experimental equipment is continuing in Halls A, B and C. A big challenge for Facilities is to help vacate the Test Lab by the end of June to prepare for extensive demolition work in the Test Lab, and to assist in the transition to the Test Lab Addition, which is critical for supporting the SRF activities for the 12 GeV Project and external collaborators and customers.
Last week, the FEL team continued delivery of the third harmonic vacuum ultraviolet (VUV) beam at 124 nanometers to the Argonne National Lab/Old Dominion University users who are seeking to improve the sensitivity of atomic trap trace analysis experiments. This exercise provided valuable on-demand FEL operational experience, which will help guide development efforts for the FEL's main customer, as well as other users. At the end of the week, FEL staffers continued installation of the Darklight hardware in the 3F region of the infrared machine.
Center for Theoretical and Computational Physics
Unlike Wilson fermions, domain wall fermions (DWF) are a lattice fermion formulation that preserves chiral symmetry at finite lattice spacing. Given that chiral symmetry is an important property of QCD that spontaneously breaks due to quantum dynamics, it is important that lattice fermion formulations preserve this symmetry. In a new paper, an extension to the standard DWF formulation is presented, resulting in a potentially order of magnitude reduction of the computational cost of lattice QCD calculations that preserve chiral symmetry at finite lattice spacing. This would have significant impact on the JLab lattice QCD program to reliably compute observables that will be measured in future JLab experiments.
The magnet re-manufacturing area has been set up and is in a minimal operating status. The area delivered the first XD magnet for assembly and testing to the magnet measurement group. The CLAS 12 High Threshold Cerenkov Counter (HTCC) mold mirror facet block 2 assembly and the mirror assembly fixture for Hall B were completed. Additionally, 170 dipole-lengthening shims for 12 GeV were delivered. Thirty strip-line beam position monitors were also worked on.
The shop has received the new vertical milling machining center that is needed for reworking magnet cores associated with the 12 GeV Upgrade. It has been assembled and is mechanically operational; however, programming problems are still being resolved.
Facilities Management and Logistics
Pardon the progress being made in CEBAF Center. The L102/104 conference room is getting new doors and will be unavailable during removal of the old doors and installation of the new ones. The plastic sheeting is there to minimize the mess that will be generated during this process.
Environment, Safety, Health and Quality
Unintentionally Leaving Traps
These are just some examples of traps that may be unintentionally set for co-workers – don't be the source of one.
Computing and Networking Infrastructure
Network Maintenance Planned for Tonight
New JLab Email to Report Phishing, Spam Emails
Cyber Attacks can also begin on the phone. Remember, JLab IT staffers will never call you to ask for your user name or password. If you receive a call asking for this information, note the phone number if you are able, hang up, and immediately report the call to the Helpdesk. Any time you experience any difficulties with your computer or you have any doubt about the validity of a message, contact the IT Division Helpdesk, x7155, for advice.
Email Migrations into New System Continue
JLab Personal Dosimeter Change Out Set For Monday
JSA Initiatives Fund Call for Proposals Announced
Tracking Thomas at JLab
Congratulations this week go to Bryan Moffit, who was the first person to correctly identify the location for June 13 and June 20. Honorable mentions go to Buddhini Waidyawansa, Narciso Gomez, Michael Darcy, Dick Owen, Percy Harrell, Doug Higinbotham, Zhe Chen, Eric Forman, Josh Magee and Ron Bartek. 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
July 4: Independence Day holiday, JLab closed