Jefferson Lab Weekly Briefs
July 11, 2012
12 GeV UpgradeThe new SL23 zone (C100-5 cryomodule and new radiofrequency system) has been operated at 109 Megavolts in the linac; a full test with beam loading will be done later. Testing of the latest new zone (C100-4 and associated new RF) has begun. Deliveries of new klystrons now exceed the 80 needed for the 12 GeV installations. Removal of the beamlines from the tunnel is making good progress: the east and west recombiners and the west spreader have been removed; removal of the east spreader is underway. The first fully reworked spreader/recombiner dipole magnet, which included modification to the iron core, has been tested; field measurements were within specifications, giving further validation to the design model used for these complicated magnets. All M15 and M20 beam position monitors are ready for installation on the new beamline girders. Progress on the Hall D 4.5 Kelvin refrigerator continues, with installation of the pan legs and nitrogen separator. The vendors for the major components of the Central Helium Liquefier-2 4.5 K plant are on-site completing their work, including installing the very large transfer line for the coldbox. All of the high-voltage power supplies for the beamline ion pumps have been received.
PhysicsWith 6 GeV de-installation essentially complete, a program of necessary maintenance and repair work in Hall A is underway. Efforts directed at first 11 GeV era experiments has begun, with work progressing on the beamline and Compton and Moller polarimeters.
In Hall C, the Q-weak target has been removed from the beamline, and other Q-weak de-installation work continues, including the removal of the Qtor power supply and many shielding blocks from the hall.
Long ShutdownOperations of the injector ended on June 29 with two days of beam studies after the successful run of the PEPPo experiment. LSD activities are in full swing in the accelerator enclosures, buildings and in the halls. The Test Lab was vacated by Superconducting Radiofrequency Institute personnel and equipment on July 2, and after a few days of preparation, the main demolition work in the Test Lab starts this week. SRF personnel are now fully focused on the challenging task of getting the new Test Lab Addition (TLA) ready to support SRF activities and production again: rooms needs to be certified, equipment must be reconnected and recommissioned, and all that requires an enormous amount of coordination and cooperation within SRF and the entire laboratory.
Free-Electron LaserThe FEL team had a very good start of operations of the infrared beamline with the DarkLight experiment in place and was even able to set up the beam to allow an initial target insertion. The team was able to get the beam cleanly through the 6 mm aperture and is presently optimizing the machine for transmission through the 2 mm aperture.
Center for Theoretical and Computational PhysicsA collaboration of theorists and experimentalists from JLab and Hampton University has completed an analysis of the impact of the nuclear dependence of the longitudinal to transverse cross section ratio R=σL/σT on the extraction of ratios of structure functions of heavy nuclei (A) to those of deuterium (D), F1A/F1D and F2A/F2D. Guided by world data indications of a small enhancement of R in nuclei compared to hydrogen, the analysis of selected EMC, BCDMS, NMC and SLAC data sets revealed that the nuclear enhancement (antishadowing) for F1A/F1D in the interval 0.1 < x < 0.3 becomes significantly reduced, suggesting that antishadowing is dominated by the longitudinal structure function, FL. Precise measurements of nuclear modifications of R and FL, including those at JLab, have the potential to constrain the poorly known gluon distribution in nuclei over a wide range of x.
EngineeringHall D Cryogenics Design and Installation
Fabrication and installation of the warm gas management control valve rack and gauge panel were completed. Fabrication and installation of the warm helium and cooling water wall piping continues. Fabrication of the cryogenic valve box that will sit on top of the four coils of the superconducting solenoid magnet is progressing. The helium and nitrogen vessels, shield system, and some internal piping and instrumentation have been installed inside the vacuum vessel. Work on the programmable logic controller and input/output controller software and the accelerator control system (EPICS - the Experimental Physics and Industrial Control System) control screens is progressing.
CHL2 Warm Compressor and Warm Gas/Oil/Water/Air Management Systems
Work continues on the final phase of piping installation for the warm compressor systems. PHPK personnel arrived on site in June and installed the primary motor-to-compressor couplings and completed motor alignments. PHPK also completed repairing defective instrumentation identified during the initial checkouts of the compressor skids.
CHL2 300 - 4.5 K Coldbox Systems
Linde and PHPK have returned to JLab and are continuing assembly of the 300 - 60 K outside and 60 - 4.5 K inside coldboxes. This work will take several months. JLab has installed the PLC control termination enclosure on the mezzanine of the 4.5 K coldbox and completed installation of the cable tray and duct system containing the control and power field cabling. Work has begun to terminate the cabling. Large headers connecting the compressor and coldbox systems have been installed.
CHL and Linac Summer Shutdown
Planning continues for the CHL and Linac warmup scheduled to begin in mid August. The CHL1 cryogenic system will be shutdown and the Linac warmed to room temperature until January. This will allow modifications to the Linac piping systems to enable the installation of the remaining 12 GeV cryomodules. It will also allow maintenance tasks on the transfer line systems to be completed.
End Station Refrigerator and Cryomodule Test Facility Refrigerator
The ESR was shut down and cryogenic equipment in the halls was warmed to conserve utilities during the Long Shutdown. The ESR will be restarted in January. The CTF was recently shut down to allow demolition and refurbishment work to continue in the Test Lab. The CTF will be restarted in approximately 6-8 weeks.
Environment, Safety, Health and QualityResolving ES&H Concerns
To ensure the welfare and productivity of its workforce, JLab has several mechanisms for employees, or anyone who comes into contact with the lab, to report issues potentially affecting the safety of workers, visitors, lab neighbors or the environment without fear of retaliation or reprisal. ES&H Manual Chapter 2310 lists a variety of mechanisms for resolving and reporting ES&H concerns and for preventing similar concerns from occurring in the future. Here is a list of the options you have for resolving an ES&H concern:
Computing and Networking InfrastructureCNI Systems Maintenance Set for Tuesday, July 17, 5-10 p.m.
The CNI Systems Team is planning a maintenance period for 5-10 p.m. on Tuesday, July 17. During this period, the central scratch file server (jlabscr) will be replaced with a new system with more available space. In addition, the jlabscr file server will be available via Windows as jlabscrscratch. Central systems, such as jlabl1-4, will be rebooted once the new file server is in place to finalize the mounting of the new scratch area. Plan accordingly. Additionally, Windows and Linux patches will be pushed out to all desktop systems. Plan to reboot your system to finalize the patch installation on the following Wednesday. If you have questions or concerns, contact the IT Division Helpdesk, x7155.
AnnouncementJSA Initiatives Fund Proposals Due
Proposals for support from the 2013 JSA Initiatives Fund program are due by Aug. 3. 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.
Lab Voluntary Separation Program Application Deadline Approaching
The lab is currently accepting applications for the Voluntary Separation Program. As a reminder, employees who are eligible and wish to participate have until Thursday, July 19, to complete their applications to be considered for the program. To review the severance calculator, fill out the application, and/or review the All-Staff presentation slides, visit the program web page.
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.
Congratulations this week go to Harry Fanning, Michael Haddox-Schatz and Jim Follkie, who were the first to correctly identify the location for June 27. Honorable mentions go to Jason Willoughby, Subashini De Silva, Dave Fazenbaker, Dick Owen, Russell Mammei and Chris Perry. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.
JLab Calendar of EventsJuly 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
Aug. 6: Safety Shoe vendor onsite
Aug. 6-10: 7th International Workshop on Chiral Dynamics
Aug. 20: Safety Shoe vendor onsite
Aug. 22: Colloquium and Public Lecture
Sept. 3: Labor Day holiday, JLab closed