Jefferson Lab Weekly Briefs
April 11, 2012
12 GeV Upgrade
The first sector of the preshower calorimeter for CLAS12 is complete and has been tested successfully with cosmic rays. Stacking of lead sheets and scintillator bars threaded with wavelength-shifting fibers is also complete for the second sector and has been started for the third. Two of the CLAS12 region 3 wire chamber sectors are being strung at JLab. The fifth wire chamber sector for region 2 is underway at Old Dominion University, and the third region 1 chamber is being strung at Idaho State University. High voltage and readout boards are being added to wire chamber sectors that are strung, and cosmic ray testing is underway. The first complete module of the silicon vertex tracker barrel detector has been undergoing testing for two months, and layout improvements in the readout circuitry are being implemented.
Hall A is in a production mode this week, taking physics data for the g2p experiment at 2.2 GeV and completing a significant fraction of its momenta scan for this energy. Next week, Hall A will go to its first special energy for the g2p/gep runs and start its second scan.
Q-weak continued taking production data in Hall C using the liquid hydrogen target and an aluminum target for background determination. With the linac energy change, the collaboration is taking a set of low-current tracking measurements at 877 MeV. These measurements are in preparation for making a measurement of the parity-violating asymmetry of the Nucleon to Delta transition.
The week began with Halls A and C receiving beam and Hall B in Restricted Access to allow for replacement of the HDIce target with a new version manufactured in the Test Lab. On Monday, a faulty compressor in Hall A caused a fire alarm, interrupting beam delivery to the hall during repairs. The next day, the dump dehumidifier in Hall C failed, causing it to compromise the VESDA (Very Early Smoke Detection) system. This interrupted Hall C beam until it was fixed. By Tuesday evening, problems in both halls were resolved and beam operation was restored. While repairs were being conducted, the accelerator took advantage of some parasitic beam studies time to conduct model calibration tests in the arcs. All halls were up and receiving beam through an uneventful weekend.
The machine was run for several internal and external users this week and got good data in laser deposition, non-thermal ablation, and measurements of coherent synchrotron emission effects on the electron microbunches. The FEL team started some measurements on new infrared mirrors.
Facilities Management and Logistics
JLab will hold an Open House on May 19. In preparation for that event, the lab will conduct a sitewide cleanup May 7-11. The cleanup will involve all divisions and all employees. All managers are responsible for ensuring the participation of their individual staffs. The cleanup is not optional; Everyone is expected to participate.
The goal is to clean up individual work areas, as well as to remove scrap wood, cardboard, metals and other excess items that may have piled up over time both indoors and out. During the clean up, be careful not to mix recyclables. In other words, wood scrap goes into a wood dumpster, recyclable metals in their dumpster, and paper and other permissible recyclable office waste goes into the paper dumpster. If you will need a dumpster or other equipment to clean your area, contact Carl Iannacone, x5430, or Bill Brisiel, x7233.
The cleanup also will be an excellent time to identify excess equipment or furniture. You can contact the Property Office at x6270 for removal of these items.
JLab Calendar of Events
Environment, Safety, Health and Quality
Critters and Insects
Computing and Networking Infrastructure
The CNI group is planning a maintenance period on Tuesday, April 17, 5-7 p.m. During this time, updated software applications will be pushed out, and Windows and Linux patches will be released. Windows terminal servers will be rebooted to apply the latest patches and updated applications. More information on these tasks is available in the announcements below. If you have any questions or concerns, contact the IT Division Helpdesk, x7155.
Software Application Update on Windows
Delivery of Windows and Linux Patches
JAG Run-A-Round Registration Open
Help Make the Run-A-Round a Success: Volunteer!
William & Mary Hosts Public Colloquium Today
Tracking Thomas at JLab
Congratulations this week go to Kevin Banks and Narciso Gomez, who were the first to correctly identify the April 4 location. Honorable mentions go to Sam Holben, Casey Heck, Mike Mayer and Robert Martin. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.