Jefferson Lab Weekly Briefs February 17, 2016
Jefferson Lab Weekly Briefs
February 17, 2016
In November 2015, the heating element for the current lead mass flow overheated the lexan-like cover around the Super High Momentum Spectrometer Q1 magnet leads in Hall C, causing a small fire. The thermometers of the lead mass flow heaters were cross-connected so that the thermostat controls were not properly matched to the correct heater. The top of the cryo can is congested with piping, valves and associated wiring, so tracing the lines visually is difficult. This is compounded when equipment is similar and not labelled or otherwise identifiable. The system initial setup was done in February 2015, and parties are not aware of any changes that were made to this setup since then.
Statement of Lessons Learned:
Jefferson Lab Published Journal Articles, Feb. 8-12
Remember to submit your papers for approval to the Jefferson Lab Publications database.
Publications Refresher Course Offered Feb. 23
Apply Now for the Graduate Fellowship Program at Jefferson Lab
JSA Offers Sabbatical and Research Leave Support at Jefferson Lab
Center for Theoretical and Computational Physics
A new set of parton distribution functions (PDFs) from the CTEQ-Jefferson Lab collaboration (dubbed "CJ15") has been presented, which take advantage of developments in the theoretical treatment of nuclear corrections as well as new data. The analysis includes, for the first time, data on the free neutron structure function from the BONuS experiment at Jefferson Lab and new high-precision charged lepton and W-boson asymmetry data from Fermilab. These significantly reduce the uncertainty on the down-quark to up-quark PDF ratio at large parton momentum fractions x and provide new insights into the partonic structure of bound nucleons.
The Machine Shop is presently manufacturing or continuing to manufacture the following items. For Hall A, the Super BigBite Spectrometer conical vacuum chamber has been complete and manufacturing of all related shielding continues, a gear motor diffuser support assembly is being manufactured, and workers are estimating the cost to fabricate a personnel access target system platform. For Hall B, stainless steel parts for the dilution refrigerator for the HDice experiment are being manufactured, and modifications of the cryogenics helium vessel nozzles are being made to obtain the proper length. For Hall C, horizontal mirror box assemblies, viewer tubes and connectors are being made. Additionally, various small machining jobs are underway for lab customers.
Jefferson Lab Calendar of Events
Feb. 18: Colloquium and Public Lecture: Tunnel Visions by Micheal Riordan
Environment, Health, Safety and Quality
Niels Bohr is credited with saying, "Prediction is very difficult, especially if it's about the future." This is especially true in the safety and health business, where we review work plans, processes and materials to mitigate hazards today that may have effects that will only be seen in the future.
For example, it is not easy to predict whether or not occupational disease will manifest 20 to 40 years in the future for a particular individual, depending on that individual's biological constitution and a varying exposure pattern. However, the epidemiological sciences can show us that a population exposed to certain hazards will most likely suffer a known negative outcome down the road. Since we can't control an individual's susceptibility factors, we need to eliminate or control an individual's exposures.
At Jefferson Lab, the goal is to take precautions to prevent unnecessary exposure by, for example, substituting a less hazardous material, properly using local exhaust ventilation, and wearing respiratory protection or the correct type of glove or hearing protection. Taking advantage of these precautions today can prevent problems that are likely to manifest down the road.
Computing and Networking Infrastructure
Group Directory Survey Planned
As part of this process, IT personnel are doing some analysis to better understand our environment. One step we are taking is to better understand the directories housed on the group fileserver. If you are on Windows, you access this on the M:\ drive; on Linux/Mac, the equivalent is the /group directory. If you are the owner of a group directory, you will be receiving an email in the near future with a link to answer a few questions about the group and group directory. Please take the time to fill out this information, as IT Division personnel will be using that information to make some important upcoming decisions. As always, if you have any questions or concerns about this group directory audit, please contact the IT Division Helpdesk, firstname.lastname@example.org or x7155.
Watchguard Spam Quarantine Report Guidance Offered
Jefferson Lab Open House Set for April 30
Tunnel Visions - Colloquium and Public Lecture
Free Health Screenings Offered on March 23
2016 Annual T-Shirt Design Contest Is On
JLab Golf League Forming for 2016 Season
Ending Soon: Benefits Open Enrollment for All Regular and Term Employees
|JLab Weekly Briefs is an ongoing publication providing information on the status of safety, accelerator operations, experiments, free-electron laser, reviews, upcoming activities and special events. Deadline for submission is every Tuesday by 10 a.m. Submit new items to: Public Affairs or contact Kandice Carter at x7263.|