Jefferson Lab Weekly Briefs April 1, 2009
Jefferson Lab Weekly Briefs
April 1, 2009
12 GeV Upgrade
The plans for installation of 12 GeV equipment in the experimental halls have been reviewed. In preparation for this, hall technical and scientific staff mapped the 12 GeV schedule into detailed installation schedules typically used for hall work coordination. The review committee checked timelines, logic of task sequence and manpower requirements. Valuable recommendations were made to further streamline installation schedules, formalize involvement of support groups and assign laydown spaces, amongst others.
In Hall C, the BigCal electronics platform and surrounding concrete bunker have been removed. The removal of 2,000 signal and high-voltage cables, weighing approximately 5 tons, was also completed. With the completion of these tasks, work on extending the raised concrete floor has started. This floor will allow the High Resolution Electron Spectrometer and the High Resolution Kaon Spectrometer to be moved into position for the upcoming hypernuclear experiment (E05-115).
The second week of the scheduled accelerator down went well. Work on Gun2 high-voltage chamber vacuum continued. Cryomodules NL12 and SL07 were installed; cryomodule SL15 was removed. General maintenance items continued to be addressed. A Personnel Safety System functional certification was complete. A Low-Conductivity Water leak was found near the Free-Electron Laser building in underground piping. The excavation started over the weekend. The modification and repair of the piping will start soon.
Free-Electron Laser (FEL)
FEL staff made great progress in getting set up and taking initial run data for the Light Pseudoscalar and Scalar Search experiment last week. As a sidelight, the new Optical Transport System is proving to be much more stable against drift than the previous system. By Friday, the team was on its way toward completion of that experiment when a major underground rupture in the CEBAF/FEL low-conductivity water feed shut the FEL down. The full impact to the schedule has yet to be determined.
When calculating the hadronic spectrum in a lattice QCD calculation, it is necessary to extract the masses of the states from the hadronic correlators, usually by multi-exponential fitting or the variational method. In a new paper <arXiv:0903.2314 [hep-lat]>, an extension to the commonly used "effective mass" technique is derived, which uses simple analytic formulae to extract both ground and excited-state masses. These black-box methods, which do not require initial conditions or hand-tuning, provide a simple and useful alternative to current methods.
JLab's Safety Numbers
86 Days since Last Recordable Accident (JLab record: 331)
JLab Calendar of Events
April 14: 12 GeV Upgrade Groundbreaking
Environment, Safety, Health & Quality
The Quality-Value-Safety triad is one of the most important aspects of our quality assurance work at JLab. When a problem or opportunity for improvement arises, all three criteria should be balanced in order to propose a feasible solution. To meet these criteria, the fundamental questions are:
The Space Shuttle Challenger disaster shows the importance of using all three criteria to make a balanced decision. NASA managers had known that the contractor design of the solid rocket boosters contained a potentially catastrophic flaw in the O-rings since 1977. They continued, however, to use the design. NASA then eliminated an extinguishing system for solid rocket motors because of cost and weight, reducing the cost by about $100K-$375K per motor. The safety aspect of the Quality-Value-Safety triad was not properly addressed, a significant shortcoming with disastrous consequences.
Computing and Networking Infrastructure (CNI)
Beware of Suspicious Holiday E-mail
In general, this has been a tough year. One security provider (www.scansafe.com) has reported that in 2008 there was a six-fold increase in malware and a 16-fold increase in data-theft trojans (those that steal your passwords, credit card information, etc.). This increase seems to be associated with the difficult economic times. At the lab, we have seen a substantial increase in the last two months in systems that had to be rebuilt due to infections.
One good rule of thumb to follow is to always be suspicious of documents and links whose source is unknown.
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