Jefferson Lab Weekly Briefs
June 18, 2008
12 GeV Upgrade
The R&D task to re-measure the Higher-Order Mode (HOM) damping in the 12 GeV-style superconducting radio frequency (SRF) cavities is proceeding. Initial measurements are complete, and the data are being reviewed. The final lot of laminations for the prototype beam transport quadrupoles have been received from the vendor. Inspection is underway prior to beginning stacking quadrants.
Design status and safety reviews for three accelerator systems were held recently: the Cryogenics system, the Instrumentation, Controls & Safety systems, and the Beam Transport system together with the magnets of the Extraction system. The review panels found that the work is progressing well and is on track for completion consistent with the overall 12 GeV Upgrade Project schedule.
Data taking for E04-108 (Measurement of GEp/GMp at high Q2) was successfully completed in Hall C. The experiment successfully captured data at the highest momentum transfers for which the polarization transfer method of measuring proton form factors has been applied. In addition, facility development studies were done for the Q-weak experiment. These studies tested both a new type of luminosity detector and methods of minimizing asymmetry noise from target boiling. A large part of these studies was done parasitically to the experiment, allowing some of the time lost due to zero beam polarization to be recovered.
The Scheduled Accelerator Down began after nine hours of beam studies. The sitewide power transformer overhaul work was begun; it will continue with maintenance of one transformer at a time to limit disruptions to other maintenance activities. Injector work included electrode replacement and the installation of a direct current Verdi laser for cathode lifetime studies. The capture water supply pump was replaced, and vacuum leak checks in the North and South Linacs were started. Warmup of several cryomodules was started as the Central Helium Liquefier reduced cooling load prior to maintenance work on the CHL and running the facility at 4 Kelvin on the Standby Refrigerator (SBR).
In a new Theory Center paper, arXiv:0805.4629 [hep-lat], JLab staff and users review the status of lattice QCD calculations of hadronic interactions. In particular, computations of hadronic interactions (scattering lengths) in meson-meson and baryon-baryon scattering are considered. For mesonic systems, precision calculations have already been performed, while for the baryon sector, the authors argue that present-day computational resources, if devoted to these calculations, are capable of achieving reliable results.
Environment, Safety, Health & Quality
Floods are one of the most common hazards in the United States. Be aware of flood hazards no matter where you live, but especially if you live in a low-lying area, near water or downstream from a dam. Even very small streams, gullies, creeks, culverts, dry streambeds or low-lying ground that appear harmless in dry weather can flood.
Every state is at risk from this hazard. If a flood is likely in your area, follow these tips from FEMA to prepare:
Additional flood information and resources can be found on the FEMA website.
JSA Initiatives Fund Website Update
Red Cross Accepting Donations for Flood Relief
JLab's Safety Numbers
273 Days since Last Recordable Accident (JLab record: 319)
JLab Calendar of Events
June 30-July 2: Science & Technology Review