JLab Weekly
Briefs |
Jefferson Lab Weekly Briefs
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12 GeV UpgradeOver the last few months, four independent reviews have been held of various physics detector systems, and five more reviews are planned in April and May. These reviews give valuable feedback to the scientists and engineers as they complete system design packages in preparation for the July 2008 DOE SC Office of Project Assessment Independent Project Review. Last week, the Hall D tracking and related particle identification systems were reviewed. During the closeout, reviewers provided high marks on progress in the last year and the quality of the presentations. A review of the CLAS12 Silicon Vertex Tracker detector will be held this week. Both Halls B and C are in the final preparations for a design review of their seven superconducting spectrometer magnets. In Hall C, particle background simulations are ongoing to finalize the shield house design.PhysicsHall A has successfully completed installation activities for experiments E04-007 (Pi-Zero Electroproduction near Threshold) and E08-007 (GEp/GMp at low Q2-values) on schedule. On Monday, March 31, the cryotarget system was cooled down as the final step before taking beam into the hall.
AcceleratorThis week saw the Scheduled Accelerator Down (SAD) come
to a successful conclusion and the ramp up of Accelerator Operations to
get ready for beam delivery to the experimental halls. Various factors
made the optics setup very difficult. However, an excellent setup was
achieved after some very hard work by many staff members. Production
beam delivery was started to all three experimental halls. Efforts of
Note:
Free-Electron Laser (FEL)FEL staff continued preparations toward producing
high-charge bunches in the gun test stand by optimizing drive laser
performance and revisiting the PARMELA modeling to account
for the final configuration. The team is working to produce and measure
the bunches as this is being written. Staff also finished mapping
the last sextupole and received a new ultra-sensitive terahertz (THz)
detector for that lab. Theory CenterRecently, Myhrer and Thomas showed (arXiv:0709.4067 [hep-ph]) that the fraction of the spin of the proton carried by its quarks, now experimentally around 33 percent, can be understood in terms of the basic features of its nonperturbative structure, namely relativity, chiral symmetry and the one-gluon-exchange hyperfine interaction. A new Theory Center paper (arXiv:0803.2775 [hep-ph]) has now shown that the missing spin is actually carried as orbital angular momentum, primarily by up and anti-up quarks. While this picture changes dramatically under QCD evolution, the predictions are in rather good agreement with recent lattice calculations, as well as with the recent results from deeply virtual Compton scattering from JLab and Hermes.AnnouncementsProperty Custodians Must Complete Validation of Personal Property by April 15The annual property custodian validation process continues through April 15. Each custodian must "validate" all of the items on his or her inventory list and take the Property Custodian Refresher GEN 150 training (about 5 minutes). As noted in the March On Target newsletter, changes in the property program have reduced the number of items that the Lab must track and inventory. For example, the dollar threshold for “sensitive” items that have no electronic memory has been raised from $150 to $300. The validation link can be found on the JLab Insight page. On the Insight Front Page tab, look down the Personal Information column on the left, and click on the “Property validation” link. National Library Week is April 13 - 19 The 2008 theme is "Join the Circle of Knowledge@Your Library." Information Resources wishes to thank all JLab staff and users for their cooperation and support over the years. Information Resources staff takes your needs and concerns seriously and wants to provide the best resources possible. Tell us what you think: Complete the online survey. JLab Calendar of Events
April
4-5: USQCD All
Hands Meeting |
Environment, Safety, Health & QualityWith the weather starting to turn warmer, many of us are
starting another year of yard work. The American Society of Hand
Therapists suggests some basic gardening safety practices. It is
important to remember that yard/gardening activities involve many
repetitive tasks such as raking, weeding, digging and pruning. You can
help avoid injuries by following these safety tips:
"Suspect" Rigging Items Discovery A number of rigging hardware items (2-ton lifting shackles) discovered recently in the JLab machine shop did not have appropriate markings, such as manufacturer information. These rigging hardware items were identified as "suspect" using applicable DOE Suspect/Counterfeit item (S/CI) criteria. The items were withdrawn from use. These types of items present not only a potential personnel safety hazard but an operational threat to the success of critical equipment handling. Contact Brian Murphy of the Lab's Quality Assurance/Continuous Improvement Department at x5515 if you have questions about any materials or items that do not have appropriate required markings. Computing and Networking Infrastructure (CNI)
User Audit Starting |