Jefferson Lab Weekly Briefs
December 19, 2012
12 GeV Upgrade
As work activities related to the 12 GeV Upgrade Project pick up in the experimental halls, personnel need to be aware of changing conditions. For example, the upcoming cooldown of the large solenoid magnet in Hall D will result in changes to the Oxygen Deficiency Hazard (ODH) ratings in Buildings 200, 203 and 204. An email notification of this change was sent out to alert all employees. Personnel need to ensure that they review all current postings, even if they are entering a familiar area, and comply with their instructions.
2013 Postdoctoral Research Prize Deadline Nears
2013 Outstanding Nuclear Physicist Award Deadline Nears
The FEL team has held detailed scheduling meetings as members prepare for the start of operations in January. The team achieved an optical contrast ratio of nearly five orders of magnitude in the drive laser pulse contrast improvement project. Also last week, following gun conditioning, the cathode was cesiated and found to be in excellent condition.
Center for Theoretical and Computational Physics
The predictions of a three-Pomeron model for total, elastic and inelastic cross sections at high energies are confronted with new proton-proton data from the Large Hadron Collider (LHC) and proton-antiproton data from the Tevatron. The LHC data from the TOTEM, CMS, ALICE and ATLAS collaborations, alongside the D0 data from the Tevatron, are found to be in good agreement with the predictions. The model can be used in the future to study diffractive vector meson production at JLab in the 12 GeV era.
The alignment group has completed the stand alignment in the west recombiner and west spreader. These stands are multi-arm stands, which each can hold multiple girders and/or bending dipoles and are difficult to align. Additionally, the group completed the preliminary alignment of all the components in the east spreader. This initial alignment is to a tolerance (+/- 1 millimeter) that allows the vacuum, electrical and installation groups to complete their necessary hookups. A final alignment to less than a quarter millimeter tolerance will follow when the other groups complete their work.
The dogleg magnets in the southwest/northeast extractor regions were checked and aligned. Using the controller box and the mechanical adjustment system, the magnets were aligned to the revised control monuments and exercised to their extreme limits. A dogleg magnet is typically moved whenever additional range is needed for path-length correction, which adjusts the phase of the beam with respect to the downstream linac. This is the first time the dogleg magnets have been moved in 15 years. Physical movement of the dogleg magnets can provide up to 24 centimeters of beam adjustment (18 degrees of radiofrequency phase), and using the magnets' magnetic deflection can provide an additional 24 centimeters and 18 degrees of phase, if needed.
Additionally, the alignment crews are providing support in all the experimental halls. Hall A's Moller magnets have been aligned; Hall B's region 2 and 3 detectors have been fiducialized; Hall C's control is being upgraded following removal of the Short Orbit Spectrometer carriage and experimental equipment; and work continues in Hall D with the alignment of the main equipment.
Environment, Safety, Health and Quality
Don't Do the "Twist & Shout"
In short, do not hold items and twist around to lay them down or even twist around to pick them up. You will be doing the old dance - twisting and then shouting in pain! For more information on proper lift technique, see this OnTarget article.
Quark Cafe's Annual Holiday Bake Sale
Radiation Worker Classes Offered in January
Reminder: Limited Cafeteria Service on Friday, Dec. 21
Dosimetry Changeout Reminder
Tracking Thomas at JLab
Congratulations this week go to Jason Willoughby, Debra Brand, Samika Hawkins and Doug Higinbotham, who were the first to correctly identify the location for Dec. 12. Honorable mentions go to Annie Tran, Michael Haddox-Schatz, Harry Fanning, Deborah Dowd, Anusha Liyanage, Robert Martin and Tony Dela Cruz. Check out the Tracking Thomas webpage for a better view of his last location and this week's new mystery photo.
JLab Calendar of Events
Dec. 20: Quark Cafe's Holiday Bake Sale