12 GeV Upgrade

Twenty-eight of the 48 barrel calorimeter (BCAL) modules for Hall D have arrived at JLab from the University of Regina, Saskatchewan, with four more expected in early May. Following a successful construction readiness review, assembly of the forward drift chamber cathode and wire planes is underway. The custom preamplifier ASIC, used for the forward and central drift chambers, has been ordered via the MOSIS service at the University of Southern California. First shipments of the lead-glass blocks have arrived from Indiana University for the forward calorimeter for Hall D.

Physics

Last week, Hall A took beam for the x > 2 experiment, except for the target change, which required three days, as planned. Over the weekend, x > 2 ran smoothly, making good progress on its run plan. On Saturday morning, there were some instabilities in the accelerator, which were fixed by the afternoon. Otherwise, beam delivery has been great.

In Hall C, the Q-weak experiment completed data taking for an auxiliary measurement of the asymmetry of the electro-induced proton to Delta transition. Production data taking continued with elastic scattering on liquid hydrogen.

Research Assistantship Nominations Due May 31
JLab has extended the deadline for candidates from SURA universities for a research assistantship. The program will sponsor a minority undergraduate student to work on projects that are part of the lab’s research program or directly related to the scientific or engineering aspects of the research program. This assistantship is funded by the JSA Initiatives Fund and will provide funds to support the student at the university during the 2011-2012 academic year. Nominations must be submitted by the faculty sponsor before the student may apply. Faculty sponsors may obtain more information and submit their nomination online.

JSA Promising Young Scientist Program
The JSA Promising Young Scientist program is now accepting applications for the academic year 2011-2012. Applications are due May 2. With the support of JSA, the best and brightest postdoctoral researchers affiliated with JLab are invited to present a colloquium and meet with the faculty at one of the participating institutions. The candidates are assisted in crafting an accessible colloquium talk. Following the presentation, positive criticism is collected from the audience. Ultimately, this will provide the candidate with valuable experience when competing for permanent positions.

Accelerator

Last week, 278 microamps of combined beam current was delivered to Halls A and C, resulting in a CEBAF accelerator record for the integrated charge of 17.1 Coulombs extracted from the cathode in a 24-hour period. The beam availability was 74.2 percent. On Wednesday, the Central Helium Liquefier tripped due to 2K cold box oscillations. The cause of the oscillations has been under investigation. On Saturday, high-current beam delivery was interrupted due to machine instability. Experts quickly identified the cause and resolved the issue; beam delivery was resumed without problems.

Free-Electron Laser

The FEL performed a temperature bump in the injector cryounit to drive off helium. This will permit high-current running tests at 2 microns planned for the coming weeks. The FEL team also installed the required 2.2 micron optics and began setting up the machine for this effort.

Theoretical and Computational Physics

In a recent paper <arXiv:1104.4101>, the volume dependence of the octet baryon masses and relations among them were explored with lattice QCD. A comparison of the volume dependence with the predictions of heavy baryon chiral perturbation theory was performed in both the two- and three-flavor expansions, and predictions of the three-flavor expansion for the hadron masses were found to describe the observed volume dependences reasonably well.

Engineering

Mechanical Engineering reports preparations are continuing for the six-month down. The existing dipoles in both the east and west arcs need to be removed from the tunnel, brought to the surface to the magnet measurement test facility (General Purpose Building #36), refurbished and then re-installed back into the exact positions they were in prior to removal. Currently, the group is conducting refurbishment practice, manufacturing of fixturing and documentation efforts.

Additionally, the magnetic measurement of all the XP-style magnets has concluded, with vacuum chambers, magnet pairing and magnet locations  now assigned. Synchrotron radiation coils for the XPs are being manufactured and installed, along with vacuum chambers. All of the Arc 10 quadruples have been mounted on girder assemblies and have been moved to storage pending installation.

Part of the refurbishment efforts include installing an H-steel return leg, which is needed to reduce the field saturation caused by the higher energies running at 12 GeV. The H-steel required for the west arc during the six-month down has arrived, and shipments of H-steel required for the remainder continue to arrive weekly.

Several new families of dipole magnets have arrived for the spreader/recombiner/extraction regions of the accelerator. The septa contract was awarded to a new vendor and all of the material has been transferred and inventoried to begin manufacturing.

Environment, Safety, Health and Quality

Inspecting Safety Equipment
When was the last time you inspected your safety equipment? Independent inspectors critically assess big items, such as fall protection, on a long-term, periodic basis. However, you should check your safety equipment before each use in the event of damage during the last use or storage. Here are some tips for checking commonly used items:

• Are your safety glasses scratched or are the temple bars bent? These need to be fully functional.
• Are your gloves the correct type for the hazard and are they intact, with no holes or ripped seams?
• Is your hearing protection clean and functional?
• When was the last time you cleaned your respirator, if you have a reusable type? Cleaning is required after every use, and it must be stored in a dust-free and protected manner.
• Do you wear safety shoes where needed, and are they in good shape?
• If you have other types of personal protective equipment, such as face shields, aprons or coveralls, are these in good shape?

Take a few seconds to inspect any personal protective equipment before use; your well being could depend upon it.

Announcements

Check Training for Shutdown Activities
If you are going to be involved in work related to the six-month shutdown, check your individual training plan to make sure all of your training is current. If it will come due during the down, you might want to get it taken care of before the down is underway. Check with your supervisor to see if any new training will be required for specialized work you will be undertaking during the down.

Pressure Systems Fundamentals Class Offered
*Editor's Note: Class Location Changed* Will Oren will offer a class on "Pressure Systems Fundamentals" on Friday, April 29, 9-11 a.m. in CEBAF Center room F113. This class will fulfill the requirement for skill SAF130A. Register online.

Annual Property Validation Ends This Week
All property custodians must log in to their Property Validation account and validate each item on their respective inventory list and take the Property Custodian Refresher GEN 150 training (about 5 minutes) before COB April 30.

Annual Key Validation Ends This Week
Every person who has been issued one or more JLab keys must complete their key validation by COB April 30. Non-essential or non-functional JLab keys should be returned to Dennis Merritt, Mail Stop 28G. Note: The key validation webpage link only works onsite. To complete the key validation from offsite, email Dennis Merritt with your first and last name, your key ID number and the key serial number (usually a separate, a one- or two-digit number located above the key ID number).

Onsite TIAA-CREF Counseling Offered
TIAA-CREF will offer individual counseling sessions onsite on May 19-20. In these sessions, employees can discuss their personal financial situation with a TIAA-CREF consultant on a confidential basis. To discuss your plan and options for managing your retirement savings or to schedule an appointment with a TIAA-CREF individual consultant, call TIAA-CREF at (800) 732-8353, Monday-Friday, 9 a.m.-8 p.m.

Run-A-Round Is Set for May 11
The 26th annual JLab Run-A-Round will be held Wednesday, May 11, 3-6 p.m. JLab staff, users, students, full-time contractors and immediate family members are invited to participate. Staff and users who participate in the run or who volunteer can receive a free 2011 JLab T-shirt. Online registration is open on the JAG webpage. All runners/walkers must register before 5 p.m. on Tuesday, May 10, to be eligible for prizes. Race bibs will be available for pickup on Wednesday, May 11, 9 a.m.-2:30 p.m. in the CEBAF Center lobby.

Radiation Worker Classes Scheduled
The next full day in-person Radiation Worker I class and half-day Radiation Worker II class will be scheduled slightly out of turn on Wednesday, July 6 and Thursday, July 7, respectively. Normally, these courses are offered the first and second Tuesday of each new quarter. Visit the Training website to sign up. Questions may be addressed to Maya Keller, x6021.

Tracking Thomas at JLab
Little Thomas has headed indoors to escape the pollen. If you can identify his location, email Kandice Carter with your guess. The first correct response will receive special recognition on this page. Guesses are accepted through Fridays.

Congratulations to David Fazenbaker, Jason Willoughby and Stephanie Vermeire, who were the first people to correctly identify the April 20 location. Honorable mentions go out to Percy Harrell, Brian Kross, Will Oren, Mary Beth Stewart, Greg Adams, Narciso Gomez, Dick Owen, Russell Mammel, Casey Heck, Lori Zukerman, Calvin Mealer, Jim Follkie, Mike Martin, Brita Hampton, Stephen Smith, Susan Brown, Greg Marble, Johnie Banks, Tonya Evans, Evelyn Akers, Doug Higinbotham and Dena Polyhronakis. 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

May 3-4: CEBAF Pre-Shutdown Safety Meetings (All Staff)
May 6-7: USQCD Collaboration Meeting
May 9: Safety Shoe vendor onsite
May 16: Nucleon Resonance Structure Workshop
May 17-20: NSTAR 2011
May 23: Safety Shoe vendor onsite
May 30: Memorial Day holiday - JLab closed