Jefferson Lab Weekly Briefs
March 10, 2010

12 GeV Upgrade

Deliveries of materials for the accelerator systems continue. Forty-two beamline quadrupole magnets have been delivered, as well as the first 10 of the cold tuners for the cryomodules. Of particular note is the receipt of the first article 4-meter dipole magnet for arc 10. Site visits and discussions were held with the vendor of the superconducting radiofrequency cavities, and the vendors of the cryomodule end cans and helium vessels. A team also reviewed the 4K coldbox vendor’s design package. A review was held of the magnet measurement and mechanical/electrical quality control plan for the beam transport magnets; the reviewers were generally pleased and gave constructive comments. The project received approval from DOE for the contract award package for the warm compressors to be used in the upgraded helium plant.


Hall B is getting ready for the g9-FROST run, a group of five experiments running in parallel to search for predicted excited states of the proton that so far have escaped detection. The experiment uses the energy-tagged photon beam in Hall B and a dynamically polarized butanol target, where the free hydrogen atoms have their spins aligned at a level of 80 percent or more. At the very low temperature of 30 milliKelvin, the spin polarization is "frozen" for about a week. After that, it will have to be regenerated. The target was built by the JLab target group and in a previous run showed a performance that is superior to similar targets at other laboratories. The target is now installed in the Hall B beamline and is ready to be inserted into CLAS. Thanks to Chris Keith and his team, the run can begin as scheduled.


The scheduled winter accelerator down ended Monday. Over the weekend, five-pass tuned beam was recovered to the beam switchyard dump. All issues encountered during the recovery of the beam were being addressed.

Free-Electron Laser

The FL03 cryomodule was cooled down to 2K in preparation for re-commissioning. The team also made progress toward upgrading the injector diagnostics. Work is underway to refurbish trim cards and deal with a corrosion issue in the infrared wiggler chamber. The FEL is heading toward resumption of beam the week of March 15.

Theory Center

A new Theory Center paper <arXiv:1001.2553 [hep-ph]> has shown that pion exchange in s-wave between hadrons, that are themselves in relative s-wave, can shift energies by hundreds of MeV, potentially leading to deeply bound quasi-molecular states.  In the case of the D*-D1 charmed mesons, a spectroscopy arises consistent with the enigmatic charmonium states observed in e+e- annihilation above 4 GeV. A search in the D-ar{D} three-pion channel is recommended to test this hypothesis, and the paper predicts an exotic JPC = 1-+ in the vicinity of the Y(4260) meson.

JLab's Safety Numbers

47 Days since Last Recordable Accident (JLab record: 331)
47 Days since Last Lost Workday Accident (JLab record: 676)

JLab Calendar of Events

March 10: Colloquium: Physics and Forensics
March 14: Daylight Saving Time begins
March 25: Safety Shoe Vendor onsite
April 14-15: AVS Mid-Atlantic chapter meeting and short course
April 21: JLab Teacher Night
May 1: Jefferson Lab Open House




Environment, Safety, Health & Quality

Lithium-ion batteries come in a wide variety of shapes and sizes and are often much lighter than other batteries with the same capacity. They do not suffer from memory effect and have a comparatively low self-discharge rate.

There are, however, several important safety considerations during use and upon disposal. Lithium-ion batteries are not as durable as nickel metal hydride or nickel-cadmium designs and can be extremely dangerous if mistreated - they should never be used in a manner inconsistent with the manufacturer's recommendations. Lithium-ion batteries can rupture, ignite or explode when exposed to high-temperature environments, such as areas exposed to prolonged direct sunlight. Short-circuiting a lithium-ion battery can also cause it to ignite or explode, and any attempt to open or modify the casing or enclosed circuitry is dangerous.

Although these batteries are classified by the federal government as non-hazardous waste, they can be recycled. JLab has battery recycling collection containers at strategic locations. If you can't find a container near you, ask your Safety Warden for assistance. In addition, contact Jennifer Williams at x7882 or Brett Lewis at x6254 for assistance with disposal or recycling of larger batteries.

Computing and Networking Infrastructure

Jefferson Lab has been seeking ways to decrease energy consumption in areas that will not adversely impact the laboratory's science mission, yet comply with Department of Energy policy to increase energy efficiency. The Computing and Networking Infrastructure group (CNI) has come up with a way to manage the energy settings on Windows desktop systems. On March 23, the laboratory will begin reducing its power draw (without impacting its mission) by putting Windows desktop computers into standby or sleep mode when they are not in use for long periods of time or not used after work hours. Many computer users already do this themselves both during and after hours, but now the CNI group is going to make the process easier and the results of the power management program measurable.

The program will work like this: after 5:30 p.m. everyday, if there is no mouse or keyboard activity for 30 minutes on a Windows desktop system, the computer will automatically go into standby mode. The computer can be awakened by either mouse movement or pressing any key on the keyboard. To minimize impact on those who choose to log in to their systems remotely after hours, users will still have offsite access to their computer systems. These users can log in to to wake their systems before attempting to remotely log into their onsite desktop. All systems in standby mode will be awakened for overnight patch installations and virus scans.

For the next few weeks, the JLab CNI group will implement these power management settings on select systems for testing and evaluation. They will implement the program for all Windows desktop systems sitewide, excluding mission critical systems and servers, on March 23.

For more information, visit the website.


Education Seeks Mentors for Summer Programs Participants
The Science Education staff needs your help. Seven regional high school students will be at the lab June 21-July 30 for the High School Summer Honors Program. A mentor with an appropriate project is needed for each student. In addition, 20 teachers will be here July 5-30 for the DOE Academies Creating Teacher Scientists program. Mentors with hands-on projects where groups of three teachers could work about 40 hours each over the length of the program (about 10 hours per week per teacher) are needed. Participants will develop a poster about their project and present it on the last day of their program.

If you have a project or projects that would be appropriate for a high-achieving high school student or for a small group of dedicated science teachers, e-mail a short project description and the proposed work requirements to Christine Wheeler.

Physics and Forensics Colloquium and Public Lecture
A colloquium on the connections between physics and forensics will take place at 3:30 p.m. in the CEBAF Center auditorium today. John A. Reffner, John Jay College of Criminal Justice, CUNY, will show how physics underlies many of the tools of the trade that are used in forensic science. In particular, spectroscopy and spectroscopic imaging are critical in many analytical situations. Ultra-bright light sources, such as are produced by accelerators, allow higher spatial resolution work for specialized applications. Reffner will not focus on accelerator-produced light, but rather give a more general introduction to the forensic science field, with examples drawn from his personal experience solving cases.

Annual T-Shirt Design Contest Underway
The deadline for submissions for the 25th Annual JLab T-shirt Design Contest is March 26. Submissions should be in color, on 8.5x11 paper and include a front (pocket) and back design. Submission rules and past winning designs are posted on the JAG website.