Jefferson Lab Weekly Briefs
December 8, 2010

12 GeV Upgrade

Seventy of the total order of 86 niobium cavities for the 12 GeV cryomodules have been received. Welding has been completed of the helium vessels onto the cavities for the first 12 GeV cryomodule. Thirty-one of the total order of thirty-six 4-meter dipole magnets for the beam transport lines have been received; testing of those magnets continues. All beam transport quadrupole magnets have been received and accepted. Forty-five RF circulators/isolators have been received. The results from the klystron-circulator/isolator testing found that the second harmonic amplitude is less than -40 decibels of the fundamental mode’s power; that result simplifies the design of the second harmonic filters that will go into the waveguides between the isolator/circulators and the cavities. The request for proposals was released for the purchase of two hundred and sixty 20 Amp/70 Volt power supplies for the beam transport quadrupole magnets and corrector dipole magnets.

Physics

The Q-weak experiment has been taking high-current hydrogen target production data in Hall C, mixed with commissioning activities. The electron detector in the Compton polarimeter achieved an important milestone with the observation of the Compton edge, which arises from the most head-on collisions of the laser photons with the beam. The high-current power supply for the Qtor magnet is down for repairs and is awaiting delivery of replacement parts this week. The experiment has been able to use the beam to perform tests to understand and reduce backgrounds, identify noise sources and commission the beamline polarimeters.

APS April Meeting Abstracts Due
Celebrate 100 Years of Sub-Atomic Physics at the APS April Meeting, April 30-May 3. Abstracts are due Jan. 14. The meeting will take place at the Hyatt Hotel Orange County in Garden Grove, Ca. The April Meeting will offer its usual outstanding scientific program, consisting of three plenary sessions (nine plenary talks), approximately 75 invited sessions, more than 100 contributed sessions, poster sessions, and an evening public lecture.

AIP Seeking Applicants for Congressional Fellowship Program
Members of the physics community who want to spend a unique year learning about the inner workings of Congress should consider applying to the American Institute of Physics Congressional Science Fellowship Program. The application deadline is Jan. 15. Benefits include a stipend, a relocation allowance, an allowance for in-service travel for professional development and reimbursement for health insurance up to a specified maximum. Application instructions can be found online.

Accelerator

The week started with instabilities in the solid state amplifier for the first pass radiofrequency beam separator. A replacement spare unit also suffered from instabilities. With the RF separator down, the beam was separated magnetically, allowing only one hall to receive beam at a time (Halls A and C split the time the beam was available). An offline inductive output tube amplifier was temporarily rigged in place of the solid state amplifier and has been working well since. On Tuesday, the late-day startup of Hall B was hampered by interlocks left in place for vacuum valves that were no longer installed; the interlocks were reconfigured for the new lineup. Thursday was a beam studies day, with a cathode spot move and some Q-weak parity beam development time. Some time was lost Sunday due to a loose connector on a safety system beam current monitor. Beam optics troubleshooting determined that a 1 millimeter change in what already appeared to be a clean vertical orbit in the 9S region eliminated trips due to beam loss and eliminated current instabilities seen all weekend in Hall B.

Free-Electron Laser

After some final FEL characterization studies, the team spent the week preparing to make measurements of the vacuum-ultraviolet harmonic radiation. A new mirror and photon characterization instrumentation were installed on the beamline for tests this week. The FEL team also worked to repair the UV wiggler drive mechanism and beamline vacuum hardware and performed a gun bake.

Center for Theoretical and Computational Physics

In one of the first calculations of its kind, researchers in the Theory Center and at Trinity College Dublin have demonstrated in <arXiv:1011.6352 [hep-ph]> that an energy-dependent scattering phase shift can be mapped out using lattice QCD methods. The techniques developed will soon be applied to hadron-scattering channels with resonant behavior to study excited-hadron decays of the type that will be measured in GlueX and CLAS12.

Facilities Management and Logistics

Appropriate Use of Golf Carts Onsite
All of those who use a golf cart are reminded that golf carts are to be used on paved roads and are to be parked in designated parking spots. Golf carts are not permitted on sidewalks, nor are they to be parked on sidewalk areas.

Holiday Shutdown Power Outage Planned
Planning is underway for a power outage affecting all JLab campus buildings outside the accelerator site, excluding the VARC and ARC, for work on the campus electrical distribution system. The outage is currently scheduled to last for nearly the entire holiday shutdown period, beginning at 5 p.m. on Dec. 23 and ending at 6 p.m. on Jan. 2. There will be no power in these buildings during this period. More details will be announced as plans are finalized. If you have any immediate questions, contact Rusty Sprouse in FM&L, x7589.

JLab Calendar of Events

Dec. 10: Toys for Tots Toy Drive concludes
Dec. 11: JAG Children's Winter Wonderland Party
Dec. 20: Safety Shoe Vendor onsite
Dec. 22: Personal Dosimeter Change Out
Dec. 24-Jan. 2: Winter holidays/Shutdown days - JLab closed

 

 

 

Environment, Health, Safety and Quality

With the Northeast already hit with its first snowstorm, it's time to review cold weather protection basics. According to OSHA, prolonged exposure to freezing or cold temperatures may cause serious health problems such as trench foot, frostbite and hypothermia. In extreme cases, including cold water immersion, exposure can lead to death. Danger signs include uncontrolled shivering, slurred speech, clumsy movements, fatigue and confused behavior. If these signs are observed, call for emergency help.

OSHA's Cold Stress Card provides a reference guide and recommendations to combat and prevent many illnesses and injuries. Tips include:

  • Learn the signs and symptoms of cold-induced illnesses and injuries and what to do to help workers.
  • Wear proper clothing for cold, wet and windy conditions, including layers that can be adjusted to changing conditions.
  • Workers in extreme conditions should take frequent, short breaks in warm, dry shelters to allow their bodies to warm up.
  • Try to schedule work for the warmest part of the day.
  • Avoid exhaustion or fatigue, because energy is needed to keep muscles warm.
  • Use the buddy system – work in pairs so that one worker can recognize danger signs.
  • Drink warm, sweet beverages (sugar water or sports-type drinks) and avoid drinks with caffeine (coffee, tea, sodas and hot chocolate) or alcohol.
  • Eat warm, high-calorie foods, such as hot pasta dishes.
  • Remember that workers face increased risks when they take certain medications, are in poor physical condition or suffer from illnesses such as diabetes, hypertension or cardiovascular disease.

Announcements

JLab's 2011 Holiday Calendar Posted Online
The official list of JLab observed holidays for 2011 has been posted on the Human Resources webpage.

Radiation Worker I Training Credit Change
Radiation Control has recently changed how training credit for Radiation Worker I is reflected in JLab’s training database. Although the requirements for qualification have not changed (class, written test and practical), it is now essential that new trainees register their completion of the online RW-I training class by clicking on the link at the end of the slides (as is done in GERT). If an individual uses the paper handout to study, he/she must inform Radiation Control during the practical portion, so that the training completion can be updated manually. Class credit will be reflected as SAF801C, the test will continue to be reflected as SAF801T, and the practical will be shown as SAF801P. For questions, contact Maya Keller at x6021.

2011 General Access RWP Available for Signature
The 2011 General Access Radiological Work Permit is now available for signature. The current General Access RWP will expire on Dec. 31, while the new 2011 General Access RWP is effective from Jan. 1-Dec. 31, 2011. If you are a radiation worker, to retain your accelerator site access, you must sign the new RWP before Dec. 31. To access the RWP, visit the web-based training page and open document SAF801kd (under the subheading "Documents").

Holiday Hideaway at the SURA Residence Facility
Rooms are available to JLab users, staff and family members every day, even during the Holiday Shutdown. For reservations, visit the website or call 757-223-1167.

JLab Children Invited to Winter Wonderland Party
The Jefferson Activities Group is hosting a children's Winter Wonderland Holiday Party on Saturday, Dec. 11, 10 a.m. -1 p.m., in the CEBAF Center lobby. All children of JLab employees, contractors and users are invited. Kids may share their Christmas lists and be photographed with Santa, play games and make crafts. Light snacks and drinks will be provided. All children must be accompanied by an adult. Each family is asked to bring a new, unopened toy donation for the Toys For Tots toy drive.
 
Volunteers Needed to Help With Children’s Party
A number of volunteers are needed to help with the children's holiday party, mostly as crafts-table and game helpers. Volunteers are needed to assist younger children with basic cutting, gluing or tying. Volunteers are also needed for the snack area and as Santa's Helpers. Sign up will soon be available online.
 
Toys For Tots Toy Drive Dec. 1-10
JLab is participating in the U.S. Marine Corps' annual Toys For Tots toy drive. Bring in your donation of new, unopened toys for children ages 1-12 and deposit them in the collection boxes. Marked drop boxes will be located near the main entrances of CEBAF Center, VARC, ARC, Test Lab and the MCC from Wednesday, Dec. 1 through Friday, Dec. 10.
 
Holiday Decoration Contest
Unleash your inner decorator in the Holiday Office Door/Cubicle Decorating Contest. To enter, e-mail Bridget Paul by COB, Dec. 15. Include your name(s), building number and office/cube location. Judging will take place Dec. 17.

Quark Cafe Hosts Holiday Bake Sale on Tuesday, Dec. 21
Just in time for the holidays, Quark Cafe will host its annual Holiday Bake Sale on Tuesday, Dec. 21, 10:30 a.m.–1:30 p.m. in the CEBAF Center lobby. Stop in and pick up a special dessert, bread or gift item.

Personal Dosimeter Change Out Will Be Dec. 22
JLab's semi-annual personal dosimeter change out will take place during the afternoon of Wednesday, Dec. 22. This includes the dosimeters of all JLab staff, users and subcontractors. If you will need to use your dosimeter during the change out period on Dec. 22, you may exchange it that morning in the Radiation Control Dosimetry Office in Bldg. 52B, Room 4, 8 a.m. - 1 p.m.  If you have questions, contact Becky Mosbrucker, x7236.