6He is the simplest nucleus with a “halo”: two loosely bound neutrons in an orbit around a compact core formed by two protons and two neutrons, also known as an alpha particle. (Lower right) The symbol of the medieval princes of Borromeo was a trio of rings intertwined in such a way that removing any of the rings caused the entire structure to fall apart. Today, physicists use the term “Borromean” to describe atomic nuclei like 6He that behave in a similar way: if any one constituent is removed, the rest of the nucleus disintegrates.

Oct. 25 , 2004 -- Some of this week's stories:

Physicists determine size of helium-6 nucleus

By Dave Jacque

The symbol of the medieval princes of Borromeo was a trio of rings intertwined in such a way that removing any of the rings caused the entire structure to fall apart. Today, physicists use the term "Borromean" to describe some atomic nuclei that behave in a similar way: if any one constituent is removed, the rest of the nucleus disintegrates.

Recently, researchers at Argonne's Physics Division teamed up to conduct the most precise measurement ever made of the charge radius — one aspect of the size — of the Borromean nucleus helium-6 ( 6 He).

The results are so precise that they can be used to determine the accuracy of predictions made by a variety of nuclear structure theories. The data also offer new insight into how neutrons affect the structure and dynamics of nuclei and shed light on the structure of all neutron-rich systems, including neutron stars.

The 6 He nucleus is a proving ground for nuclear physicists probing the complex, subtle atomic forces that shape the central core of every atom in the universe. 6 He is the simplest nucleus with a "halo": two loosely bound neutrons in an orbit around a compact core formed by two protons and two neutrons, also known as an alpha particle (see diagram). 6 He lasts about one second — that's almost forever on the timescales of nuclear forces. But take away one neutron or the alpha particle and the system will immediately fall apart.

Measurements of 6 He were made in the 1980s and 1990s, some by Isao Tanahata, now a visiting scientist in Argonne's Physics Division. From those measurements, physicists have known that the nucleus of 6 He is much larger than that of 4 He — regular party-balloon helium, which doesn't have the extra pair of neutrons in orbit around the alpha particle — although they couldn't pin down the size of the 6 He nucleus precisely enough to distinguish among various theoretical predictions.

The recent Argonne project involved a team of physicists and engineers from all four groups in the Physics Division and was funded by the U.S. Department of Energy's Office of Nuclear Physics. Led by Ernst Rehm and Zheng-Tian Lu (both PHY), the collaboration brought together the needed expertise in nuclear structure theory, nuclear reaction, accelerator and atomic physics. Conducting new, high-precision measurements began with the production and extraction of 6 He. At the Argonne Tandem Linac Accelerator System (ATLAS), a beam of lithium-7 ions was accelerated into a graphite target. Some of the lithium ions lost a proton, becoming 6 He. From there, the 6 He atoms were directed to an atom trap and probed with lasers.

Trapped

To measure the size of the 6 He charge radius required trapping the atoms with a combination of magnetic fields and laser beams. Cooled to within a milli-kelvin above absolute zero, an atom can be held with laser light to within a cubic millimeter of space in the middle of a vacuum chamber. When illuminated by laser beams tuned to its resonant frequency, a helium atom absorbs and re-radiates the light at a rate that depends on the state of the atom's electrons. The size of the nucleus has an effect on electron orbits, causing a very small shift in frequency — about one part per billion.

In one brief moment, several years of preparation came together in a blip of light on a computer screen — on the very first attempt. Surprised, Li-Bang Wang, a Ph.D. student from the University of Illinois at Urbana-Champagn, literally fell out of his chair onto the floor.

"Physics experiments rarely work on the first try," Lu said. "It was amazing."

The charge radius was determined to be two fermis — two trillionths of a millimeter. The results of this research were published in Physical Review Letters on Oct. 1.

Next steps

In the near future, the collaboration hopes to tackle 8 He, which is the most neutron-rich matter on Earth.

"In the last century, we learned to understand atomic structure very well," Lu said. "Atoms we can calculate to exceedingly high precision using quantum mechanics and electromagnetic theory. But our understanding of nuclear forces is still growing rapidly. And I hope that in this century, we'll be able to solve this part of the mystery."

Changes ahead for Argonne's healthcare plans

Substantial changes will be made to Argonne's healthcare plans in 2005, and employees should carefully read open enrollment information for details. The open enrollment cover letter provides information on rate changes, plan changes and health care and dependent care flexible spending enrollment.

Open enrollment for Argonne's medical plans and flexible spending accounts will be held Nov. 1-19.

Employees who have an e-mail account will be sent an e-mail message regarding open enrollment materials. Open enrollment materials are also online an Argonne login ID and password are required to access the site.

Employees without e-mail accounts will receive an open enrollment package at their lab addresses. Employees who do not have access to a computer can use the machines available in the Human Resources - Employee Benefits Conference Room in Building 201. HR representatives will be available for assistance.

Contact Human Resources at ext. 2-2985 or 2-2992 for more information.

Nobel laureate to present '04 Fermi lecture

The 2004 Enrico Fermi Lecture in Physics, "The Origin of Mass and the Feebleness of Gravity" will be presented Friday, Oct. 29, by Nobel Laureate Frank Wilczek, Hermann Feshbach professor of physics at the Massachusetts Institute of Technology.

Wilczek's lecture will begin at 3:30 p.m. in Argonne-East's Building 402 Auditorium.

Wilczek is considered one of the world's most eminent theoretical physicists. He is known, among other things, for the discovery of asymptotic freedom — for which he shared the 2004 Nobel Prize in Physics — the development of quantum chromodynamics, the invention of axions, and the discovery and exploitation of new forms of quantum statistics.

All Argonne, U.S. Department of Energy and University of Chicago employees whose schedules permit are invited to attend the lecture.

Friday Forums' future topic of meeting

November's First Friday Forum (FFF) will be held Nov. 5 at 12:15 p.m. in Building 205, Room L252.

FFF Initiator Cristina Negri will lead the discussion on the future direction of the forum. Participants are encouraged to bring suggestions for future topics and speakers.

The First Friday Forum is an informal gathering of Argonne women usually held on the first Friday of the month. Meetings are open to all Argonne and U.S. Department of Energy employees.

For more information, or to send suggestions in advance, e-mail Negri at negri@anl.gov.

Argonne joins city spirit in 2004 Chicago Marathon

By Raquel Harper

Sticky Gatorade, male cheerleaders, one-man bands, personal records, chocolate-chip cookies, screaming fans, supportive family members and glorious sunshine made the event memorable for Argonne runners and volunteers who took part in the Chicago Marathon Oct. 10.

"I enjoyed the day immensely," said first-time marathon runner Heidi Hartmann (EA). "I just couldn't believe the incredible support from the city. That's what makes this event so special. The city really comes together for this."

The Chicago Marathon route passes through 15 different neighborhoods, all contributing various flavors of music and entertainment for the athletes. Supporting fans line the streets and thousands of volunteers provide support along the way and at the finish, including members of the Argonne Running Club.

The Argonne Running Club has been sending runners and volunteers to the Chicago Marathon for about 25 years. This year the club had roughly 125 volunteers from both Argonne and the Department of Energy (DOE), handing out Mylar blankets, finisher medals, Gatorade, water, cookies and fruit.

"Two particular Argonne volunteers actually came extra early to help set up for the race at the start line and then they ran ahead to the five-mile mark to work at a water stop for about an hour," said Corrie Patterson-Kamiya (NE-EO), who has been involved in the Argonne Running Club for 13 years. "Once the last few runners had passed the five-mile station, the volunteers ran back to the start-finish line. I'm just amazed by the tremendous support these people give year after year."

"I had a great time volunteering. It was a beautiful, sunny day," said Argonne Running Club President Karl Grimm (NE). Grimm alternates between supporting the event with the Argonne Running Club and running in the race.

"My wife and daughters volunteered with the Argonne Running Club while I ran," said nine-time Chicago Marathon runner Lester Erwin (AOD). "My wife just loves helping out at the finish of this event. She was handing out chocolate chip cookies. By the end, she looked like someone had shot her with chocolate chips because she had so much chocolate goo on her clothes."

Erwin set his own personal record this year with 3:35:55, despite the Gatorade-glue that challenged his momentum, "There was just so much of this sticky liquid all over the place. So much Gatorade gets spilled and your feet just feel like glue while you're running along."

The male cheerleaders and unique music bands, such as the Big Red Calliope (a one-man band circus act) entertained and motivated runners to keep going.

"I especially enjoyed the male cheerleaders doing the `YMCA' chant. They were fantastic," said Hartmann.

"There were probably a dozen places that had music playing. But I really loved the calliope," said Erwin, "All the music and support really helps you keep moving."

Some of the Argonne Running Club members who ran in the Chicago Marathon are: Marco Arroyo (DOE), Tom Buffington (ASD), Adam Cohen (EQO), Lester Erwin (AOD), Larry Harding (CHM), Heidi Hartman (EA), Keith Knepper (PFS), Joe Mavec (DOE), Dan Milinko (EQO) and Al Wagner (CHM).

Appraisal resources available for supervisors online

At this point in the performance appraisal process most supervisors are completing the performance appraisals. Screen captures and directions to the Web application to complete supervisor responsibilities are online.

Supervisors have a variety of information available from their desktop to support them in this process. Supervisors can view the position description, the job hazards questionnaire and the training profile for each of their supervisees. If an employee has uploaded a formal statement of accomplishments the supervisor can also view that file. Matrix input is also available through the Web application if a supervisor has requested it.

Mail delivery changes will save $200,000 per year

As part of the laboratory's efforts to reduce costs, the branch U.S. Post Office at Argonne-East will close Oct. 29, and changes will be made in the way mail is distributed to many buildings on site.

Direct-to-office mail delivery and pickup will be discontinued in favor of a "mail drop" system already in longtime use in buildings 201 and 900. Mail drops will be located at each building; mail will be delivered and picked up once a day at these locations. Postal clerks will deliver mail from the mail drops to "mail stop" locations throughout each building; each mail stop will serve about 20 offices. Division employees will distribute mail from mail stops.

These changes are expected to be complete by the end of November, and should save the laboratory about $200,000 per year.

LDRD projects to be discussed at mini-symposium

Researchers will present short summaries of their laboratory-directed research and development (LDRD) projects at a "mini-symposium" from 2-3:45 p.m. Tuesday, Oct. 26, in Argonne-East's Building 201, Rooms 190 A&B.

Presenters and topics will include:

2 p.m — "Investigation of Passive Safety Features for SCWRs" by Dae Cho (NE)

2:15 p.m — "Advanced Fast Reactor — System Integration and Concept Development" by Chris Grandy (NE)

2:30 p.m — "Analysis and Development of Liquid Metal Targets for RIA" by Isak Konkashbaev (ET)

2:45 p.m — "Demonstration of a Full Power Test Model of the 12 MHz Hybrid-RFQ for Acceleration of Radioactive Ions with Charge-to-Mass Ratio 1/240" by Peter Ostroumov (PHY)

3 p.m — "Integration of Automated Systems and Robotics for a Recycle Facility" by Young Soo Park (NE)

3:15 p.m — "Linear Collider R&D at Argonne: High Gradient Accelerating Structures" by Michael Kelly (PHY)

3:30 p.m — "Investigation of Power-Flow Instability Phenomena in SCWR Designs" by Won Sik Yang (NE)

Halloween party set for Oct. 28

The Argonne Club will host a Halloween party Thursday, Oct. 28, at Argonne-East's Building 617 Lower Level from 4:30 - 8 p.m.

Cost is $3. Adult beverages and food will be available; costume and door prizes will be awarded. All visitors must be badged by the Argonne Information Center prior to 4 p.m.

For more information, contact the Argonne Club at argonneclub@anl.gov or visit the Web site.

Veterans to be honored at Nov. 4 ceremony

The 8th Annual Veteran's Recognition Day at Argonne-East will feature "Let Freedom Ring," a talk by Medal of Honor recipient Allen J. Lynch, and music by the Argonne Choral Group.

The program will be held Thursday, Nov. 4, in Argonne-East's Building 402 Auditorium and is open to all whose schedules permit. The musical presentation will start at 11:30 a.m., and the program will begin at noon.

Lynch will share the lessons he learned from his experience during and after the Vietnam War.

Visitors to the laboratory must pre-register; contact Paul Neeson (DOE) at ext. 2-2258.

Dirty bomb' topic of lunch seminar

Dave Raske (STA) will discuss "The Dirty Bomb: The Terrorist's Weapon of Mass Disruption" Friday, Oct. 29, at 12:15 p.m. in the Private Dining Rooms of Argonne-East's Building 213 Cafeteria.

Raske will briefly describe the dangers of radioactive materials, where terrorists may try to obtain these materials and the effects of the resulting long-term radiological contamination. He will show that the current regulations governing radiological cleanup may need to be modified to avoid abandoning contaminated areas of affected cities.

The seminar is co-sponsored by the retirees of Argonne and the Center for Reactor Information. All employees are welcome to attend.

Another `bomb joke' results in second arrest this year

For the second time this year, a "joke" made by a driver at Argonne-East's main gate led to an arrest by the DuPage County Sheriff's Department.

The incident began at about 8 p.m. Oct. 10, when a limousine driver pulled into the main gate to deliver a visitor to the laboratory. A protective force employee asked the driver to declare any weapons or explosives. The driver responded that he had C-4 (plastic explosive) in the trunk.

All such remarks — whether made by visitors or employees — must be treated as genuine threats, said Deputy Director of Security David Metta.

"These types of comments can no longer be treated as jokes in a post-9/11 environment," Metta said. "The protective force won't take any chances with the safety and security of the site, and they won't think it's funny."

Protective force employees searched the vehicle, and the DuPage County Sheriff's Department was called. The department's bomb squad performed another search of the limousine. No explosives were found, but the driver was arrested and taken to DuPage County Jail where he was charged with two felonies.

On May 27, a similar remark by a visitor led to the evacuation of two buildings, a visit by the bomb squad and an arrest.

Dell recalls AC adapter for laptop computers

AC adapters for certain models of Dell laptop computers have been recalled. The affected adapters can overheat, which poses the risk of fire or electrical shock.

Dell has recalled affected adapters for some models of Dell Latitude, Dell Precision and Dell Inspiron notebook computers.

For details, see the online edition of Argonne News at www.anl.gov/news.html.

Joliet Junior College plans registration at ANL-East

Registration for the Joliet Junior College spring term, which begins Jan. 10, 2005, will be offered at Argonne-East Tuesday, Nov. 9.

College Representatives will be available in Building 201, Room 190 from 12:30 a.m. to 2:30 p.m. to register students for spring 2005 classes. Employees must bring completed and approved educational assistance forms (ANL-89) to the registration.

Call Betty Iwan (HR) at ext. 2-3410 for more information.

String orchestra to play famous film songs, tango music

A distinguished international chamber ensemble will perform film theme songs and tango music Saturday, Nov. 6, in the auditorium of Argonne-East's Advanced Photon Source Conference Center at 8 p.m.

I Solisti di Venezia will play a selection of rare film scores by Nino Rota (including suite from "The Godfather") and Ennio Morricone as well as a few Astor Piazzola pieces. The mainly Italian orchestra has toured extensively and performed in major venues, including the Metropolitan Museum of Art in New York and the Kennedy Center in Washington. The group plays without a conductor and alternates all musicians as soloists and leaders.

Admission to the concert is $25. Tickets can be purchased over the phone (630) 252-3751 or ordered by mail using an Arts at Argonne ticket request form. Remaining tickets will also be sold the week of Monday, Nov. 1 in the Building 213 Cafeteria from noon to 1 p.m.

Retirement interest rates

Staff and non-staff retirement plan interest rates effective Oct. 1, 2004 are:

Vendor	Rate	Contributions From	Through
TIAA Traditional	4.25%	10/01/04 - 10/31/04	02/28/05
TIAA Supplemental	3.00%	10/01/04 - 10/31/04	02/28/05
Prudential Guaranteed (Plans 5017 & 4245)	4.79%	07/01/04 - 06/30/05	06/30/05
Prudential Guaranteed (Plan 7680)	3.00%	10/01/04 - 12/31/04	12/31/05
Prudential Guaranteed (Plan 4643)	3.00%	10/01/04 - 12/31/04	12/31/05
Lincoln National (Old Account)*	3.50%	N/A	12/31/04
Lincoln National (No Load)*	4.00%	N/A	12/31/04
(* No longer accepting contributions)

Choral group seeks singers for 24 th year

The Argonne Choral Group is welcoming new singers for its 24th season at Argonne-East. The group will perform at the Nov. 4 Veteran's Recognition ceremonies and will present its holiday program in December.

For more information, contact choral group director Harry Bell (PFS) at ext. 2-9625.

CIS classes

Computing classes offered by the Computing and Instrumentation Solutions Division are held in Argonne-East's Building 201, Room 167. Unless otherwise noted, classes cost $215 and are limited to eight participants. Complete class descriptions, schedules and enrollment forms are online. For more information about enrollment procedures, contact Diane Cavazos (CIS) at ext. 2-7153 or dkcavazos@anl.gov.

Classes offered in November will include:

"Intermediate Word 2002" (CIS115) — Monday, Nov. 1, 8:30 a.m. - 4:30 p.m. Prerequisite: "Introduction to Word 2002."

"Intermediate Excel 2002" (CIS116) — Tuesday, Nov. 2, 8:30 a.m. - 4:30 p.m. Prerequisite: "Introduction to Excel 2002."

"Intermediate Access 2002" (CIS117) — Wednesday, Nov. 3, 8:30 a.m. - 4:30 p.m. Prerequisite: "Introduction to Access 2002."

"Introduction to PowerPoint 2002" (CIS114) — Thursday, Nov. 4, 8:30 a.m. - 4:30 p.m. Prerequisite: An understanding of Windows.

"Advanced PowerPoint 2002" (CIS118) — Friday, Nov. 5, 8:30 a.m. - 4:30 p.m. Prerequisite: "Introduction to PowerPoint 2002."

HR classes

Human Resources, Performance Development has openings in several classes at Argonne-East during November.

"Grammar Skills for English as a Second Language" (HR368) — Tuesday and Thursday, Nov. 9 _ Jan. 20, 2005, from 11:30a.m.-1 p.m., Building 201, Room 167C.

"Project Management" (HR354) — Wednesday, Nov. 10, 1:30-3 p.m., Building 401, Room E1100.

"Assertive Communication Skills" (HR371) — Wednesday, Nov. 10, 12:30-4:30 pm, Building 202, Room B169.

"Situational Leadership" (HR360) — Wednesday, Nov. 17, 9 a.m.-4:30 p.m., Building 201, Room 190.

Enrollment is available online or contact a Training Management System Representative. For more information, call Betty Iwan (HR) at ext. 2-3410.

No dinner at Guest House on Nov. 5

The Argonne Guest House Restaurant will be closed for dinner on Friday, Nov. 5.

Time to `fall back'

Daylight-saving time ends at 2 a.m. Sunday, Oct. 31. Clocks should be set back one hour.