BURSTER — This double-star system, located approximately 28,000 light-years away in the constellation Sagittarius, is a source of powerful bursts of X-ray emission. Argonne physicists have made precise measurements of exotic isotopes that explain the characteristic X-ray spectrum and luminosities of such “X-ray bursters.” Illustration courtesy Dana Berry, Space Telescope Science Institute.

Physicists find new clues to X-ray bursters

By Dave Jacqué

Argonne physicists have succeeded in measuring with unprecedented precision the masses of nuclear isotopes that can only be produced in tiny -- almost nonexistent -- amounts in the laboratory. Some of the more exotic isotopes had their masses accurately measured for the first time ever.

The results help explain the characteristic X-ray spectrum and luminosities of strange astronomical objects called “X-ray bursters.” These systems comprise a relatively normal star and a neutron star. Neutron stars are as massive as our sun but may only be about 10 miles across. The neutron star pulls gas from its companion; eventually enough gas piles up on the neutron star surface to ignite in a runaway fusion reaction. The entire surface of the neutron star becomes, in effect, a thermonuclear bomb. For a few tens of seconds, the burst of light from the explosion may become the most brilliant source of X-rays in the sky.

The rapid proton capture process, or “rp-process,” is the dominant source of energy in a common type of X-ray bursters. It’s a type of nuclear fusion reaction in which nuclei capture protons and transmute into a heavier element. For example, arsenic-67 can capture a proton to become selenium-68.

But the rp-process proceeds in fits and starts, due to what physicists call “waiting point nuclei.” Some nuclides, like selenium-68, can’t absorb an incoming proton as quickly as others can. The reaction must “wait” for the nucleus to absorb a proton -- which may take up to 30 minutes, a relative eternity -- or for beta decay (essentially the decay of a neutron to a proton) to convert the nuclide into one with a more favorable capture rate.

“How long the nova or X-ray burst lasts, and how far the rp-process reactions proceed, is determined by the properties of these few waiting-point nuclei,” said Physicist Guy Savard, principal investigator. “Although there are hundreds of nuclei involved in an X-ray burst, the properties of half a dozen of them make all the difference. The others are there for the ride, but they don’t determine what’s happening.”

But measuring the masses of some of these waiting-point nuclei is extremely difficult. Some decay in fractions of a second; others can only be produced in such small amounts that standard spectrometry techniques give imprecise results.

Highly accurate mass measurements required the unique facilities available in Argonne’s Physics Division. The nuclei to be studied were created using the Argonne Tandem Linac Accelerator System (ATLAS). For example, selenium-68 was created by accelerating beams of nickel-58 to 220 million electron volts and slamming them into a carbon target. Some of the ions in the beam combine with nuclei in the target to create the nuclei of interest.

The nuclei to be studied are slowed to a crawl in a “gas catcher” -- a tube filled with pressurized helium. A gentle electric gradient pulls ions into a Canadian Penning Trap Spectrometer developed by Savard and other scientists at Argonne, the University of Manitoba and McGill University, Montreal. Scientists at Texas A&M University and the State University of New York also contributed.

The Penning trap confines ions using magnetic and electric fields. A measurement may involve perhaps only a dozen individual ions, which can stay suspended in the trap for many seconds. Their masses can then be measured using radio-frequency (RF) fields.

“The ions will accept energy from the RF field only at certain frequencies,” Savard said. “These frequencies are related to properties of the ion, particularly the mass. By looking at what energies they accept, you can determine the mass with very high precision.”

Ions with previously unknown masses included antimony-107 and -108. The mass of selenium-68 was determined with 30 times more precision than previous, and contradictory, measurements.

“This is a unique system, because with the new gas catcher, we can inject any species that can be produced here at ATLAS,” Savard said. “Research is still ongoing. We’re now exploring around the tin region, where the rp-process is expected to terminate.”

Grid connects small classrooms to experts

By Rhianna Wisniewski

Scientific experts are spread out all over the country and may seem inaccessible to small undergraduate institutions with limited finances and technology. However, through the use of Access Grid technology developed at Argonne, students and teachers can be brought together with experts from opposite ends of the nation.

The Access Grid is a group-to-group interaction system that allows groups from institutions nationwide to interact by voice and video for scientific and technical collaborations. Terry Disz (MCS) recently demonstrated Access Grid technology to a group of 30 undergraduate professors from 20 states gathered for the 2003 BioQUEST Summer Workshop at Beloit College in Wisconsin.

The BioQUEST workshop focused on “Collaboratories, Digital Libraries, and Computational Biology” in biology education. Beloit College currently does not have access to the Grid, so MCS loaned Beloit a set of Access Grid equipment. A high-speed network connection was made available by the University of Wisconsin-Madison.

“A lot of them had their eyes opened,” Disz said. “They’d not been exposed to the Access Grid before, and they saw the possibilities for doing distributed tutorials and workshops.”

Disz said that one focus of BioQUEST was to find a way to teach biology in the new century. Disz demonstrated how Access Grid technology can be used for visualization and collaboration.

“They were able to see what the technology can be used for, both in a scientific sense and an academic sense. I think that this is something that they will definitely try to access in the future,” Disz said.

His presentation, “Scientific Workspaces of the Future (SWOF)”, conveyed the different uses of the technology, including how it is used at Argonne for bioinformatics and atmospheric science research. He was able to connect the workshop to computational biologist Natalia Maltsev (MCS) for a demonstration of how even small institutions could access resources that would normally be unavailable to them.

“None of them had ever seen it before, and they went away pretty excited about it. I think we made believers out of some of them,” he said.

The BioQUEST Workshop also marked the debut of the Access Grid Toolkit 2.0 software, which was developed at Argonne and released June 1.

“The new software makes the Access Grid more automatic, easier to use and easier to set up. It also allows us to add software to it,” said Disz, who is part of the team that developed the software.

John Greenler, who is the co-director of BioQUEST’s Bio-complexity project and a current biology professor at Beloit College, said that Disz’s presentation fit perfectly into the theme of the workshop and that Disz was able to provide the attendees with both technical expertise and demonstrations.

“We were able to have a session with individuals and make use of tools that are normally in such a distant environment that we wouldn’t be able to bring all of those people to the workshop,” he said. “The Access Grid enabled us to have a panel discussion on distinct collaborative environment.”

Greenler is currently proposing to embed the use of the Access Grid into future BioQUEST workshops.

City of Chicago honors laboratory

By Jennifer Wisz

Argonne’s emphasis on employee learning and development has been acknowledged with the 2003 Workforce Chicago 2.0 Award. Argonne was one of two recipients of this annual award.

The Workforce Chicago 2.0 award is the collaborative effort of several local organizations, including the Council for Adult and Experiential Learning (CAEL), World Business Chicago and the Human Resources Management Association of Chicago (HRMAC). Mayor Richard Daley presided over the first award ceremony in July 2002.

CAEL solicited nominations from Chicago area businesses, civic organizations, trade associations and workforce practitioners. Thirty nominees were reviewed by an expert panel of human resources professionals.

The criteria for selection included the integration of employee development strategies into the organization’s goals and operation, the commitment of investing in employee training and development, the extent to which training and development initiatives reach employees, the depth of the organization’s training and employee development and the effectiveness and efficiency of the organization’s learning activities.

“The laboratory supports a culture of continuous learning where employees can develop their talents and apply their knowledge and skills to achieve their personal and professional potential,” said John Hyzer, assistant Human Resource director. “Lab management views employee training and development as a means of attracting and retaining good people, and we work hard to do an effective job.”

Scientists maneuver their way from the lab to the cockpit

By Rhianna Wisniewski

As if a full work week weren’t enough of a challenge, on weekends Argonne’s Jim Klick (ASD) and David Underwood (HEP) spend time in their airplanes attempting to execute perfect aerobatic maneuvers.

Aerobatic flying, the performance of stunts in an airplane, is challenging and difficult. Klick, a senior electronics technician in the Accelerator Systems Division at the Advanced Photon Source, has been flying since 1960, but he and Underwood, a physicist in High Energy Physics, have only been competing in aerobatic flight for the past decade. Klick compared the sport to figure skating, with each maneuver assigned a point value.

“The higher the difficulty, the higher point value, and points are added up, and the most points wins,” Klick said. “A rounded loop has to be perfectly round or points are taken off. A vertical line has to be very vertical.”

Underwood, who flies an airplane called an Extra 200, a two-seat German airplane with an American engine, competed most recently June 14-15 in Wisconsin. His love for aerobatic flying comes from the challenge it presents him.

“It is fun to make an airplane do things that contradict what we are taught in school about how they fly,” Underwood said

Both Klick and Underwood fly in the intermediate category, the third of five categories of aerobatic flight. Although Klick and Underwood are often in the same competition, Klick feels the competition is not with the other pilots but with his own previous scores.

Klick flies a bright yellow Pitts Special, a single-seat plane, and he competes in Midwest competitions. He will compete in the Robert L. Heuer Classic in August in Aurora and will direct and compete in the Illinois State Championship in Peru, Ill. in September.

Part of the attraction to aerobatic flying is the thrill of it. Underwood said he enjoys the thrill of flying straight up in the air. Klick, who called himself an adrenaline junkie, said flying upside down gives him a thrill.

When not flying, both pilots spend time judging competitions. Pilots can judge at the same competitions they fly in since they cannot judge the divisions they compete in.

The 2003 World Aerobatics Championship in Florida is one competition that Klick was asked to judge in late June and early July. There are expected to be 800 to 1,000 pilots, officials and judges participating in the event from 18-25 countries.

Aerobatic flying has practical applications as well. Klick said aerobatic flying requires quite a bit of stamina and effort. He said pilots learn to do things with such precision that flying aerobatics actually makes you a better pilot.

“I fly every chance I have the opportunity. I’d rather fly than do anything,” said Klick. “As long as I’ve known what an airplane is I’ve wanted to fly them.”

Experiments are crucial to accelerator

The proposed Rare Isotope Accelerator (RIA), an ambitious physics facility concept now in the design stages, is in some ways an outgrowth of the mass-measurement experiments at Argonne. The gas catcher cell developed to slow nuclei to a near-stop so they can be analyzed is a crucial technology for RIA.

RIA will enable physicists to explore the nature of nuclei -- the clusters of particles that occupy the center of every atom. RIA will produce intense beams of short-lived nuclei 10,000 times more intense than any now available. Physicists will use these beams to study the origin of the elements and test current models of physics. RIA also holds promise for important applications to medicine, industry and other applied physics research.

The Argonne-developed concept has been approved by a U.S. Department of Energy advisory committee. Michigan State University and other institutions are involved with Argonne in the design and prototyping work.

Argonne is well-positioned to be the host site for RIA, based on the laboratory’s pathbreaking and enduring expertise in advanced accelerator technology.

ACA raffle ticket sales continue

Raffle tickets will be sold this week, July 7-11, during lunch in Argonne-East’s Building 213 Cafeteria. Tickets cost 50 cents each or 12 for $5. Employees can either buy tickets from ACA steering committee members and coordinators or at the Argonne-East picnic.

The prize list includes the grand prize of two United Airlines roundtrip tickets, an overnight stay at the Baymont Inn, a DJM Travel & Cruise gift basket, an overnight stay at Holiday Inn, dinner for two at the Omega Restaurant, a $50 gift certificate for Tassos Porterhouse, $60 gift certificate for Caring Hands Massage Therapy and much more.

The raffle supports the Argonne Combined Appeal, which allows employees to contribute money to various agencies, including Chicago’s United Way, the American Diabetes Association and the American Cancer Society.

The raffle drawing will take place at the Argonne picnic Saturday, July 12. Winners do not need to be present to receive their prizes.

More information is available on the ACA home page.

CIS CLASSES

Classes offered by Computing and Instrumentation Solutions are held in Argonne-East’s Building 201, Room 167. Unless otherwise specified, class sizes are limited to eight participants and cost $215.

August classes include:

Intermediate Word 2000 (CIS103) -- Monday, Aug. 4, 8:30 a.m. - 4:30 p.m.

Intermediate Excel 2000 (CIS104) -- Tuesday, Aug. 5, 8:30 a.m. - 4:30 p.m.

Intermediate Access Version 2000 (CIS105) -- Wednesday, Aug. 6, 8:30 a.m. - 4:30 p.m.

Introduction to PowerPoint 2000 (CIS106) -- Thursday, Aug. 7, 8:30 a.m. - 4:30 p.m.

Complete computer class descriptions, schedules and enrollment forms are available online.

For information about enrollment, contact Diane Cavazos (ECT) at ext. 2-7153 or dkcavazos@anl.gov.

HR CLASSES

Human Resources has scheduled the following classes in July at Argonne-East:

“Russian Language” (HR164) -- Thursday, July 10 - Sept. 11, at 11 a.m. for beginners, 9:30 a.m. for intermediate learners and 1:30 p.m. for advanced instruction, Building 208, Room E251.

“Brown Bag Lunch: Business Etiquette and Professionalism” (HR298) -- Thursday, July 10, 11:30 a.m. - 1 p.m., Building 201, Room 238.

“Certified Professional Secretary Review: Office Administration” (HR327) -- Tuesdays and Thursdays, July 15 - Aug. 14, 11:30 a.m. - 1 p.m., Building 201, Room 238. 

“Business Writing Skills” (HR292) July 22, 1-4 p.m., Building 201, Room 190.

“Time Management” (HR486) July 30, 1-5 p.m., Building 201, Room 190.

Coming in August:

“Aligning Goals for Results” (HR293) Wednesday, Aug. 13, 8:30 a.m. - 4:30 p.m., Building 201, Room 190 

To enroll, contact a Training Management System representative. For more information, call Betty Iwan at ext. 2-3410. For complete course descriptions, visit the Inside Argonne Web site. Click on “Resources,” “All Employees” and “Professional Development.”

Rep to demonstrate software

Research Systems Inc. is scheduled to demonstrate its powerful new interactive data language (IDL) software on Wednesday, July 23.

The presentation will start at 10 a.m. in Building 401, Conference Room A1100 followed by a question and answer segment. Some of the new features of IDL 6.0 are iTools, IDL-Java Bridge™ and IDL Virtual Machine™.

To reserve a seat, contact Keith Nicholson at keithn@rsinc.com or (303) 544-4414 or call Roger Dejus at ext. 2-9163.

Retiree takes 1st in racquetball tournament

By Jennifer Wisz

A 76-year-old Argonne-East retiree is now a racquetball champ.  Tony Lang, who formerly worked in Central Shops, recently grabbed first place in the Illinois state singles championship in the 75-plus bracket at the Chalet Fitness Center in Willow Springs. 

Lang began working at Argonne in 1944.  He started out when he was in high school, going to school for a half day and to the University of Chicago Metallurgical Laboratory -- the birthplace of the world’s first nuclear reactor -- for the second half. Lang worked at Argonne for 44 years, retiring in 1988. 

Lang has been playing racquetball for 30 years.  He currently plays about three times a week. He enjoys racquetball because it’s great exercise and keeps him in good shape. 

“I get a better workout from racquetball than five rounds of golf,” he said. “And it’s an indoor sport, so I can play anytime.”

This is Lang’s first gold medal for the state racquetball tournament; however, he has placed second several times.  He said there are some annoyances that come with tournaments.  

“Tournaments take up a whole weekend sometimes,” he said. “It’s a lot of driving back and forth.”

However, he said he will likely compete in the state tournament next year to keep his title. Either way, Lang said he doesn’t plan to stop playing racquetball any time soon.

“I will play no matter what condition I’m in.” he said. “Even if I’m in a wheelchair.”

Employees invited to ball game...

The Argonne Club will host an outing to see the Joliet Jackhammers play the St. Paul Saints Friday, July 25.

The minor league baseball game will begin at 7:05 p.m. at Silver Cross Field in Joliet. There will be fireworks after the game. Tickets are $8.

For more information, contact Todd Hayden at tahayden@anl.gov or ext. 2-6143.

... as well as to canoe on the Kankakee

The Argonne Club will sponsor a canoe trip on the Kankakee River Saturday, Aug. 2.

The 12-mile trip costs $42 per canoe. Life preservers will be provided for adults and children above 30 pounds. Children less than 30 pounds will need to bring their own life preservers.

For more information, contact Peggy Stepuszek at pstepuszek@anl.gov or ext. 2-3247.