STAR SIMULATION — This supercomputer simulation from the Center for Astrophysical Thermonuclear Flashes shows the density changes in the material of a white dwarf star, a star that has burned most or all of its nuclear fuel. The star is smaller than Earth but much denser.

Stars surrendering secrets to supercomputers

By Steve Koppes

University of Chicago and Argonne scientists are preparing to run the most advanced supercomputer simulation of an exploding star ever attempted. Tomasz Plewa, senior research associate at the university's Center for Astrophysical Thermonuclear Flashes, expects the simulation to reveal the mechanics of exploding stars, called supernovae, in unprecedented detail.

The simulation is made possible by a special allocation of 2.7 million hours of supercomputing time to the Flash Center from the U.S. Department of Energy. The Flash Center typically uses less than 500,000 hours of supercomputer time annually.

"This is like a big grant. This is beyond imagination," said Plewa, who submitted the Flash Center proposal on behalf of a research team at the university and Argonne. At Argonne, the team includes MCS Director Rick Stevens, Justin Binns, Anthony Chan, Randy Hudson, Rusty Lusk, Michael Papka, Katherine Riley and Andrew Siegel (all MCS).

The Flash Center project was one of three selected to receive supercomputer time allocations under a new competitive program announced last July by Secretary of Energy Spencer Abraham. The other two winning proposals, which will receive a combined 2.2 million processor hours, came from the Georgia Institute of Technology and Lawrence Berkeley National Laboratory.

The supercomputer time will help the Flash Center more accurately simulate the explosion of a white dwarf star, one that has burned most or all of its nuclear fuel. These supernovae shine so brightly that astronomers use them to measure distance in the universe. Nevertheless, many details about what happens during a supernova remain unknown.

Simulating a supernova is computationally intensive because it involves vast scales of time and space. White dwarf stars gravitationally accumulate material from a companion star for millions of years, but ignite in less than a second. Simulations must also account for physical processes that occur on a scale that ranges from a few hundredths of an inch to the entire surface of the star, which is comparable in size to Earth.

Similar computational problems vex the DOE's nuclear weapons Stockpile Stewardship and Management Program. In the wake of the Comprehensive Test Ban Treaty, which President Clinton signed in 1996, the reliability of the nation's nuclear arsenal must now be tested via computer simulations rather than in the field.

"The question ultimately is how is the nuclear arsenal aging with time, and is your code predicting that aging process correctly," Plewa said.

Flash Center scientists verify the accuracy of their code by comparing the results of their simulations both to laboratory experiments and to telescopic observations. Spectral observations of supernovae, for example, provide a sort of bar code that reveals which chemical elements are produced in the explosions. Those observations currently conflict with simulations.

"You want to reconcile current simulations with observations regarding chemical composition and the production of elements," Plewa said.

Scientists also wish to see more clearly the sequence of events that occurs immediately before a star goes supernova. It appears that a supernova begins in the core of a white dwarf star and expands toward the surface like an inflating balloon.

According to one theory, the flame front initially expands at a relatively "slow" subsonic speed of 60 miles per second. Then, at some unknown point, the flame front detonates, and accelerates to supersonic speeds. In the ultra-dense material of a white dwarf, supersonic speeds exceed 3,100 miles per second.

Another possibility: the initial subsonic wave fizzles when it reaches the outer part of the star, leading to a collapse of the white dwarf, the mixing of unburned nuclear fuel and then detonation.

"It will be very nice if in the simulations we could observe this transition to detonation," Plewa said.

Flash Center scientists already are on the verge of recreating this moment in their simulations. The extra computer time from the DOE should push them across the threshold.

The center will increase the resolution of its simulations to one kilometer (six-tenths of a mile) for a whole-star simulation. Previously, the center could achieve a resolution of five kilometers (3.1 miles) for a whole-star simulation, or 2.5 kilometers (1.5 miles) for a simulation encompassing only one-eighth of a star.

The latter simulations fail to capture perturbations that may take place in other sections of the star, Plewa said. But they may soon become scientific relics.

"I hope by summer we'll have all the simulations done and we'll move on to analyze the data," he said.

Argonne-West helps Idaho's Hispanic youth shine

By Margret Chang

Idaho Governor Dirk Kempthorne honored representatives of the Hispanic Youth Symposium with a Brightest Stars Award for their dedication to improving the lives of Hispanic students. Argonne-West, the Department of Energy, University of Chicago and the Idaho National Engineering and Environmental Laboratory (INEEL) play important roles in supporting the symposium.

Since its start in 1990, the symposium has helped to curb Idaho's dropout rate for Hispanic high-school students by about 40 percent.

The Brightest Stars Award is given to individuals and businesses making a positive difference in the lives of children across the state. The award, which includes a $5,000 check that will fund scholarships at the upcoming 2004 Symposium, was presented during a special ceremony at the Idaho Statehouse.

"To receive this honor is a big achievement for the symposium," said Manny Sanchez (NPS-OTD), an Argonne-West Office of Oversight manager involved in coordinating the event. "It recognizes the efforts of many people and organizations who have committed themselves to help Hispanic students succeed in all aspects of their lives."

The Hispanic Youth Symposium is an annual event held in Sun Valley, Idaho, that encourages Hispanic teens to seek brighter futures for themselves and their families by staying in school.

Each year, around 300 Hispanic high school students from Idaho converge on Sun Valley to participate in the symposium. Featuring motivational speakers and interactive workshops designed to enhance self-esteem, leadership and problem-solving skills, the event gives students plenty of opportunities to examine possible career paths for the future. In addition, the students compete in speech, talent, athletic and interactive skill contests for awards and scholarships valued at more than $500,000.

"Over the years, this symposium has proven to be a tremendous success," explained Terry Brooks (NPS-HR), a human resource specialist who was involved in the initial planning stages of the event. "Not only have we made an impact on the number of Hispanic students staying in high school, but we've also managed to increase the number of students that go to college."

At least 12 Argonne-West employees volunteer every year for the countless hours of hard work required to organize the annual symposium. Program logistics manager Jesse Ruiz (FAC-PS), for example, works around the clock for three days prior to the event and countless hours throughout the year to make sure everything is in place. Mary Adamic (NT-AW) spreads her love for science to the students by presenting memorable chemistry demonstrations at workshops that are talked about year after year.

Indeed, many Argonne-West volunteers prepare and present hands-on science and engineering workshops such as Adamic's -- events that have been successful in encouraging young people to be excited and enthusiastic about science.

"The success of the symposium owes a lot to the efforts of people like Jesse and Mary," affirmed Sanchez. "Even though it's an event that only happens once a year, it truly is a daylight-to-dark type job for those who have to organize it. You need to truly want to do it or you wouldn't volunteer."

Such efforts have not gone unnoticed. Over the years, the Hispanic Youth Symposium has gained the attention of high-profile senators and governors who view the event as an exemplary model for youth initiatives. As a result, the symposium's format has been reproduced in programs all over the West Coast in addition to receiving national recognition from several Fortune 500 corporations.

Argonne-West employees remain committed to improving the lives of Hispanic students.

"What constantly amazes me is the sheer resilience of the students who attend the program," Brooks remarked. "Some of these kids grow up without a desire to go to college since they spend so much time helping their parents. Yet, after learning about opportunities at the symposium, many of them finish high school and go on to pursue wonderful careers."

"These young people," added Sanchez, "are an inspiration to all of us involved with the symposium here at Argonne-West, and it reaffirms that our future is in good hands if these young people are given a chance to succeed."

Administrative professionals to be honored

Argonne-East will celebrate the contributions of its administrative professionals Wednesday, April 21 in the Building 213 Cafeteria. Sue Thoma, assistant to the president of the University of Chicago, will be the featured speaker for the event.

A free buffet breakfast will be served at 8 a.m., and the program will start at 8:45 a.m. All secretaries and clerical employees are invited to attend.

Forum to hear WIST initiator, steering panel

The First Friday Forum will meet Friday, April 16, at 12:15 p.m. in Argonne-East's Building 203, Room R150. The speaker, Maryka Bhattacharyya, will give a summary of Women in Science and Technology (WIST) accomplishments during her tenure as WIST program initiator.

Members of the WIST Steering Committee will introduce themselves and say a few words about their roles on the committee and their views and plans.

The First Friday Forum is an informal gathering of Argonne women usually held on the first Friday of each month. The group explores career and gender issues related to women. Meetings are open to all Argonne and U.S. Department of Energy employees. More information is online.

The Onion gives ATLAS an upgrade

The Onion, a weekly satirical newspaper that proudly makes up all its stories, reported last week that a University of Chicago particle physicist "drove halfway home before he was struck with the fear that he'd left the Argonne Tandem Linac Accelerator System running Tuesday night."

"I think I powered it down after smashing those 9-GeV electrons into 3.1 GeV positrons, but I don't specifically remember flipping the switch," the physicist is quoted as saying.

Of course, since ATLAS is available to its many researchers around the clock, "flipping the switch" is not a major issue. ATLAS manager Jerry Nolen (PHY) said he appreciated The Onion giving the facility an upgrade of a factor of 1,000. In addition, "we prefer uranium over electrons," Nolen said.

Native plants will be focus of Earth Day

Argonne's Pollution Prevention Program will mark Earth Day 2004 with activities and exhibits in the Argonne-East Building 213 Cafeteria Thursday, April 22, from 11 a.m. to 2 p.m.

Earth Day was first celebrated in 1970, when an estimated 20 million Americans demonstrated in support of a cleaner environment. The theme for this year's forum is "Sustainable Design --Landscaping with Native Plants."

Exhibitors will include:

Chicago Wilderness Society

Natural Gardens

Possibility Places

Argonne's Center for Transportation Research

For more information contact Barb Markwenas (PFS-WMO) at ext. 2-8306.

`Super outbreak' anniversary is
reminder to review tornado procedures

For survivors of the April 1974 super tornado outbreak, the coming of spring brings memories of much more than April showers.

This week marks the 30th anniversary of the worst tornado outbreak in U.S. history, when 148 twisters touched down in 13 states. The outbreak lasted more than 16 hours, killing 330 people and injuring 5,484 others while carving a total damage path more than 2,500 miles long.

Now, as the heart of tornado season approaches, such deadly outbreaks of severe weather are a reminder to Argonne employees to be prepared. Some 25-30 tornadoes occur annually in Illinois during March, April and May. Though they are much rarer in western states, Idaho has been known to average about one tornado a year.

Gary Winner, Emergency Management Officer at Argonne-East, reminded employees at both sites to follow these procedures when severe weather is a possibility:

Know the difference between a watch and a warning (see below).

Know where to seek shelter and how to get to it quickly.

Monitor weather conditions by paying attention to public announcements or listening to a specialized weather radio.

Be mindful and responsible to visitors on site. Guide them to shelter areas when necessary.

All buildings have an emergency plan that outlines the locations of tornado shelters. Employees should know the safest place and the best route. General guidelines include heading for a basement or interior hallway; staying low, preferably under a stairwell, heavy table or workbench; and avoiding windows.

While outside or driving

Do not try to outrun a tornado or remain in an automobile in the path of a tornado. Immediately seek shelter in the closest permanent building. Look for shelter signs for the safest locations. If caught outside or in a vehicle, try to drive at a right angle away from the tornado. If you cannot drive away, get out of the vehicle, find a ditch or the lowest ground surface to lie down in, and cover your head. Highway overpasses do not provide shelter from tornadic winds. Be aware of flying debris. Flying debris from tornadoes causes most fatalities and injuries. After the tornado passes, employees caught outside should let others know of their whereabouts and if they need medical attention. This can be done via 911 or by dialing (630) 252-1911 on a cell phone.

Cafeteria shelters

If a tornado warning is sounded during meal service hours, all occupants of Argonne-East's Building 213 Cafeteria will be directed to one of the building's shelter areas. The basement locker rooms, dock area stairwell, kitchen area, supply and storage rooms on the southeast corner of the building, and the bathrooms near the entrance are all tornado shelter areas.

Watch or Warning?

A watch means conditions are right for a tornado to develop. Watch announcements will be made on the site-wide public address system. Hazardous materials may have to be secured, and classified documents have to be ready to be locked up. Workers in trailers may have to move to a permanent building.

A warning means a tornado has been sighted in the area or detected by radar. Outdoor sirens will sound and an announcement will be made to direct employees to head to designated tornado shelters immediately and remain there until the all-clear announcement. Watch for and assist others needing help getting to shelter. Follow directions of emergency personnel. Try to remain quiet in the shelter area to better hear any announcements.

Both sites plan `Take Your
Child to Work Day' events

"Take Your Child to Work Day" programs are planned at both Argonne sites Thursday, April 22.

At Argonne-East, the program is limited to 150 children, ages 8-12. There will be tours, demonstrations and hands-on activities from 8:45 a.m. to 4 p.m., starting with a welcome and registration in Building 203. For a registration form, call Pat Boley (C&PA) at ext. 2-1790, or to register online, visit the Inside Argonne Web site at www.inside.anl.gov.

At Argonne-West, employees will present workshops and presentations at the all-day event. Participation will be limited to the first 100 children, ages 8-15, to be registered. For more information, or to volunteer, contact Gaylene Flores at ext. 3-7499 or Shelly Havlovick at ext. 3-7653.

Working while pregnant
topic of telephone seminar

"Working while pregnant and beyond" is the subject of a one-hour telephone seminar by Jeff Vanpelt of CIGNA Behavioral Health Employee Assistance Program.

The talk will begin at 1 p.m. Wednesday, April 21. Employees can pre-register online or 15 minutes prior to the event by calling (888) 747-3493.

`Tom Braid's Run' planned for April 14

The Argonne Running Club will hold its fifth annual "Tom Braid's" cross-country run Wednesday, April 14, starting from the Argonne Park Pavilion at noon.

There will be a 2¹/₂-mile running course and a two-mile walking course. Site employees and their guests of all skill levels are welcome to participate. Refreshments will be served after the event.

More information about the Argonne Running Club is onlinehttp://chemistry.anl.gov/ARC/.

Lab softball league gets ready to play

The Argonne Softball League will hold its first league meeting at noon Thursday, April 15, in the Building 213 Cafeteria.

Team captains, umpires and new teams interested in playing are invited to attend. The softball league opening day is Wednesday, May 12.

For more information, contact Mike Jagger (APS) at ext. 2-0435 or jagger@cars.uchicago.edu.

Junior college offers on-site registration

Early registration for Joliet Junior College fall 2004 classes will be offered at Argonne-East Friday, April 16, from 11:30 a.m. to 2:30 p.m. in the Human Resources office in Building 201.

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 on Joliet Junior College and Argonne's educational assistance program.