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The 100 million dollar project

MSU scientists use high-energy collisions to study how elements are created in stars

November 21, 2006
A tour group at the National Superconducting Cyclotron Laboratory, or NSCL, receives a brief overview of the S800 Spectrograph on Nov. 5. The NSCL employs about 10 percent of the nation's nuclear scientists. Terry Monahan, an environmental health and safety manager said the open house was held at the lab to "get people interested and involved in the science we're doing."

MSU houses one of the world's few atom smashers, but few people have ever visited it or even know where it is.

The Cyclotron, which is located next to the Chemistry Building on Shaw Lane, houses the National Superconducting Cyclotron Laboratory, or NSCL. The building is about a city block long, and the Cyclotron lab is about the length of a football field.

The lab is comprised of two cyclotrons and many other beams, magnets and other gadgets and parts.

"In the end, we are trying to explain the origins of the elements," said Zach Constan, outreach coordinator for the NSCL. "With high-energy physics nowadays, in order to study the smallest things, you need high energy. That's what we're doing. We are giving high amounts of energy to a nucleus, sending it at about half the speed of light, smashing it into other nuclei and getting out a lot of rare isotopes."

A rare isotope is an atom that has significantly more or less neutrons than protons.

Finding rare isotopes has other benefits and can be key in solving scientific questions, said Peter Miller, senior physicist for the NSCL.

"(Scientists) want to understand the process that creates elements in stars," Miller said, adding that chemical elements found in stars can also be found on Earth. "We think complex stars may produce these especially heavier elements."

Constan said scientists are pretty sure the big-bang theory — the theory that the universe began with an atom explosion — explains how hydrogen and helium were created. After stars began to burn, those elements were fused together to create other elements found on the periodic table. Scientists can account for the creation of elements up to iron, Constan said. Using the cyclotron, scientists are trying to figure out the origin of the other elements.

"We have to make (elements) in order to study them because they are not just sitting around," Constan said, adding that the elements they are most interested in studying have a short life span. "We're studying ones that will come apart pretty fast, some as fast as a millionth of a second."

After iron, scientists do not know how the rest of the elements are created, Constan said, adding the answer may lie in the rapid process. When a star blows up, neutrons are constantly adding to an iron atom and producing new elements.

"The idea is lots of neutrons added on really fast create all of these rare isotopes," he said, adding that as the elements decay, they turn into other elements and isotopes.

Cyclotrons can also be used in the medical field. A superconducting cyclotron was built in Harper University Hospital in Detroit to help cancer patients.

"We have a cyclotron that will accelerate nuclei and smash them into things and produce neutrons," Constan said. "Then we can direct those neutrons specifically to the site of the cancer, and those neutrons kill cancer cells."

Radiation therapy can help cure cancer patients whose bodies have become resistant to chemotherapy.

The facility is also used by scientists all over the world who come to MSU to conduct their research, Constan said.

NASA officials visited the Cyclotron lab earlier this month to test equipment they were considering putting on the Hubble Telescope, Constan said. The officials placed laptops in one of the vaults of the lab that contains high levels of radiation when the cyclotron is running to see if the computers could withstand the high levels of radiation present in space.

The ECR ion source and the cyclotrons

The Electron Cyclotron Resonance, or ECR, ion source creates whatever element the scientist wants to begin with to try to find a rare isotope. After the element is produced, it is sent to the K500 cyclotron. The lab contains two cyclotrons: the K500 and K1200. The K500 cyclotron was the world's first superconducting magnet and began accelerating atoms in 1982. The K1200 was completed in 1989 and was used alone until it was coupled with the K500 in 1999 because with both of them, scientists could accelerate high-energy beams of heavier elements. With the use of the two cyclotrons, the atoms are accelerated to about half the speed of light, Miller said.

The magnets

After the K1200 cyclotron accelerates the atoms up to 90,000 miles per second, the atom is sent to a production target, where its ions hit a thin piece of metal and protons or neutrons are stripped from the atoms, Constan said.

Scientists cannot control the reaction caused by the collision, Constan said.

"You get this huge variety of isotopes, depending on what had been stripped off," he said. "The rarest ones you will probably get the least of because it had to strip off a very specific number of protons and neutrons."

The beam is then sent to the A1900 fragment separator, which has magnetic fields tuned to a certain strength to help find the rare isotope scientists want to study.

"(The A1900 fragment separator) is basically a series of magnets, and those magnets work like a prism," Constan said. "You have charged particles that go into a magnetic field, and they turn. Depending on the charge of the particle, it will bend a different amount."

Once the isotope is sorted out, it is sent to the beam switchyard. The switchyard then sends the beam to one of the many detectors, similar to the way trains are directed onto different tracks.

The detectors

There are five vaults that house detectors, which each measure something different about the rare isotope. Each of the vaults are surrounded by six feet of removable bricks stacked on top of one another. Constan said with technology constantly advancing, the vaults need to be flexible to allow for new equipment to be added.

• The 4 pi Array, which resembles an oversized soccer ball, detects particles from all directions and records how nuclear matter responds to compression and heating. When the atoms collide with the metal sheet, everything that is produced can be measured. This allows scientists to work backward to determine what happened during the collision and which elements were produced at impact.

• The scattering chamber is a 92-inch barrel that allows scientists to use other detectors.

• The user station determines a beam's properties and is housed in one vault, along with the gas-stopping station and the sweeper magnet.

• The gas-stopping station collects the beams to be weighed by the Low Energy Beam and Ion Trap.

• The sweeper magnet moves all charged particles to the side so the Modular Neutron Array, or MoNA, can detect the neutrons.

• The MoNA measures a neutron's speed and where it hits the detector.

• The S800 spectrograph is a three-story, 300-ton detector that works the same way as the A1900 fragment separator, except the rare isotope is sent through the S800 to study particles produced by the second collision. This detector has the ability to rotate 150 degrees and is used during one-third of the experiments conducted at the Cyclotron lab.

The money

In October, NSCL officials announced they received a $100-million grant renewal from the National Science Foundation, which will last five years.

The grant was an increase from their previous funding and includes new ideas for the lab and improvements to the equipment, Constan said.

NSCL officials are also hoping to receive further funding for a new building, Constan said.

Raising awareness

Earlier this month, NSCL officials shut down the Cyclotron laboratory, which is the nation's largest nuclear science facility on a college campus, to hold an open house. About 800 people visited the building, which is usually restricted, to tour the lab.

As outreach coordinator, Constan said he feels it is his duty to help the public understand what type of work is done in the Cyclotron.

"People hear 'nuclear science,' and their brain turns off," Constan said. "It is kind of mysterious, and they don't want to think about it — (but) I want them to. If everybody understood, then people would enjoy it and appreciate what we are doing and want to support it."

The last time the entire lab was open to the public was in 2005, Constan said.

Constan said the entire operation could be shut down with one switch, but officials had to go through and make sure the radiation levels and magnetic fields were low enough for visitors.

When the cyclotron is running, the vaults are shut and secured with doors and walls that are 6-feet thick, Constan said.

Anna-Grace Claassen, a first-year graduate student in labor and industrial relations, said she never visited the Cyclotron before the open house. She added that because her friend is a doctoral student at the Cyclotron lab, she wanted to get a better understanding of what he does.

"I thought (the open house) was really informative," Claassen said. "It was a little over my head, but they did a good job explaining it in layman's terms. It was very interactive and interesting."

Visitors were given the opportunity to view demonstrations and were given popcorn while watching a movie about the Cyclotron.

"I thought the movie was really good at explaining what the whole point of the Cyclotron is," Claassen said. "Then actually walking around through the tour and seeing it put together and what they are really trying to do is exciting."

Derek Moy, a geography department staff member, attended the open house with his 3-year-old son Cameron, who seemed intrigued by a demonstration of what happens when an atom is propelled at another atom that is stationary to show what the Cyclotron does.

"I've never been here before," Moy said. "I knew it was on campus, but I didn't know much about it. It was quite enlightening.

"Everyone can relate to collisions, I think."

Fredricka Paul can be reached at paulfred@msu.edu.

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