Timothy Koeth, director of Nuclear Reactor and Radiation Facilities at the University of Maryland, with some of his collection of radioactive materials. (Andre Chung/For The Washington Post)

Koeth is leading a team of undergrads who are building a cyclotron similar to this version he began building as a high-schooler. (Andre Chung/For The Washington Post)

One evening last year, more than a dozen students gathered in a radiation safety training office at the University of Maryland’s Department of Materials Science and Engineering. On the conference table was a lumpy-looking object under a piece of black velvet .

Timothy Koeth, an associate research professor and director of nuclear reactor and radiation facilities at the university, stood at the head of the table dressed in jeans and a lilac-colored oxford.

The students — undergrads, PhD candidates and one high-schooler — edged closer as Koeth removed the velvet cover with the flair of David Copperfield.

What lay beneath looked like a large, open, space-age Army knife, fully loaded with metal cylinders and tubes. It was not, in fact, an evil Romulan weapon but the heart of a small particle accelerator called a cyclotron.

“The insides are clean, so don’t touch it,” Koeth warned, as the gawkers leaned in for a better look at the metal chamber where proton particles spin around and around, gaining speed every time they cross an electric field created by two metal canisters until they are beamed at a target.

“Cyclotrons might not save the world, but the kids who build them will.”

U-Md. Professor Tim Koeth

This was an event dubbed Cyclotron Night. Seniors Luke Bittner and Brian Heligman, both materials engineering majors, had secured $2,000 from the student government association toward building a working cyclotron as a teaching tool. Then they rallied a group of students to help and, because there seem to be no instruction manuals for how to build a cyclotron, recruited Koeth, along with Brian Beaudoin, a course instructor and particle physics research scientist, and Kiersten Ruisard, a PhD student in physics, to guide them.

If all goes according to plan, over the next few years students will not only construct the largest cyclotron built by undergraduates, they will wind up with a machine that will continue its hands-on educational mission by allowing students to conduct experiments in nuclear physics. “This is for kids who need to build to learn,” says Koeth.

And Koeth is just the guy to lead the charge. 

Tall and unassuming, with wire-rimmed glasses and neatly combed hair, Koeth, 41, doesn’t immediately register as the dynamic and charismatic presence he can be when talking about the wonders of modern physics. But when it comes to cyclotrons, he is a mixture of promoter, preacher and sorcerer. To hear him talk about the beauty and simplicity of the cyclotron’s operation is to see its inner workings personified: His rapid-fire speech has the same urgency and purpose as the charged particles he is describing. His hands dart around in a blur, only coming to rest when he takes a breath. He is, in a word, magnetic.

Luke Bittner, left, and Brian Heligman, who got the cyclotron project started at Maryland last fall, in front of the six-ton magnet built by GE. (Andre Chung/for The Washington Post)

For those of you who bombed physics: A cyclotron is a particle-accelerating instrument that uses high-frequency electricity and a magnet to create and focus a stream of protons to probe the nucleus of an atom. Koeth is hard-pressed to describe what about cyclotrons gets him going, but he says the people who build and operate them are innovators and creative problem-solvers. His students, he says, will go on to develop better, faster and safer energy production, make advances in biological research and save lives. (Hospitals use the particle beams generated in cyclotrons in imaging studies or cancer radiation treatments.)

“Cyclotrons might not save the world,” he says, “but the kids who build them will.”

The largest cyclotron is 59 feet in diameter and run at TRIUMF, Canada’s national laboratory for particle and nuclear physics. U-Md.’s School of Medicine also has one in its recently constructed $200 million Maryland Proton Treatment Center in West Baltimore.

The small one on the table belongs to Koeth, who began building it as an undergraduate student in physics at Rutgers University in 1995; it first became operational in 1999. “It’s a lesson in how to build stuff, how to get your hands dirty, how to count your fingers before and after, and how to develop practical skills that will really set you aside when you get a job,” says Koeth, who earned his PhD at Rutgers and is still a visiting professor in the department of physics and astronomy.   

It’s also a lesson in ambition. “It’s very common to work on them and work on them and work on them, but to actually get them working is less common,” says Mark Yuly, a physics professor at Houghton College in New York state and organizer of the world’s first (and only) small cyclotron conference. Yuly says he knows of only two schools with working student-built cyclotrons: Houghton and Rutgers.

To build a cyclotron, “You have to know a bit about magnets, radio frequency, amplifiers, high vacuum systems, instrumentation,” says physicist Todd Johnson, an operations specialist in Fermilab’s Accelerator Division. “Getting exposed to that many fields that early in life would be an extraordinarily valuable experience for a young person.”

This project also could be one for the record books. The Rutgers cyclotron, with a diameter of 12 inches, has the distinction of being the largest undergraduate-built cyclotron. The cyclotron being built by U-Md. students will be 19 inches in diameter.

As with most amateur cyclotrons, almost every part has been begged, borrowed or scrounged. Koeth found the nearly 21/2 -ton magnet for his Rutgers cyclotron scheduled for demolition at Argonne National Laboratory, outside Chicago.

Koeth scored an even bigger one for the Maryland cyclotron, a six-ton magnet built by the General Electric Co. in 1947 to be the first electromagnet used in nuclear magnetic resonance (what would later be known as MRI). He received the iron giant as a birthday present in 2008 from a friend who bought it for scrap value in 1980. The U-Md. physics department kicked in $5,000 to move it from a high bay at Rutgers to his lab at Maryland. Fermilab, where Koeth did his PhD work, donated the 4,000 pounds of copper wire needed to wrap around the magnet and create the magnetic field for acceleration to be possible. One of the first hurdles for the students has been to raise enough money — $16,000 — to ship the wire off to a facility in New Hampshire called TechniCoil, a goal they haven’t reached.

But tenacity is one of the job requirements for amateur nuclear physicists, as evidenced in Koeth who, when 10, laid out plans to build a reactor in his parents’ basement in Piscataway, N.J.


A cyclotron has two hollow electrodes called DEEs (because of their shape) sandwiched in a vacuum chamber between opposite magnetic poles. A radio frequency oscillator generates rapidly changing high voltage between the DEEs. Because of the magnetic field, ions injected into the center of the chamber follow a circular path, speeding up every time they enter each DEE and are attracted to the opposite charge. The ions continue spiraling until they reach the chamber’s edge, where they are directed onto a target. (Graphic courtesy of Symmetry Magazine)

“At age 10, Timmy had a goal in life,” says his father, Bill. “He wanted a PhD after his name so people would have to call him doctor.” A retired heavy-equipment mechanic, Koeth senior remembers his son walking around the house dressed in a white lab coat.

Young Koeth’s toy boxes were two 50-gallon garbage cans full of wires, plugs and outlets. As a 2-year-old, he requested a circuit breaker box for his birthday (“Of course he wanted the biggest one,” says his father), and when he was in first grade, he rewired his teacher’s broken lamp. 

“He had a yellow extension cord, and he would carry it around with him all through the house,” laughs Janet Koeth, who was a stay-at-home mother and helped her son overcome an early reading problem by making him read aloud to her while she cooked dinner. His go-to reading material, says Janet, was a story about an alien baby in the National Enquirer, which Tim insisted she buy at the Stop & Shop.

Math was also a hardship. In seventh grade, Tim received an F in algebra and took calculus three times. Janet says a chemistry teacher told her, “Your kid isn’t as smart as you think he is, but he has the most perseverance of any child I’ve ever taught.”

The Koeths can tell story after story about their son, but there is one in particular, which they recount in tag-team fashion, that stands out. When Tim was 13, the story goes, his high school science teacher gave him a Geiger counter. “He would measure everything with that thing,” says his dad. Tim brought it to   his old middle school and found a hot spot in a closet in a room previously used by the school’s science class. The closet turned out to hold a radium device used for treating nasal tumors.

“I picked him up at school, and he comes out with this cardboard box,” says Janet, continuing the story. “He got it home and said, ‘Dad, look what I found.’ ”

His father, worried that their house was contaminated with radiation, phoned the Atomic Energy Commission. “The guy said, ‘You’re in a lot of trouble,’ ” Bill recalls.

Before they knew it, Janet continues, “the street was closed down, an X-ray technician comes over from a nearby hospital, police show up, a psychiatrist shows up, news vans were lined up around the block.”

The story made national news, garnered an article in the Scholastic publication Science World with the headline, “Teen Discovers and Isolates Radioactive Device,” and, says Janet Koeth, “took 10 years off my life.”

Koeth’s reaction was a bit different. “It was amazing!” he laughs, adding that he was upset when officials contained the radioactive device and took it away. (How it got inside the school remains a mystery.)

He does, however, still possess his Geiger counter, and 20 more, including one made by Ludlum Measurements, which he saved up to buy when he was 14. “I paid $527.31 for it,” Koeth says with pride, “and it has never left my side.”

It was with him in his car the day he picked up a strong signal coming from another vehicle. He tracked the driver around College Park, eventually following him into a 7-Eleven with Geiger counter in tow.  “I said, ‘Do you know your whole body is radioactive?’ ” It turned out that doctors had given the man a nuclear stress test that morning to check for a blockage in his heart.


Kiersten Ruisard, a course instructor at U-Md., worked on the Rutgers cyclotron as an undergraduate. (Andre Chung/For The Washington Post)

Claudia Richoux worked with Koeth on her senior project for Thomas Jefferson High School for Science and Technology. (Andre Chung/For The Washington Post)

If it were on, the Geiger counter would be crackling away in Koeth’s second-floor office, which holds an impressive collection of radiological antiques such as Fiestaware, Vaseline glass and, under lock and key, some Lone Ranger Atomic Bomb Rings, cereal prizes from the 1950s that contained a small amount of polonium 210. (According to the packaging, when kids looked through a small hole, they’d see “genuine atoms split to smithereens!”)

There is also a dish of shrunken quarters, each one smaller than a sequin. Koeth, along with a friend, makes them in a lab whose location he declines to reveal and through a process he refuses to describe.

More precious than the objects he collects are the students he draws. Graduate student Kiersten Ruisard, 26, worked on the Rutgers cyclotron as an undergraduate and is now a U-Md. course instructor in a newly launched Capstone Program called simply Cyclotron. Jason Osheroff, assistant director of U-Md. Radiation Facilities, and Matthew Teperman, a faculty assistant working on the university’s electron ring, were both students of Koeth’s.

“Tim is the only reason I’m here,” says Heidi Baumgartner, 24, who had wanted to build a cyclotron since her days in astronomy camp. As a senior at Hunter College High School in Manhattan, Baumgartner traveled to New Jersey on weekends, often staying with Koeth and his parents, to work on the Rutgers cyclotron.

After high school, Baumgartner attended the Massachusetts Institute of Technology, majoring in physics. As a junior, she started a company called OneTesla, which sold kits that fired lightning-like sparks, creating pressure waves that made music. In three years, the company had generated more than $1 million in sales. Last year, Baumgartner stepped down as chief executive to attend grad school at U-Md., where Koeth offered her a staff position as a faculty assistant in the electrical engineering department.

“My children are all coming back home,” notes Koeth.

Claudia Richoux, alas, has flown the nest. Now 18, Richoux became interested in cyclotrons as an 11th-grader at Thomas Jefferson High School for Science and Technology near Alexandria, Va.  “The teacher spent around 15 minutes talking about particle acceleration and I was hooked,” she says. “I pulled out my phone and started Googling ‘cyclotron.’ It’s such an elegant design, I knew that I wanted to build one.”

After she barraged Koeth with emails and phone calls, he invited her to U-Md. to do her senior research project. She spent three days a week taking the Metro from the Pentagon to College Park, where she set about designing a more-efficient voltage delivery (RF) system to compensate for the destabilizing effects of reaching relativistic speeds in large cyclotrons.

This fall, Richoux is studying physics and computer science at the University of Chicago. Koeth has already paved the way for her with his friend Young-Kee Kim, a professor who is starting an accelerator physics lab there. Through Koeth’s other channels, Richoux also has a standing job offer from the European Center for Nuclear Research, known as CERN. “All good things come from Tim,” Richoux says. “He’s Accelerator Dad to all of us.”

“He’ll bring you into his world like the Pied Piper.”

Michelle Koeth

To his wife, Michelle, it’s especially gratifying that Koeth is so encouraging to women. Married for 16 years, the couple met at Rutgers, at an activity fair for the ham radio club. Friends of Michelle had dragged her along.

“The hobby is dominated by socially inept men,” Michelle says. But Koeth was different. “He isn’t your typical nerd. He’s kind, gregarious and outgoing.”

While they were dating, he’d bring over parts of his cyclotron to her dorm room. “Partly because there wasn’t enough space to store the parts in his own room and partly because he was looking for ways to work on it while he was visiting me.”

Soon after Michelle graduated in 2000 with a degree in electrical and computer engineering, Tim proposed by tapping “Will you marry me” in Morse code on her knee. “He always wanted to propose like Thomas Edison did,” she says.

Now a patent examiner at the U.S. Patent and Trademark Office, Michelle grew up at a time when “a girl who was into technology was stigmatized.” She describes her husband as emotionally intelligent, which has helped him become an ally to the movement for women in science, technology, engineering and math. “There is a certain amount of misogyny and discrimination in the technical field,” she says. “There is a need for good men who are pushing it.”

Her husband sometimes refers to her as “The Cyclotron Widow,” which makes her laugh. “He’s so deep into it, but he’ll bring you into his world like the Pied Piper,” she explains. “His students will follow him anywhere — but he’s bringing them to a good place.”

Bill Barletta, head of the U.S. Particle Accelerator School, calls Koeth the chief evangelist. “Tim is a man with a mission,” he says. “He’s spreading the word about cyclotrons being an exciting learning experience.” And he’s doing so at the university that has produced more PhDs in accelerator physics than any other university. Another part of his mission, adds Barletta, “is that the university keeps on this path.”

This past spring, Koeth offered a course called Building the Maryland 5 MeV Cyclotron as part of the university’s Senior Capstone Design Program. Since then, the seniors who started the project have graduated: Luke Bittner is now a welding engineer at General Dynamics Electric Boat, the primary manufacturer of the U.S. submarine fleet, and Brian Heligman is starting a PhD in materials science focusing on energy storage at the University of Texas at Austin.

The U-Md. accelerator remains in the early stages, with the vacuum chamber, ion source, magnetic field and radio frequency system still in the design phase. But according to Koeth, the completion of the cyclotron is not as important as the people around it.

“I was never an athlete in school, didn’t play any sports and was always envious of the collaboration of teams where a group got together, worked together and accomplished something together,” he says. “I call the cyclotron my football team. It’s a joy to bring people together.”

Cathy Alter last wrote for the magazine about “The Fusioneers.” She co-edited the book “Crush,” published in April.

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