His bomb detector is out of this world

Jim Ryan started using techniques for detecting neutrons and gamma rays in outer space to help soldiers detect dirty bombs. (Mark Wilson/Globe Staff)

Jim Ryan says the problem with being an astrophysicist is that you often get asked the same question: What good is all this stuff you're studying in outer space?

"Because we're curious and want to be smarter," used to be his short answer. Now, thanks to two bits of serendipity, he has a more direct response: because it could save you from bad guys with bombs.

Ryan's tenure as a bomb hunter began when he and colleagues at the University of New Hampshire's Space Science Center were developing an instrument to be put inside the orbit of Mercury to look for low-energy neutrons coming from the sun.

"It just so happened that was the same energy range as neutrons coming out of plutonium," said Ryan, the center's director. "You don't have to be an astrophysicist to see the connection" to why the Department of Energy came knocking on his door, he said, asking whether the instrument could be developed for terrestrial use in the hunt for nuclear weapons.

Then last year, as he was working on that project, Ryan, 61, was invited to a National Guard exercise on Cape Cod to watch a mock cleanup of a terrorist site filled with the material for dirty bombs (they emit a different sort of radioactivity than plutonium). As Guardsmen combed the booby-trapped house with hand-held sensors, a light bulb went off in Ryan's head.

"We detect radioactive aluminum from across the galaxy," he said, so "I knew we should be able to detect it from across the street." And he could do it with equipment that was sitting in his lab from an earlier project whose demise still upsets him.

For 16 years, Ryan had worked on the COMPTEL, a gamma-ray imaging telescope aboard the Compton Gamma Ray Observatory, one of NASA's four "great observatories" (along with the Hubble Space Telescope, the Chandra X-Ray Observatory, and the Spitzer Space Telescope). He joined the project in 1984, saw it launch in 1991, and then made quite a public fuss when NASA chose to "deorbit" the observatory in 2000 because of a mechanical failure. Ryan believes the observatory could have continued working despite the failure, and calls the decision to crash it to Earth a "poor day for NASA."

But as he stood on Cape Cod at the dirty bomb drill, watching the National Guard play a game of warmer/colder with their hand-held instruments, he realized that some of the spare parts from the Compton Observatory could be used to pinpoint the location of the dirty bomb material with much greater accuracy than traditional Geiger counters and spectrometers, and from a safer distance.

Ryan said he finds some "poetic justice" in the fact that parts from COMPTEL will ultimately be used to serve humanity. "It lives on and does something that is useful to society as well as pure academic science," he said as he stood in his lab next to the instrument he presented to a Homeland Security conference in May.

Gerald Share, an astrophysicist who is a senior visiting research scientist at the University of Maryland, said Ryan's recent work on the device is another example of why he's a "Renaissance man in astrophysics."

"He does so many different things," Share said. "He's written theoretical papers. He's developed instruments. He's a great teacher. He's good at bringing people together in his administrative role at the Space Science Center. I'm always impressed by what he can accomplish with all the different things he's involved in."

Ryan has always been hands-on with the instruments, a trait he developed as a child who liked to "reverse engineer" gadgets by taking them apart. He has become the sort of guy who gets the call when "they need someone who can run a high-tech program with lots of gizmos," he said, and that is part of the reason he "got roped in" to being the primary investigator on a new meteorological endeavor, the National Oceanic and Atmospheric Administration's "Balloon Winds" project.

Last month, Ryan went to New Mexico to launch a balloon that would use the laser light equivalent of a radar to study wind speed at high altitudes, which could lead to better weather forecasts. Unfortunately, the balloon got hung up on the crane used to launch it and didn't record any data, but officials plan to launch again in the spring.

For Ryan, it is the opportunity to dabble in various corners of research that attracts him to his chosen field. "What I've always found interesting about astronomy and astrophysics is it relies on all kinds of science, from thermodynamics to nuclear physics. It's a huge sandbox to play in," he said. "There's so much more to do than just looking at the cosmos."

Fact Sheet

Hometown: Chicago; lives in Lee, N.H.
Education: Bachelor's degree in physics and mathematics from the University of California at Riverside in 1970; master's in applied physics from University of California at San Diego in 1974; PhD in physics from Riverside in 1978.

Family: Wife, Nancy, is a healthcare advocate and the New Hampshire state coordinator for the National Breast Cancer Coalition. They have a golden retriever named Shadow.

Hobbies: Ryan has always loved playing sports (he was on the track, cross-country, and wrestling teams in college) and enjoys cycling and photography.