CAS CONNECT 2022

Outside of health and safety, radiation also plays a key role in the ever-advancing technology age. “A lot of electronics are quite sensitive to radiation,” Benton said. “And they are getting more sensitive because they’re shrinking the size of these electronics down. So they’ve got to pay attention to that.” This detector was developed as part of a program called the AIRE Institute, which Benton started at OSU with a couple of colleagues. “AIRE stands for atmospheric ionizing radiation environment,” he said. “And so, as the name says, we’re really interested in the radiation environment that’s found in the atmosphere, especially at higher altitudes.” The institute is something that’s evolved out of work that all got started because of NASA EPSCoR, Benton said. “NASA EPSCoR in Oklahoma and nationwide, but in Oklahoma especially for me, has been really generous in supporting our work,” Benton said. “In 2008, when we got our first NASA EPSCoR grant for this radiation detector technology — that really started this.” Benton had been doing space research before using other kinds of detectors called passive detectors that act like film. But as technology improved, there was a demand to be able to see the time radiation occurred as well, Benton said. “That meant abandoning these passive radiation detectors and going for what is called active radiation detectors: electronic devices that store the data on a computer,” he said. “So it was really clear, this is where I had to go.” It turns out that one of the people who developed this active technology had retired to Stillwater and was working with a researcher named Stephen McKeever, who was in the physics department at OSU and later served as vice president of research from 2003-2013. “And I realized that I need to learn how to do this. I need to learn this new technology, this is where my future is,” Benton said. “So, we started from scratch. I mean, similar detectors had been flown before, but they were very expensive. And it was pretty much proprietary technology. We had to reinvent the whole thing from scratch for ourselves. And the real major emphasis we put on it was to make it a lot cheaper.” Since then, most of what the team has worked on in the past has been space oriented, which would be at an altitude of around 400 kilometers. But now they are looking more toward the sky, and not past it. “With Blue Origin and Virgin Galactic, they’re starting this whole idea of space tourism,” Benton said. “And we hope to be the radiation dosimetry providers for space tourism, and this is sort of our first shot at that.” From a scientific point of view, very few measurements have ever been taken on these suborbital flights, Benton said. “There’s lots of data from space and from aboard the space station, and before that from space shuttles and spacecraft like that, but up at these higher altitudes in the atmosphere, there’s practically none,” he said. “We’re very interested in filling in that gap in our knowledge.” The detector itself consists of several parts, but the main piece is called a tissue equivalent proportional counter. “This is a spherical detector that is filled with low-pressure gas. And the tricky thing is that it’s a rather large sphere, maybe about two inches in diameter, but the gas is under very low pressure,” Benton said. “And the walls of the chamber are made of plastic, which is essentially the same as tissue — it’s carbon, oxygen and hydrogen — so the density is very similar to human tissue.” This means the response of the detector to radiation, which is monitored on a computer, is very similar to that of what human tissue would be to that same radiation, which simplifies how the radiation is going to affect passengers and pilots quite a bit, Benton said. And everything fits into a small container a little smaller than the size of a shoe box. For the Blue Origin flight, the team has been assigned one of 36 lockers aboard the ship where they will not only mount their detector, but also plan to include more detectors from other organizations to compare data with. This radiation detector, or dosimeter, was developed at the AIRE Institute at Oklahoma State University. 14 CONNECT 2022