Terry McAfee started coming to the ALS during his PhD. The Northern California native is glad to be back as a postdoc and hopes to stay on as a beamline scientist. He enjoys developing new techniques and working with users, always looking for ways to contribute to the community.
What do you work on at the ALS?
I’m working with Cheng Wang at Beamline 184.108.40.206, which does resonant soft x-ray scattering (RSoXS), and I’m co-advised by Brian Collins at Washington State University. We’re working on adding in situ measurement capabilities to the beamline. I’m also working with David Kilcoyne to build a new miniature endstation to go on the existing chamber. That’s specifically for in situ work because it will accept a transmission electron microscope (TEM)-style sample holder, so you’ll be able to take measurements here, quench or halt it, and go over to NCEM (the National Center for Electron Microscopy at the Molecular Foundry) to look at the same sample under the same conditions. It’ll also be compatible with the COSMIC beamline. This adds multimodality and the ability to change the samples quickly.
Right now, I’m working on things that self-assemble in liquids, which have a lot of biological applications. We want to know how these materials behave in the body, so we start by putting them in water. If you dry them out, their properties are different. So, to be able to measure them in the native environment is a huge benefit. You can have things that self-assemble, absorb a drug, and then are able to release it using different mechanisms. One of our collaborators has successfully delivered drugs to the target area in mice.
I really like the RSoXS technique. It’s fairly new and combines traditional small-angle scattering with resonant absorption. With traditional techniques like hard x-ray scattering or neutron scattering, they can’t get contrast between different polymers. Resonance is bond specific, so you can get so much more information.
How did you become a postdoc here?
I’m a first-generation college student, and the Upward Bound program helped because I had no idea what I was doing. The program helps low-income and first-generation students go to college, and I worked for them for three years in college. I’ve always worked really hard, and I’ve gotten a lot of help along the way from a lot of different people, so I try to give back. If someone’s trying their best, then I’ll go out of my way to help them.
Growing up, I didn’t really know what I wanted to do. I just wanted to go to college, and I thought physics was easy because I was good at it. It turned out, I was very wrong—high school physics was easy. I studied physics at Chico State and did my PhD at North Carolina State University with Harald Ade. He helped build the STXM program here, so I started coming over to the ALS routinely in 2011, and I just liked it. My first postdoc was at Tulane, where I did automated polymer synthesis, but then this job came along, and I wanted to come back to synchrotron science. It’s great, and the weather is awesome, especially in Berkeley.
What are your goals for your work?
We use soft x-rays, which have to be in vacuum, so in situ is extra challenging. You have to encapsulate the liquid between two silicon nitride membranes. The commercial membranes haven’t been optimized for our setup, so I’m making my own chips at the Molecular Foundry and going to Stanford to use their wafer dicing saw. The ultimate goal is to make this available for users. We’ve trained one user to be able to do this by themselves, and several others have sent in their samples.
I’d like to become a beamline scientist here. My family’s nearby, and my ideal job is to maintain instrumentation and develop new stuff. I like to try to figure things out and help users figure out how to do their experiments. One of the first things I noticed when I came here was the atmosphere and energy—everyone’s motivated to be here, and it’s a good working environment. David Kilcoyne has definitely mentored me professionally and personally. He even told me to start dressing more professionally!
What do you like to do in your free time?
After being away for seven years, it’s been good to be able to visit my family a lot. I’m about to be a great uncle—my nephew is about to have a daughter any day now. I’ll teach her anything she wants to know. If I don’t know it, I’ll learn it.